Please visit these other Brian Miller's websites: A-1 Miller's Performance Enterprises - Parts & Services Online Catalog | Miller's ATV, UTV and Local/Stock Garden Tractor Pulling Sled Rental | Hot Rod Garden Tractor and Mini-Truck Pullers Association

Copyright © 1996-Present. This website created, designed and maintained by Brian Miller.

10-18hp Kohler (or Carter [model N]) CarburetorInformation about Carburetors, Various Fuels and Fuel Systems for Small Engines and Garden Pulling Tractor Engines

Where Science and Common Sense Come Together for Safety and Better Engine Performance

This page was updated 5/20/17. (Click Refresh to see changes or updates.) Optimized for 1024 x 768 screen resolution. Easy and simple to use website. To search for a word or phrase in any of my websites, with Microsoft Internet Explorer 6.x, or Google Chrome, press CTRL+F to open the Find dialog box. Although every effort has been taken to check the accuracy of information contained herein, I cannot assume responsibility for errors.


Unsportsmanshiplike Conduct -

There's a cheater in every sport, and competition tractor pulling is no different. Honest pullers who ignore the cheater(s) are fools. And when there's prize money involved, a fool and their money are soon parted. Anyway, to make competition pulling a fun and fair sport for the entire family, be protective of your equipment! While at the pulls, keep an eye on your carburetor and fuel shut-off valve! When a competitive or winning pulling tractor is left alone, it's been known that certain disgruntled pullers (sore losers ) belonging to various associations/clubs, virtually anywhere and everywhere, will turn the high speed air/fuel adjuster one way or the other, or close the fuel shut-off valve to keep the engine from running at it's full potential, or from running at all. This is one of the easiest, dishonest and sneaky ways to retard or disable and sabotage a competitor's tractor. All a cheater needs is an opportunity in an attempt to gain an advantage on the track. This is also the fastest way for a pulling association or club to gain a bad reputation and lose honest pullers. (Bad news travels fast.) This type of dishonest behavior doesn't happen often, but you need to be prepared if or when it does happen. To be prepared for this unforeseeable event, it'll be a good idea to cover the entire carburetor with a drawstring bag, or better yet, cover the entire tractor with a canvas or heavy blanket. Keep an eye on your killswitch plug, too! Always try to stay one step ahead of a cheater.


Use a Remote Fuel Primer System to Start a Cold Engine - An ingenious, thoroughly researched and innovative concept by Brian Miller, because nobody else advertise the use of this system for use on a lawn and garden tractor. Top of page | Return To Previous Paragraph or Website.

If a Carter and Kohler carburetor (or virtually any type of float carburetor) that's used on a lawn or garden machine, or pulling tractor don't have a choke plate assembly installed, but does have an air cleaner/filter assembly, or an air filter with a velocity stack, and if the engine have to be "hand choked" to start it, then you probably already know how hard it is to get your hand sealed over the entire velocity stack or end of the carburetor, and also have a wet hand from the raw fuel afterwards. The remote fuel primer system installed will prevent this. Having a small hose connected to the atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor) in the carburetor is a lot safer than having raw fuel spilling out of the drilled hole on the side of the carburetor when pulling! An inexpensive and safe way to get extra fuel in the throttle bore to start a cold engine is to use a remote fuel primer system. This system can also be adapted for use on ordinary garden tractors, lawn and garden equipment or virtually any type of small engine equipment with virtually any type of float-type carburetor. This system is similar to the same set up that many small engine manufacturers use on their engines nowadays. Works great with pump gas, race gas, E85 or alcohol fuel.

NOTE: If an engine is hard to start, even with the choke plate fully closed and tuned correctly, then it may need a professional valve job performed and valve clearances reset. The reason some older engines is hard to start is because the valve faces, especially the intake valve, wears slightly away against the valve seat, and this causes the clearance between the valve stem and lifter to be lessened, which will prevent the valve(s) from fully closing to trap adequate compression in the combustion chamber [so the engine can start easier]. This remote fuel primer system will not fix this type of problem.

How the Remote Fuel Primer System Works: With the original atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor)) in the carburetor plugged, a short brass tube is inserted into a drilled hole in the float bowl area on the side of the carburetor body, and with a small fuel hose connecting the carburetor to the primer bulb assembly, which is mounted on the steering column support pedestal, one quick push on the primer bulb (with your finger over the hole in the bulb to seal in the air) creates air pressure within the bulb, tubing and float bowl, which force fuel up through the main jet/nozzle (emulsion tube), creating a slight flooding condition in the throttle bore. Thus, helping a cold engine without a choke plate start much easier. With this system, the engine cannot be "over-choked," which could foul the spark plug. The fuel primer system can also be used as a manual accelerator pump when an engine hesitates to accelerate on its own.

How to Install and Use My Remote Fuel Primer System:

  1. Remove the carburetor from the engine, remove the float bowl and float.
  2. Plug the atmospheric vent passageway (from inside the float bowl area to outside of carburetor that's located at the 2:00 position next to the choke plate) with a 1/4" Allen set screw. Cut some short threads for a 1/4" coarse or fine thread x 1/4" length Allen set screw, and install the screw in the opening. If there's a small hole to the right of the choke plate, plug this hole with a 3-48 screw using high strength liquid threadlocker. And if there's a small hole drilled on the outside of the carburetor body, this will need to be plugged with JB Weld two-part epoxy or a short screw. See the photos to the right. (The installed tube, hose and hole in the primer bulb will be the new atmospheric vent for the float bowl.)
  3. Be sure to use [150± psi] compressed air to clear out the metal cuttings from the entire carburetor.
  4. Drill an 1/8" hole into the float bowl area just above the float fuel level on the side of the carburetor body to install the 1/8" tube to connect the primer hose. On the Carter/Kohler carburetor, this would be just above the bowl seal and below the atmospheric vent opening (air passageway from outside the carburetor to the float bowl area) on the right side of the carburetor when viewed from the choke end. The drilled hole should be a press-fit for the 1/8" tubing. Use high strength liquid threadlocker to permanently secure the tube in the hole then gently tap the tube in the hole with a small hammer until it's flush with the inside of the float bowl area. See photo to the right.
  5. Reassemble the carburetor, and use a hammer to flatten the hole from inside the float bowl on a hard, flat surface so when the bowl bolt is tightened against the carburetor, it will place more pressure against the neoprene rubber O-ring seal and fuel baffle/splash shield to prevent an air leak (and possible fuel leak). Reinstall the carburetor on the engine, and connect the fuel line.
  6. Drill a 17/64" hole to install the primer bulb assembly someplace on the tractor's steering column support pedestal within easy reach of the driver. Mount the primer bulb on side of the pedestal so rain water and/or when washing off tractor, water will not enter in the hole in the bulb and contaminate the fuel in the carburetor.
  7. Route the primer hose along the tractor so it won't get kinked, pinched or damaged and away from moving parts and hot exhaust area. Then attach the hose from the primer bulb assembly to the tube on the carburetor.
  8. Fill carburetor with fuel, and press the primer bulb quickly a couple of times with your finger to create pressure within the float bowl (be sure to place a finger over the hole in the bulb), and at the same time, look inside the carburetor. Fuel should squirt from the main nozzle and into the throttle bore with each push. Now then the engine should be quick to start! NOTE: It only takes a couple of pushes of the primer bulb to thoroughly prime the carburetor to start the engine. Any more pushes, the carburetor may become flooded and the engine could take longer to start! Another useful thing about the fuel primer system is, if an engine hesitates upon acceleration, especially before reaching its operating temperature (cold engine), this system can be used as a manual accelerator pump.
  9. NOTE: If an engine is hard to start, even with the choke plate fully closed and tuned correctly, then it may need a professional valve job performed and valve clearances reset. The reason some older engines is hard to start is because the valve faces, especially the intake valve, wears slightly away against the valve seat, and this causes the clearance between the valve stem and lifter to be lessened, which will prevent the valve(s) from fully closing to trap adequate compression in the combustion chamber [so the engine can start easier]. This remote fuel primer system will not fix this type of problem.

FYI - Most [cold] engines will not start when fuel is introduced directly into the combustion chamber through the spark plug hole. Doing this only results in a flooding condition and the engine may not start. Gas (or starting fluid) needs to be mixed with incoming air through the carburetor intake so the air can atomize the fuel (break down into a fine mist) to burn more thoroughly so the engine will be able to start quicker.

When removing the choke shaft, there's a tiny (1/8" or 5/32") steel ball and small compression spring located at the 9:00 position when facing the choke end with the float area down. When the choke shaft is removed, hold one finger over the screw hole and end of the choke shaft hole to prevent the ball and spring from popping out and possibly getting lost. By the way - the ball and spring is required only for hand-operation of the choke to keep it in the open position on stand-alone engines, such as on a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. The ball and spring is not needed if the choke is remotely operated with a choke cable, such as in a tractor, etc.

Advertisement:
If you need a remote fuel primer system kit, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends (except Holidays). Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Go here for more parts: Carburetor, Fuel System Parts & Machine Shop Services | Please click here to place an order. You can also make the drive to A-1 Miller's shop to personally drop off and pick up your engine, transaxle, tractor, etc. for rebuilding or repairs. "The road to a friend's house (or shop) is never long."

Small Engine Remote Fuel Primer System Kits. Safe to use and works flawlessly! With the fuel bowl atmospheric vent opening plugged (air passageway from inside the float bowl area to outside of carburetor), then with one or two pushes of the primer bulb, air pressure within the carburetor float bowl forces fuel through the main jet and out the nozzle, creating a slight flooding condition inside the carburetor throttle bore allowing a cold engine to start quicker. With this setup installed, the choke plate and shaft can be removed. No more binding of remote solid wire choke cable and/or bent choke plate, or messy "hand choking" of carburetor. The fuel baffle splash shield is not needed with this setup. For ordinary lawn and garden tractors, garden pulling tractors or virtually any small engine lawn and garden or snow removal equipment with a choke plate on the carburetor. Works with pump gas, race gas, E-85 or alcohol fuels. Requires 1/4" mounting hole. Kit includes primer bulb assembly w/serrated mounting nut and integrated 1/8" barbed hose fitting, 1/8" i.d. x 3/16" o.d. x 3' length clear vinyl hose, loop-type clamp and 1/8" diameter x 1" length brass tube. Click here for installation instructions. An ingenious, thoroughly researched and innovative concept by Brian Miller, because nobody else advertise this kit for lawn and garden tractors or various small engines. NOTE: If an engine is hard to start, even with the choke plate fully closed and tuned correctly, then it may need a professional valve job performed and valve clearances reset. The reason some older engines is hard to start is because the valve faces, especially the intake valve, wears slightly away against the valve seat, and this causes the clearance between the valve stem and lifter to be lessened, which will prevent the valve(s) from fully closing to trap adequate compression in the combustion chamber [so the engine can start easier]. This remote fuel primer system will not fix this type of problem. [Return to Previous Section]

  • Fuel Primer Bulb Assembly Only. Includes serrated mounting nut. $6.00 each, plus shipping.
  • High Quality Universal Complete Fuel Primer Kit. $15.00 each, plus shipping & handling.
  • XT Fuel Primer Kit. OEM Kohler part # 14 755 36-S. $13.75 each, plus shipping.


Identification of Carter and Kohler Carburetors -

The carburetors that's used on Kohler engine models K90/K91, K141, K160 and K181/M8 are as follows:

FYI - When Edelbrock bought out the [automotive division of] Carter Carburetor Corporation sometime before 1984, Carter sold their line of small engine carburetors to Kohler Engines in 1985. Kohler changed the throttle shaft/lever on the Carter Model N #16, #18, #20 and #22 carburetors, and also maintained the Carter name on them. And on the Carter #26 and #30 single cylinder engine carburetors, Kohler redesigned the throttle shaft/lever and made slots in the mounting holes for easier installation and removal on the engine block. Everything else is the same on the Carter and Kohler carburetors, with the exception of the throttle shaft/lever and various choke shaft levers. Six different variations of the Carter/Kohler carburetors was made for the K-series K241 through K361 engines, KT-series and the K482, K532 and K582 opposed (flathead) twin cylinder engines. NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts are still available in aftermarket.)

The differences between the Carter (#26, #28, #30) and Kohler (#26, #30) carburetors

The size number (diameter of throttle bore) for the Carter/Kohler carburetors is embossed inside the upper part of the choke end, just above the venturi. But not all Kohler carburetors have a number embossed. In this case, the throttle bore (throttle plate area) will need to be measured to determine the size of the carburetor. The size number refers to the amount of air that can flow through the carburetor. A #26 carburetor has a 26 millimeter diameter throttle bore, which converts closely to 1.024 inches (26 ÷ 25.4 = 1.024"), but actually measures 1.07". A #28 carburetor has a 28 millimeter diameter throttle bore, which converts to 1.102 inches (28 ÷ 25.4 = 1.102"), but actually measures 1.17". And a #30 carburetor has a 30 millimeter diameter throttle bore, which converts to 1.181 inches (30 ÷ 25.4 = 1.181"), but actually measures 1.200". For precision, when measuring the throttle bore to determine the size, it's best to use a dial or digital caliper.

Carburetors that's used on Kohler engines are as follows:

  1. The first carburetor is a number "26". It was originally designed and made by the Carter Carburetor Corporation, then later made by Kohler Engines. It has a 26mm or 1.07" diameter throttle bore. The venturi (smallest part of the throttle bore) is .812" in diameter. It's designed to be used on models K241/M10, K301/M12, K3303/K331, KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20 MV20, K482 and K532 engines. The carburetor for the single cylinder engines have been discontinued by Kohler L, but still available in aftermarket J. The replacement carburetor from Kohler is a Walbro WHG #52. OEM Kohler part # 47 853 23-S.
  2. And yet there's another #26 type of Kohler carburetor designed specifically for Kohler engine models K482 and K532. The throttle shaft is positioned horizontally and the idle fuel mixture screw is positioned directly on top of the carburetor body instead of at an angle on the side. This carburetor have been discontinued from Kohler. L
  3. The next carburetor is a rare one, number "28". It was originally designed and made by the Carter Carburetor Corporation, and was used on the early model K321 and on some early K341 engines. It has a 28mm or 1.17" diameter throttle bore. The venturi measures .937" in diameter. The carburetor may have the part number 236636 stamped on the flange. This carburetor have been discontinued by Carter many years ago. L The replacement is OEM Kohler part # 45 053 20-S. Which is the fully adjustable #30 Kohler carburetor. The Walbro WHG #60, #64 replacement is OEM Kohler part # 47 853 30-S.
    • FYI - Carter manufactured the #28 carburetor and they were installed on the early K321 Kohler engines with the small (1-1/8") exhaust valve. When Carter sold their line of small engine carburetors to Kohler Engines in 1985, Kohler discontinued the #28, and installed their #30 carburetor on all of their K321 and K341 engines. Kohler also gave their K321 engines the larger (1-3/8") exhaust valve and made the intake port larger (on specification suffix D and later) to move more air in and out of the combustion chamber due to the slightly bigger (#30) carburetor, and so the engine will produce a full K321 at 3,600 RPM.
  4. The third carburetor is a number "30". It was originally designed and made by the Carter Carburetor Corporation, then later made by Kohler Engines. It is used on the later model K321/M14 (later K321's with the 1-3/8" exhaust valve), K341/M16 and K582 engines. It has a 30 millimeter or 1.200" diameter throttle bore. The venturi measures 1.000" in diameter. This original fully adjustable Kohler carburetor for the K321/M14 and K341/M16 engines is still available under OEM Kohler part # 45 053 20-S, and in aftermarket J. And the Walbro WHG #60, #64 replacement is OEM Kohler part # 47 853 30-S.
  5. There's another #30 carburetor designed specifically for the Kohler engine model K582. The throttle shaft is positioned horizontally and the idle fuel mixture screw is directly on top of the carburetor body instead of at an angle on the side. This carburetor have been discontinued from Kohler. L
  6. Lastly, there's another type of Kohler #30 carburetor. Its throttle bore measures 1.250" and the venturi measures 1.062" in diameter. Otherwise, it's identical in every other way to the (1.2") #30 carburetor above È. It's used only on Kohler engine model K361. The carburetor for the K341 engine (Kohler part # 45 053 20-S), which have a venturi diameter of 1", can be used on the K361 engine, but the venturi will need to be bored to 1.062" so the K361 will produce full power at higher governored RPM. This carburetor have been discontinued by Kohler. L
  7. NOTE: If a too large of a carburetor is used on a smaller engine, not enough velocity (rapid movement) of air can be drawn through the carburetor at higher RPMs. Therefore, the insufficient amount of moving air cannot draw (vacuum) enough fuel from the main fuel nozzle to sufficiently feed the engine. The exception of this rule is if the engine has oversize valves (larger than factory-installed valves), then there should be enough vacuum to draw sufficient amount of air through the carburetor.

By the way - the part number for any particular Kohler-made carburetor is stamped on the right side of the mounting flange. Don't refer to the numbers just below the fuel inlet port. They represent nothing that I know of. Click here to identify a Kohler or Walbro carburetor and matching parts: Kohler Carburetor Reference Manual TP-2377-E.pdf. (require Adobe Acrobat Reader and use Google Chrome web browser for a faster download of websites with large files.)

Airflow (CFM = Cubic Feet per Minute) -

FYI - The throttle bore in the Carter/Kohler #26/1.07" carburetors can be bored to 1.17" (#28 size) or 1.2" (#30 size), and the main jet/nozzle (emulsion tube) will still bottom out against the throttle bore, and of course, a 1.17" or 1.2" throttle shaft and plate would need to be used. But the boring process will break through the idle fuel mixing well (the idle progression holes and the expansion/welch plug hole) that's next to the throttle plate. Modifications to this area would need to be made by threading in an 1/8" Allen pipe plug where the expansion/welch plug is (was), and drilling and installing a small brass or copper tube from the idle fuel mixture adjuster screw down into the float bowl, next to the float, with enough clearance so it won't interfere with the movement of the float. A 1/4-28 UNF (fine thread) (fine thread) x 3/4" thread length bolt will also need to be installed where the high speed air/fuel needle adjuster is (was) to block off a vacuum leak to will occur with the modifications of the idle air/fuel mixing well. Actually, it would be MUCH easier and less cost effective to just convert either a Carter/Kohler #28 or #30 carburetor for high performance use and not having to do anything to modify the idle fuel passageway.

And boring of the venturi in the carburetor alone will not help to increase engine performance. To increase the overall airflow in and out of the combustion chamber for improved engine performance, and if sanctioning club's rules allow this, the intake (and exhaust) port runners must be enlarged, too. This is called "porting an engine." The [stock size] valves will also need to be reworked for more airflow. Or larger valves and a bigger cam will need to be installed.

For competition pulling, carburetor design and size depends on port sizes, valve sizes, if the intake valve and seat have 30º/31º angles and undercut heads, and the cam profile (lift and duration) is important. If an engine has stock ports, valves and cam, a plain stock carburetor can be used. But if the ports and valves have been reworked for more airflow, and a bigger cam is going to be used, then a bored-out carburetor with a .995" or 1" venturi can be used for best performance.

The 26mm carburetor obviously has a smaller throttle bore. Therefore, is restricted as to how much air can flow through it, even with the venturi removed. It'll work excellent on a hot K241 or mild K301 engine, but the larger 28mm and 30mm carburetors flows more air, 7.7% more for the 28mm, and 15.5% more for the 30mm. Which are ideal for a hot K301 and larger engines with porting, polishing, bigger valves and a big cam. If you feel that a single 30mm carburetor won't flow enough air for your particular engine, then either a "Super Carb," Dellorto, Mikuni, S&S Super D or a twin Kohler carburetor setup (on a "Y" intake) should be used. If you have a K321 Kohler engine, and you can't find a #28 or #30 carburetor, then a Carter or Kohler #26 carburetor will work just fine for general lawn and garden use. Personally, I ran a stock Kohler #26 on the K321 Kohler engine that's on my 6,000 lb. self-propelled pulling sled for 10 years and the engine didn't lack any power whatsoever.


Identification and Information About Walbro WHG #52, #60 and #64 Carburetors -

The Walbro WHG #52, #60 and #64 carburetors originally come on all Magnum engines. These carburetors are direct replacements for the Kohler carburetors. The Walbro #52 carburetor has a throttle bore diameter of 1.07" and is designed for use on models K241/M10, K301/M12, KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20 and MV20 engines. And the Walbro #60 or #64 carburetor have a throttle bore diameter of 1.2" and is designed for the K321/M14, K341/M16 engines, and being the 1.25" Kohler carburetor that was originally designed for the K361 engine is longer available, the only option is to use the Walbro #60 or #64 carburetor.

The older Walbro WHG #52, #60 and #64 carburetors are reliable and they seem to last a long time before requiring service. Most older Walbros are worth rebuilding, because the float valve seats are made of hardened solid bronze, which is actually harder than cast iron. They were manufactured back in the day when most business owners took pride in their products and offered their customers a quality product.

But the newer Walbro carburetors, especially the ones that come on recently-built aluminum block small air-cooled engines, are notorious for leaking gas after several years of use. Although overhaul/rebuild carburetor kits are available, it really does no good to rebuild them and install a new fuel inlet valve because the float valve seat is made of soft brass, which erodes with use due to microscopic particles of dirt/debris that pass through the filtering material in the fuel filter, and in most Walbro carburetors, the seat is not replaceable. The fuel inlet seat in older Walbro carburetors are made of hardened compressed bronze, which is actually harder than cast iron. There is no indication or records of when Walbro made the change from the hard seat to the soft seat.

The filtering material in fuel filters can only filter out so small of particles of dirt/debris. Any heavy particles that can pass through the filter will build up in the bottom of the float bowl and can eventually clog the main jet. Lightweight and suspended particles gets sucked up through the main jet and is burned in the combustion chamber. On very rare occasions, a hair can pass through the filter and become lodged in the float valve fuel inlet seat, causing the carburetor to flood with gas. When this happens, the hair can be removed with [150± psi] compressed air and the same float valve and seat can be reused.

To put it in plain English: If your Walbro carburetor doesn't leak gas out the choke end, but need an overhaul/rebuild, then it may be worthwhile to install a new kit. But if it does leak gas, then I doubt that a new float valve will fix the problem. Your only options are: install a fuel shut-off valve and turn off the fuel every time the engine is not in use, or install a rebuilt Carter/Kohler K-series carburetor.

About 90% of small engine carburetors are made by Walbro nowadays, and I don't think that one is better than the other. The trick to getting the soft brass seat (and needle/float valve) to last longer is to use a fuel filter with a very fine mesh or pleated paper element. The finer, the better. Because it's the microscopic dirt/debris/grit that passes through the filter that causes the seat (and needle/float valve) to erode and wear. And every pressed-in brass seat that I've replaced ALWAYS leaked gas. There's just no way to get them to seal with the carburetor body, not even with high strength liquid thread locker.

If a Walbro carburetor drips fuel, and a new carburetor is out of the question, the only options is to either install an under-the-[gas] tank or in-line fuel shut off valve (lots of people do this). Or a new carburetor can be purchased, and hope the leaking fuel situation doesn't happen again in a few years. (Walbro is like Walmart or Sam's Club, they want 'em keep coming back. This undoubtedly is how many world-wide, major businesses nowadays keep selling new high-dollar replacement Chinese-made carburetors and other engine parts to unknowing or ignorant customers.)

The only problem using a Walbro on a pulling tractor or for high performance application is they can't be bored-out or modified in any way because the throttle bore wall (where the venturi is located) is too thin. Therefore, they're limited to how much air can flow through them. The US government EPA laws required that Kohler and all other small engine manufacturers redesign their carburetors so the engine will produce less air pollution. So they started using a redesigned emissions-controlled, EPA-approved Walbro carburetor with a fixed/non-adjustable main jet. This is to prevent people from setting the air/fuel ratio too rich and create more air pollution. The older-designed Walbros that have an adjustable main jet, which is located on the lower right side of the carburetor, are still available new. main jets of various sizes are available for most carburetors with a fixed/non-adjustable main jet so the engine will run correctly depending on the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used.

Walbro WHG #52, #60 and #64 carburetors work great for ordinary lawn and garden equipment, general lawn work and they're perfect for basic stock low RPM/low performance pulling tractors with an engine that's governed to a maximum of 3,200 RPM with a fixed/non-adjustable main jet, or at 3,600 RPM with an adjustable main jet. A carburetor with a fixed/non-adjustable main jet is limited to just 3,200 RPM and should never be operated faster for an extended length of time. Although the venturi cannot be bored-out on a Walbro, they work equally as well as the older Carter/Kohler carburetors when used on a stock engine. The main jet in the newer Walbro WHG #52, #60 and #64 carburetors are calibrated at the factory to provide the engine with just the right amount of fuel at 3,200 RPM. Therefore, the fixed/non-adjustable main jet inside the carburetor cannot be replaced with an adjustable one.

Advertisement:
If you need the products listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Please click here to place an order.
High Quality Inductive Handheld Small Engine Wireless Tachometer. For gas/spark ignite engines only. Very accurate. This handheld analog tachometer works great for checking/setting the RPM on various small engines in the shop, and/or for checking/setting the RPM [tech] on stock governored engines at pulling events, ATVs/UTVS, etc. Hold sensor (antenna) close to spark plug wire for reading. Operates off a self-contained replaceable 9 volt battery. Has built-in battery voltage check. Reads up to 5,000 RPM on the low scale, and 15,000 RPM on the high scale.
  • $85.00 each, plus shipping & handling.
High Quality Inductive Small Engine Tachometer and Hour Meter. High quality and very accurate. Large 3/8 inch LCD display. Works with all spark ignition engines by selecting engine type using S1 and S2 buttons. Instructions included. Tachometer reads up to 99,999 RPM. Hour meter reads up to 9999:59 hours/minutes. Can be manually reset to Zero hours. Programmable maintenance hour setting with service icon, a reminder when to change oil or other service. Easy installation: Single wire wraps around spark plug wire and secured with two supplied nylon zip-ties. No wire terminal connections required. Tachometer can be surface-mounted and secured with two screws. Has built-in battery rated up to 4 years. Sealed unit; weather and water resistant. Dimensions: 2" wide x 1-3/4" depth x 3/4" height.
  • $20.00 each, plus shipping & handling.
High Quality Digital Tachometer/Proximity Sensor Kits. Will work with small engines or automotive engines, gas or diesel. This precision digital tachometer is triggered by the same method as crank trigger ignition with a proximity sensor to detect a target, which can be a small ferrous steel screw or pin, or magnet in a rotating disc or on/in flywheel. A sturdy steel or aluminum bracket will need to be fabricated by customer to mount the sensor in close proximity of the detector/trigger target. Set air gap/clearance at .010"-.188". Tachometer can be dash- or panel-mounted. Tachometer works with 8-24 volts DC, proximity sensors works with 6-36 volts DC. Tachometer can be dash- or panel-mounted. Tachometer works with 8-24 volts DC, proximity sensors works with 6-36 volts DC. Dimensions of each proximity sensor below: 15/32" (12mm) diameter x 1-3/8" thread length. Some proximity sensors have an LED (Light Emitting Diode) on the rear of unit. If the proximity sensor is wired incorrectly, the LED will stay on and go off when activated. Displays up to 9,999 RPM. Very accurate. Tachometer returns to zero [0000] when power is turned off. Wiring Instructions: #1 wire on tachometer connects to brown wire on (either) proximity sensor and ignition switch (battery positive (+) post), #2 wire on tachometer connects to blue wire on (either) proximity sensor and engine/chassis ground (battery negative (–) post), and #5 wire on tachometer connects to black wire on (either) proximity sensor. Wires #3 and #4 connects to nothing. Wiring can also be integrated with crank trigger ignition with a proximity sensor. Choice of RED or BLUE numeric display.
  • Tachometer only. To be used with a 3-wire hall effect, inductive or cube-shaped proximity sensor. $12.00 each, plus shipping & handling.
  • Complete Kit with Hall Effect Proximity Sensor. $22.00 each, plus shipping & handling.
  • Complete Kit with Inductive Proximity Sensor. $25.00 each, plus shipping & handling. Return to previous section.

Carter/Kohler or Walbro Fully Adjustable main jet Carburetors VS. Walbro Fixed/Non-Adjustable Main Jet Carburetor RPM to Horsepower Specs -

Walbro WHG #52, #60 and #64 carburetors with a fixed/non-adjustable main jet are designed with emission controls in mind to run leaner to create less air pollution. However, the main problem with most Walbros having a fixed/non-adjustable main jet is during cooler weather operation. During cool weather, and running at 3,200 RPM, the engine will sometimes run too lean on fuel and operate erratically. To fix this, first of all, make sure the hole (orifice) in the main jet is not partially clogged. If it is, use a carburetor jet cleaner wire set or an oxy-acetylene welding torch tip cleaner to clear any debris that may be lodged in the hole. Then use [150± psi] compressed air to clear out any dirt/debris. If the engine still runs too lean on fuel, simply enlarge the hole (orifice) in the main jet a few thousandths of an inch. Then use [150± psi] compressed air to clear out any metal particles. Be careful not to enlarge the hole (orifice) in the main jet too much, or the engine will run rich on fuel! The hole (orifice) diameter in the OEM factory main jet for 100% gasoline is 3/64" (.047"). If necessary, enlarge the main jet and fuel inlet holes with a #55 (.052") drill bit. That's a .0052" difference. After doing this, for cool weather, the engine should run better, last longer and produce more power. But don't enlarge the hole (orifice) in the main jet too much! A too big of a hole (orifice) will cause an engine to run too rich on fuel, making it blow black smoke out the exhaust and possibly fouling the spark plug. If the hole (orifice) is made too large, the carburetor will be useless for gasoline, and E85 fuel must be used. But if an engine is going to be used only during warm weather and if it runs okay [during warm weather], don't enlarge the hole (orifice) in the main jet.

On the newer carburetors with a fixed/non-adjustable main jet, the hole (orifice) in the main jet may need to be enlarged .002"-.003" to give the engine a little more fuel so it'll run better at higher RPM. Otherwise, the engine could "burn up" or wear out prematurely due to the lean air/fuel mixture. I have an assortment of tiny drill bits that I use on our customer's lawn & garden equipment carburetors.

IMPORTANT! A new style Walbro carburetor with a fixed/non-adjustable main jet should never be used on a non-governed (wide-open throttle) engine or on an engine that's going to turn at 3,200 RPM! The reason for this is because if an engine operates faster with a carburetor having a fixed/non-adjustable main jet, it'll run too lean on fuel at high RPM (it'll draw much more air than fuel), which will cause the combustion chamber to overheat and the excessive heat will likely damage the piston and rings and possibly warp the cylinder head and/or exhaust valve or even crack the cast iron engine block. A lean fuel mixture can also melt away part of the aluminum in the combustion chamber of an aluminum block engine.

The size number on the Walbro WHG #52, #60 and #64 carburetors is embossed inside the carburetor and can be seen by looking inside the upper part of the choke end, just above the venturi. A "52" carburetor has a 26 millimeter diameter throttle bore, which converts closely to 1.024 inches (26 ÷ 25.4 = 1.024"), but actually measures 1.07".

And being the venturi in the old-style Carter #16, #18, #20, #22 carburetors used on Kohler engine models K90/K91, K141, K160/K161 and K181 can't be bored-out either, the only option for pulling competitively with these is to fabricate an adapter to fasten to the intake port on the engine block and use a #52 Walbro or #26 Carter/Kohler carburetor.

The best way to determine which engine any particular carburetor is made for is to measure the diameter of the throttle bore. Because a set of numbers that's stamped on the carburetor body mean nothing, not even to Kohler Engine dealers. If a carburetor measures .822" (13/16"), then it's designed for the K141, K160/K161 or K181 engines. If it measures 1.07", then it's for the 10hp or 12hp engines. And if it measures 1.17" or 1.2", it's for a K321, K341 or K361 engine.


The Wrong Type of Choke Lever!

Whenever I get a carburetor with the choke lever in the wrong position, if it has a steel choke shaft, I just grind the lever off at the flare and weld it back on the shaft in the right position. But if it has a brass shaft, I use a steel choke shaft out of a junk carburetor. Or if I don't have a used one in stock, I machine a steel choke shaft from a 1/4" mild steel rod. Like the old saying goes: "There's more than one way to skin a cat."

The Choke Shaft Detent Ball and Spring -

When removing the choke shaft, there's a tiny (1/8" or 5/32") steel ball and small compression spring located at the 9:00 position when facing the choke end with the float area down. When the choke shaft is removed, hold one finger over the screw hole and end of the choke shaft hole to prevent the ball and spring from popping out and possibly getting lost. By the way - the ball and spring is required only for hand-operation of the choke to keep it in the open position on stand-alone engines, such as on a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. The ball and spring is not needed if the choke is remotely operated with a choke cable, such as in a tractor, etc.

Installing the choke shaft over the friction (detent) ball can be tricky. This is how it's done:

  1. Place the carburetor on a sturdy work bench or table with the choke end facing upward and the float area facing toward you, or gently clamp it in a bench vise.
  2. Install the ball and spring in the threaded air cleaner/filter assembly mounting hole located at the 9:00 position with the choke end facing you and float bowl downward. Certain Walbro carburetors have the ball and spring at the 3:00 position. Make sure the ball is centered with the spring.
  3. Use an 1/8" roll pin punch with a blunt end to firmly compress the spring/ball.
  4. When using your left hand to compress the ball/spring with the punch, place a finger over the outside shaft hole to ensure the ball will not "pop out" and go flying across your shop.
  5. Use your right hand to gently slide the shaft in through the hole until it makes contact with the punch, then at the same time while still pushing on the shaft, reposition the punch at an angle (toward your right), then slowly pull up on the punch at the same time continuing pushing the shaft through the hole so the shaft can slide over the ball. Make sure your finger is still over the end hole!
  6. The end of the shaft should now be flush with the outside of the carburetor body. Gently rotate the shaft to feel the ball "catch" in the detent hole.
  7. If this goes well, install the choke plate and apply clean motor oil, gear oil or lubricating grease through the screw holes for smooth choke operation and less wear to the shaft and/or carburetor body.


How to adjust the fuel mixture screws on a Kohler (or virtually any early small engine) carburetor - Top of page

First of all, as long as the engine runs well, don't worry about how the idle and high speed air/fuel mixture adjustments are made. The adjustments depend on the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used. In higher elevations, air is thin, therefore the engine require more air than fuel to run well. And in lower elevations, air is heavy, and the engine require less air than fuel. So there is obviously no "one set adjustment" for all carburetors. And no new or rebuilt carburetor with adjustable jet(s) for small engines, automotive or whatever, come from the manufacturer or rebuilder with the idle speed, idle air/fuel mixture or the high speed air/fuel mixture adjustments set correctly.

The High Speed Needle Adjuster -

On the Carter/Kohler carburetors, the hole towards the bottom of the long main needle adjuster is supposed to be open, so the engine can draw fuel through it for idling from the float bowl. The idle fuel passageways for a Carter/Kohler carburetor goes as follows: Fuel is first drawn through the high speed needle adjuster via the tiny lower hole (orifice) towards the bottom, then through engine vacuum, it is drawn upward through the tube, then over and down toward the idle mixture screw (which sets at an angle), and then the fuel is drawn into the throttle bore, next to the throttle plate. The information below Ê is mainly for Carter/Kohler carburetors. The fuel mixture screws are used as follows:

Many times when cleaning a Carter/Kohler carburetor, the expansion/welch plug that's on the side of the carburetor doesn't need to be removed. The only time it needs to be removed is when the tiny fuel feed hole that's next to the throttle plate becomes clogged with dried gas or debris. To clear this hole, with the idle air/fuel mixture screw and the high speed needle adjuster removed, thread a 1/4-28 UNF (fine thread) (fine thread) screw/bolt in place of the high speed needle adjuster (this will place more air pressure against the idle fuel feed hole), apply [150± psi] compressed air in the idle mixture screw hole, and place your finger inside the throttle bore over the fuel feed hole, and if you feel air come out of the hole, the hole is cleared out. If air does come out of the idle fuel feed hole, then the expansion/welch plug will need to be removed and manually cleared out with a carburetor jet cleaner wire set or an oxy-acetylene welding torch tip cleaner. A new expansion/welch plug will need to be installed.

Advertisement:
If you need any of the parts or services listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Please click here to place an order.
Quality High Speed Steel Spiral Drill Bit. Size: .039" / #60 / 1mm diameter x 1-3/8" length. Perfect size to enlarge lower hole (orifice) on high speed needle adjusters above È for Carter/Kohler carburetors so engine will start quicker and idle better. An ingenious, thoroughly researched and innovative concept by Brian Miller, because nobody else advertise the use of this part.
  • $1.60 each, plus shipping & handling. Many other small size drill bits also available.
Air Cleaner/Filter Assembly and Velocity stack Mounting Screws - TIP: When installing a screw to keep it from falling out of the screwdriver, either apply a dab of grease in the head of the screw or temporarily magnetize the screwdriver by rubbing a magnet along the length of the shank.

8-32 UNC x 3/8" thread length Phillips Head Screws. Use to fasten air cleaner/filter assembly base to Carter #16, #18, #20, #22 and Walbro WHL #44 carburetors.

  • High quality aftermarket. Hardened zinc-plated steel. .50¢ each, plus shipping & handling.
  • OEM Kohler part # 25 086 99-S. $1.75 each, plus shipping & handling.

10-32 UNF (fine thread) (fine thread) x 3/8" thread length Phillips Head Screws. Use to fasten air cleaner/filter assembly base to Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors.

  • Slotted head. Used and in excellent condition. OEM Kohler part # X-167-2-S. .25¢ each, plus shipping & handling.
  • Phillips head. High quality aftermarket. Hardened zinc-plated steel. .50¢ each, plus shipping & handling.
  • Slotted head. OEM Kohler part # X-167-2-S. $1.75 each, plus shipping & handling.

10-32 UNF (fine thread) (fine thread) x 1/2" thread length Stainless Steel Hex Socket (Allen) Head Screws. Use to fasten velocity stack to Carter/Kohler #26, #28, #30 or Walbro WHG #52, #60, #64 carburetors. (For competition pulling only.)

  • $8.00 per pair, plus shipping & handling.

Many other small screw sizes available at reasonable prices.

Quality High Speed Steel TAPER Hand Taps. Taper taps allow for the tip to be inserted deeper in the hole for straightener and easier cutting of threads. Click here to learn how to cut new threads, the professional way
  • 8-32 UNF (fine thread) (fine thread) size. For rethreading or cutting new threads in choke flange of Carter #16, #18, #20, #22 or Walbro WHL #36, #44 carburetors for mounting of air cleaner base. $8.00 each, plus shipping & handling.
  • 10-32 UNF (fine thread) (fine thread) size. For rethreading or cutting new threads in choke flange of Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors for mounting of air cleaner base or velocity stack. $8.00 each, plus shipping & handling.
  • Many other taps of various sizes available at reasonable prices.

Removing a Broken-Off Tap - A threading tap that has broken off in an engine block or metal casting can be very difficult to remove. About all I can tell you is to either take your block to a reputable machine shop to have the tap removed, or click here and try to do it yourself: https://www.google.com/?gws_rd=ssl#q=removing+broken+tap+from+hole. Actually, it's best to use a TAPER hand tap to cut new threads and clean out existing threads. If used correctly, a TAPER tap is less likely to break off. Click here to learn how to cut new threads, the professional way.


If an engine blows black smoke out the exhaust while running, then here are the main causes:

Black exhaust smoke is when an engine is getting too much gas and/or not enough air in the combustion chamber. The causes for this are either... (listed from most common to rare causes)

  1. Choke plate isn't fully opening.
    • Solution: Check for bent choke plate, binding of remote solid wire cable-controlled choke operation or adjust cable that controls opening/closing of choke plate.
  2. Too rich of fuel mixture adjustment on the carburetor.
    • Solution: Adjust carburetor or repair as needed.
  3. Worn float valve (needle and seat).
    • Solution: Install new float valve and seat.
  4. Bad float.
    • Solution: Install new or good used float.
  5. Float out of adjustment.
    • Solution: Set the float so it's level with the carburetor body with the carburetor turned upside-down.
  6. If the fuel baffle shield is hard and stiff, it can push down on the float after the float bowl is installed, preventing the float from shutting off the fuel at the float valve (needle and seat).
    • Solution: Install new baffle shield.
  7. Too much fuel pressure if using an electric fuel pump.
  8. Hole (orifice) in the main jet/nozzle (emulsion tube) have been drilled too large.
    • Solution: Either plug the hole (orifice) with electrical solder and soldering gun, and redrill to .0625" (1/16") or install new main jet/nozzle (emulsion tube).
  9. Only one [Kohler or aftermarket] condenser being used with a high-output/performance ignition coil.
    • Solution: Install two [Kohler or aftermarket] condensers or one automotive (Chevrolet/GM) distributor condenser.

Also, sometimes flooding of the carburetor will deposit gas in the motor oil, but only in a vertical shaft engine. Because gas can't seep into the crankcase on horizontal shaft engines. The cause of the problem is the carburetor is flooding. The gas seeps past the piston ring gaps and into the crankcase. To fix this, clean the float valve (needle and seat) in the carburetor, or install a new carburetor overhaul/rebuild kit with a new float valve needle and seat. Also, clean out the fuel hoses with [150± psi] compressed air and install a new fuel filter. And then the oil will need to be drained and fresh motor oil installed.

NOTE: Use a thin-wall deep well 3/8" size socket for easy removal and/or installation of the hex-shaped float valve seat in the Carter #16, #18, #20, #22 or Carter/Kohler #26, #28, #30 carburetors. The socket may need to be machined down to 1/2" diameter in a metal lathe so it will fit into the seat depression in carburetor body. And use a large, wide flat blade screwdriver to remove and/or install the slotted float valve seat.

The Cause of Carburetor Flooding at Slow Idle with a Long Duration/High Performance Camshaft -

Sometimes when using a long duration/high performance camshaft, despite if the engine has a modified or stock carburetor, if the engine idles for a long period of time, it may run rich on fuel at slow idle speeds. What happens is with a long duration cam, intake vacuum is low and with a single cylinder engine, excess fuel builds up in the intake extension/port. Any engine that has a long duration camshaft have low vacuum at slow idle speeds. The longer the duration, the lower the vacuum. What causes excess fuel to build up in the intake is the long duration of the cam lobes holds the [intake] valve open longer, and at slow idle, the pressure of the piston blows some of the air/fuel back into the intake tube. The more duration a cam has, the worse this will be. As the engine is accelerated, black smoke or raw unburned fuel will blow out the exhaust until the fuel is cleared out of the intake tube. With the engine running well above idle, air becomes trapped within the combustion chamber and the piston don't have time to blow any air/fuel back into the intake. This happens with automotive gasoline, E85 or 100% methanol fuels, and there's nothing that can be done about it. There's probably nothing wrong with the carburetor, and nothing can be done to the idle circuit to prevent this. Just make a simple adjustment with the idle air/fuel mixture screw so the engine idles smoothly, and don't allow the engine to idle for a long period of time.

The Major Causes of Carburetor Flooding -

Personally, I don't put any additives in my gas. I think it's a waste of money and effort. I just dump any left-over gas from my customer's small engine equipment in my car or truck, let it mix with the fresh gas that's already in the tank, then I use fresh gas in my customer's small engine equipment. If there's water in the gas, I separate the gas from the water in a bucket (water always goes to the bottom). And if there's dirt/debris in the gas, I strain/filter the gas through a clean shop towel placed in a large funnel in a gas can.

What prevents most carburetor and fuel system from having problems when using gasoline is to run the engine out of fuel or draining the entire fuel system if it's not going to be used for more than 30 days at a time. If there's no fuel left in the system, then there should be no problems. The following causes are listed from most common to rare.

If fuel drips out of or from the carburetor...

  1. Dirt/debris, lint or hair lodged between float valve and seat. This will prevent the float valve from fully closing against the seat.
    • Solution: Clean float valve and seat, clear out entire fuel system with [150± psi] compressed air and install new fuel filter.
  2. Old, dry-rotted pleated paper fuel filter. The filtering material is brittle, can tear easy, which will allow dirt/debris to pass through the torn opening.
    • Solution: Clean carburetor, clear out entire fuel system with [150± psi] compressed air and install new fuel filter.
  3. [150± psi] compressed air blown through pleated paper fuel filter too many times to clean it out. This will cause the filtering material to tear, rip or "blow out," allowing dirt/debris to pass through the torn opening.
    • Solution: Clean carburetor, clear out entire fuel system with [150± psi] compressed air and install new fuel filter.
  4. Worn or damaged fuel inlet valve and/or seat.
    • Solution: New replacement required.
  5. Loose float valve seat in carburetor body (if it's the threaded-in type). Sometimes these are not installed tight enough, resulting in a light flooding condition.
    • Solution: If tightening the seat doesn't stop the fuel leak, then a new float valve and seat with a new sealing gasket will need to be installed.
  6. Fuel leak at the carburetor float bowl rubber O-ring seal. Only happens when engine is in use.
    • Cause: Circumference of float bowl not sealing tight against the neoprene rubber O-ring seal and fuel baffle/splash shield in carburetor body.
    • Solution: Remove float bowl, and from inside the bowl, use a small to medium size hammer to flatten the area around the hole where the bolt fastens the float bowl to the carburetor body. Doing this will place more pressure on the circumference of the float bowl against the carburetor body so the O-ring will seal better. Don't over-tighten the float bowl bolt because the threads in the carburetor could strip out. Also, make sure the O-ring and baffle shield are in place when reinstalling the float bowl.

If gas constantly pours out of the carburetor...

  1. Bad or damaged float (hole in float). To test for a bad float, if it's a hollow brass float, remove it from the carburetor and either move it around in your hand or hold it next to your ear. If you feel and hear a sloshing sound, then there's gas inside it. NOTE: Repairing by re-soldering a brass float will most likely not work or last long. NOTE: Do NOT use a propane torch or small oxy-acetylene torch to solder a hole in a brass float that had gas in it! The gas fumes inside WILL cause the float to explode!
    • Solution: New or good/used float replacement is required.
  2. Small hole in bottom of float bowl. This happens to aluminum float bowls and is caused by corrosion from water in the fuel system. Water is heavier than gas. So it goes below the gas and straight to the carburetor. Water will corrode an aluminum float bowl. And during winter, it'll freeze in the float bowl and crush the float.
    • Solution: New replacement of either part is required.
  3. Float stuck to bottom of float bowl. This is caused by engine setting in long term storage with gas left in the fuel tank and carburetor. To prevent this from happening or happening in the future, drain the entire fuel system, then loosen the float bowl retaining bolt to finish draining all the fuel from the float bowl.
    • Solution: Cleaning of float and bowl is required.
  4. Float valve installed incorrectly. (When installing a new overhaul/rebuild kit.)
    • Solution: The rubber tip (pointed end) goes in the fuel inlet seat and not against the float.
  5. If the carburetor on an engine has been setting for some time without an air cleaner/filter assembly, and if gas pours out of the carburetor only when cranking the engine, especially with a mechanical fuel pump, then the gas stops pouring out when the engine isn't cranked, check for a clogged atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor) in the carburetor. Sometimes a mud dauber (wasp-like insect) will build their nest in a place like this. (I've seen this happen a few times with carburetor rebuilds.)
    • Solution: Clear out the atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor) and entire carburetor with [150± psi] compressed air.
  6. If an electric fuel pump is used, it either has too much pressure, or if there's a fuel pressure regulator in-line, it's set too high or stuck in position.
    • Solution: Repair or adjust regulator as needed.

What makes crankcase oil black is blow-by due to either worn piston rings, carburetor flooding or the engine running rich on fuel (gas). And if there's gas in the oil (you can smell the presence of gas), this means there's a hole in the diaphragm in the mechanical fuel pump. Being there are no fuel pump repair kits available nowadays, an either good used or new replacement fuel pump is required.

How to Separate Gas from Water - (With the price of gasoline nowadays, this would be a wise thing to do.)

  1. Drain the water-contaminated gas from the entire fuel system (fuel tank, fuel hose, fuel pump, filter and carburetor) into a clean container of adequate size. The water (and dirt/debris) should immediately settle to the bottom of the container and the gas will be on top. You should be able to see the separation under a bright light.
  2. Slowly pour the gas into another clean container, but watch that the water don't enter the other container, too. If there's dirt/debris in the water-contaminated gas, place a filtering material, such as a paint filter, coffee filter, fine mesh screen wire, clean cloth shop towel or a fine woven fabric window curtain, over a large funnel in a clean container of adequate size, and pour the gas through the filtering material/funnel, but again, watch that the water don't enter the other container. The water can be seen under the gas.
    • NOTE: If water-contaminated gas have been treated with a gas line anti-freeze treatment (to break up the water into tiny droplets), doing the above may not separate the water from the gas in the container. If this is the case, then the water can be easily separated from the gas by using genuine (not synthetic) chamois leather. The surface fibers in chamois leather will absorb the water and allow gas and other liquids to pass through. If the gas has any amount of alcohol (10% or E85), the alcohol will also pass through the chamois. Place the chamois over a large funnel in a container of adequate size, and pour the water-contaminated gas through the chamois/funnel. The chamois will also filter out any dirt/debris that may in the water-contaminated gas. When finished, twist or wring out the chamois to remove the water and allow it to air-dry.
  3. Use [150± psi] compressed air to clear out the remaining water-contaminated gas from the entire fuel system and use a dry shop towel clamped to a long, needle nosed pliers to soak up the gas/water in the fuel tank. Make sure the tank is dry.
  4. Pour the water-free gas back in the fuel tank and dispose the contaminated water in the container.

DANGER! IMPORTANT! Gasoline and alcohol fuels are both extremely flammable! Use caution and don't smoke, avoid making sparks or don't have an open flame exposed when working near or with either of them. Work in a well-ventilated area, too.

By the way - We've been to a lot of garden tractor pulls through the years and noticed that some pulling tractors leak fuel in places where a fuel leak shouldn't be. Therefore, I think the safety inspections should include checking the fuel hoses for dry-rotting, cracks, fuel leaks, loose fittings, etc. (The tractors should have sturdy wheelie bars, too.) The inspectors should grab hold of the fuel hose(s) with their hand, bend it and slightly jerk on it to check for durability. This is very important. Especially in a kid's class. Don't wait until a small issue becomes a major problem, then turn in to a catastrophe. If a pulling club's sanctioning safety rules are enforced, and pullers would build their tractors right and maintain them regularly, there wouldn't be any injuries, fires, or fear of a fire. Click here to read more about a garden pulling tractor catching on fire.


If an engine won't idle or idles poorly, then the following should be checked and corrected...

  1. If it's a Carter/Kohler carburetor, chances are, there's dirt/debris or dried gas inside the high speed air/fuel needle adjuster screw tube.
    • Solutions: Remove the high speed air/fuel adjuster and if it has only one lower hole, carefully enlarge the hole by hand with a .039" / #60 / 1mm diameter drill bit clamped in a mini micro pin vise hand drill chuck. This is the perfect size to enlarge lower the hole on high speed needle adjusters so the engine will start quicker and idle better. Be careful when handling any tiny drill bit because they can break easily. Anyway, being the tube is made of soft brass, there's no need to use an electric drill. Then use [150± psi] compressed air to clear out any dirt/debris from inside the tube, and then suck through the tube with your mouth to make sure it's clear and unclogged. If the tube has two lower through-holes, there's no need to enlarge them because both of them together makes the opening plenty big. Anyway, if the tube is still clogged, use a small, bendable steel wire, such as a bread wrapper twist tie (with the plastic coating stripped off), to clean out the inside of the tube. Then use the [150± psi] compressed air to thoroughly clear it out. Suck through the tube with your mouth to make sure it's clear and unclogged. If performing either of the above È doesn't clear out the tube, then acquire a new main high speed air/fuel needle adjuster screw or one in good condition. But make sure it's the correct adjuster for your particular carburetor!
  2. If it's a Carter/Kohler carburetor, and if the inside of the high speed air/fuel needle adjuster tube is clear of debris, but the engine still fails to idle...
    • Solution: The carburetor probably has the wrong high speed needle adjuster. If the adjuster has four tiny holes midway, thoroughly clean the area around the holes with fine emery cloth or wire wheel, and solder over (block off) two of the holes opposite of each other with a soldering gun and electrical solder. Doing this will create a stronger suction (vacuum) of fuel through the tube so the engine will idle. Be sure to smooth the solder (get rid of any lumps) so it won't obstruct the flow of air through the carburetor.
      NOTE: Certain high speed adjusters are designed specially for a particular carburetor. I list the part number of the carburetor to match the type of adjuster it require. Kohler don't give their dealers much information on this. I did some research, and I have several used carburetors in stock, and compared the type of adjuster to the part numbers on the carburetor and found that some are in fact different. The air bleed holes midway on the high speed adjuster allows a small amount of air to be mixed with fuel through the idle circuit so the engine won't idle too rich or too lean on fuel. And the absence of holes midway allows full flow of fuel through the idle circuit, which when used in a wrong carburetor, may cause the engine to idle too rich on fuel. So if an engine idles well (with the present adjuster), then the carburetor has the correct adjuster. Also, being the high speed adjusters are made of soft brass, if the pointed tip is slightly bent, it can be easily straightened with pliers and reused, and should not effect engine performance whatsoever. It's a valve that regulates the amount of fuel that goes into the engine. The tip does not need to be centered with the hole (orifice) in the main jet/nozzle (emulsion tube). Gas will still get around it. And over-tightening the needle into the main jet hole (orifice) will crush the tip out of shape, making it difficult to regulate the fuel. If the tips is damaged from being overtightened, the high speed adjuster will need to be replaced. Or the damaged tip can be broken off at the lower hole(s), and the [#26, #28 or #30] carburetor can be converted for use with a bottom adjuster.
  3. Dirt /debris or dried gas in the idle fuel passageway.

If an engine idles slow when the throttle lever is held to the slowest position by hand, but refuses to idle down on its own, the following may be the causes:

But if an engine idles well, but runs only at higher RPM (up to 3,200 RPM with a fixed/non-adjustable main jet; or 3,600 RPM with an adjustable main jet) with the choke partially closed, or if it surges or hesitates to rev up upon acceleration, this means the engine is running too lean on fuel, and following are the most likely causes: (listed from most common to rare)

FYI - If you've had your carburetor apart about 10 times, and you found nothing wrong with it, but the engine still runs the same with the same carburetor installed, then the problem obviously isn't in the carburetor. As an older, experienced mechanic once said, "Most carburetor problems are electrical." (Meaning faulty ignition system.) This has proven true more times than I can remember.


Backfiring out the exhaust upon deceleration is normal for virtually all engines since gas is still going through the combustion chamber, compressing in the exhaust and exploding from the exhaust heat. But if an engine constantly backfires out the exhaust at any speeds after running for several minutes, the problem may be...


The Anti-Backfire Fuel Solenoid (and Valve) -

Kohler's Magnum Fuel Solenoid came on certain models K181, M18 and K582 engines, and virtually all M20 and MV20 engines. The anti-backfire solenoid valve [in the carburetor] shuts off the engine when the ignition is turned off. The valve only blocks off the main jet in the carburetor to prevent fuel from entering the combustion chamber. It does not prevent fuel off from entering the float bowl. The way the solenoid works is, upon engine shut down, the valve blocks air from entering the float bowl through the atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor; which is where the solenoid valve is located). When this happens, the engine can't draw fuel, so it shuts down. The solenoid is energized the entire time the ignition switch is on. The reason Kohler installed this feature is to prevent the engine from producing a loud backfire out the muffler when it's shut off. With the solenoid in working condition and upon engine shut down, no unburned fuel enters the hot muffler, therefore, no backfire. When the solenoid fails or goes bad, the engine will not start.

NOTE: Being the solenoid for various M18, M20 and MV20 engines (OEM Kohler part # 25 755 06-S) is no longer available, to convert these engines without use of the solenoid, remove the failed solenoid and valve, cut some short threads in the hole (remove the float bowl first and use compressed air to clear out the metal cuttings), and install a 3/8" Allen set screw in the hole. Don't thread the set screw deep in the hole, or it will block off air from entering the float bowl. Without a solenoid, the engine would require a different ignition switch to shut off the spark. And the engine should be idled down before shutting it off to lessen the chance of a backfire out the muffler.

The fuel solenoid used on newer Briggs & Stratton, Kohler, etc., engines is located on the bottom of the float bowl. The spring-loaded plunger in it stops the fuel supply to the combustion chamber by blocking off the main jet as soon as the ignition is turned off. With this type of fuel solenoid, the engine will die immediately when the ignition is turned off. This solenoid also prevents a loud BANG out the muffler when the ignition is turned off while the engine is hot. Without it, when the [hot] engine is turned off while throttled up, unburned gas will continue to pass through the combustion chamber, build up in the still red-hot muffler where the gas is compressed with hot air, and then produce a loud BANG out the muffler.

If the solenoid goes bad (it's supposed to make a "click" sound when the ignition is turned on), it can be replaced with a new one, or remove it and simply snip off the protruding pin (plunger rod), and reinstall it. Doing this will allow the engine to draw fuel and run. But remember to idle the engine down for a few minutes each time before shutting it off, or like I said, it may produce a loud BANG out the muffler.

Advertisement:
If you need any of the parts or services listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Please click here to place an order.

Kohler Anti-Backfire Solenoid Kit.

  • Fits various K181, M18, M20 and K582 engines. OEM Kohler part # 25 755 05-S. $71.15 each, plus shipping & handling.


How To Loosen a Gummed-Up, Stuck, Corroded or Rusted-In-Place Throttle or Choke Shaft, or Adjusting Screw -

EVAPO-RUST® and Metal Rescue are very safe products to use and works wonders to remove rust and loosen virtually any rusted or corroded metal part! Just soak the carburetor body for 1 hour for light rust and up to 12 hours for extremely heavy rust. Then use small locking pliers (Vise Grip) to GENTLY rotate the shaft back and forth . Don't force it because it could become twisted and/or break off at the closest plate retaining screw hole! It may rotate (loosen) just a few thousandths of an inch. After it rotates slightly, spray it again and gently rotate it again. Eventually, it should rotate more and swivel 100% free. These products are very safe to use and they work wonders on virtually anything that's rusted!

Or use a heavy duty bathroom toilet bowl cleaner. Most of them will remove rust and scale. If it reads on the label that it will remove rust, then that's the one to use. Pour the cleaner in a container that's large enough for the carburetor body, and allow it to soak for about 30 minutes and then rinse it off with water. The throttle or choke shaft should swivel with no problems.

Or use distilled white vinegar to remove rust from inside gas tanks, tools, bolts/nuts, clutch pressure plates or virtually any steel or cast iron part: vinegar rust removal - YouTube.

GUNK Liquid Wrench® also works wonders to loosen virtually any rusted or corroded metal part! Just spray the ends of the throttle or choke shaft, let soak for about 30 minutes or perhaps overnight, then use small locking pliers (Vise Grip) to GENTLY rotate the shaft back and forth . Don't force it because it could become twisted and/or break off at the closest plate retaining screw hole! It may rotate (loosen) just a few thousandths of an inch. After it rotates slightly, spray it again and gently rotate it again. Eventually, it should rotate more and swivel 100% free.

If the shaft(s) refuse to loosen with either Evapo-Rust, Liquid Wrench or heavy duty bathroom toilet bowl cleaner, remove the float bowl, float, baffle shield and O-ring seal. Clamp the carburetor in a bench vice, then use a propane torch or an oxy-acetylene torch to LIGHTLY heat the carburetor body next to the shaft (don't get the carburetor body too hot!), and use the locking pliers (Vise Grip) to GENTLY rotate the shaft back and forth . The shaft should swivel 100% free within a few seconds of heating. Heating might also work to remove a stuck-in-place idle speed adjuster screw, idle fuel mixture screw or the main adjuster screw. Be very gentle rotating a brass screw to loosen it because being brass is a soft metal, it could snap off! And be careful not to get cast aluminum too hot, it may crumble or split into pieces! Don't use a torch in an attempt to remove a stuck main jet/nozzle (emulsion tube) from a carburetor that's in good condition. Being the aluminum surrounding the main jet/nozzle (emulsion tube) is thin, it will most likely crumble or split into pieces under the severe heat, rendering the carburetor useless.

How to Clean the Inside of a Heavily Rusted or Dirty Fuel Tank -

Fill the fuel tank with EVAPO-RUST® or Metal Rescue™, leave it for 1 hour for light rust and up to 12 hours for extremely heavy rust, drain and flush with clean water, allow to thoroughly dry. These products are very safe to use and they work wonders on virtually anything that's rusted! Or use distilled white vinegar to remove rust from inside gas tanks, tools, bolts/nuts, clutch pressure plates or virtually any steel or cast iron part: vinegar rust removal - YouTube.

Another method to clean an internally rusted or especially dirty fuel tank, put some small driveway gravel in the tank with water, seal the fuel outlet fitting and gas cap vent holes (make sure the gas cap has a good seal), then literally and vigorously shake the heck out of it! Or for less tiresome labor, put the gravel and water in the tank, seal it up, securely tie a blanket around it and then put it in a clothes dryer or fasten it in an electric paint shaker. Set the dryer on the cold or "No Heat" setting, and let the dryer tumble or paint shaker shake for a couple of hours. When the water is drained and majority of the gravel removed, use a garden water hose to thoroughly clean out inside the tank. It should look new inside. If there's still some rust or dirt/debris in it, repeat the process until all the rust or dirt/debris is broken loose. And despite of what you've probably heard, putting sugar in a fuel tank will NOT ruin the engine! Don't believe in everything you hear. Read about it here: snopes.com: Sugar in the fuel tank. YouTube link: Sugar in Your Gas Engine Fuel Tank.

How to Repair a Hole in a Fuel or Oil Storage Tank -

If virtually any kind of ferrous metal (steel) tank have a rusted or dented hole in it and leaks fuel or liquid, it can be successfully repaired by using a quality-made fuel tank sealant. But if the hole is too large for the sealant, and if the tank is made of steel, a reputable automotive radiator repair shop can solder a [tin] patch over the hole. Then ask them to pressure test the tank filled with air submerged in water to see if the patched hole leaks (bubbles). They usually have rubber expansion plugs of various sizes to block-off the inlet and outlet openings or ports.


How to Professionally Remove the Soft Brass Retaining Screws from Carter/Kohler Throttle or Choke Shafts Without Breaking Them Off -

First of all, I hate when people throw away a reusable throttle or choke shaft just because it has a broken off screw in it. The only reason most carburetor manufacturers install soft brass screws in the throttle and choke shafts for the throttle and choke plates is because the protruding threaded ends can be easily flared to prevent the screws from loosening and dislodging from the shaft and becoming lodged between the intake valve and seat, or from being sucked into the combustion chamber. This saves them money from not having to use lock washers or liquid threadlocker.

When removing these screws and to prevent from breaking them off, first, grind down the protruding/flared ends with a Dremel or equivalent small rotary grinder chucked with either a very small grinding stone (chainsaw sharpening stone) or an 1/8" high speed steel end mill until the threads are flush with the shaft. Then the screws can be easily removed from the shaft without breaking them off. Be sure to use a quality-made screwdriver with a flat blade and square edge that fits the slot in the screw head perfectly to prevent from distorting or "stripping out" the slot, too. (This is why I use and offer for sale hardened stainless steel screws [with split lock washers]. Unlike [OEM] soft brass screws, stainless steel will not strip out or break off.)

But should a brass screw break off in the throttle or choke shaft without first grinding down the protruding/flared end, sometimes the shaft can be difficult to remove from the carburetor body due to the protruding flared end. Or if the slot in the screw head gets "stripped out." In this case, use the Dremel to grind the flared end of the [broken] screw and/or grind off the head of the screw until it's flush with the shaft. Then the shaft can be removed. Afterwards, the broken screw can be drilled out using a milling machine clamped in a vise with a 1/16" center bit drill to make a small depression in the exact center of the broken screw to prevent "drill bit skating" so either a 5/64", #46 or 2mm drill bit can be used to drill out the rest of the broken screw, and then the threads may need to be straightened/cleaned with a 3-48 UNC (coarse thread) taper hand tap. Don't use a center punch on the broken screw. This could bend the shaft, create a crack when straightened, possibly cause it to break later when in use. The throttle and choke shafts in Carter and Kohler carburetors originally come with 3-48 UNC (coarse thread) screws. A #3 split lock washer should be used with a 3-48 UNC (coarse thread) screw. Should the threaded hole become enlarged from drilling out the broken screw, the hole(s) can be made bigger with a 4-40 UNC (coarse thread) tap, and a 4-40 UNC (coarse thread) screw with a #4 split lock washer will need to be installed. By the way - liquid threadlocker is not required with a lock washer.


Correct Orientation and Installation of the Throttle Plate and Choke Plate -

All OEM factory-made throttle plates, rather small engine, automotive, farm tractor engine, etc., are made 3% oblong and have a slight angle on the sides that seal against the sides of the throttle bore. The angle and oblong shape prevents the majority of incoming air from entering the combustion chamber in the idle position so the engine can idle at a slow speed. To reinstall the throttle plate correctly, on the Carter, Kohler and Walbro carburetors that's used on Kohler engines, the C (Carter), K (Kohler) or W (Walbro) stamped on the throttle plate faces outward and toward your right when facing the throttle bore with the carburetor positioned right side up and float bowl down (as shown in the picture to the right à), and make sure the throttle plate is centered with the throttle bore in the fully closed position when the screws are installed and tightened. Back off the idle speed adjustment screw to allow the throttle plate to be in the fully closed position. Then use the tips of small [pointy] needle-nose pliers to align the holes in the throttle (or choke plate) with the screw holes in the throttle (or choke shaft). If the throttle plate is installed in reverse or not 100% centered with the throttle bore, too much air will by-pass the throttle plate and the engine will not be able to idle down at a slow speed. Most aftermarket (Chinese-made) oblong throttle plates are not stamped with a letter and don't have an angle on the sides, so they can be installed in either direction, and they'll still seal 100% and the engine should idle down just as well.

And when reinstalling a choke plate, make sure it's centered with the carburetor intake in the fully closed position. If the choke plate is not aligned with the carburetor intake in the fully closed position, the engine will be hard to start or may not start at all.

IMPORTANT! Be sure to use a split lock washer of the correct size on the throttle plate and choke plate retaining screws or apply medium strength liquid threadlocker on the threads of the screws to prevent the screw from becoming dislodged from the shaft and possibly being sucked into the combustion chamber, resulting in a possible bent intake valve, damaged valve seat or severe damage to the piston, cylinder head and/or cylinder wall. Return To Previous Paragraph or Website.


How to Remove the Main Jet/Nozzle (Emulsion Tube) from a Carter/Kohler #26, #28 or #30 Carburetor -

10-18hp Kohler (or Carter [model N]) CarburetorWhen rebuilding a plain, stock Carter/Kohler #26, #28 or #30 carburetor, there is really no need to remove the main jet/nozzle. If the main jet/nozzle will not come out, don't worry about it. All that has to be done is make sure that the bottom hole and side holes in the main jet/nozzle are open. To check if the side holes are open, simply spray WD-40 or aerosol carburetor cleaner through the small hole just beneath the choke plate and observe if it comes out the main jet/nozzle inside the throttle bore and float bowl area.

But if the main jet/nozzle is clogged, or if you're boring the venturi to modify the carburetor for high performance use, then the main jet/nozzle must be removed. Before attempting to remove the main jet/nozzle, and if the screwdriver slot is in good condition, then I found the best, easiest and proven way to remove it is by the following process. This method works great most of the time and the main jet/nozzle should loosen with no problems.

  1. Remove the idle fuel mixture screw (so it won't get bent) and the high speed needle adjuster so the tip won't get damaged when performing the below Ê procedure.
  2. Cradle the carburetor body upside down (float area facing up) lengthways on the open jaws of a large bench vise.
  3. Place a hand impact tool or a quality-made flat blade screwdriver with a good, square end wide enough to fit the entire width of the threaded hole and thick enough for more contact with the slot in the main jet/nozzle.
  4. Using a medium size hammer, strike the impact driver or screwdriver sharply and perpendicular several times while at the same time rotating the main jet/nozzle counterclockwise by hand (with the screwdriver) to loosen it. Do not use a wooden handle screwdriver because the handle could break.
  5. If the above È didn't work, then perform the removal method below Ê.

If the above È method still didn't work, then unfortunately, sometimes the main jet/nozzle (emulsion tube) will get stuck in place and the screwdriver slot will strip out. (I hate when this happens.) Do not use an Easy Out [Broken] Screw Extractor! With this tool, the tapered shape will force the main jet/nozzle to swell or spread outward (cause it to increase in diameter), and the deeper it goes, it could possibly crack the aluminum tube, rendering the carburetor body useless. The alternative method to remove the main jet/nozzle is to drill it out. This process is performed as follows:

  1. First, remove the high speed needle adjuster so it will not interfere with the main jet/nozzle and get damaged.
  2. Firmly clamp the carburetor body with the mounting and choke ends making contact with the jaws of a bench vise with the float area facing up.
  3. Drill perpendicular directly through the center of the main jet/nozzle with a 3/16" drill bit, then carefully enlarge the hole with a 9/32" drill bit, and finally finish drilling the hole with a 19/64" drill bit. Drill about 1" depth into the main jet/nozzle.
  4. Being very gentle, use a long, slender taper punch with a very pointed end and a small hammer to collapse the thin threads of the main jet/nozzle. NOTE: Be extremely careful when doing this! Because the aluminum tube could crack, rendering the carburetor body totally useless.
  5. Pry out the remains of the main jet/nozzle with needle-nose pliers. If you're not able to remove the entire main jet/nozzle with needle-nose pliers, insert a 3/16" diameter steel rod through the high speed needle adjuster hole and drive out the remains of the main jet/nozzle. May have to hold the rod angled through the hole so it can make contact with the end of the nozzle to drive it out.
  6. With the main jet/nozzle removed, use a 3/8-24 UNF (fine thread) (fine thread) plug hand tap to reshape and clean the threads for installation of another main jet/nozzle. Install a new main jet/nozzle, or a good used one from a junk carburetor. If the main jet/nozzle in a junk carburetor is stuck, you can just split the threaded tube with either a flat cold chisel, nut splitter or heat the tube with a propane torch or an oxy-acetylene torch until it splits apart. If attempting to use the flat cold chisel or nut splitter, be careful not to damage the main jet/nozzle itself!


How to Remove the Main Jet/Nozzle (Emulsion Tube) from a Carter #16, #18, #20 or #22 Carburetor for Cleaning -

If the main jet/nozzle in a Carter #16, #18, #20 or #22 carburetor that's used on Kohler engine models K90/K91, K141, K160/K161 or K181 needs to be removed for cleaning, being this type of nozzle is pressed in the carburetor body. It removes and reinstalls a lot easier than the above È main jet/nozzle. The removal and installation process is as follows:

  1. Remove the idle fuel mixture screw (so it won't get bent upon reinstallation of the main jet/nozzle), high speed needle adjuster, float bowl and float.
  2. Place the carburetor body right-side up (float area facing down) on the open jaws of a bench vise. Position the carburetor body crossways on the vise jaws so the float hinge loops won't break off. Do not tighten the vise jaws against the carburetor body.
  3. Using a 4" length x 11/64" (.172") diameter steel punch with a blunt end and a small hammer, go through the high speed needle hole from the top side of the carburetor, and drive the main jet/nozzle out from the bottom of carburetor body.
  4. To reinstall the main nozzle, place the carburetor body upside-down on the open jaws of the vise and use a 1/4" diameter steel [roll pin] punch and small hammer to drive it in until it bottoms out, and the end can be seen in the venturi.

By the way - as far as I know, new main jet/nozzles for the Carter #16, #18, #20 or #22 carburetor is not available from any source.


How to Remove a Broken-Off High Speed Air/Fuel Mixture Adjuster Needle Screw from a Carter/Kohler Carburetor -

Sometimes when an engine sits with gas in the fuel system, the old, dried gas residue will cause the high speed adjuster to become seized in the carburetor body. And when attempting to remove it, the hollow tube could will break off flush with the carburetor body. (Anything is possible with soft brass and old, dried gas.) Anyway, The removal process of a broken-off main adjuster is as follows:

  1. Reach in through the choke end with needle-nose pliers or small long/needle-nose Vise-Grips locking pliers and break off the needle part of the adjuster.
  2. From the top of the carburetor body, drill out the threaded part of the adjuster with a 3/16" drill bit, then work up to a 7/32" bit. Be sure to drill straight down into the adjuster! For precision and full control of the drilling process, this is best performed with the carburetor body clamped in a vice that's fastened on the table of a milling machine. (The broken adjuster may screw on out on its own when drilling it.)
  3. If it don't screw out when drilling it, use a long, slender taper punch with a very pointed end to collapse the remains of the adjuster so it can be removed with the needle-nose pliers.
  4. Use a 1/4-28 UNF (fine thread) (fine thread) plug hand tap to straighten and clean the threads for installation of another adjuster.

If you don't feel comfortable removing the broken adjuster yourself, I charge $30.00 labor, plus return shipping & handling, to remove a broken adjuster.


Using Pump Gas with 10% Ethanol Versus 100% Race Gas in a Pulling Tractor -

First of all, in an daily-driven vehicle, gasoline with no lead is hard on soft cast iron exhaust valve seats. A soft cast iron valve seat is one that's been machined directly into an engine block or cylinder head, and it have not been heated-treated or no hardened insert is installed. In a daily-driven automobile, the seat(s) will eventually deteriorate or the metal will literally "wear away" because the absence of lead in gas to provide a protective coating to prevent wear. And being most exhaust valves are made of extremely hardened steel, they're not likely to wear at all. The intake valve and the cast iron seat is not likely to wear as much, if any. And an engine block or cylinder head with heat-treated seats or have hardened steel exhaust valve seat insert(s) installed, they should not wear whatsoever.

Anyway, the 10% ethanol in pump gas (common everyday automotive fuel) lessens exhaust emissions. Plus, the alcohol content boosts the octane, making it somewhat of a high performance fuel. The lead content in race gas (VP, Turbo Blue, Sunoco, Torco, etc.) boosts the octane also, except it's alcohol-free to pass the tech fuel test for tractor pulling. And the valve seat(s) that's ground in a cast iron block in a pulling engine burning 87 octane unleaded regular gas should last a long time, no longer than the tractor runs down the track (2-3 minutes per pull). They're not being driven a long distance, like in a car or truck. Click here to learn how to test for alcohol content in gasoline. (require Adobe Acrobat Reader and use Google Chrome web browser for a faster download of websites with large files.)

Older-formula mothballs have also been used by drag racers to enhance the octane rating of fuel, by dissolving the mothballs in some of the fuel and filtering out the remains with a filter paper.

Average Octane Rating of Various Fuels | Remember - Only high compression engines benefit from the use of high octane fuel to increase the power output. High octane fuels have no effect whatsoever when used in a low compression engine.
  • Regular unleaded automotive gasoline w/10% ethanol: 87 octane.
  • Premium unleaded automotive gasoline w/10% ethanol: 91-92 octane.
  • Leaded aviation gas (piston engine airplane fuel): 100 octane.
  • E30: 98.6 octane.
  • E85: 105 octane.
  • LP or Propane Gas: 100-110 octane.
  • Leaded race gas (VP, Turbo Blue, Sunoco, Torco, etc.): 110 octane.
  • Hydrogen fuel: approximately 130 octane.
  • 100% methanol: 135 octane.
  • 100% ethanol: 110-112 octane.
  • Denatured alcohol: 130 octane.
  • Compressed Natural Gas (CNG): 130 octane.

By the way - I've never had problems with gas having 10% ethanol in any of my small engines or automotive engines. I don't know why anyone else would. Maybe that's because when one is having problems with a small engine not running right, it's much easier to just blame it on "bad gas" than to look for the real problem elsewhere with the engine. Remember - it takes three things to make an internal combustion engine run: carburetion, compression and ignition. A professional, thorough and energetic mechanic don't blame the problem on one thing and overlook the other two. Unless of course, he's lazy and looking to make some quick money by doing an easy fix.

NOTE: The main jet (and fuel inlet hole) should not be enlarged for alcohol-free, high octane racing gas, such as VP, Turbo Blue, Sunoco, Premium gas, or gas with 10% ethanol, because these fuels require the same air/fuel mixture ratio as for ordinary, low octane automotive gas. The only time the main jet and fuel inlet holes needs to enlarged is when burning E85 or methanol fuels. If the main jet hole (orifice) is intentionally enlarged for gas, the engine will run too rich on fuel, and there'll be no way to lean it out. Click here to learn how to test for alcohol content in gasoline. (require Adobe Acrobat Reader and use Google Chrome web browser for a faster download of websites with large files.)


E-85 Fuel Using E85 Fuel in a Garden Tractor or Lawn & Garden Equipment -

What is E85? E85 is the term for motor fuel blends (special blend of automotive fuel) of 85% ethanol (corn alcohol AKA "moonshine") and 15% gasoline. E85 is an alternative fuel as defined by the U.S. Department of Energy. Besides its superior performance characteristics, ethanol burns cleaner than pure gasoline; it is a completely renewable, domestic, environmentally friendly fuel that enhances the nation's economy and energy independence. The addition of ethanol boosts octane and, because it is an oxygenate, ethanol contributes to a more complete fuel combustion resulting in reduced emissions of carbon monoxide and other ozone-forming emissions. Ethanol also degrades quickly in water and, therefore, poses much less risk to the environment than an oil or gasoline spill. To learn more about E85, visit this website: National Ethanol Vehicle Coalition (http://www.e85fuel.com). Click here to learn how to test for alcohol content in gasoline. (require Adobe Acrobat Reader and use Google Chrome web browser for a faster download of websites with large files.)

Fueling with E85 is not only beneficial to the environment, you'll most likely see a small increase in performance, which will be accompanied by a small decrease in fuel economy. On average, when an engine is powered by E85, the engine will have about 5% more horsepower and a 10% drop in fuel-efficiency. The added power comes from ethanol's higher (105) octane rating. The fuel economy decrease comes from the fact that ethanol has a lower energy content than gasoline, which means the engine will have to use more of it. Only high compression engines benefit from the use of high octane fuel to increase the power output. High octane fuels have no effect whatsoever when used in low compression engines.

E85 is available from most gas pumps at about 15% less than 91 octane. It can be used in virtually any gas engine fuel system, new or old. The only problem is, the rubber-like fuel hose, seals and gaskets in the fuel system might deteriorate due to the alcohol content in E85. Click here to learn how to test for alcohol content in gasoline. (require Adobe Acrobat Reader and use Google Chrome web browser for a faster download of websites with large files.) But if the fuel system has neoprene rubber or synthetic rubber parts, there should be no problems. E85 works great for competition pulling, general lawn use or for any small engine equipment. It'll create less carbon build up in the combustion chamber, too. I've reworked lots of carburetors for people who use their garden tractor just to mow grass with and they love how the E85 produces more power. Their only complaint is the engine burns more fuel. But that's the sacrifice for more power. If an engine is converted correctly, E85 should cause no problems with engine wear or fuel system deterioration. Basically, all that needs to be done to the engine is the main jet and fuel inlet (float valve) hole in the carburetor will need to be made about 80% bigger and the ignition timing will need to be advanced about 150% more than stock. If the main jet isn't enlarged, the engine probably won't run on E85, or if it does, it will run too lean on fuel, overheat the engine, possibly damage the valves, piston and piston rings because of the excessive operating temperature. And if the timing isn't advanced enough to thoroughly burn the [slower burning] E85 fuel, some of it will exit out the exhaust unburned, with no increase in power.

No special motor oil is required with E85. But with prolonged idling, the oil may need to be changed more often. The 20% increase in the main jet and fuel inlet holes, and ignition timing applies to virtually all small engine carburetors and engines, despite the make or manufacturer.

E85 can be purchased at select gas stations in the U.S. It cost less per gallon than regular unleaded gasoline. And an engine will burn about 20% more fuel than gas with E85, but it'll also produce about 10% more power, operate cooler, have a cleaner combustion chamber and the engine will last longer.

On the K161 and K181 Kohler K-series and Magnum engines, with the Carter #16, #18, #20, #22 carburetor, the hole (orifice) in the main jet for 100% gasoline measures exactly 3/64" (.046") in diameter. To convert these carburetors for use with E85, enlarge the main jet and fuel inlet (float valve) holes with a 5/64" or #47 (.078") drill bit. NOTE: Drill the fuel inlet from the inside out (opposite flow of fuel) to prevent a burr that may cause the carburetor to leak fuel or flood out. For accuracy, use a small metal lathe to drill the hole bigger. The ignition timing will also need to be advanced to 24º BTDC so the engine will take full advantage and make maximum power of the slower burning, higher octane fuel. Then with the engine running at 3,600 RPM, adjust the high-speed fuel mixture needle valve so the engine runs smooth.

On the K241-K341 single- and twin-cylinder Kohler K-series and Magnum engines with the older Carter/Kohler carburetors, the factory hole (orifice) in the main jet size for 100% gasoline measures exactly 1/16" (.0625") in diameter. To convert these carburetors for use with E85, enlarge the main jet and fuel inlet (float valve) holes with a 3/32" or #42 (.094") drill bit. NOTE: Drill the fuel inlet from the inside out (opposite flow of fuel) to prevent a burr that may cause the carburetor to leak fuel or flood out. For accuracy, use a small metal lathe to drill the hole bigger. The ignition timing will also need to be advanced to 24º BTDC so the engine will make full advantage and make maximum power of the slower burning, higher octane fuel. Then with the engine running at 3,600 RPM, adjust the high-speed air/fuel mixture needle valve until the engine runs smoothly.

To convert virtually any 4-cycle engine to run well and produce full power on E85 fuel...

  1. If an OEM factory [restrictive] air cleaner/filter assembly is going be used, drill the main jet and fuel inlet (float valve) holes to 35% bigger than their original size. For an engine that's going to use a less restrictive air cleaner/filter assembly or no air filter at all, drill the holes to 40% bigger than their original size. To calculate the size hole that needs to be drilled, with a calculator, multiply the exact diameter of the main jet and fuel inlet hole by 135 (with factory air filter) or 140 (with less restrictive or no filter), hit the percent (%) key, which shows the approximate size drill bit to use. NOTE: If the fuel inlet hole itself isn't made bigger, when pulling down the track at high RPM or wide open throttle, as soon as the float bowl fills with fuel, the engine will suck it dry, and as the engine winds down due to the lack of fuel, this allows more fuel to get dumped into the bowl and the process repeats itself over and over. The engine will run up and down, up and down, etc.
  2. Enlarge the lower hole on the high speed adjuster (Carter/Kohler carburetors) so the engine will idle smooth. There's need to modify anything else regarding the idle fuel passageway.
  3. Advance the ignition timing 150% more than the stock setting. If the OEM timing is 20º BTDC, advance it to 30º BTDC. (20 x 150% = 30) The ignition timing will need to be set slightly more advanced to 32º BTDC when the spark plug is positioned over the exhaust valve. If the timing isn't advanced at all or advanced enough, some of the E-85 will exit the exhaust unburned and the engine won't produce full power. The excess raw E-85 in the combustion chamber will travel past the ring gaps (especially when the engine is cold) and dilute the crankcase oil even more.
    When advancing the ignition timing past 24º± BTDC, and if the camshaft has a working automatic compression release mechanism, the compression release will need to be disabled (tied down) with a nylon zip tie or baling wire, or removed entirely. The reason being, with the excessive advanced timing, the compression release will open the exhaust valve when spark occurs, and the engine will pop out the exhaust, not be able to start, or be hard to start. Without a compression release, to make the engine easier to crank over and start under full compression, a high torque starter motor with separate starter and ignition switches will need to be used to prevent engine "kick back." If the engine "kicks back" too many times when attempting to start it, this could bend or break the starter motor armature shaft, or break the aluminum casing!
  4. Increase the fuel flow with a low-pressure electric fuel pump. If an insufficient amount of alcohol is delivered to the carburetor, the engine will run like it's starving for fuel. The engine will run up and down, up and down, etc. Use a low pressure electric fuel pump that delivers 3-4± psi of pressure.
  5. And that's it. The engine should run cooler, produce about 10% more power, but it'll burn 30-40% more fuel! NOTE: In cool weather, starting fluid (ether) may need to be sprayed into the carburetor throttle bore just to get the engine started. And the crankcase oil will need to be changed more frequently when burning high alcohol content fuels. Click here to learn how to test for alcohol content in gasoline. (require Adobe Acrobat Reader and use Google Chrome web browser for a faster download of websites with large files.)

How to Convert a Briggs & Stratton 16hp, 18hp or 20hp Opposed Twin Cylinder Engine for Use With Methanol Fuel - (This is recommended for competition pulling only and not for general lawn and garden work.)

For competition pulling only, the Briggs & Stratton 16hp, 18hp or 20hp opposed twin cylinder engines can be converted for use with methanol fuel. As for the carburetor, there is two ways to make this happen. The hole in the main jet for gasoline is .036" in diameter. This hole can either be drilled out to .078" (5/64" or 2mm), or it can be drilled out slightly larger and then the same main fuel adjuster for the bottom of Carter/Kohler carburetors can be installed to "fine tune" the air/fuel mixture at higher RPM. Also, the fuel inlet hole (float needle valve hole) will need to be increased to about twice its size. The OEM B&S float valve can be (re)used. And being methanol requires more fuel delivery than gas, the diaphragms and springs in the integrated fuel pump will need to be removed, reinstall the cover gasket, the OEM fuel pump pulse port on both the fuel pump part of the carburetor and engine block will need to be blocked off with 1/4" vinyl vacuum caps with a small clamp, and a low pressure electric fuel pump will need to be connected to the fuel inlet port on the OEM fuel pump. The methanol will flow directly through the OEM fuel pump internals and to the carburetor.

Special-made offset flywheel keys for Briggs & Stratton engines.Briggs & Stratton's Magnetron™ Solid State ModuleAnd for the engine to make full power from the slower-burning methanol fuel, the ignition timing will need to be advanced more than the OEM setting. The OEM timing for B&S engines is fixed at 11º BTDC. For methanol, the timing will need to be advanced to 17º BTDC. To advance the timing for methanol fuel, a special-made 3/16" square offset flywheel key must be used. Offset flywheel keys are originally made for racing go-karts and Junior Dragsters with the 5hp Briggs & Stratton engine. They come in 2º, 4º, 6º and 8º increments (to advance the timing 2º, 4º, 6º and 8º more than the OEM setting). Use the 6º offset key for a setting of 17º BTDC (11º + 6º = 17º). Make sure the offset flywheel key is installed correctly so the timing will be advanced (BTDC) and not retarded (ATDC)! Do a Google search for offset flywheel keys. Also, for an older B&S engine with points and condenser, it's highly recommended to install a new Magnetron™ electronic ignition module or a universal electronic transistorized ignition module for stable timing and a stronger spark. And as usual, the crankcase oil will need to be changed more often when burning methanol fuel.


The Advantages of Using 100% Methanol Fuel -

If the carburetor have been reworked and the ignition timing are adjusted and set correctly, methanol can produce up to 13% increase in horsepower. If the fuel is set slightly rich (which it should be), there's no need to constantly adjust the carburetor settings and/or ignition timing to compensate for changes in hot or cold weather conditions. Because of its low volatile octane rating (ability to burn quick), methanol shouldn't be used for general lawn use. It's primarily a high performance fuel only, and should be used only in a high performance engine. Starting fluid (ether) or gasoline may need to be sprayed or squirted into the carburetor to get the engine started in cooler weather, though. And, faster gearing may be needed because of the increase in horsepower and torque.

It may take some experimentation to get a particular tractor to perform on methanol. Just because most experienced pullers get their tractors hooked-up good on it is no reason anyone else can't. Once one do get their tractor to perform on methanol, they'll be reluctant to go back to gas. By the way - methanol can be purchased at most places that sell racing fuels. And it cost less than 1/3 of racing gas fuels (per gallon).

Using Methanol in a Garden Pulling Tractor -

Methanol, also known as wood alcohol, is made primary from natural gas. And is the best high performance fuel available. Far better than any expensive "racing" petroleum fuel. It'll help any 4-stroke high performance engine produce more power and run much cooler. Methanol is a safe fuel to use, too. But if anyone feels uncomfortable using or converting an engine for use of methanol, please consult with a professional engine builder.

Methanol will mix equally with water and it evaporates quickly. The important thing to remember when storing methanol is the keep it in an air tight container in a dry place. Because it can easily draw moisture when stored for a long period, especially in a metal container. (Unlike plastic, steel gets cold, which draws condensation.) If one suspects that water had gotten into the methanol, it can be separated easily by using chamois leather. The chamois will absorb the water and allow the methanol to pass through. If gas has 10% alcohol, then the alcohol will mix the water with the gas and it will appear to have no water at all. The only way to separate the water from the gas and alcohol is through a chamois. Again, the chamois will absorb the water and allow the fuels to drain through.

If your club's sanctioning rules say that the methanol fuel must be able to pass a water test, then just use 100% pure methanol with no oil. (To some clubs, oil is also known as a "contaminant.") Pure methanol will remain clear in water, but turn cloudy in water when mixed with oil. And it's important that the high speed air/fuel mixture screw on the carburetor be richened slightly, to keep from burning the piston (because of the lack of oil in the fuel). Click here to learn how to test for alcohol content in gasoline. (require Adobe Acrobat Reader and use Google Chrome web browser for a faster download of websites with large files.)

Methanol has absolutely no effect on rubber, neoprene rubber or OEM carburetor or fuel system parts nor does it get stale like gas does. (Don't just theorize about such things, believe in myths, rumors or what some [delusional] people/mechanics/technicians tell you. Perform a scientific test to prove to yourself and debunk the myths. I always do.) But methanol will corrode aluminum as plain water does if it is not drained and allowed to evaporate from the fuel system over an extended length of time. After the methanol is drained and flushed out of the fuel system, motor oil should be applied to the metal parts to protect the surfaces from oxidation.

Because methanol will ignite only in a narrow range of high temperatures, it is less likely to catch on fire should an accident occur. If methanol does catch on fire, unlike gasoline, water can extinguish the flames.

Methanol burns much slower than the highest octane gasoline. (It has about 135 octane rating.) Therefore, the ignition timing must be advanced more than for gas when burning methanol. If the timing isn't advanced enough, some of the methanol will go unburned and little will be gained. Modifications to the point lobe on the camshaft may need to be made in order to achieve the full ignition timing setting. Methanol also require a hotter spark. Therefore, a high-output/performance ignition coil is needed, along with a wide spark plug gap (.060"). NOTE - Never run over-advanced ignition timing with any petroleum-based fuel (gas) just to try to get "more power." All that does is seriously overheat the engine and could weaken (collapse) the piston rings, shrink the piston, warp the cylinder head and exhaust valve and it could even cause the engine block to crack.

Details of the Cylinder Restraint System As methanol burns, it produces tremendous combustion chamber pressures under wide-open throttle conditions, especially in engines that's been ported, with oversized valves and a big cam, and even more so during cooler weather. To prevent possible cylinder/crankcase separation or an "engine explosion," the cylinder must be securely "strapped" or fastened to the crankcase. Especially on K301 engines and up. So strap it now, or scrap it later! Methanol works best in a high compression engine, too.

"Strapping" the cylinder to the crankcase is when a flat piece of heavy steel or aluminum is across the cylinder head and fastened by means of two minimum 1/2" diameter threaded rods, one located just behind the flywheel and the other on the PTO end of the block. It keeps the cylinder from literately breaking loose from the crankcase because of a thin cylinder wall and/or due to extremely high compression.

Moreover, if you had a K241 block bored for a K301 piston, or a K301 block bored for a K321 piston, and if the tractor is used to push snow, definitely strap the cylinder to the crankcase! Because it now has a much thinner cylinder wall, and the cold winter air is more dense (like the air is thicker or there's more of it). Dense air will build up the compression pressure within the combustion chamber, causing the engine to produce more power. But what also happens is at full throttle, this high compression is pushing upward on the cylinder head, and pulling upward on the cylinder wall. And sometimes the cylinder wall will break, ruining the whole engine. I know, I've seen this happen to a good engine. No joke.

Advertisement:
If you need a Professionally-Made Cylinder Restraint Strap Kit, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public, including weekends. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Click here for more parts and services. | Please click here to place an order.

Cylinder Restraint Strap Kit for Kohler K241-K341/M10-M16 K-series and Magnum Engines. Professionally made. This setup is easy to remove and reinstall when it comes time to freshen the engine. It looks nice and very strong. Prevents cylinder/crankcase separation (engine explosion) during cool weather when cylinder is bored thin for an excessively oversize piston. A must for methanol burning engines. NOTE: An additional 3/8" threaded hole may need to be made for mounting of brace on PTO end of block.

  • A-1 Miller part. $45.00 each kit, plus shipping & handling.

Methanol fuel produces a "cooling effect" as it enters an engine at high velocity (wide open throttle). And, it's a clean burning fuel, it won't carbon up the combustion chamber, foul-out the spark plug or even harm the ozone layer. The crankcase motor oil may need to be changed periodically though.

Here's another thing concerning methanol fuel - when methanol evaporates, it leaves behind very small particles of white, flaky residue deposits in the entire fuel system, which is completely normal and unavoidable. These deposits can clog and ruin a good fuel filter, but will not harm any other parts of the fuel system or the engine. So to keep from having any [future] fuel flow problems and help prevent from losing a good pull, don't install a fuel filter in the system to trap any dirt/debris, because it will also trap the white, flaky residue deposits! Instead, strain the fuel through a filtering material, such as a coffee filter, paint filter, fine mesh screen wire, clean cloth shop towel or a fine woven fabric window curtain, while it's poured into the fuel tank. Place the filtering material in a large funnel, and pour the fuel through it into the tank. The filtering material should be thoroughly cleaned for use next time. But first, make sure the fuel tank and the rest of the fuel system is perfectly clean, and kept clean! And if there are any very small particles of dirt/debris present in the fuel, they should pass through the carburetor, being the fuel passages have been enlarged for the methanol.

Fuel filters can only filter so much of a grain of dirt/debris/grit. Anything smaller will pass through, most of time causing no harm. Sometimes a hair will pass through a wire mesh fuel filter, lodging in the float valve, keeping it from fully closing because the hair can't get past the bend. It'll cause the carburetor to over-flow and flood in a short time if the fuel tank is higher than the carburetor (gravity feed system). On certain small engines, the flooding gas will seep down into the motor oil, ruining it. Briggs & Stratton riding mower engines are notorious for this. All that can be done to fix this is clean out the carburetor and hope it doesn't happen again, or take the time to filter the gas before it's poured in the tank. And if there's enough fresh gas in the crankcase, sometimes the crankcase will explode if the engine backfires through the carburetor. If the crankcase breather is connected to the carburetor or air cleaner/filter assembly, the flame from the backfire will travel through the breather cover and into the crankcase. (I've also seen this happen a few times.)


METHANOL vs GAS -

Most garden tractor carburetors can be easily converted for methanol use. The main thing to keep in mind is that methanol require about twice the volume of fuel than gas. (Approximately a 5-6:1 ratio for methanol versus 10-12:1 ratio for gas). To run methanol, the main jet and fuel inlet (float valve) holes will need to be enlarged to about 95% of their original size.

High compression engines naturally operate at a higher operating temperature. When using low octane gasoline (Regular Unleaded or 87 octane rating) in a high compression engine, the octane of the gas is reduced by 1 point for every 10º above the normal operating combustion chamber temperature that it is formulated for. This will cause the gas to burn faster. When trying to restart a high compression overheated engine on low octane gas, what is happening is the gas is burning quickly and entirely in the combustion chamber, and producing expanding heat before the piston reaches TDC, driving the piston back down in the cylinder before it reaches TDC. This is the cause of detonation (pounding of the piston) and it'll cause the engine to "grunt" or momentarily make the crankshaft rotate in the opposite direction (but the weight of the flywheel prevents this from happening). Overheating could also crack the [cast iron] cylinder, shrink the piston, burn a hole in the piston (detonation) and weaken the expansion of the piston rings. Methanol fuel has an octane rating of 135. This is why methanol works best in a high performance, high compression engine.

White deposits on the exhaust valve and in the combustion chamber is normal with gas fuels. Due to the lesser amount of gas in E-85, it leaves behind very little deposits, and methanol doesn't leave any deposits because there's no carbon in the fuel. Only fossil fuels have carbon in them and that's what's left behind in the combustion chamber and on the exhaust valve.

Did you know that high octane gas or "race car gas" (approximately 109-110 octane) is much better than any filling station pump gas when used in a high performance engine? Higher octane gas burns slow, producing more heat, thus allowing an engine to develop more power. Because heat is how an engine produces power. Methanol fuel produces even more heat than gas does.

Methanol never gets stale while setting around. It's burning factors (the qualities that produce power) remain intact until all of the fuel evaporates. Gasoline on the other hand, as it gets old or stale, it's burning factors is the first thing to go. Unlike methanol, eventually all that is left of the old gas is some "foul smelling residue." Methanol never smells "old" or "stale."

If the air/fuel ratio isn't properly adjusted with both methanol or gasoline, possible engine damage may result. If either fuel is leaned-out too much, possible piston to cylinder wall scuffing, scoring or even seizure may result. If methanol is ran too rich, the oil on the cylinder wall may be diluted, causing excessive wear to the piston, rings and sometimes the cylinder wall. And if gas is ran too rich, loss in power may result with possible spark plug fouling. (Methanol is more forgiving to an engine than gas.)

A high performance cam, larger piston, big valves and a bigger carburetor will undoubtedly help gas-burning engines develop more power. But only from the use of the parts themselves. Methanol on the other hand, will help give an engine a little more boost. Simply from the fuel itself.

Engines will consume less fuel burning gas than methanol. Something good for gas and not for methanol. Which is why methanol is not used on the open market in daily driven automobiles.

Some racing gasolines could eventually cause an engine to wear prematurely when used under high performance conditions (and if the ignition timing is over-advanced). Piston wear, piston ring expansion failure, valve warping, even motor oil breakdown could result over time due to the high operating temperatures of gas in a high compression engine. (Especially on air cooled engines with no cooling system.)

An engine runs cooler burning methanol than gas. The reason why? Approximately twice the amount of methanol fuel enters an engine. There's more fuel per parts of air. As a result, this allows an engine to operate at a much cooler temperature. Gasoline on the other hand, runs less fuel per parts of air. Therefore, it's a "lean" burning fuel. Gas allows a high-compression engine to operate at a higher temperature. Which in turn could cause premature engine wear. Simply because too much heat itself will cause a good engine to wear out faster than anything else.

For more information on methanol, click here: Erowid Alcohol Vault : Methanol Material Safety Data Sheet and Race fuel - Alcohol fuels.

100% ethanol (AKA moonshine) and denatured alcohol burns pretty much the same as 100% methanol. There's very little difference between these alcohol fuels. If an engine is converted correctly for use with these fuels, it will produce the same amount of power, run cooler and last longer.

By the way - If you've ever wondered if moonshine runners burned moonshine in their cars, well, they probably didn't. Because first of all, they needed to make money off the moonshine that they made. And second, the engine would need to be converted and car modified for use with 100% pure alcohol so it would burn thoroughly and it wouldn't cause harm to the engine at higher RPM. This means the hole in the fuel inlet seat and main jet hole (orifice) in the carburetor would need to be drilled twice their original size, a bigger fuel line would need to be installed for more fuel flow, a bigger electric fuel pump would also need to be installed to pump twice the volume of fuel from the tank to the carburetor, a high-secondary voltage ignition system would need to be installed with wider spark plug gaps, and the ignition timing would need to be advanced to 38º BTDC to thoroughly burn the alcohol. And after all this, the car would burn TWICE as much fuel resulting in VERY poor mileage. And they couldn't stop and fill up along the way with more moonshine while the cops were on their tail! (Gasoline would be a lot more economical!)

On the K90, K141, K160, K161, K181/M8 Kohler K-series and Magnum engines, with the Carter #16, #18, #20, #22 carburetor, the hole (orifice) in the main jet size for 100% gasoline measures exactly 3/64" (.046") in diameter. To convert these carburetors for use with methanol, enlarge the main jet and fuel inlet (float valve) holes with a 3/32" (.094") diameter drill bit. NOTE: Drill through the fuel inlet hole from inside out (opposite flow of fuel) to prevent a burr that may prevent the float valve from sealing, which could cause the carburetor to leak fuel or flood. The ignition timing will also need to be advanced to 30º BTDC so the engine will take full advantage and make maximum power of the slower burning, higher octane fuel. Then with the engine running at 3,600± RPM, adjust the high-speed fuel mixture needle valve so the engine runs smooth.

On the K241-K341 single- and twin-cylinder Kohler K-series and Magnum engines Carter/Kohler carburetors with the fully adjustable high speed main jet, the factory hole (orifice) in the main jet size for 100% gasoline measures exactly 1/16" (.0625") in diameter. To convert these carburetors for use with methanol, enlarge the hole in the fuel inlet (float valve) with a 7/64" (.109") drill bit, and then enlarge the hole (orifice) in the main jet/nozzle (emulsion tube) with a #32 or 3mm drill bit. NOTE: Drill through the fuel inlet hole from inside out (opposite flow of fuel) to prevent a burr that may prevent the float valve from sealing, which could cause the carburetor to leak fuel or flood. The ignition timing will also need to be advanced to 30º BTDC so the engine will take full advantage and make maximum power of the slower burning, higher octane fuel. Then if it's a stock engine, with the engine running at 3,600± RPM, adjust the high-speed air/fuel mixture needle valve until the engine runs smoothly.

To convert virtually any 4-cycle engine to run well and produce full power on 100% methanol or denatured alcohol fuels...

  1. If an OEM factory [restrictive] air cleaner/filter assembly is going be used, drill the main jet and fuel inlet (float valve) holes to 35% bigger than their original size. For an engine that's going to use a less restrictive air cleaner/filter assembly or no air filter at all, drill the holes to 40% bigger than their original size. To calculate the size hole (orifice) that needs to be drilled, with a calculator, multiply the exact diameter of the main jet and fuel inlet hole by 135 (with factory air filter) or 140 (with less restrictive or no filter), hit the percent (%) key, which shows the approximate size drill bit to use. NOTE: If the fuel inlet hole itself isn't made bigger, when pulling down the track at high RPM or wide open throttle, as soon as the float bowl fills with fuel, the engine will suck it dry, and as the engine winds down due to the lack of fuel, this allows more fuel to get dumped into the bowl and the process repeats itself over and over. The engine will run up and down, up and down, etc.
  2. Advance the ignition timing 180% more than the stock setting. If the OEM timing is 20º BTDC, advance it to 36º BTDC. (20 x 180% = 36) The ignition timing will need to be set slightly more advanced to 38º BTDC when the spark plug is positioned over the exhaust valve. If the timing isn't advanced at all or advanced enough, some of the alcohol will exit the exhaust unburned and the engine won't produce full power. The excess raw alcohol in the combustion chamber will travel past the ring gaps (especially when the engine is cold) and dilute the crankcase oil even more.
    When advancing the ignition timing past 24º± BTDC, and if the camshaft has an automatic compression release, it will need to be removed because the spark will occur when the exhaust valve opens slightly to relieve some of the compression, possibly preventing the engine from starting or making it hard to start. And to make the engine easier to crank over easier and start under full compression, a high torque starter motor with separate starter and ignition switches to prevent "kick back" will need to be used.
  3. Increase the fuel flow with a low-pressure electric fuel pump. If an insufficient amount of alcohol is delivered to the carburetor, the engine will run like it's starving for fuel. When pulling down the track, the engine will run up and down, up and down, etc. Use a low pressure electric fuel pump that delivers 3-4± psi of pressure.
  4. And that's it. The engine should run cooler, produce about 10% more power, but it'll burn 30-40% more fuel! NOTE: In cool weather, starting fluid (ether) or gasoline primer may need to be sprayed in the carburetor just to get the engine started. And the crankcase oil will need to be changed more frequently when burning alcohol fuels. By the way - Starting fluid (or gas primer) is supposed to be sprayed or applied in the carburetor, not directly in the combustion chamber through the spark plug hole. Because it needs to first mix with hydrogen in the air to create a combustible mixture. This is exactly how my remote fuel primer bulb system kit works to start a cold engine.


Testing Methanol Fuel for Contaminants -
IMPORTANT! Methanol by itself is clear, like water. To test it for an added lubricant or water, pour a small amount of methanol in a clean, clear capped glass container with a small amount of oil or water, then shake it. If it appears "cloudy," it's contaminated. You can also smell methanol for contaminants.

It's a good idea to use a small amount of special upper cylinder lubricant (such as Lucas Oil Upper Cylinder Lubrication, M2 Upper Lube & Lead Additive, Marvel Mystery Oil, etc.) mixed with methanol to prevent possible piston to cylinder scoring and to help lubricate the valve stems and guides. If a lubricant isn't used and if methanol is ran too lean (especially in cool weather), this could ruin a good high-dollar piston and possibly score the cylinder wall. Methanol must be ran rich if no lubricant is mixed with it. But some sanctioning pulling rules don't allow lubricant to be mixed with methanol because it boosts the octane and will likely fail in a fuel test, which means the tractor will be disqualified after competing. The more oil that is added, the higher the octane will be.

When pulling under rules that require 100% methanol fuel, and if a tractor have been using methanol with a lubricant, be sure to completely drain and flush the entire fuel system. Use [150± psi] compressed air to clear out the fuel tank, fuel hose, fuel pump, carburetor, etc. Because any trace amount of lubricant remaining will mix with the methanol and be cause for failure in a fuel test. Some new neoprene rubber fuel hoses contains oil. This means if 100% methanol is supposed to be used, the fuel hose must be flushed with a solvent (paint thinner), then use [150± psi] compressed air to clear it out, and then allow it to thoroughly air-dry.

I remember when gasoline for various automotive engines were for the following compression ratios: Anything up to 9.25:1, it was safe to use Regular gasoline (low octane); between 9.25:1-10.50:1 required Premium or High Test gasoline (mid octane); and anything above 10.50:1 required Ethyl gasoline (high octane). Until the late 1960s, most Chevrolet small block muscle car engines had a compression ratio as high as 11.25:1, and certain Chevrolet 427 big block muscle car engines had a compression ratio as high as 14:1! (That was the good ol' days!) I'd also like to share this old gas station joke:

Car owner that just pulled up to the pump: "Fill 'er up... Ethyl!"

Gas station attendant: "I'll fill up your car, but don't call me Ethel."

Using a Gravity Feed Fuel Flow System -

When burning gas only (not methanol) and if an engine is going to turn no faster than 4,000± RPM (governed limit; the factory setting of maximum RPM for virtually all small gas engines, including all of Kohler engines is 3,600), then a gravity feed fuel system with the fuel tank positioned higher than the carburetor, stock fuel fittings and fuel hose should work fine. (Gravity feed is defined as when the fuel is drawn by gravity; the lowest part of the fuel tank is positioned higher than the carburetor, and there's no fuel pump involved.) If the fuel tank sets higher than the carburetor, and if a large inside diameter fuel hose and fittings are used, and if the float level is set a little high, then a gravity feed fuel system should work great for a stock engine turning no more than 4,000 RPM.


Information About the Crankcase Vacuum-Operated/Pulse Fuel Pump -

All vacuum-operated/pulse-type fuel pumps operate off of the air pressure/vacuum inside an engine's crankcase. The moving piston(s) inside the crankcase create a pulsating effect of air ç back and forth to activate the pump's diaphragm. And all vacuum-operated/pulse fuel pumps come with three fittings - one that connects to the engine crankcase, and an IN and OUT fuel hose fittings. It should read on the body of the pump which each fitting connects. But if it doesn't, then the fitting coming from the center of the pump connects to the crankcase port. And as for the other two fittings, one connects to the fuel tank outlet and the other fitting connects to the carburetor inlet.

If the engine in a lawn and garden tractor, or ATV/UTV sputters and/or dies after going over rough terrain, this could be caused by a defective vacuum-operated/pulse fuel pump. Overtime, the fuel pump bodies become warped and oil in the crankcase is preventing air from pulsating the diaphragm the way it should. If the engine has a 12 volt electrical system with a charging system, it'll be better to install a low pressure electric fuel pump. These rarely give trouble.

To test a plastic body vacuum-operated/pulse fuel pump, first check that the fuel hose between the fuel tank and fuel pump is open and unobstructed, or if it has dry-rot cracks, which can cause a vacuum leak. To test it, disconnect the fuel hose from the fuel pump and wrap a shop/business towel or clean rag around an air blower nozzle and then insert the nozzle with the rag or towel in the fuel tank filler neck. Apply light air pressure in the tank. If fuel comes out of the fuel hose, then it's open. After that, reconnect the fuel hose to the fuel pump. To test the fuel pump itself, first check the hose that connects the fuel pump to the engine crankcase to see if it has a kink in it or if it has dry-rot cracks, which can also cause a vacuum leak. If it's in good condition, then the final step is to disconnect the fuel hose from the carburetor and with adequate amount of fuel in the fuel tank, crank the engine and at the same time observe how much fuel is being pumped out of the pump. If there seems to be adequate amount of fuel coming from it, hold your finger over the end of the line and while still cranking the engine, it should build up a small amount of pressure. If none or very little fuel comes out of the pump, then it's bad and needs replacing.

When a vacuum-operated/pulse fuel pump fails to pump fuel, in most cases, the body of the fuel pump will become warped, causing a vacuum leak either from within or from the outside, preventing the diaphragm from pulsating. If the diaphragm is still flexible, chances are, the pump can be repaired by resurfacing the body halves on a wide, flat belt or disc sander to remove any warpage and restore flatness. (Be sure to use eye protection!) If the body halves is warped, the sander will make contact where the screw holes are, but not between the screw holes.

If the bottom of the fuel tank is lower than the carburetor, then the engine definitely need a fuel pump. If the engine didn't originally come with a fuel pump, and has no provision for a mechanical fuel pump and/or no 12 volt power output/supply to use an electric fuel pump, here's how to install a universal vacuum-operated/pulse fuel pump on virtually any small gas engine:

  1. Locate a place that's easily accessible on the engine crankcase, valve cover (OHV engines only) or fabricate a plate to block-off/cover the existing mechanical fuel pump opening, and drill/tap 1/8" NPT threads, and install a 1/8-NPT x 1/4" barbed end [fuel] hose fitting to serve as the vacuum-pulse port. Don't install the fitting in the outer crankcase breather cover on a flathead engine. It don't hold crankcase vacuum. The plate behind it with the reed valve does.
  2. Drill a 21/32" hole in the desired location, and cut 1/8" NPT threads in the drilled hole. Make sure the metal cuttings don't enter inside the crankcase!
  3. Install the [fuel] hose fitting in the threaded hole with Teflon®/plumber's thread seal tape to prevent an oil and/or vacuum leak.
  4. Connect a 1/4" i.d. neoprene rubber vacuum or fuel hose from the fitting to the appropriate fitting on the vacuum fuel pump (this will activate the pump).
  5. Connect a 1/4" i.d. fuel hose from the fuel tank to the fitting on the pump marked IN ç.
  6. Connect a 1/4" i.d. fuel hose from the carburetor to the fitting on the pump marked OUT è.
  7. Be sure to install clamps on the hoses/fittings to prevent a vacuum and/or fuel leak.
  8. Mount the fuel pump and position the hoses securely away from any exhaust heat. Also, it doesn't matter if crankcase oil gets inside the vacuum-pulse hose. This is normal and the fuel pump will still work being it'll be pulsating air ç back and forth (with a small amount of oil in the hose, too) created by the movement of the piston(s) that will be activating the diaphragm in the pump. [Return To Previous Paragraph, Section or Website]


What Exactly Is "Vapor Lock"?

Vapor lock only happens with certain older carbureted cars and trucks with a mechanical fuel pump that's fastened to the engine block. Vapor lock occurs when the [metal] gas line is too close to the hot exhaust, and when the vehicle is in slow traffic, the fuel is moving very slow in the line. Due to extreme heat from the exhaust and on a hot day, and the fan blade not blowing that much air past the exhaust, sometimes the heat will cause the gas to boil, forming air bubbles or air pockets, and the fuel vaporizes, and then the fuel pump can't pump vaporized fuel (air). So as soon as the carburetor runs out of fuel, the engine stalls. The fuel pump will "lock" with vapors trapped inside it. When the vehicle cools, incoming gas will force the air out of the fuel pump and through the carburetor, allowing the fuel to return to the pump, and then the engine will start and run again. This don't happen nowadays with automobiles having fuel injection because the entire fuel hose is pressurized.

But on lawn tractors or garden tractors, the fuel hose is located nowhere near the hot exhaust. What is really happening when the engine stalls, is either the fuel system is dirty, the ignition coil is bad, or there's insufficient valve to lifter clearance.


Using a Mechanical Fuel Pump -

When running a pulling engine at high RPM or wide open throttle, sometimes the engine will starve for fuel with gravity feed fuel system. Therefore, Kohler's camshaft-driven mechanical fuel pump or a low-pressure electric fuel pump should be used to guarantee that the carburetor will receive plenty of fuel at all times. The mechanical pump should be used on a pulling tractor when burning gas only. They're not capable of delivering sufficient amount of fuel with E85 or methanol at high RPM like an electric pump will.

Mechanical plastic and metal body fuel pumps are very durable and they work pretty well, for both lawn machines and stock competition pulling with gas. The diaphragm or gaskets rarely go bad in the mechanical fuel pump. It's usually one or both of the poppet valves that goes bad. They can become dislodged, or rusted or corroded from long term water contamination. If the poppet valves are in good condition and snug in their counterbores, but if the pump doesn't pump fuel, then in most cases, the fuel pump body halves become warped, creating a vacuum leak at the diaphragm. The pump body halves can be resurfaced on a wide, flat belt- or disc-sander to remove warpage and restore flatness, and then after reassembly, the pump should work as good as new. (I use the side of the abrasive cutting wheel on my 14" electric chop saw with a metal cut-off wheel. Works great! Be sure to use eye protection!) After resurfacing, use a deburring tool to get rid of any melted plastic burrs and/or sharp edges, and thoroughly clean all parts with [150± psi] compressed air before reassembly! If this doesn't fix the problem, then perhaps a new or used reconditioned pump will need to be acquired.

To test the fuel pump for fuel flow off the engine, submerge the inlet port in a container of clean (filtered) cleaning solvent (paint thinner) and then work the lever quickly by hand. The solvent should squirt forcibly out the outlet port. If the pump doesn't start pumping right away, submerge the entire fuel pump in the solvent and work the lever to prime it and remove the air internally. After checking to see how well it works, to test the psi, a low-pressure gauge can be connected to the outlet port. The pressure should be 1-½ to 2 psi. To increase the pressure to about 2-½ psi (maximum), disassemble the pump and physically stretch the diaphragm pressure spring until it's about 3/4" longer than original length. To increase the volume (more fuel flow), the stroke of the fuel pump lobe on the camshaft would need to be lengthened approximately 1/8" by welding it up on the high side and reground deeper on the low side. Or better yet, use an electric fuel pump.

The only problem when using a gasket to fasten the fuel pump to the block is, being the mounting flange is so thin, it will warp over time, causing an oil leak. (This happens to every pump I've seen.) To fix this, and to [possibly] prevent an oil leak in the future, completely disassemble the pump, remove the lever and arm (be careful not to lose the spring) and use a wide, flat belt- or disc-sander to resurface the mounting flange on a wide, flat belt- or disc-sander to remove warpage and restore flatness. The trick to reinstalling the spring is, reinstall the arm, lever and support pin in the pump body first, then install the spring with a small, flat screwdriver. (The pumps with the manual fuel primer lever is harder to reassemble.) To keep the flange from warping again, fasten it directly to the block using only Clear RTV Silicone Adhesive Sealant and use no gasket, or use a very thin gasket. Finally, install a flat washer (and of course, a split lock washer) under each mounting screw head to distribute even pressure on the flange and to prevent the screws from loosening. By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for three reasons: Gaskets don't always seal the irregularities and imperfections between mating metals, especially thin metal covers; being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean and professional-looking repair job. When applied sparingly, it can't be easily seen or noticed between the parts.

The purpose of Kohler's older and now obsolete mechanical fuel pump with the hand lever (thin metal piece that hangs down under the pump body) is for when the engine runs out of fuel, after refilling the fuel tank, it takes less time to manually prime the fuel pump with the lever by hand to refill the carburetor than it would to crank the engine so the fuel pump can draw fuel from the tank and deliver it to the carburetor. This was a nice feature, especially on engines with a rope or rewind starter! It also saved wear and tear on the starter motor from cranking for a long time, which could burn up the starter or run down the battery.

FYI - All of Kohler's K241-K341 and the K361 engines come with a lobe on the cam to activate the mechanical fuel pump. The fuel pump installs with the lever positioned upwards. And if there's no provision for mounting a mechanical fuel pump, a 3/4" center hole and two small threaded bolt holes will need to be drilled, and the mounting holes tapped for 1/4-20 UNC (coarse thread) threads. Use a fuel pump mounting gasket as a templet.

Troubleshooting a Faulty Vacuum-Operated/Pulse Fuel Pump and Mechanical Fuel Pump -

If an engine sits for about one week or longer, if the fuel in the carburetor evaporates and it's hard to start, or fuel must be squirted into the carburetor to get the engine started, then this means that the vacuum-operated/pulse fuel pump mechanical fuel pump may be bad. The inlet valve in the pump is leaking, which is allowing the fuel to drain back into the fuel tank with the engine off. As the pump tries to syphon fuel from the tank to refill the carburetor, it's unable because the inlet valve is bad. Solution: a new fuel pump will need to be installed. When a vacuum or mechanical fuel pump quits working, below Ê are the causes:
  • Gasket/diaphragm mating surfaces on pump halves warped, causing vacuum leak and/or external fuel leak.
    • Solution: Disassemble fuel pump, resurface both halves on a wide, flat belt- or disc-sander to remove warpage and restore flatness. Deburr any rough edges afterwards.
  • Poppet valve dislodged from its cavity inside pump cover. (This happens often.)
    • Solution: Disassemble fuel pump, reinstall valve in its recess and carefully peen the metal or plastic around it. If the valve won't stay in place, the only option is to acquire another good fuel pump cover, or an entire fuel pump. By the way - the halves of the plastic and metal body fuel pumps cannot be interchanged.
  • Corrosion damage due to contamination with water.
    • Solution: If it can't be cleaned internally, acquire another good fuel pump.
  • Deteriorated diaphragm. (This is rare, and there'll be presence of gas in the crankcase oil.)
    • Solution: Being no rebuild kits are available, the only option is to acquire a good diaphragm from a damaged fuel pump, or acquire an entire good fuel pump. By the way - the diaphragm in the plastic and metal body fuel pumps cannot be interchanged. And the rebuild kit for a Kohler mechanical fuel pump is no longer available from Kohler. And if you do find a kit online, it's like $90.00. A new high quality aftermarket mechanical fuel pump is about half that much!
  • Cracked (split) threads in tapered threaded inlet or outlet ports. (This happens when the tapered thread fuel fittings are over-tightened.)
    • Solution: Acquire another good fuel pump cover, or an entire fuel pump. By the way - the cover of the plastic and metal body fuel pumps cannot be interchanged.

When to Use an Electric Fuel Pump -

Low Pressure Electric/Electronic Fuel PumpsWhen burning E85 or methanol fuels, more fuel volume (increase in flow) is required and a low pressure electric fuel pump should be used. The carburetor on most garden tractor engines don't require a lot of fuel pressure. One nice thing about electric fuel pumps besides they're very reliable, is that they're self-priming. Meaning when an engine runs out of fuel, there's less risk of burning up the starter motor from excessive cranking for a vacuum or mechanical pump to pump gas to the carburetor. As soon as the ignition is turned on (if the electric pump is wired in with the ignition circuit), the electric pump immediately puts gas to the carburetor.

Most electric fuel pumps are compact, vibration-proof (has solid state dependability), self-priming, easy to install and connect the wiring. They work with either gas, E85 or methanol fuels, won't flood the carburetor, draw very little amperage from the battery, and they cost less than most OEM electric fuel pumps. They're perfect for garden tractors having either a single- or two-cylinder engine.

An electric fuel pump that's made for an import car/truck produce more flow than any of Kohler's mechanical pumps, and in most cases, they don't produce not enough pressure to flood the carburetor. With some high-pressure electric fuel pumps however, an adjustable fuel pressure regulator with a fuel gauge may need to be used in-line. Install a "T" in the fuel hose and connect the gauge between the fuel pump or fuel regulator and carburetor. To begin with, set the regulator at about 2-1/2 p.s.i. Make the final adjustment on the fuel pressure at high RPM or wide open throttle, hooked to the sled, while going down the track. Use a quality fuel pressure gauge that can withstand the vibration of a garden pulling tractor to monitor the pressure. A low pressure gauge can be purchased off of eBay.

Another good thing about an electric fuel pump verses a mechanical pump (if the mechanical pump doesn't have a primer lever, which must be primed manually) is if an engine runs out of fuel, the engine will not have to be cranked for a long time to get the fuel pumped up to the carburetor, which can be hard on an electric starter motor.

When connecting the wires for an electric fuel pump on the tractor with battery ignition, the pump should come with detailed instructions. But if there's no instructions, then connect one wire (usually black in color) to the chassis of the tractor (ground), and the other wire (usually red in color) to the ignition system. The wire going to the coil from the ignition switch is a good one to connect to. On a tractor with magneto ignition, use a separate OFF/ON toggle switch for the fuel pump.


How to Prepare an Electric Fuel Pump for Wintertime or Long Term Storage -

If the equipment is equipped with an electric pump, for winter-time or long term storage, drain and clear out all fuel, leave the fuel hoses disconnected so the entire fuel system can "air dry," and apply WD-40 or light in the fuel pump to prevent oxidation, which could cause the moving parts to "freeze up" or stick. For a pulling tractor, if methanol fuel is subject to a water-test, don't add WD-40 or oil in the pump. Just drain and clear out all fuel, use compressed air to remove any remaining fuel from the pump, and store the tractor in a cool, dry environment. Click here for more information of long term storage of an engine.

Advertisement:
If you need any of the parts or services listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Please click here to place an order.
Plastic Body Vacuum-Operated/Pulse Fuel Pump. Operates off engine crankcase vacuum. Can be used on and fits many makes and models of various small engines. Use for general lawn and garden work or a 4,000± RPM stock pulling engine. Non-serviceable. Replaces Briggs & Stratton part # 808656.
  • High quality aftermarket. $10.00 each, plus shipping & handling.
  • OEM Kohler part # 24 393 16-S. $56.20 each, plus shipping & handling.
All-Metal Body Vacuum-Operated/Pulse Fuel Pump. Operates off engine crankcase vacuum. Can be used on and fits many makes and models of various small engines. Use for general lawn and garden work or a 4,000± RPM stock pulling engine. Replaces Briggs & Stratton part # 808656.
  • High quality aftermarket. Our part # 10876. $45.00 each, plus shipping & handling.
  • OEM Kohler part # 15 393 01-S. $55.75 each, plus shipping & handling.
Mechanical fuel pumps for Kohler K90/K91, K141, K160/K161 and K181/M8 K-series and Magnum (flathead) single cylinder cast iron block engines. Use the supplied snap ring to press the tabs in the fittings to install and rotate them. New pumps for thread-in fittings and/or with primer lever no longer available. L Kohler part # 41 559 05-S. FYI - The alternative to replacing a [high dollar or obsolete] OEM mechanical fuel pump on a small engine is to use a modern crankcase vacuum-operated/pulse fuel pump low pressure electric fuel pump. Click here to learn how this is done.
  • Reconditioned and tested plastic or metal body OEM Kohler (Carter ) fuel pump for thread-in fittings. $45.00 each, plus shipping & handling. [When available.]
  • New aftermarket "new style" plastic body fuel pump to resist corrosion from water contamination. $55.00 each, plus shipping & handling.
  • New OEM Kohler "new style" plastic body fuel pump. $106.50 each, plus shipping & handling.
Plastic Body Mechanical fuel pumps for Kohler engine models K241/M10, K301/M12, K330/K331, K321/M14, K341/M16, K361 and K660/K662. Use the supplied snap ring to press the tabs in the fittings to install and rotate them. Kohler part #'s 47 559 10-S, 47 559 11-S (most common). FYI - The alternative to replacing a [high dollar or obsolete] OEM mechanical fuel pump on a small engine is to use a modern crankcase vacuum-operated/pulse fuel pump low pressure electric fuel pump. Click here to learn how this is done.
  • Reconditioned and tested "old style" plastic body OEM Kohler fuel pump for thread-in fittings. Reversible ports. (Remove top half, rotate 180º, reinstall.) $25.00 each, plus shipping & handling. [When available.]
  • New aftermarket "new style" plastic body fuel pump to resist corrosion from water contamination. Reversible ports. (Remove top half, rotate 180º, reinstall.) $40.00 each, plus shipping & handling.
  • New OEM Kohler part # 47 559 10-S "new style" plastic body fuel pump. Same as below Ê except w/left port inlet. $117.85 each, plus shipping & handling.
  • New OEM Kohler part # 47 559 11-S "new style" plastic body fuel pump. Same as above except w/right port inlet. $156.60 each, plus shipping & handling.
Mechanical fuel pumps for Kohler models KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20 and MV20 Magnum series opposed (flathead) twin cylinder engines. Use the supplied snap ring to press the tabs in the fittings to install and rotate them. New pumps for thread-in fittings no longer available. L Kohler part # 52 559 03-S. FYI - The alternative to replacing a [high dollar or obsolete] OEM mechanical fuel pump on a small engine is to use a modern crankcase vacuum-operated/pulse fuel pump low pressure electric fuel pump. Click here to learn how this is done.
  • Reconditioned and tested "old style" plastic body OEM Kohler fuel pump for thread-in fittings. $25.00 each, plus shipping & handling. [When available.]
  • New aftermarket "new style" plastic body fuel pump. $50.00 each, plus shipping & handling.
  • New OEM Kohler "new style" plastic body fuel pump. $89.35 each, plus shipping & handling.
Mechanical fuel pumps for Kohler engine models K482, K532 and K582 opposed (flathead) twin cylinder engines. Use the supplied snap ring to press the tabs in the fittings to install and rotate them. New pumps for thread-in fittings no longer available. L Kohler part # 48 559 05-S. FYI - The alternative to replacing a [high dollar or obsolete] OEM mechanical fuel pump on a small engine is to use a modern vacuum-operated/pulse fuel pump low pressure electric fuel pump. Click here to learn how this is done.
  • New aftermarket "new style" plastic body fuel pump to resist corrosion from water contamination. $80.00 each, plus shipping & handling.
  • New OEM Kohler "new style" plastic body fuel pump. $145.30 each, plus shipping & handling.
Metal Body Mechanical fuel pumps for Kohler engine models K241/M10, K301/M12, K330/K331, K321/M14, K341/M16, K361 and K660/K662. FYI - The alternative to replacing a [high dollar or obsolete] OEM mechanical fuel pump on a small engine is to use a modern crankcase vacuum-operated/pulse fuel pump low pressure electric fuel pump. Click here to learn how this is done.
  • Reconditioned and tested all metal body fuel pump for thread-in fittings and without primer lever. Discontinued from Kohler. L OEM Kohler part # A-235845-S. $45.00 each, plus shipping & handling. [When available.]
  • Reconditioned and tested all metal body fuel pump for thread-in fittings and with fuel primer lever. Discontinued from Kohler. L OEM Kohler part # A-235807-S. $65.00 each, plus shipping & handling. [When available.]
  • New all metal body fuel pump for Kohler engine models K660/K662 w/specification numbers 33264, 33270, 33510. OEM Kohler part # A-271704-S. $216.00 each, plus shipping & handling.
Fuel Pump Mounting Gasket. Fits all models of Kohler engines with a camshaft-operated fuel pump. Approximately 1/32" thick.
  • High quality aftermarket. .50¢ each, plus shipping & handling.
  • OEM Kohler part # 25 041 10-S. $1.55 each, plus shipping & handling.
Heat Isolator Fuel Pump Mounting Gasket. Fits all models of Kohler engines with a camshaft-operated fuel pump. Manufactured of heat-resistant phenolic resin. This particular gasket prevents crankcase heat from being transferred to the fuel pump. Along with the heat isolator carburetor mounting gasket, the cooler fuel atomizes better before entering the combustion chamber to improve engine performance. Ideal for heavy lawn/garden work and/or stock competitive pulling. OEM Kohler part # 277649-S.
  • $20.27 each, plus shipping & handling.
Mechanical Fuel Pump Opening Block-Off/Cover Plates. Use with gravity feed or electric fuel pump. Fits most Kohler and Tecumseh engines. Each made of 1/8" thick mild steel.
  • Economy Rectangular Block-Off/Cover Plate. When appearance isn't important. An innovative concept by Brian Miller because nobody else advertise this particular aftermarket part. A-1 Miller part. Replaces Tecumseh part # 31660 and Kohler part # 240282-S. $5.00 each, plus shipping & handling.
  • OEM Styled Block-Off/Cover Plate. When appearance matters. Replaces Tecumseh part # 31660. OEM Kohler part # 240282-S. $7.36 each, plus shipping & handling.
Mechanical Fuel Pump Opening Block-Off/Cover Plate w/Vacuum/Pulse Port. Use with vacuum-operated/pulse fuel pump. Fits most Kohler and Tecumseh engines. Use with choice of straight or angled fittings below Ê. Made of 1/8" thick mild steel. A-1 Miller part. An innovative concept by Brian Miller because nobody else advertise this particular part.
  • $10.00 each, plus shipping & handling.

Straight Fuel Hose Fitting. 1/4" barbed fitting x 1/8" NPT male threads.

  • New aftermarket fitting. $3.00 each, plus shipping & handling.
  • Used and in excellent condition. Discontinued from Kohler. OEM Kohler part # X-495-1. $4.00 each, plus shipping & handling. (When available.)

90º Fuel Hose Fitting. 1/4" barbed fitting x 1/8" NPT male threads.

  • New high quality aftermarket. $3.00 each, plus shipping & handling.
  • Used and in excellent condition. OEM Kohler steel fitting. $4.00 each, plus shipping & handling. (When available.)
  • New. OEM Kohler part # 25 155 02-S. $8.59 each, plus shipping & handling.
Mounting screws for mechanical fuel pumps and block-off/cover plates above È. 1/4-20 UNC (coarse thread) threads x 3/4" thread length. Phillips head. Includes split lock washer. NOTE: If you want to install an electric fuel pump, and your engine has a malfunctioning mechanical fuel pump and you want to replace it with a block-off/cover plate, the OEM mounting screws can be reused.
  • High quality aftermarket. .50¢ each, plus shipping & handling.
  • OEM Kohler part # X-174-2-S. $1.55 each, plus shipping & handling.
12 Volt Electric Fuel Pump Installation Kits. Low pressure, small and compact. Convert from gravity feed, or replace faulty vacuum-operated/pulse fuel pump or mechanical fuel pump (with a deteriorated diaphragm that can seep gas into the crankcase, diluting the oil, which can could severe internal engine damage), or upgrade to one of these pumps for more fuel delivery. Each produces 2.5-4.5 psi @ 30 gph, and is non-adjustable. Fuel regulator is not required, but may require one under certain conditions. Use for general lawn and garden work, or for garden tractor pulling. Will work for most single- and twin-cylinder gas engines such as Kohler, Briggs & Stratton, Tecumseh, Wisconsin, etc., on virtually all models of Cub Cadet, John Deere, Wheel Horse, Sears Suburban, Massey Ferguson, and just about any lawn & garden equipment with a 12 volt electrical system. These electric fuel pump kits come with fittings that accepts 1/4" i.d. fuel hose, the same size that's on most Kohler and other makes and models of engines. If it's a Kohler AQS (Quiet Line) engine, the fitting in the carburetor would need to be changed to 1/4". If the engine has magneto or solid state ignition, but no charging system, and only a 12 volt battery is used to power the fuel pump, the battery will need to be recharged with portable battery charger every now and then so the fuel pump will work at peak efficiency. Alcohol resistant and very durable. For stock engines or engines running at high RPM or wide open throttle. Suitable for small gas engines up to 4 cylinder carbureted engines. Instant fuel prime to the carburetor as soon as pump is powered up. Ideal when equipment runs out of gas and no need to crank engine for a long time to refill carburetor to restart engine. Saves on starter motor wear. Each operates on 12 volts DC. Rather than a motor or diaphragm, these solenoid pumps use a piston actuated by an electromagnetic coil to generate fuel pressure and flow. By using only short pulses of electricity, this pump is very efficient. IMPORTANT: For long term storage, drain and clear out all fuel, leave fuel hoses disconnected so entire fuel system can "air dry," and apply WD-40 or light oil in the fuel pump to prevent oxidation, which could cause the moving parts to "freeze up" or stick. For a pulling tractor, if methanol fuel is subject to a water test, don't add WD-40 or oil in the pump. Just drain and clear out all fuel, use compressed air to remove any remaining fuel from the pump, and store the tractor in a cool, dry environment. Wire Connections: The BLACK wire connects to negative (–) ground (tractor chassis or frame), and the RED wire connects to the positive (+) battery post or a terminal on the ignition switch that connects to the positive (+) battery post. If the wires are connected in reverse, the fuel pump will pump fuel in the opposite direction. It will not harm the pump. And the filter connects on the side closest to the fuel tank to help keep the inside of the pump clean so it will last longer.

NOTE: Electric fuel pumps listed here come with a one year warranty. Install the inline fuel filter before the pump (inlet port) to prevent any debris from becoming lodged in the pumping mechanism. If there is debris lodged, it may be removed with 150 psi compressed air when applied in the reverse direction of fuel flow. If the pump still won't work right after clearing it out, please remove the fittings, return the pump and I'll send you another new fuel pump without the hardware and fittings. [Return To Previous Paragraph or Section]

  • Round Body Electric Fuel Pump Installation Kit. Includes: Fuel pump, mounting bracket w/bolt/nut, two straight 1/4" barbed fuel hose fittings, 4 hose spring-type clamps, 1/4" i.d. x 12" length reinforced fuel hose and fuel filter. High quality aftermarket. $32.00 each, plus shipping & handling.
  • Square Body Electric Fuel Pump Installation Kit. Includes: Fuel pump, two straight 1/4" barbed fuel hose fittings, 4 hose spring-type clamps, 1/4" i.d. x 12" length reinforced fuel hose and fuel filter. High quality aftermarket. $32.00 each, plus shipping & handling.
  • Square Body Electric Fuel Pump Installation Kit. Pressure: 1/2 - 2 lb. psi. Suitable for aluminum block engines. Includes: Fuel pump, two 1/4" barbed fuel hose fittings, reinforced fuel hose, 4 hose spring-type clamps, and fuel filter. OEM Kohler part # 25 559 01-S. $188.85 each, plus shipping & handling.
  • Square Body Electric Fuel Pump Installation Kit. Pressure: 2 - 3-1/2 lb. psi. Suitable for cast iron block engines. Includes: Fuel pump, two 1/4" barbed fuel hose fittings, reinforced fuel hose, 4 hose spring-type clamps, and fuel filter. OEM Kohler part # 41 393 45-S. $358.05 each, plus shipping & handling.

Advertisement:
If you need your Carter/Kohler or Walbro carburetor rebuilt for daily use or if you want your carburetor professionally reworked for high performance use on a Stock, Hot-Stock, Stock-Altered or Pro-Stock pulling tractor, or if you wish to purchase a rebuilt carburetor, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends (except Holidays). Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Go here for more parts: Carburetor, Fuel System Parts & Machine Shop Services | Please click here to place an order.

FYI: I can professionally rebuild older vintage and antique carburetors virtually of any kind as well as newer ones, as long as replacement parts are available. I also have the capability to fabricate new throttle and choke shafts.


Rebuild and/or Repair YOUR K241-K361 Carter/Kohler or Walbro Carburetor. Basic rebuild with no "high performance" modifications whatsoever, according to the condition of the carburetor, the minimum rebuild cost is $35.00 for thorough cleaning of the carburetor, install overhaul/rebuild kit and labor. This includes the parts and services it may need that's listed below Ê. Anything else it may need will be an additional charge. FYI - Many of my customers send me their carburetors for rebuilding, but lots of times I couldn't find anything wrong them. So I'd call my customers just before returning their carburetor asking how their engine acted. And after hearing their story, I told them that their engines might need a valve job performed instead. And lo and behold! Many of them either adjusted the valves or had a professional valve job performed and said that their engines ran like new. This doesn't happens with all older engines, only the majority of them.

When I rebuild a carburetor, I completely disassemble the carburetor, including the choke and/or throttle shafts if they're worn. I resurface the each mounting flange on the carburetor on my wide, flat belt- or disc-sander to remove any roughness/warpage and restore flatness to prevent a vacuum leak, then I place all the parts in my ultrasonic cleaning machine (with automotive windshield washer cleaning fluid and high quality and non-corrosive laundry detergent for more thorough cleaning) for about 5 minutes. I take the parts out, use 150 psi compressed air to blow-dry all the parts, then I inspect each part for wear or any previous damage and repair or replace the damaged part(s) and replace the worn parts with new parts. I also install a new bushing and foam rubber seal for the throttle shaft, and a new carburetor overhaul/rebuild kit. I enlarge the lower hole on the high speed needle adjuster so engine will start quicker and idle better. And I repair any stripped threads in the carburetor body for the air cleaner mounting base. And the only way to remove all the paint from the carburetor body is to sandblast it. But sandblasting can allow tiny particles of sand to become embedded in the fuel passageways, which could break loose and cause problems later. Therefore, I do not sandblast carburetors. An original, ingenious and innovative concept by Brian Miller, because nobody else advertise this repair service.

Additional Parts and Labor Your Carburetor May Need That's Listed Below Ê

  • If I receive carburetor with broken off screw(s) in choke and/or throttle shaft: Drill out broken choke and/or throttle shaft screws and install choke and/or throttle shaft in carburetor body with new screws and split lock washers. $3.00 per broken screw, includes supply new screw and split lock washer.
  • If needed, for Carter/Kohler or Walbro carburetors with a vertical throttle shaft: Install new bronze bushing for throttle shaft, new felt or foam seal (to keep out dust and dirt) and reinstall original throttle shaft with new screws/lockwashers.
    • Install new flat bronze bushing, new felt or foam seal (to keep out dust and dirt) and reinstall original throttle shaft with new screws/lockwashers. $20.00 extra for parts and labor.
    • Bore-out upper throttle shaft hole, install new sleeve bronze bushing, new felt or foam seal (to keep out dust and dirt) and reinstall original throttle shaft with new screws/lockwashers. $35.00 extra for parts and labor. An innovative concept by Brian Miller, because nobody else advertise this type of service.
  • If needed, machine carburetor body, install oversize fabricated throttle or choke shaft and reinstall original throttle or choke lever with new screws/lockwashers. $75.00 for parts and labor. An innovative concept by Brian Miller, because nobody else advertise this repair service.
  • If needed, repair stripped 10-32 UNF (fine thread) (fine thread) air cleaner/filter assembly mounting threaded hole(s).
    • No extra charge to tap threaded hole bigger for 12-24 UNC (coarse thread) threads for use with a 12-24 UNC (coarse thread) screw. .50¢ each per screw.
    • $5.00 each for installation of Heli-Coil thread insert for 10-32 UNF screw.
    • $10.00 each for installation of 1/4" metal plug thread insert for 10-32 UNF (fine thread) (fine thread) screw. An innovative concept by Brian Miller, because nobody else advertise this repair service.
  • If needed, repair stripped threads in float bowl retaining bolt hole and install a 10mm thread bolt. $10.00 for parts and labor. An innovative concept by Brian Miller, because nobody else advertise this repair service.
  • The idle speed and air/fuel mixture adjustments will be preset on the carburetor just to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth.

IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.

"Old School" Technology High Performance Stock-Appearing Carburetor Modifications - Bore out and rework YOUR #26, #28 or #30 Carter/Kohler carburetor for use with Gas, E85 or Methanol fuels. Carburetor is modified internally to improve engine performance. $85.00 labor, plus return shipping & handling. Extra charge if any parts are needed. Work includes what's listed above È plus whatever parts and services it may need that's listed below Ê.

ü Bore venturi to a limit of .995" or 1", straight-through design (to match the diameter of throttle bore) or whatever your club's sanctioning rules allow. Read your rules carefully to make sure! I'll need a copy of your club's sanctioning rules regarding the legality of the carburetor, so when I rework it, it'll be legal for use in the class you plan to pull in.

ü If needed, drill out main jet/nozzle so venturi can be bored: $35.00 extra. Price includes new main jet/nozzle.

ü Eliminate choke shaft and plate and plug shaft holes. If your rules require a working choke or if you wish to have a working choke, please let me know and I will not remove it.

ü Eliminate choke shaft and plate, and convert carburetor for use with my remote fuel primer system kit. $20.00 extra for labor and kit. Click here for remote fuel primer installation instructions. An ingenious and innovative concept by Brian Miller, because nobody else advertise this kit.

ü Convert to bottom high speed air/fuel adjuster: $17.00 extra.

ü Convert your carburetor for use with E85 or methanol fuels with the high-performance modifications: No extra charge.

ü Missing, worn or broken parts are extra charge.

All the carburetors we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty. And remember - performance carburetors are like women, it's what's on the inside that matters.

Professionally Rebuilt and New Carburetors For Sale - NOTE: I set the air/fuel adjusters on all carburetors just so the engine will start and run, but because of the attitude where the engine will be used, atmospheric/barometric pressure and air temperature, the customer will need to make the final adjustments so the engine will run smoothly. No carburetor with an adjustable high speed air/fuel adjuster screw comes preset, not even new ones. And all the carburetors that I repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty. Other carburetor services listed further down in the website.
Carburetors for Kohler K-series K90/K91 flathead cast iron block engines. These are plain, stock carburetors that's been completely disassembled, thoroughly cleaned and rebuilt. All fuel passageways cleared, new parts and if necessary, a bushing and/or new throttle shaft installed. No performance modifications are made to these carburetors whatsoever. All carburetors that we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty. The idle speed and air/fuel mixture adjustments will be initially set on the carburetor to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth. Carter carburetor part # G-220517. NOTE: Not all carburetor numbers are listed with Kohler.
  • Rebuilt Genuine OEM Carter #16 carburetor. Discontinued from Kohler. L
    • $65.00 each with a rebuildable or non-rebuildable (certain parts can be reused off of it on a good carburetor) core trade-in, plus shipping & handling. [When available.] IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.
    • $85.00 each outright with no core trade-in, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM [US] manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
Carburetors for Kohler K-series and Magnum engine models K141, K160/K161, K181/M8. These are plain, stock carburetors that's been completely disassembled, thoroughly cleaned and rebuilt. All fuel passageways cleared, new parts and if necessary, a bushing and/or new throttle shaft installed. No performance modifications are made to these carburetors whatsoever. All carburetors that we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty. The idle speed and air/fuel mixture adjustments will be initially set on the carburetor to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth. Carter carburetor part #'s B-231739, C-231738, 41 053 01, 41 053 13, 41 053 18 or 41 053 20. NOTE: Not all carburetor numbers are listed with Kohler.
  • Rebuilt Genuine OEM Carter #16, #18, #20 or #22 carburetor. Discontinued from Kohler. L
    • $65.00 each with a rebuildable or non-rebuildable (certain parts can be reused off of it on a good carburetor) core trade-in, plus shipping & handling. [When available.] IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.
    • $85.00 each outright with no core trade-in, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
Carburetors for Kohler K-series and Magnum engine models K241/M10 and K301/M12. These are plain, stock carburetors that's been completely disassembled, thoroughly cleaned and rebuilt. All fuel passageways cleared, new parts and if necessary, a bushing and/or new throttle shaft installed. No performance modifications made to these carburetors whatsoever. Includes choke plate installed. For gas or E85. Please indicate if for a Kohler AQS (Quiet Line) engine with the oblong-shaped air cleaner/filter assembly , or for an engine with the round air cleaner/filter assembly . (The choke lever and air cleaner/filter assembly mounting holes are different.) All carburetors that we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty. The idle speed and air/fuel mixture adjustments will be initially set on the carburetor to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth. Kohler carburetor part #'s 47 053 07, 47 053 08, 47 053 12, 47 053 13, 47 053 14, 47 053 24, 47 053 29, 47 053 40, 47 053 62 or 47 053 80. NOTE: Not all carburetor numbers are listed with Kohler.
  • Rebuilt Genuine OEM Carter/Kohler #26 carburetor. Discontinued from Kohler. L
    • $65.00 each with a rebuildable or non-rebuildable (certain parts can be reused off of it on a good carburetor) core trade-in, plus shipping & handling. [When available.] IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.
    • $85.00 each outright with no core trade-in, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
  • 10-18hp Kohler (or Carter [model N]) CarburetorNEW high quality Kohler-replicated #26 "Made in China" fully adjustable carburetor. Same quality as OEM Kohler carburetor. Direct replacement. No modifications required. Reuse the same linkage and everything else. Just transfer the 1/8" NPT fuel hose fitting, install, adjust the idle speed and air/fuel mixtures until the engine runs smooth.
Carburetors for Kohler engine models K321/M14, K341/M16 and K361. These are plain, stock carburetors that's been completely disassembled, thoroughly cleaned and rebuilt. All fuel passageways cleared, new parts and if necessary, a bushing and/or new throttle shaft installed. No performance modifications made to these carburetors whatsoever. Includes installed choke plate. For gas or E85. Please indicate if for a Kohler AQS (Quiet Line) engine with the oblong-shaped air cleaner/filter assembly , or for an engine with the round air cleaner/filter assembly . (The choke lever and air cleaner/filter assembly mounting holes are different.) All carburetors that we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty. The idle speed and air/fuel mixture adjustments will be initially set on the carburetor to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth. Kohler carburetor part #'s 45 053 08, 45 053 09, 45 053 12, 45 053 20, 45 053 26, 45 053 68, 45 053 70, 45 053 76, 45 053 77, 47 053 03, 47 053 09, 47 053 15, 47 053 16, 47 053 17, 47 053 20, 47 053 30, 47 053 35, 47 053 41, 47 053 63 or 47 053 78. NOTE: Not all carburetor numbers are listed with Kohler.
  • 10-18hp Kohler (or Carter [model N]) CarburetorRebuilt Genuine OEM Carter/Kohler #30 carburetor. Discontinued from Kohler. L
    • $75.00 each with a rebuildable or non-rebuildable (certain parts can be reused off of it on a good carburetor) core trade-in, plus shipping & handling. [When available.] IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.
    • $100.00 each outright with no core trade-in, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
  • NEW high quality Kohler-replicated #30 "Made in China" fully adjustable carburetor. Same quality as OEM Kohler carburetor. Direct replacement. No modifications required. Reuse the same linkage and everything else. Just transfer the 1/8" NPT fuel hose fitting, install, adjust the idle speed and air/fuel mixtures until the engine runs smooth.
  • Rebuilt Kohler 1.250" throttle bore carburetor for K361 engine outright. OEM Kohler part #'s 45 053 38-S, 45 053 39-S, 45 053 40-S. $200.00 each, plus shipping & handling. [When available.] NOTE: Please don't discard your rebuildable Carter/Kohler carburetor core. These are considered valuable nowadays.
  • Rebuilt Kohler 1.250" throttle bore carburetor for K361 engine with a rebuildable or non-rebuildable (certain parts can be reused off of it on a good carburetor) core trade-in. $175.00 each, plus shipping & handling. [When available.] IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas.
Carburetors for Kohler KT-series and Magnum models KT17, KT17 series 2, KT19, KT19 Series II, M18, MV18, M20 and MV20 opposed (flathead) twin cylinder engines. These are plain, stock carburetors that's been completely disassembled, thoroughly cleaned and rebuilt. All fuel passageways cleared, new parts and if necessary, a bushing and/or new throttle shaft installed. No performance modifications made to these carburetors whatsoever. Includes choke plate installed. Set up for gas. When ordering, please specify the position of the choke lever. All carburetors that we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty. The idle speed and air/fuel mixture adjustments will be initially set on the carburetor to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth. Kohler carburetor part #'s 52 053 09, 52 053 18 or 52 053 28. NOTE: Not all carburetor numbers are listed with Kohler.
  • Rebuilt, outright with no core trade-in. Genuine OEM Kohler #26 fully adjustable carburetors for Kohler engine models KT17, KT17 Series II, KT19, KT19 Series II, M18 and M20 (horizontal shaft engines, without anti-backfire shut-off valve). Please indicate if the choke lever needs to be in the downward or upward swing position. $125.00 each, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM [US] manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
  • NEW high quality Kohler-replicated #26 "Made in China" fully adjustable carburetor for Kohler engine models KT17, KT17 Series II, KT19, KT19 series 2, M18 and M20. Same quality as OEM Kohler carburetor. Direct replacement. No modifications required. Reuse the same linkage and everything else. Just transfer the 1/8" NPT fuel hose fitting, install, adjust the idle speed and air/fuel mixtures until the engine runs smooth. Please indicate if the choke lever needs to be in the downward or upward swing position. $75.00 each, plus shipping & handling.
If the throttle and/or choke shafts and/or shaft holes are worn in a K482, K532 or K582 carburetor, if the holes aren't worn beyond for reuse, I make a new throttle shaft for it. But if the holes are worn too, and being the metal is too thin on one side for installation of a bushing, the shaft holes will need to be enlarged a few thousandths bigger than 1/4", and a steel rod that's slightly bigger than the enlarged holes (for a slip-fit) will need to be fabricated for use as a throttle shaft. I then align and weld the OEM throttle lever to the new shaft. I also install a foam seal on the throttle shaft and a thin, hardened steel thrust washer next to the throttle plate to prevent it from wearing against the carburetor body. And I install a new overhaul/rebuild kit. I've performed this type of repair many times with excellent results. I offer this repair service. If interested, I will need for you to send me your carburetor. And for dimensional measurements, I will need the complete carburetor with the throttle and choke shafts with the levers and the throttle and choke plates. I will fabricate new shaft(s), and install the lever(s) on the shaft(s), and install the throttle and/or choke plates on the shafts in the carburetor. FYI - Bearing bronze is very hard, porous, absorbs oil and lasts a long time when lubricated regularly and used as a bushing. Brass, on the other hand, is soft, non-porous and wears quickly when used as a load-bearing bushing or shaft. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off. An innovative concept by Brian Miller, because nobody else advertise this repair service.
  • New throttle or choke shaft installation repair price for a K482, K532 or K582 carburetor is $100.00 per shaft for parts and labor, plus return shipping & handling. IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you. Please send to: A-1 Miller's Performance Enterprises, 1501 W. Old Plank Rd., Columbia, MO (Missouri) 65203-9136 USA.
  • Rebuilt OEM Kohler carburetor for Kohler engine models K482 and K532. (1.07" throttle bore.) OEM Kohler part # 48 053 07-S. $150.00 each outright, plus shipping & handling. (When available.)
  • NEW high quality Kohler-replicated "Made in China" fully adjustable carburetor for Kohler engine models K482 and K532. (1.07" #26 throttle bore.) Same quality as OEM Kohler carburetor. Replaces Kohler part # 48 053 07-S. $125.00 each outright, plus shipping & handling.
  • Rebuilt OEM Kohler carburetor for Kohler engine model K582. (1.2" throttle bore.) OEM Kohler part # 48 053 06-S or 48 053 16-S. $150.00 each outright, plus shipping & handling. (When available.)
  • NEW high quality Kohler-replicated "Made in China" fully adjustable carburetor for Kohler engine model K582. (1.2" #30 throttle bore.) Same quality as OEM Kohler carburetor. Replaces Kohler part # 48 053 06-S or 48 053 16-S. $150.00 each outright, plus shipping & handling.
Rebuilt, reworked and modified only for high performance use, #26 Carter/Kohler carburetors. These carburetors have been internally modified to outperform a stock OEM carburetor under heavy pulling load and will not run lean while going down the track. Will pass tech with any club. The venturi in these carburetors can be bored so they'll have either a 7/8", .995" or 1" venturi or a 1.07" straight-through throttle bore for high RPM operation, setup for gas, E85 or methanol fuels, whatever your club's sanctioning rules allow or whatever you desire for all-out engine performance. These carburetors are completely disassembled, then thoroughly cleaned. All fuel passageways cleared, new parts and a new throttle shaft and/or bushing are installed if necessary. The idle speed and air/fuel mixture adjustments will be initially set on the carburetor to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth.

NOTE: These carburetors are designed for use on Stock and Stock-Altered pulling engines with a stock size or an oversize intake valve. Also, a high performance carburetor is designed solely for a high performance engine. Just bolting on a high performance carburetor is not how to gain more power and torque for a stock engine. If your engine is not a high performance engine built to race specs, then it will not benefit from a high performance carburetor whatsoever. These carburetors will not allow a stock "factory-built engine" to produce lots of power just by bolting it on. Everything in the engine MUST work together to prevent air restriction or a "bottleneck" to slow down air flow. With a bigger carburetor, the engine needs to breath A LOT more air in and out of the combustion chamber. This means the intake and exhaust ports will need to be made bigger, the valves reworked for more airflow, a bigger cam will need to be installed, and the ignition system will need to be up to standards.

Also, these carburetors are "built to order." So when placing an order, please specify if your engine has a factory stock size or oversize intake valve, if you want it with a straight-thru throttle bore (no venturi) or a .995" or 1" venturi, if the engine is going to turn 4,000± RPM or wide open throttle, and if you want the choke plate/shaft installed.

All carburetors that we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty.

  • High quality aftermarket NEW fully adjustable Kohler #26 carburetor bored-out and reworked for high performance use.
    • Carburetor with top high speed air/fuel adjuster. (For up to 4,000± RPM operation.) $100.00 each outright, plus shipping & handling.
    • Carburetor with bottom high speed air/fuel adjuster. (For wide open throttle operation.) $115.00 each outright, plus shipping & handling.
  • Carburetor with top high speed fuel adjuster. (For up to 4,000± RPM operation.)
    • Outright: $200.00 each, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
    • With rebuildable core trade-in: $175.00. IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.
  • Carburetor with bottom high speed air/fuel adjuster. (For wide open throttle operation.)
    • Outright: $215.00 each outright, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
    • With rebuildable core trade-in: $190.00. IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.
Rebuilt, reworked and modified only for high performance use, #30 Carter/Kohler carburetors. These carburetors have been internally modified to outperform a stock OEM carburetor under heavy pulling load and will not run lean while going down the track. Will pass tech with any club. The venturi in these carburetors can be bored so they'll have a 1.2" straight-through throttle bore, setup for gas, E85 or methanol fuels, whatever your club's sanctioning rules allow or whatever you desire for all-out engine performance. These carburetors are completely disassembled, then thoroughly cleaned. All fuel passageways cleared, new parts and a new throttle shaft and/or bushing are installed if necessary. The idle speed and air/fuel mixture adjustments will be initially set on the carburetor to get the engine running, but due to the altitude level, atmospheric/barometric pressure and air temperature where the engine will be used, final idle and high speed air/fuel mixture adjustments will need to be made by the customer so the engine will run smooth.

NOTE: These carburetors are designed for use on Stock and Stock-Altered pulling engines with a stock size or an oversize intake valve. Also, a high performance carburetor is designed solely for a high performance engine. Just bolting on a high performance carburetor is not how to gain more power and torque for a stock engine. If your engine is not a high performance engine built to race specs, then it will not benefit from a high performance carburetor whatsoever. These carburetors will not allow a stock "factory-built engine" to produce lots of power just by bolting it on. Everything in the engine MUST work together to prevent air restriction or a "bottleneck" to slow down air flow. With a bigger carburetor, the engine needs to breath A LOT more air in and out of the combustion chamber. This means the intake and exhaust ports will need to be made bigger, the valves reworked for more airflow, a bigger cam will need to be installed, and the ignition system will need to be up to standards.

Also, these carburetors are "built to order." So when placing an order, please specify if your engine has a factory stock size or oversize intake valve, if you want it with a straight-thru throttle bore (no venturi) or a .995" or 1" venturi, if the engine is going to turn at 4,000± RPM or wide open throttle, and if you want the choke plate/shaft installed.

All carburetors that we repair, rebuild or sell come with a 30 day workmanship warranty and are guaranteed to be free of defects. Technical support includes part of the warranty.

  • High quality aftermarket NEW fully adjustable Kohler #30 carburetor bored-out and reworked for high performance use.
    • Carburetor with top high speed air/fuel adjuster. (For up to 4,000± RPM operation.) $120.00 each outright, plus shipping & handling.
    • Carburetor with bottom high speed air/fuel adjuster. (For wide open throttle operation.) $135.00 each outright, plus shipping & handling.
  • Carburetor with top high speed air/fuel adjuster. (For up to 4,000± RPM operation.)
    • Outright: $250.00 each, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
    • With a rebuildable or non-rebuildable (certain parts can be reused off of it on a good carburetor) core trade-in: $225.00 each, plus shipping & handling. [When available.] IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.
  • Carburetor with bottom high speed air/fuel adjuster. (For wide open throttle operation.)
    • Outright: $265.00 each outright, plus shipping & handling. [When available.] NOTE: Please don't discard your Carter/Kohler carburetor core. If not rebuildable, certain parts can be reused on a good core. (The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.)
    • With a rebuildable or non-rebuildable (certain parts can be reused off of it on a good carburetor) core trade-in: $240.00 each outright, plus shipping & handling. [When available.] IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you.

Advertisement:
If you need any of the parts or services listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Please click here to place an order.
NOTE: All parts listed here are NEW, unless otherwise stated. I do not sell cheap junk! As a matter of fact, most OEM Kohler parts are made in China now. Kohler owns some of the factories in China that make the parts. And most aftermarket parts are also made by Kohler in China. Kohler just place the part(s) in a generic box and sell them for less money. So when purchasing a genuine OEM Kohler part that comes in a box with the Kohler name on it, you're really just paying more money for the name.
Carburetor to Block Mounting Gasket for Carter #16, #18, #20, #22 and Walbro WHL #36, #44 carburetors used on Kohler K-series and Magnum engine models K90/K91, K141, K160/K161 and K181/M8. Also replaces Tecumseh part # 31960A. Approximately 1/64" compressed thickness.
  • High quality aftermarket. Our part # 14-1084. $1.00 each, plus shipping & handling.
  • OEM Kohler part # 210223-S. $3.05 each, plus shipping & handling.
Carburetor to Air Cleaner/Filter Assembly or Intake Elbow Adapter Mounting Gasket for Carter #16, #18, #20, #22 and Walbro WHL #36, #44 carburetors used on K90/K91, K141, K160/K161 and K181 Kohler K-series flathead cast iron block engines, and most aluminum block Tecumseh engines. Approximately 1/32" compressed thickness. Use with two mounting screws. (This is a Tecumseh part that happens to fit the Carter and Walbro WHL carburetors perfectly.) Discontinued from Kohler. L Replaces Kohler part # 220537.
  • OEM Tecumseh part # 27272A. $1.00 each, plus shipping & handling.
Carburetor to Air Cleaner/Filter Assembly or Intake Elbow Adapter Mounting Gasket for Carter #16, #18, #20, #22 and Walbro WHL 36, #44 carburetors used on K90/K91, K141, K160/K161 and K181/M8 Kohler K-series and Magnum flathead cast iron block engines. Use with two or three mounting screws. Approximately 1/32" compressed thickness. Alternative gasket to the left.
  • High quality aftermarket. Our part # 7795. $1.10 each, plus shipping & handling.
  • OEM Kohler part # 41 041 11-S. $1.65 each, plus shipping & handling.
Carburetor to Block Mounting Gasket for Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors used on Kohler engine models K241/M10, K301/M12, K330/K331, K321/M14, K341/M16 and K361 and opposed (flathead) twin cylinder engines. Approximately 1/32" compressed thickness. For general lawn work. Approximately 1/32" compressed thickness.
  • High quality aftermarket. $1.00 each, plus shipping & handling.
  • OEM Kohler part # 271030-S. $3.75 each, plus shipping & handling.
Carburetor to Block Heat Isolator Mounting Gasket for Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors used on Kohler engine models K241/M10, K301/M12, K330/K331, K321/M14 and K341/M16. Approximately 5/32" compressed thickness. Has gaskets adhered to each side of heat resistant phenolic resin center. NOTE: This particular gasket prevents engine heat from being transferred to the carburetor. Along with the heat isolator fuel pump mounting gasket, the cooler fuel atomizes better before entering the combustion chamber to improve engine performance. Ideal for heavy lawn/garden work and/or stock competition pulling when rules require that carburetor cannot be mounted with any kind of extension.
  • High quality aftermarket. $7.00 each, plus shipping & handling.
  • OEM Kohler part # 47 049 01-S. $12.75 each, plus shipping & handling.
Carburetor to Air Cleaner Base Mounting Gaskets for Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors used on Kohler K-series and various Magnum engine models K241, K301/M12, K321/M14, K330/K331, K341/M16. Use each with three mounting screws.
  • Universal Gasket for Round, Oblong or Various Magnum Air Cleaners. $1.50 each, plus shipping & handling.
  • High quality aftermarket for Round Air Cleaners only. $1.50 each, plus shipping & handling.
  • OEM Kohler part # 275341-S. For Round Air Cleaners only. $3.66 each, plus shipping & handling.
Carburetor to Air Cleaner Base Mounting Gaskets for Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors used on Kohler K-series AQS (Quiet Line) and various Magnum engine models K241/M10, K301/M12, K321/M14 , K341/M16 and K361. Use each with three mounting screws.
  • Universal Gasket for Round, Oblong or Various Magnum Air Cleaners. $1.50 each, plus shipping & handling.
  • OEM Kohler part #'s 45 041 07-S, 52 041 12-S. For Oblong or Various Magnum Air Cleaners. $3.60 each, plus shipping & handling.
Carburetor to Air Intake Elbow Adapter Mounting Gasket for Kohler engine models K321, K341, KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20, MV20, K482, K532, K582.
  • High quality aftermarket. Approximately 1/32" compressed thickness. $1.50 each, plus shipping & handling.
  • OEM Kohler part # 25 041 06-S. Approximately 1/16" compressed thickness. $1.90 each, plus shipping & handling.
Elbow Adapter to Air Cleaner/Filter Assembly Mounting Gasket for Kohler engine models CH25, CH730-740, KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20, MV20, K482, K532, K582. Approximately 1/32" compressed thickness.
  • OEM Kohler part # 277093-S. $4.65 each, plus shipping & handling. Not available in aftermarket. L
Intake Manifold to Cylinder Mounting Gasket for Kohler opposed (flathead) twin cylinder engine models KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20 and MV20. Approximately 1/32" compressed thickness.
  • High quality aftermarket. $3.00 each, plus shipping & handling.
  • OEM Kohler part # 52 041 09-S. $5.84 each, plus shipping & handling.
Exhaust Manifold to Cylinder Mounting Gasket for Kohler opposed (flathead) twin cylinder engine models KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20 and MV20.
  • High quality aftermarket. $4.40 each, plus shipping & handling.
  • OEM Kohler part # 52 041 14-S. $6.42 each, plus shipping & handling.
Intake Manifold to Block Mounting Gasket for Kohler opposed (flathead) twin cylinder engine models K482, K532 and K582.
  • OEM Kohler part # 48 052 02-S. $3.70 each, plus shipping & handling. Not available in aftermarket. L
Exhaust Manifold to Block Mounting Gasket for Kohler opposed (flathead) twin cylinder engine models K482, K532 and K582.
  • OEM Kohler part # 25 041 11-S. $6.80 each, plus shipping & handling. Not available in aftermarket. L
Carburetor Overhaul/Rebuild Kits for Carter #16, #18, #20, #22 and Carter/Kohler #26, #28, #30 carburetors used on Kohler K-series and early Magnum single and opposed (flathead) twin cylinder engines. Includes Viton-tip fuel inlet float valve/brass seat, bowl O-ring seal, fuel baffle/splash shield, bottom fiber washer and float hinge pin. All parts made of alcohol resistant neoprene rubber.
  • High quality aftermarket. $10.00 each, plus shipping & handling.
  • OEM Kohler part # 25 757 02-S. $13.05 each, plus shipping & handling.
Carburetor Overhaul/Rebuild Kit with Viton-tip fuel inlet float valve for Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors that's used on Kohler Magnum models M8, M10, M12, M14, M16, MV16, M18, MV18, M20 and MV20 single- and twin-cylinder flathead cast iron block engines. Includes carburetor mounting gasket, but not the seat for the float valve.
  • OEM Walbro part # K1-WHG. $9.00 each, plus shipping & handling.
  • Kohler part # 25 757 11-S. (Same as above È, made by Walbro.) $49.95 each, plus shipping & handling
Float Bowl O-Ring Seal for Carter/Kohler carburetors. Dimensions (±): 2-3/16" i.d. x 2-7/16" o.d. x .040" thickness. Rectangular cross-section. Fits Carter #16, #18, #20, #22 and Carter/Kohler #26, #28, #30 carburetors used on the Kohler K-series and early Magnum single cylinder 4hp-16hp, 18hp OHV single- and twin-cylinder flathead cast iron block engines. Also fits Briggs & Stratton 7-11hp engines, and Tecumseh engines with the Carter or Walbro carburetors (large bowl). Made of alcohol resistant neoprene rubber. Included in overhaul/rebuild kit above È. NOTE: To install the O-ring and baffle/splash shield correctly, with the carburetor turned upside-down, the O-ring goes in the groove first (may have to stretch it slightly so it will fit), then the baffle/splash shield lays on top of it (center it with the groove/O-ring, of course), install the float (make sure it's level), and then install the float bowl to "clamp" the baffle/splash shield against the O-ring and carburetor body to prevent splashing gas from leaking around the float bowl while the engine is running. But first, place the [used] float bowl on a flat surface, and use a medium size hammer from inside the float bowl to flatten the bolt hole so the bowl will seal the O-ring and baffle/splash shield better.
  • High quality aftermarket. $1.00 each, plus shipping & handling.
  • OEM Briggs & Stratton part #'s 146700, 270511. $1.50 each, plus shipping & handling.
  • OEM Kohler part # 200375-S. $4.71 each, plus shipping & handling.


Float Bowl O-Ring Seal for Walbro carburetors. Dimensions (±): 2-3/8" i.d. x 2-1/2" o.d. x .065" thickness. Square cross-section. Fits Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors that's used on Kohler Magnum engine models M8, M10, M12, M14, M16, MV16, M18, MV18, M20 and MV20 single- and twin-cylinder flathead cast iron block engines. Made of alcohol resistant neoprene rubber.

  • OEM Walbro part # 92-301-8. $1.00 each, plus shipping & handling.
  • Kohler part # 25 041 04-S. (Same as above È, made by Walbro.) $5.74 each, plus shipping & handling.
Fuel baffle/splash Shield. Fits all Carter #16, #18, #20, #22 and Carter/Kohler #26, #28, #30 carburetors used on the Kohler K-series and early Magnum single cylinder K90-K361 single- and twin-cylinder flathead cast iron block engines. Goes between bowl seal and float bowl; prevents splashing fuel from entering into throttle bore through the atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor). Made of alcohol resistant neoprene rubber. Included in overhaul/rebuild kit above È. NOTE: To install the O-ring and baffle/splash shield correctly, with the carburetor turned upside-down, the O-ring goes in the groove first (may have to stretch it slightly so it will fit), then the baffle/splash shield lays on top of it (center it with the groove/O-ring, of course), install the float (make sure it's level), and then install the float bowl to "clamp" the baffle/splash shield against the O-ring and carburetor body to prevent splashing gas from leaking around the float bowl while the engine is running. But first, place the [used] float bowl on a flat surface, and use a medium size hammer from inside the float bowl to flatten the bolt hole so the bowl will seal the O-ring and baffle/splash shield better.
  • High quality aftermarket. $3.00 each, plus shipping & handling.
  • OEM Kohler part # 25 041 02-S. $4.92 each, plus shipping & handling.
Float bowl for Carter #16, #18, #20, #22 carburetors used on Kohler K-series engine models K90/K9, K141, K160, K161 and K181. Available in aluminum only. Dimensions: 2-3/8" o.d. x 1-1/4" height x 5/16" bottom hole.
  • OEM Kohler part # 200418-S. $17.55 each, plus shipping & handling. Not available in aftermarket. L


Float bowls for Carter/Kohler #26, #28, #30 carburetors used on Kohler K-series engine models K241, K301, K330/K331, K321, K341, K361, KT17, KT17 series 2, KT19, KT19 Series II and KT21. Also fits Briggs and Stratton 7hp-12hp vertical shaft engine carburetors. Dimensions: 2-3/8" o.d. x 1-1/4" height x 3/8" bottom hole. The dimensions of the aftermarket and B&S anodized steel float bowls are exactly the same as the aftermarket and Kohler aluminum float bowls. Either are interchangeable. The steel bowl is better quality because it won't dent or corrode through.

  • Aftermarket [anodized steel] bowl. $4.20 each, plus shipping & handling.
  • Briggs and Stratton part # 221995. [anodized steel] bowl. $7.00 each, plus shipping & handling.
  • Aftermarket [aluminum] bowl. $11.00 each, plus shipping & handling.
  • Kohler part # 235448-S. [aluminum] bowl. $14.39 each, plus shipping & handling.


Float bowls for Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors used on Kohler Magnum engine models K141, K160/K161, K181/M8, K241/M10, K301/M12, K321/M14, K341/M16, MV16, M18, MV18, M20 and MV20. 2½" outside diameter. Each made of dent-proof, anodized, corrosion-resistant steel.

  • OEM Walbro part # 20-180-1. $3.00 each, plus shipping & handling.
  • Kohler part # 25 104 01-S. (Same as above È, made by Walbro.) $16.62 each, plus shipping & handling.
Float Bowl Retaining Bolts. Fits Carter Model N #16, #18, #20, #22 carburetors used on Kohler engine models K90/K91, K141, K160/K161, K181, including many other makes and models of various small engines. Dimensions: 1/2" head x 5/16-24 UNF threads x 3/8" thread length. Each includes fiber sealing washer.
  • High quality aftermarket. Stainless steel material A-1 Miller part. Replaces Kohler part # 41 100 01-S. $5.00 each, plus shipping & handling.
  • New Old Stock or Used and in Excellent Condition. Discontinued from Kohler. OEM Kohler part # 41 100 01-S. $7.00 each, plus shipping & handling. (When available.)

Float Bowl Retaining Bolts. Fits Carter/Kohler #26, #28, #30 carburetors, and Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors used on Kohler engine models M8, K241/M10, K301/M12, K321/M14, K341/M16, MV16, M18, MV18, M20 and MV20. Also fits the carburetor on all Briggs & Stratton opposed twin cylinder flathead engines. Replaces obsolete Briggs & Stratton part # 397882. Each includes fiber sealing washer.

  • 1/2" head x 3/8-24 UNF (fine thread) (fine thread) threads x 3/8" thread length. OEM Walbro part # 96-340-7. $3.00 each, plus shipping & handling.
  • 1/2" head x 3/8-24 UNF (fine thread) (fine thread) threads x 3/8" thread length. OEM Kohler part # 12 086 05-S. (Same as above È, made by Walbro.) $2.58 each, plus shipping & handling.
  • 9/16" head x 3/8-24 UNF (fine thread) (fine thread) threads x 3/8" thread length. New Old Stock or Used and in Excellent Condition. Discontinued from Kohler. OEM Kohler part # 47 100 06-S. $5.50 each, plus shipping & handling.
Bottom High Speed Main Air/Fuel Adjuster -

The bottom high speed main air/fuel adjuster is not an OEM Kohler part and not a modification by Kohler. This part is an absolute must for a competition pulling engine that runs at very high RPM or wide open throttle. It provides no high-performance engine enhancements whatsoever. It's an add-on feature that replaces the OEM float bowl retaining bolt above È only to prevent wearing or enlarging the fuel suction hole in the main jet by the OEM high speed needle adjuster due to normal engine vibration at very high RPM or wide open throttle engine operations. (Whoever says that the use of this part will increase the performance of an engine obviously do not know what they are talking about, or they are in the business of selling new main jet/nozzle (emulsion tube)s, which can be very difficult to remove.) The carburetor must be converted to the bottom adjuster when using this part. Fits all Carter/Kohler #26, #28 and #30 carburetors used on Kohler K-series and early Magnum engine models K241/M10, K301/M12, K321/M14, K341/M16 and K361. Can also be used in the carburetor on all Briggs & Stratton opposed twin cylinder flathead engines to "fine tune" the air/fuel mixture.

  • $17.00 each, plus shipping & handling.

Alcohol resistant neoprene rubber O-ring seal for bottom high speed main air/fuel adjuster above È. Replace dry-rotted O-ring which can cause dangerous leaking fuel. Dimensions: 5/32" i.d. x 9/32" o.d.

  • .25¢ each, plus shipping & handling.
5/16" i.d. Float Bowl Retaining Bolt Fiber Sealing Washer. Fits Carter #16, #18, #20, #22, Briggs & Stratton, Mikuni, Tecumseh and other small carburetors. Not available from Kohler, and the 5/16" size is not included in the Carter/Kohler carburetor overhaul/rebuild kit. Replaces Tecumseh part # 632673, 640042.
  • High quality aftermarket. $1.00 each, plus shipping & handling.

3/8" i.d. Float Bowl Retaining Bolt Fiber Sealing Washer. Fits Carter/Kohler #26, #28, #30 and Walbro WHL #36, #44, and WHG #52, #60, #64 carburetors. Included with the Carter/Kohler carburetor overhaul/rebuild kit. Also fits the carburetor on all Briggs & Stratton opposed twin cylinder flathead engines. Replaces obsolete Briggs & Stratton part # 397882.

  • OEM Walbro part # 92-300-8. .45¢ each, plus shipping & handling.
  • OEM Kohler part # 200372-S. $1.82 each, plus shipping & handling.
  • Kohler part # 25 041 03-S. (Same as above È, made by Walbro.) $4.37 each, plus shipping & handling.
Brass Floats for all Carter #16, #18, #20, #22 and Carter/Kohler #26, #28, #30 carburetors used on the Kohler K-series, early Magnum single cylinder K90-K361 single- and twin-cylinder flathead cast iron block engines. Dimensions (±): 15/16" i.d. x 1-15/16" o.d. x 5/8" tall. NOTE: ALL brass floats need to be adjusted when installed. They don't come preset. To set the float level, with the carburetor turned upside down, set the float parallel with the carburetor body. To adjust the float level, use a small flat screwdriver to gently bend the tang that contacts the float valve. Then make sure that the float moves up and down freely without binding.
  • High quality aftermarket. $6.00 each, plus shipping & handling.
  • OEM Kohler part # 25 757 03-S. $17.74 each, plus shipping & handling.
Plastic Floats for Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors used on the Kohler's newer Magnum M8-M16 single- and M18, M20 twin-cylinder cast iron block flathead engines.
  • OEM Walbro part # 75-566-1. $6.00 each, plus shipping & handling.
  • Kohler part # 25 757 09-S. (Same as above È, made by Walbro.) $20.59 each, plus shipping & handling.
Float Pins for Carter #16, #18, #20, #22 and Carter/Kohler #26, #28, #30, Briggs & Stratton, Lawn Boy and Tecumseh carburetors. Dimensions: .090" diameter x .881" length.
  • Briggs & Stratton part #'s 230896, 231435, 691775, Lawn Boy part # 300096; Tecumseh part # 27106. $1.50 each, plus shipping & handling.
  • OEM Kohler part # 200376-S. $3.66 each, plus shipping & handling.

Float Pins for Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors. Dimensions: .090" diameter x 1.125" length.

  • OEM Walbro part # 78-41-7. $1.00 each, plus shipping & handling.
Float Stabilizer Spring for Carter/Kohler #26, #28, #30 carburetors for pulling engines that run well above 4,000 RPM or wide open throttle. Minimizes float bouncing and due to normal single cylinder engine vibration at high RPM or wide open throttle, which could also cause momentary engine misfire and/or fuel spillage out of atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor). Listed mainly for off-road vehicles and generator/welder engines. Not necessary for general lawn and garden use or pulling engines that operate at 4,000± RPM or below.
  • Used and in excellent condition. $4.50 each, plus shipping & handling. [When available]
  • New. OEM Kohler part # 237917-S. $9.00 each, plus shipping & handling.
New Brass Main Jet/Nozzle (Emulsion Tube). Fits all Carter/Kohler #26, #28, #30 carburetors used on Kohler K-series and early Magnum engine models K241, K301, K321, K330/K331, K341, K361 and opposed (flathead) twin cylinder engines. Drilled for gas. This part is professionally CNC machined in the USA and not available from Kohler. NOTE: When rebuilding a plain, stock Carter/Kohler carburetor, there is no need to remove the main jet/nozzle. If it won't come out, then don't worry about it. All that has to be done to make sure the bottom hole and the side holes on it are open. To check if the side holes are open, simply spray carburetor cleaner or WD-40 or carburetor cleaner (in an aerosol spray can) through the small hole just under the choke plate and observe if the spray exits out the main jet/nozzle inside the throttle bore and bottom of carburetor. But if modifying a carburetor to bore the venturi, the main jet/nozzle must be removed. Click here for how to remove the main jet/nozzle.
  • $10.00 each, plus shipping & handling.
Fixed Main Jets for Walbro WHG #52, #60 and #64 carburetors. 10-32 UNF (fine thread) (fine thread) threads. Go here to identify the correct jet for any particular carburetor: Kohler Carburetor Reference Manual. NOTE: Numbers on carburetor must match numbers of main jet for engine to run correctly. Available Jet Sizes and Prices:
  • For K241/M10 and K301/M12 Kohler engines with the Walbro WHG #52 carburetor. .045" hole.
    • OEM Kohler part # 47 337 02-S. $7.61 each, plus shipping & handling.
  • For K181/M18, K321/M14 Kohler engines with the Walbro WHG #60 carburetor. .046" hole.
    • OEM Walbro part # 114-0460-1. $5.90 each
    • OEM Kohler part # 52 337 08-S. $7.53 each, plus shipping & handling.
  • For KT19/M20 Kohler engines with the Walbro WHG #52 carburetor. .047" hole.
    • Kohler part# 52 337 01-S. $8.23 each, plus shipping & handling.
  • For M20 Kohler engines with the Walbro WHG #52 carburetor. .048" hole.
    • Kohler part # 52 337 07-S. $7.43 each, plus shipping & handling.
  • For KT17/M18 Kohler engines with the Walbro WHG #52 carburetor. .050" hole.
    • Walbro part # 114-0500-1. $6.00 each.
    • Kohler part # 52 337 03-S. $8.23 each, plus shipping & handling.
  • For K341/M16 Kohler engines with the Walbro WHG #60 carburetor. .051" hole.
    • Kohler part # 45 337 01-S. $8.23 each, plus shipping & handling.
  • For K341/M16 Kohler engines with the Walbro WHG #60 carburetor. .052" hole.
    • Walbro part # 114-0520-1. $6.80 each.
    • Kohler part # 52 337 04-S. $9.61 each, plus shipping & handling.
  • For KT17/M18 Kohler engines with the Walbro WHG #52 carburetor. .055" hole.
    • Kohler part # 52 337 06-S. Discontinued from Kohler.
Idle Fuel Mixture Adjuster Screws for Carter #16, #18, #20, #22 carburetors with following numbers stamped on top of carburetor body: G-220517, C-231738, B-231739, 41 053 01, 41 053 13, 41 053 18, 41 053 20 used on Kohler engine models K90/K91, K141, K160/K161 and K181. Also for Carter/Kohler #30 carburetors with 1.17" or 1.2" throttle bore with following numbers stamped on mounting flange: 45 053 08, 45 053 09, 45 053 12, 45 053 20, 45 053 68, 45 053 70, 45 053 76, 45 053 86, 45 053 87, 45 053 88, 45 053 89, 47 053 03, 47 053 09, 47 053 15, 47 053 16, 47 053 17, 47 053 20, 47 053 30, 47 053 41, 47 053 63, 47 053 78 used on Kohler engine models K321, K341 and K361. Short step tip. Dimensions: .865" overall length x .200" tip length x 7-40 threads. NOTE: Adjusters below Ê are identical, just different listings, part numbers and prices.
  • OEM Kohler part # 200438-S. $12.40 each, plus shipping & handling.
  • OEM Kohler part # 275231-S. $10.75 each, plus shipping & handling.


Idle Fuel Mixture Adjuster Screw for Carter/Kohler #26 carburetors with 1.07" throttle bore used on Kohler K-series engine models K241, K301 and K330/K331. Designed specifically for Kohler carburetors with following numbers stamped on mounting flange: 47 053 07, 47 053 08, 47 053 12, 47 053 13, 47 053 14, 47 053 15, 47 053 16, 47 053 24, 47 053 29, 47 053 35, 47 053 40, 47 053 62, 47 053 80, 52 053 60. Long step tip. Dimensions: .925" overall length x .260" tip length x 7-40 threads.
  • OEM Kohler part # 235006-S. $5.15 each, plus shipping & handling. Not available in aftermarket. L


Idle Fuel Mixture Adjuster Screw for Kohler carburetors used on Kohler KT-series engine models KT17, KT17 Series II, KT19, KT19 Series II, and models K482, K532 and K582. Designed specifically for Kohler carburetors with following numbers stamped on mounting flange: 48 053 06 (K582), 52 053 09, 52 053 18, 52 053 28. Long tapered tip. Dimensions: 1.026" overall length x .404" tip length x 7-40 threads.
  • OEM Kohler part # 277210-S. $7.45 each, plus shipping & handling. Not available in aftermarket. L


Compression Pressure Spring for Idle Fuel Mixture Adjuster Screws above È used on Carter/Kohler carburetors.
  • High quality aftermarket. $1.00 each, plus shipping & handling.
  • OEM Briggs & Stratton part # 691592. $3.50 each, plus shipping & handling.
  • OEM Kohler part # 200380-S. $4.78 each, plus shipping & handling.


Neoprene Rubber O-Ring. Place between compression pressure spring [on idle fuel mixture adjuster screw above È] and carburetor body to prevent a vacuum leak so engine will idle better.
  • .25¢ each, plus shipping & handling.


Idle Speed Adjuster Screws for Carter #16, #18, #20, #22, Carter/Kohler #26, #28, #30 and Walbro WHL or WHG carburetors. Dimensions: 8-32 UNF (fine thread) (fine thread) x 1" length.
  • High quality aftermarket. Made of rust-proof brass. .50¢ each, plus shipping & handling.
  • OEM Walbro part # 96-349-7. .80¢ each, plus shipping & handling.
  • Kohler part # 232556-S. $4.65 each, plus shipping & handling.


Idle Speed Adjuster Screws for Kohler #26, #30 carburetors used on Kohler engine models K482, K532 and K582. Dimensions: 8-32 UNF (fine thread) (fine thread) x 3/4" length.
  • High quality aftermarket. Made of rust-proof brass. .50¢ each, plus shipping & handling.
  • Kohler part # 234945-S. $4.38 each, plus shipping & handling.

Compression Pressure Spring for Idle Speed Adjuster Screw used on all Carter, Kohler and Walbro WHL or WHG carburetors.

  • OEM Walbro part # 98-3059-7. .50¢ each, plus shipping & handling.
  • Kohler part # 232555-S. $6.36 each, plus shipping & handling.


Compression Pressure Spring for High Speed Air/Fuel Adjusters (below Ê) used on all Carter #16, #18, #20, #22 and Carter/Kohler #26, #28 or #30 carburetors.
  • High quality aftermarket. $1.00 each, plus shipping & handling.
  • OEM Kohler part # 200383-S. $3.78 each, plus shipping & handling.


High Speed Air/Fuel Mixture Needle Adjuster Screws for Carter #16, #18, #20, #22 Carburetors. NOTE: Certain main adjusters are designed for a particular carburetor. I list the part number of the carburetor to match the type of adjuster it require. Kohler don't give their dealers much information on this. I did some research, and I have several used carburetors in stock, and compared the type of adjuster to the part numbers on each carburetor and found that some are in fact different. The holes midway on the high speed adjuster allows a small amount of air to be mixed with fuel through the idle circuit so the engine won't idle too rich or too lean on fuel. And with no holes present midway allows full flow of fuel through the idle circuit, which when used in a wrong carburetor, may cause the engine to idle too rich on fuel. So if an engine idles well (with the present adjuster), then the carburetor has the correct adjuster. Also, being the high speed adjusters are made of soft brass, if the pointed tip is slightly bent, it can be easily straightened with pliers and reused, and should not effect engine performance whatsoever. It's a valve that regulates the amount of fuel that goes in the engine. The tip does not need to be centered with the hole (orifice) in the main jet/nozzle (emulsion tube). Gas will still get around it. And over-tightening the needle in the main jet hole (orifice) will crush the tip out of shape, making it difficult to regulate the fuel. If the tips is damaged from being overtightened, the high speed adjuster will need to be replaced.

High Speed Air/Fuel Mixture Needle Adjuster Screws for Carter #16, #18, #20 and #22 carburetors that's used on Kohler engine models K90/K91, K141, K160/K161 and K181. The two parts below Ê are identical in every way, except 200410-S is for Carter carburetors having the following numbers stamped on top of carburetor body: A-230798, A-231966, B-231231, B-231450, B-231469, C-231738, E-231480, E-231488, E-231489, F-230350, F-230502, G-220517, G-230500, 231287, 24588, 41 053 06, 41 053 13, 41 053 14. And Kohler parts look up says that 200410-S is for Carter carburetors having the following numbers stamped on top of carburetor body: A-231741, A-234641, C-231738, B-231739, 41 053 01, 41 053 04, 41 053 05, 41 053 06, 41 053 18, 41 053 20. IMPORTANT - Please check numbers on carburetor before ordering and go here to identify the correct part for any particular carburetor: Kohler Carburetor Reference Manual. Adjusters below Ê are identical, just different part numbers and prices.

  • High quality aftermarket. $10.00 each, plus shipping & handling.
  • OEM Kohler part #'s 200410-S, 232635-S. $20.42 each, plus shipping & handling.

Important - Please check numbers on carburetor before ordering. If in doubt about superseded numbers for any particular carburetor, refer to Kohler Engines Parts Lookup (require Internet Explorer.) Mark "I accept", scroll down, click on "Enter as Guest" and enter part number in upper right corner. Use the newest superseded part number available, click on "where used" in the pop-up dialog box. A list engine models and spec numbers should be displayed.


High Speed Air/Fuel Mixture Needle Adjuster Screws for Carter/Kohler #26, #28, #30 Carburetors. NOTE: Certain main adjusters are designed for a particular carburetor. I list the part number of the carburetor to match the type of adjuster it require. Kohler don't give their dealers much information on this. I did some research, and I have several used carburetors in stock, and compared the type of adjuster to the part numbers on each carburetor and found that some are in fact different. The holes midway on the high speed adjuster allows a small amount of air to be mixed with fuel through the idle circuit so the engine won't idle too rich or too lean on fuel. And with no holes midway allows full flow of fuel through the idle circuit, which when used in a wrong carburetor, may cause the engine to idle too rich on fuel. So if an engine idles well (with the present adjuster), then the carburetor has the correct adjuster. Also, being the high speed adjusters are made of soft brass, if the pointed tip is slightly bent, it can be easily straightened with pliers and reused, and should not effect engine performance whatsoever. It's a valve that regulates the amount of fuel that goes in the engine. The tip does not need to be centered with the hole (orifice) in the main jet/nozzle (emulsion tube). Gas will still get around it. And over-tightening the needle in the main jet hole (orifice) will crush the tip out of shape, making it difficult to regulate the fuel. If the tips is damaged from being overtightened, the high speed adjuster will need to be replaced. Or the damaged tip can be broken off at the lower hole(s), and the [#26, #28 or #30] carburetor can be converted for use with a bottom adjuster.

High Speed Air/Fuel Mixture Needle Adjuster Screw for certain Carter/Kohler #26, #28, #30 carburetors used on Kohler K-series and early Magnum flathead engine models K241, K301, K330/K331, K321, KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20, MV20 and certain K532 and K582 engines. Has four holes midway and two lower holes on stem. Designed specifically for Kohler carburetors with following numbers stamped on mounting flange: 47 053 07, 47 053 08, 47 053 12, 47 053 13, 47 053 14, 47 053 24, 47 053 29, 47 053 35, 47 053 40, 47 053 62, 47 053 80, 48 053 06 (K582), 52 053 01, 52 053 02, 52 053 09, 52 053 10, 52 053 11, 52 053 16, 52 053 18 and 52 053 28. IMPORTANT - Please check numbers on carburetor before ordering and go here to identify the correct part for any particular carburetor: Kohler Carburetor Reference Manual. Interchangeable with discontinued OEM Kohler high speed adjuster part # 52 103 01-S, which has four holes midway and one lower hole on stem.

  • High quality aftermarket. Replaces Kohler part # 235415-S. $19.00 each, plus shipping & handling.
  • OEM Kohler part # 235415-S. $31.55 each, plus shipping & handling.


High Speed Air/Fuel Mixture Needle Adjuster Screw for certain Carter/Kohler #28, #30 carburetors used on Kohler K-series and early Magnum single cylinder engine models K321, K341 and K361. Has two holes midway and one lower hole on stem. Designed specifically for Kohler carburetors with following numbers stamped on mounting flange: 4174S (Carter), 45 053 08, 45 053 12, 45 053 20, 45 053 26, 45 053 68, 45 053 70, 45 053 76, 45 053 77 and 47 053 11. IMPORTANT - Please check numbers on carburetor before ordering and go here to identify the correct part for any particular carburetor: Kohler Carburetor Reference Manual. Discontinued from Kohler. Kohler part # 45 103 01-S.
  • High quality aftermarket. $16.00 each, plus shipping & handling.


High Speed Air/Fuel Mixture Needle Adjuster Screw for certain Carter #30 carburetors used on certain Kohler engine models K321, and Kohler #26, 1.07" throttle bore carburetors used on Kohler engine models K482, K532 and K582. Each has no holes midway and one lower hole on stem. Designed specifically for certain Carter and Kohler carburetors with following numbers stamped on mounting flange: A236636 (Carter #30), 47 053 03, 47 053 09, 47 053 15, 47 053 16, 47 053 17, 47 053 20, 47 053 30, 47 053 41, 47 053 63 and 47 053 78. IMPORTANT - Please check numbers on carburetor before ordering and go here to identify the correct part for any particular carburetor: Kohler Carburetor Reference Manual. Not available in aftermarket. L
  • OEM Kohler part # 47 103 01-S. 15º pointed end; listed for Kohler engine models K241 w/spec # 46743, K482, K532, K582 w/spec #'s 36224 and 36231. $18.60 each, plus shipping & handling.
  • Used and in excellent condition. OEM Kohler part #'s 237489-S, 48 103 01-S (discontinued). 30º pointed end; listed for Carter #30 carburetor A236636 used on Kohler engine models K321 and K341 installed in Cub Cadet models 147, 149 and 169; also listed for K582 engines w/spec #'s 36202-36394, except above È. $23.00 each, plus shipping & handling.


Quality high speed steel spiral drill bit. Size: .039" / #60 / 1mm diameter x 1-3/8" length. Perfect size to enlarge lower hole on high speed needle adjusters above È for Carter/Kohler carburetors so engine will start quicker and idle better. An ingenious, thoroughly researched and innovative concept by Brian Miller, because nobody else advertise the use of this part.
  • $1.60 each, plus shipping & handling. Many other small size drill bits available.


Idle Air/Fuel Mixture Adjuster Screws for all Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors used on Kohler Magnum engine models M8, M10, M12, M14, M16 and opposed (flathead) twin cylinder engine models MV16, M18, MV18, M20, MV20. NOTE: The adjusters below Ê have the same threads and ends (tips). The only difference is the type of head.
  • Knurled head. OEM Walbro part # 102-14-1. $2.00 each, plus shipping & handling.
  • Knurled head. Kohler part # 25 368 01-S. (Same as above È, made by Walbro.) $4.24 each, plus shipping & handling.
  • Smooth head. OEM Walbro part # 102-434-1. $1.45 each, plus shipping & handling.
  • Smooth head. Kohler part # 25 368 02-S. (Same as above È, made by Walbro.) $4.92 each, plus shipping & handling


High Speed Air/Fuel Mixture Adjuster Needle Valve. Fits all Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors w/adjustable high speed jet originally used on flathead cast iron block Kohler Magnum single cylinder engine models M8-M16 and opposed (flathead) twin cylinder models MV16, M18, MV18, M20, MV20. Overall length: 1-5/8".
  • OEM Walbro part # 102-457-1. $2.10 each, plus shipping & handling.
  • Kohler part # 25 368 03-S. (Same as above È, made by Walbro.) $5.67 each, plus shipping & handling.


Compression Pressure Spring for all Walbro idle air/fuel mixture adjuster and high speed air/fuel mixture adjuster screws above È.
  • OEM Walbro part # 98-14-7. .50¢ each, plus shipping & handling.
  • Kohler part # 25 089 02-S. (Same as above È, made by Walbro.) $3.38 each, plus shipping & handling.
Plugs for Carter/Kohler and Walbro carburetors. Expansion/welch plugs are concave/dish-shaped, not cup-shaped. Expands and flattens out with hammer when installed in counterbore hole. No sealant required. Steel ball press-fit in hole. Not available from Kohler.
  • 8-32 UNF (fine thread) Allen set screw. Use to plug factory-drilled idle fuel passageway holes on top/center of carburetor when OEM cup plug is removed for carburetor cleaning. Cut short threads in holes with an 8-32 UNF (fine thread) hand tap to install.
  • 3mm Cup-Type Expansion Plug or 1/8" Steel Ball. For idle circuit; located top center of all Walbro carburetors. OEM Walbro part # 88-14-8. .50¢ each, plus shipping & handling.
  • 5/16" Concave-Type Expansion/Welch Plug. For atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor); located top of #36, #44 Walbro carburetors. OEM Walbro part # 88-54-8. .50¢ each, plus shipping & handling.
  • 3/8" Concave-Type Expansion/Welch Plug. For idle circuit; located side of Carter/Kohler #26, #28, #30, Walbro #52, 60 & 64 carburetors and at an angle on Walbro #52, #60, #64 carburetors. OEM Walbro part # 88-180-8. .50¢ each, plus shipping & handling.
Carburetor Mounting Screw (Bolt) w/Slotted Head for Carter #16, #18, #20, #22, and Walbro WHL #36, #44 carburetors that's used on Kohler engine models K90/K91, K141, K160/K161 and K181/M8. Use small screwdriver in slot to start screws in threaded holes. Size: 1/4-20 UNC (coarse thread) x 3/4" thread length. Discontinued from Kohler. L Replaces Kohler part # X-140-1-S.
  • A-1 Miller part. Grade 5 bolt w/slotted head and flat washer. $2.00 each, plus shipping & handling.


Carburetor Mounting Screws (Bolts) w/Slotted Head for Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors used on Kohler engine models K241/M10, K301/M12, K330/K331, K321/M14, K341/M16 and K361. Use small screwdriver in slot to start screws in threaded holes. Size: 5/16-18 UNC (coarse thread) x 1" thread length.

  • A-1 Miller part. Grade 5 bolt w/slotted head and flat washer. $2.00 each, plus shipping & handling.
  • OEM Kohler part # X-770-1-S. $2.63 each, plus shipping & handling.


Carburetor Stud Kits to mount Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors on Kohler engine models K241/M10, K301/M12, K330/K331, K321/M14, K341/M16 and K361. Apply medium strength liquid threadlocker on the threads of the studs to secure them in the block (or OHV head). 5/16-18 UNC (coarse thread) thread size. A-1 Miller products.

  • Kit with two 1-1/4" length studs and two serrated flange hex nuts. Use with gasket. $5.00 per kit, plus shipping & handling.
  • Kit with two 2-1/4" length studs and two serrated flange hex nuts. Use with 1" aluminum carburetor spacer. $5.00 per kit, plus shipping & handling.
A worn throttle shaft is the #1 cause of most engines wearing out and burning oil prematurely. If a carburetor has a worn throttle shaft, this will create a vacuum leak and the engine will idle poorly, if at all at times. Not to mention the engine will also draw in dirty air, causing wear on the valve faces/seats and piston rings, and engine will burn oil. More than .010" of play is considered too much for throttle shaft wear. Plus, at operating running speeds (3,600 RPM), the extra air will cause the engine to run lean on fuel, which will overheat the combustion chamber and cause the cylinder head to warp (blow a head gasket) and the piston and rings to wear prematurely, eventually resulting in severe engine wear and excessive oil burning. Along with regular maintenance, repair of a worn throttle shaft is required to help an engine last a long time. The most accurate way to check for amount of wear is with a dial indicator.

Furthermore, all Carter/Kohler and Walbro carburetors didn't come with a throttle shaft bushing installed from the factory. A new bushing (see below Ê) must be installed when the throttle shaft is worn and loose in the carburetor body, or sometimes a new bushing and a new throttle shaft both must be installed. If there's a counterbore (recession in the carburetor body) where the throttle shaft is, a short, flat bronze bushing can be installed, and if it's still in good condition, the original throttle shaft can be reused. But if there's no counterbore, the carburetor body will need to be precision aligned-bored for installation of a bronze sleeve bushing, and chances are, a new throttle shaft will also need to be installed. Special machining of the carburetor body is required for the sleeve bushing. And ALL Carter and Kohler #26, #28 and #30, and the older Walbro #52, #60 and #64 carburetors have the counterbore. Only the newer Walbro #52, #60, #64, and the Chinese-made carburetors don't have the counterbore. If the carburetor has the counterbore, the throttle shaft will need to be removed, the dirt and debris will need to be cleaned out from the counterbore, and then the short, flat bushing can be installed. But if there's no counterbore, the upper hole in the carburetor body will need to be bored out in precision alignment with the lower hole in a milling machine, and then a bronze sleeve bushing can be installed. Return To Previous Paragraph

Throttle Shaft Protective Dust/Dirt Seal. Foam Rubber Seal (reticulated polyurethane foam). Use only on Carter #16, #18, #20, #22 and Walbro WHL #36, #44 carburetors, Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors, and many other carburetors, such as Briggs & Stratton, Tecumseh, etc. For Kohler engine models K91, K141, K161, K181/M8, K241/M10, K301/M12, K321/M14, K241/M16, K361, MV16, KT17, KT17II, KT19, KT19II, M18, MV18, M20 and MV20. Dimensions (±): 7/32" i.d. (will stretch over a 1/4" shaft) x 7/16" o.d. x 5/32" thick. NOTE: Seal is compressed between throttle lever and carburetor body or bushing to prevent dust and dirt from wearing throttle shaft. Apply clean motor oil on seal before installing to trap dust and dirt to prevent wearing of throttle shaft and/or upper hole in carburetor body or bushing. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate retaining screws without breaking them off. OEM Walbro part #'s 156-18-8, 156-24-8 and OEM Briggs & Stratton part #'s 691321, 691869.
  • $2.00 each, plus shipping & handling.

Throttle Shaft Protective Dust/Dirt Seal. Felt Seal (Pressed Cloth Fibers). Use only on the carburetors of Kohler engine models K482, K532 and K582. Dimensions (±): 7/32" i.d. (will stretch over a 1/4" shaft) x 3/8" o.d. x 1/8" thick. NOTE: Seal is compressed between spring-loaded washer on throttle shaft and carburetor body to prevent dust and dirt from wearing throttle shaft. Apply clean motor oil on seal before installing to trap dust and dirt to prevent wearing of throttle shaft and/or upper hole in carburetor body or bushing. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate retaining screws without breaking them off. OEM Briggs & Stratton part #'s 270167, 271853, 692279.


Bronze throttle shaft bushingBronze Throttle Shaft Bushing for Carter #16, #18, #20, #22 carburetors with a counterbore that's used on Kohler engine models K90/K91, K141, K160/K161 and K181, as well as other makes and models of engines that use the same carburetor. Dimensions: 7/32" i.d. x .407" o.d. x 1/8" height. NOTE: Apply clean motor oil, gear oil or lubricating grease on throttle shaft before installing for smooth throttle operation and less wear to shaft, bushing or carburetor body. And some later Carter carburetors do not have the counterbore to accept this bushing. If there's no counterbore, then if the shaft hole is not severely worn, a new throttle shaft (see below Ê) can be installed. Go here to learn how to professionally remove Carter/Kohler throttle or choke plate retaining screws without breaking them off. But if the shaft hole is severely worn, it will need to be slightly enlarged to match a fabricated oversized throttle shaft made of mild steel. The original lever will need to be ground off the old shaft and welded onto the new shaft. I offer this service, too. (see below Ê) No Kohler part number available for this bushing. An innovative concept by Brian Miller, because nobody else advertise this part or services.

  • High quality aftermarket. Precision-made in the USA of CNC-machined bearing bronze. $6.00 each, plus shipping & handling
  • Installation Service: Install this throttle shaft bushing in your carburetor. $30.00 each for bushing, new screws and labor, plus return shipping & handling.
  • Installation Service: Fabricate a slightly larger throttle shaft and install in your carburetor. $60.00 each for shaft, new screws and labor, plus return shipping & handling. Please contact me if you're interested in any of the above È repair services.


Bronze throttle shaft bushingShort, Flat Bronze Throttle Shaft Bushing for all Carter/Kohler #26, #28, #30 and early Walbro #52, #60, #64 carburetors with a counterbore that's used on Kohler K-series and early Magnum engine models K241/M10, K301/M12, K330/K331, K321/M14, K341/M16, K361 and KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20, MV20. All Carter and Kohler #26, #28 and #30 carburetors have the counterbore to accept the short, flat bronze throttle shaft bushing. If there's a [worn] rubber seal in the counterbore, this bushing will replace it. Dimensions: 1/4" i.d. x 7/16" o.d. x 1/8" height. NOTE: Apply clean motor oil, gear oil or lubricating grease on throttle shaft before installing for smooth throttle operation and less wear to shaft, bushing or carburetor body. Go here to learn how to professionally remove Carter/Kohler throttle or choke plate retaining screws without breaking them off.

  • High quality aftermarket. Precision-made in the USA of compressed sintered bronze. Very hard material. $4.50 each, plus shipping & handling.
  • OEM Kohler part # 25 158 02-S. $10.75 each, plus shipping & handling.
  • Installation Service: Install this throttle shaft bushing in your carburetor. $30.00 each for bushing, new screws and labor, plus return shipping & handling. Please contact me if you're interested in this repair service. An innovative concept by Brian Miller, because nobody else advertise this service.

Installation Instructions: The above È bushings makes contact with the upper unworn 1/8" portion of the throttle shaft. The original throttle shaft can be reused with the bushing if it isn't severely damaged. To install the bushing, first of all, to avoid breaking off the soft OEM brass throttle plate retaining screws, use a Dremel or equivalent small rotary grinder chucked with either a small grinding stone (chainsaw sharpening stone) or an 1/8" high speed steel end mill to grind away the flared threads at the end of the screws, then the screws can be removed, and then the shaft can be removed from the carburetor body. If the throttle (or choke) plate retaining screws breaks off, they can be successfully drilled out. Clean out the counterbore and depending on size of carburetor, slide the bushing on a 3/16" or 5mm screw (for the Carter #16, #18, #20, #22 carburetors) or a 1/4" or 6mm screw or bolt (for the Carter/Kohler #26, #28, #30 and early Walbro #52, #60, #64 carburetors) and insert the screw or bolt in the counterbore hole (to align the bushing straight with the counterbore) and use small hammer or bench vise to drive- or press-in the bushing, and then reinstall the shaft.

Additional Note: Usually the short, flat bronze bushing will snug up a worn throttle shaft. With oil for lubrication and a felt or foam seal to keep out dust and dirt (available below Ê), the bushing and shaft should last a long time. If the bushing fits somewhat loose in the counterbore, lightly tap the sides of the counterbore with a hammer to make the counterbore slightly oblong or egg-shaped. The newer Walbro and the Chinese-made carburetors have no counterbore for the bushing, and sometimes in these carburetors, the [upper] throttle shaft hole will wear. When this happens, just installing a new shaft won't fix the problem. The upper hole must be precision-bored perfectly aligned with the [unworn] lower hole, and a bronze sleeve bushing will need to be installed along with a new throttle shaft. On other makes of carburetors, if the original shaft is worn and a new throttle shaft isn't available, then a new throttle shaft will need to be machined/fabricated. The throttle lever can be reused and welded to the new machined/fabricated shaft. And if necessary, a slightly oversized throttle shaft can be installed instead of the original diameter shaft. I can do all of these things for $50.00± each for parts and labor, plus return shipping & handling.


Bronze Throttle Shaft Sleeve Bushing for the newer Walbro WHG #52, #60, #64, and Chinese-made carburetors that have no counterbore for the short throttle shaft bushing, or for the #26, #28 or #30 Carter/Kohler carburetors with a worn/enlarged counterbore for the short throttle shaft bushing. Not available from Kohler. Precision-made in the USA of compressed sintered bronze. Dimensions: 1/4" i.d. x .313" o.d. x 3/4" length. IMPORTANT NOTE: The upper throttle shaft hole must be precision-bored exactly to .3125" (5/16") in perfect center-alignment with the lower hole for installation of this sleeve bushing. The carburetor body will need to be clamped in a machine vise fastened on the table of a milling machine, aligned, and precision-drilled so the throttle shaft will rotate without binding after installation of the bushing. A drill press will not be accurate at all. If a drill press is used, the carburetor body could be ruined and rendered useless. Apply clean motor oil, gear oil or lubricating grease on throttle shaft before installing for smooth throttle operation and less wear to shaft and bushing. Not to be used in the Kohler-made carburetors for Kohler engine models K482, K532 or K582. An innovative concept by Brian Miller, because nobody else advertise the use of this part or this service.

  • Aftermarket; not available from Kohler. Precision-made in the USA of compressed sintered bronze. Very hard material. $3.00 each, plus shipping & handling.
  • Repair Service: Bore upper throttle shaft hole, install new bronze sleeve bushing. $45.00 labor and bushing + price of new throttle shaft with new screws/lock washers (if needed), plus return shipping & handling. An innovative concept by Brian Miller, because nobody else advertise this repair service .


Professionally machine YOUR carburetor body and install bronze sleeve bushings for worn choke shaft holes and reinstall original choke shaft (if not excessively worn).

  • $50.00 for parts and labor, plus return shipping & handling.

OEM Kohler Choke Shaft Repair Kits -

  • For Carter #16, #18, #20, #22 and Walbro WHL #44 carburetors. OEM Kohler part # 25 757 20-S. $52.98 each, plus return shipping & handling.
  • For Carter/Kohler #26, #28, #30 carburetors. OEM Kohler part # 25 757 21-S. $48.74 each, plus return shipping & handling.


Throttle and Choke Plate Retaining Screws | Don't reuse the OEM soft brass throttle or choke plate retaining screws! They can break off while being tightened or possibly loosen and dislodge later, and can damage the valves or piston. | Return To Previous Paragraph or Section

3-48 UNC (coarse thread) screws and split lock washers to fasten throttle or choke plate to throttle or choke shaft in Carter/Kohler and various other carburetors. Each measures .095" outside thread diameter; Grade 18-8 stainless steel; tensile strength: 120,000 psi. Discontinued from Kohler. Replaces Kohler part # 234209-S.

  • 3-48 UNC (coarse thread) x 3/16" thread length for OEM 7/32" throttle shafts and machined/high performance 1/4" throttle shafts (throttle shaft ground/milled thin for more air flow). $2.00 per pair, plus shipping & handling.
  • 3-48 UNC (coarse thread) x 1/4" thread length for 1/4" choke shafts and OEM/unmachined 1/4" throttle shafts. $1.00 per pair, plus shipping & handling.

4-40 UNC (coarse thread) screws and split lock washers to fasten throttle or choke plate to throttle or choke shaft in Carter/Kohler, Chinese-made, Walbro and various other carburetors. Can also be used as an oversize replacement when 3-48 threads strips out. .108" outside thread diameter. Grade 18-8 stainless steel; tensile strength: 120,000 psi.

  • 4-40 UNC (coarse thread) x 1/4" thread length stainless steel for stock throttle shafts. $1.00 per pair, plus shipping & handling.
  • 4-40 UNC (coarse thread) x 3/16" thread length stainless steel for high performance use (throttle shaft ground/milled thin for more air flow). $2.00 per pair, plus shipping & handling.
  • 4-40 UNC (coarse thread) x 3/16" thread length brass. OEM Walbro part # 96-263-7. $1.00 per pair, plus shipping & handling.
  • 4-40 UNC (coarse thread) x 3/16" thread length brass. OEM Kohler part # 25 086 27-S. $5.00 per pair, plus shipping & handling.

5-44 UNF (fine thread) screws and split lock washers. Use as an oversize replacement when 4-40 threads strips out. .118" outside thread diameter. Tensile strength: 74,000 psi.

  • 5-44 UNF (fine thread) x 1/4" thread length. .50¢ per pair, plus shipping & handling.

Quality High Speed Steel Taper Hand Taps. Taper taps allow for the tip to be inserted deeper in the hole for easier cutting of threads and less chance of breaking off in the hole.

3-48 UNC (coarse thread) size. For repairing OEM threads in Carter/Kohler throttle and choke shafts. $8.00 each, plus shipping & handling.

4-40 UNC (coarse thread) size. For newer OEM Walbro and cutting oversize threads in Carter/Kohler throttle and choke shafts when 3-48 threads strip out. $8.00 each, plus shipping & handling.

5-44 UNF (fine thread) size. For cutting oversize threads in throttle and choke shafts when 4-40 threads strip out. $8.00 each, plus shipping & handling.


If the throttle and/or choke shafts and/or shaft holes are worn in a K482, K532 or K582 carburetor, if the holes aren't worn beyond for reuse, I make a new throttle shaft for it. But if the holes are worn too, and being the metal is too thin on one side for installation of a bushing, the shaft holes will need to be enlarged a few thousandths bigger than 1/4", and a steel rod that's slightly bigger than the enlarged holes (for a slip-fit) will need to be fabricated for use as a throttle shaft. I then align and weld the OEM throttle lever to the new shaft. I also install a foam seal on the throttle shaft and a thin, hardened steel thrust washer next to the throttle plate to prevent it from wearing against the carburetor body. And I install a new overhaul/rebuild kit. I've performed this type of repair many times with excellent results. I offer this repair service. If interested, I will need for you to send me your carburetor. And for dimensional measurements, I will need the complete carburetor with the throttle and choke shafts with the levers and the throttle and choke plates. I will fabricate new shaft(s), and install the lever(s) on the shaft(s), and install the throttle and/or choke plates on the shafts in the carburetor. FYI - Bearing bronze is very hard, porous, absorbs oil and lasts a long time when lubricated regularly and used as a bushing. Brass, on the other hand, is soft, non-porous and wears quickly when used as a load-bearing bushing or shaft. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off. An innovative concept by Brian Miller, because nobody else advertise this repair service.

  • New throttle or choke shaft installation repair price for a K482, K532 or K582 carburetor is $100.00 per shaft for parts and labor, plus return shipping & handling. IMPORTANT: When sending your carburetor to me, please package it and all parts to it securely in one sealed zip-lock sandwich bag to prevent loss of parts in shipping, and to prevent the odor of gas from escaping the package. If the odor of gas is still present from outside the package, apply air freshener on the carburetor to disguise the smell of gas. Because the US Postal Service or other delivery services will not deliver any packages that smell like gas. Also, be sure to include a note in the package with your name, complete and correct postal address, phone number (in case I have any questions), a description of what you want done, how the engine will be used and any other parts you may need. I will contact you when the carburetor (and list of parts) are ready to be sent back to you. Please send to: A-1 Miller's Performance Enterprises, 1501 W. Old Plank Rd., Columbia, MO (Missouri) 65203-9136 USA.
  • Rebuilt OEM Kohler carburetor for Kohler engine models K482 and K532. (1.07" throttle bore.) OEM Kohler part # 48 053 07-S. $150.00 each outright, plus shipping & handling. (When available.)
  • NEW high quality Kohler-replicated "Made in China" fully adjustable carburetor for Kohler engine models K482 and K532. (1.07" #26 throttle bore.) Same quality as OEM Kohler carburetor. Replaces Kohler part # 48 053 07-S. $125.00 each outright, plus shipping & handling.
  • Rebuilt OEM Kohler carburetor for Kohler engine model K582. (1.2" throttle bore.) OEM Kohler part # 48 053 06-S or 48 053 16-S. $150.00 each outright, plus shipping & handling. (When available.)
  • NEW high quality Kohler-replicated "Made in China" fully adjustable carburetor for Kohler engine model K582. (1.2" #30 throttle bore.) Same quality as OEM Kohler carburetor. Replaces Kohler part # 48 053 06-S or 48 053 16-S. $150.00 each outright, plus shipping & handling.
Remote Solid Wire Throttle Control Cable. All heavy duty metal construction. Conduit: 36-1/2"; Inner wire: 41-1/4"; Wire travel: 1-3/4".
  • $29.00 each, plus shipping & handling.
Remote Push/Pull Solid Wire Choke Control Cable. Durable plastic construction to resist rust w/metal conduit. Conduit length: 40-1/2"; Inner wire length: 42-1/4"; Wire travel: 2".
  • $15.00 each, plus shipping & handling.
Throttle Shaft with lever attached for Carter #16, #18 and Walbro WHL #36 carburetors used on Kohler engine models K90/K91 cast iron block flathead engines. Steel lever with 7/32" diameter hardened shaft. Includes 3-48 UNC (coarse thread) stainless steel screws and split lock washers. No threadlocker required. Can be used with OEM Carter throttle plate or the 25 146 05-S (Walbro) throttle plate below Ê. NOTE: Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth throttle operation and less wear to shaft, bushing and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • OEM Kohler part # 46 144 04-S. $24.90 each, plus shipping & handling. Not available in aftermarket. L

Throttle plates for Carter #16, #18, #20, #22 and Walbro WHL #36, #44 carburetors with .822" diameter throttle bore.

  • OEM Walbro part # 34-222-1. $14.40 each, plus shipping & handling.
  • Kohler part # 25 146 05-S. (Same as above È, made by Walbro.) $20.05 each, plus shipping & handling.
Throttle Shafts with integrated lever for Carter #20, #22 and Walbro WHL #44 carburetors used on Kohler engine models K141, K160/K161, K181 and M8 cast iron block flathead engines. Steel lever with 7/32" diameter hardened shaft. Includes 3-48 UNC (coarse thread) stainless steel screws and split lock washers. No threadlocker required. Can be used with OEM Carter throttle plate or the 25 146 05-S (Walbro) throttle plate below Ê. NOTE: Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth throttle operation and less wear to shaft, bushing and/or carburetor body. Go here to learn how to professionally remove Carter/Kohler throttle or choke plate retaining screws without breaking them off.
  • High quality aftermarket. Has 3 small holes for throttle link. $12.00 each, plus shipping & handling. (When available.)
  • OEM Kohler part # 41 144 18-S. Has one small for throttle link, and one large hole for throttle link nylon bushing. $15.40 each, plus shipping & handling.

Throttle plates for Walbro WHL #36, #44 and Carter #16, #18, #20, #22 carburetors with .822" diameter throttle bore.

  • OEM Walbro part # 34-222-1. $14.40 each, plus shipping & handling.
  • Kohler part # 25 146 05-S. (Same as above È, made by Walbro.) $20.05 each, plus shipping & handling.
Throttle Shaft Upgrade Kit -

Convert a Carter #26, #28 or #30 carburetor with the cast aluminum clamp-on throttle lever to the Kohler-style throttle shaft design. Kit consists of the Kohler-style throttle shaft w/hole in lever (below Ê), brass 8-32 UNC (coarse thread) (idle speed) screw, and compression spring for the idle speed screw. INSTALLATION INSTRUCTIONS: The steel pin will need to be ground off flush with the top of the carburetor body (don't attempt to break it off, the aluminum will break instead), and the carburetor body will need to be drilled in a specific location with a 9/64" drill bit and new threads will need to be cut through the hole with an 8-32 UNC (coarse thread) plug hand tap for the idle speed screw so it will make correct contact with the throttle lever. Click here to learn how to cut new threads, the professional way. Then a countersink hole will need to be drilled 1/8" deep with a 9/32" drill bit for the spring on the idle speed screw. An innovative concept by Brian Miller, because nobody else advertise this conversion/upgrade kit.

  • Kit with Throttle Shaft w/3/16" hole in lever. $20.00 per kit, plus shipping & handling.
  • Kit with Throttle Shaft w/integrated ball on lever. $25.00 per kit, plus shipping & handling.
Throttle Shafts for Kohler engine models K241/M10, K301/M12 and K330/K331. Each have a small hole for throttle stabilizer spring or throttle return spring (pulling). NOTE: Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth throttle operation and less wear to shaft, bushing and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • High quality aftermarket throttle shafts w/integrated lever made specifically for Carter/Kohler #26, #28, #30 carburetors. These are the old style throttle shafts with the 11/16" screw hole spacing that is no longer available from Kohler. Each come with screws and split lock washers.
    • Throttle shaft w/3/16" hole in lever. $15.00 each, plus shipping & handling.
    • Throttle shaft w/integrated ball on lever. $20.00 each, plus shipping & handling.
  • OEM Kohler #26 throttle shaft w/integrated lever, 9/16" screw hole spacing and 3/16" hole in lever made specifically for Walbro WHG #52 carburetor with a 1.07" throttle bore. Includes screws and split lock washers. OEM Kohler part # 47 144 35-S. $30.88 each, plus shipping & handling.
  • OEM Kohler throttle shaft w/integrated lever 3/4" screw hole spacing and 3/16" hole in lever made specifically for Walbro WHG #60 or #64 carburetor with a 1.2" throttle bore. Includes screws and split lock washers. OEM Kohler part # 47 144 36-S. $22.82 each, plus shipping & handling.


Throttle plate made specifically for Carter/Kohler #26 carburetors with 1.07" throttle bore originally used on Kohler K-series engine models K241, K301, K330/K331, KT17, KT17 series 2, KT19, KT19 Series II, K482 and K532. Designed to be used with the OEM or aftermarket throttle shafts above È with 11/16" screw hole spacing. Made of steel. Discontinued from Kohler. Replaces Kohler part # 236668-S. High quality aftermarket.

  • $6.00 each, plus shipping & handling.


Throttle plate made specifically for Walbro WHG #52 carburetor with 1.07" throttle bore originally used on Kohler Magnum engine models M10, M12, MV16, M18, MV18, M20 and MV20. Designed to be used with OEM Kohler part # 47 144 35-S throttle shaft above È with 9/16" screw hole spacing. OEM Kohler part # 25 146 02-S. (Walbro part # 34-112; but available only from Kohler.)
  • $6.23 each, plus shipping & handling.


Throttle plate made specifically for Carter or Kohler #30 carburetor with 1.2" throttle bore originally used on Kohler K-series engine models K321, K341 and K582. Designed to be used with OEM Carter, Kohler or aftermarket throttle shafts above È with 11/16" screw hole spacing. No Kohler part number. High quality aftermarket.

  • $6.00 each, plus shipping & handling.


Throttle plates made specifically for Walbro HDA, LMH, WHG #60, #64 carburetors with 1.2" throttle bore originally used on Kohler Magnum engine models M14 and M16. Designed to be used with 47 144 36-S throttle shaft above È with 3/4" screw hole spacing when used in a Carter or Kohler carburetor.
  • OEM Walbro part # 34-18-1. $7.00 each, plus shipping & handling.
  • Kohler part # 47 146 10-S. (Same as above È, made by Walbro.) $10.75 each, plus shipping & handling.
Throttle shaft w/foam seal and throttle plates for Kohler engine models CH11, CH12.5, CH14, CV11, CV12.5, CV13, CV14, CV15, CV16 and CV460 with the Walbro carburetor.
  • Throttle shaft w/lever. Includes foam seal, screws and split lock washers. OEM Kohler part # 12 144 09-S. $8.31 each, plus shipping & handling.
  • Throttle plate. (Same part as below Ê.) Includes retaining screws and spit lock washers. OEM Walbro part # 34-13-1. $1.30 each, plus shipping & handling.
  • Throttle plate. (Same part as above È.) Includes retaining screws and split lock washers. OEM Kohler part # 12 146 03-S. $5.84 each, plus shipping & handling.
Throttle Shaft w/Prominent Raised Lever for Walbro WHG #52 or Kohler #26 carburetors used on Kohler horizontal shaft engine models KT17, KT17 Series II, KT19, KT19 Series II, M18 and M20. 1/4" diameter hardened shaft with steel lever. Includes screws and split lock washers. No threadlocker required. Lever has a 3/16" hole for throttle bushing/linkage. NOTE: To be used with Kohler 25 146 02-S (Walbro # 34-112) throttle plate. Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth throttle operation and less wear to shaft, bushing and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off. OEM Kohler part # 52 144 22-S.
  • Used and in excellent condition. $12.00 each, plus shipping & handling. (When available.)
  • New. $25.25 each, plus shipping & handling.

Throttle Shaft w/Slightly Raised Lever for Walbro WHG #52 or Kohler #26 carburetors used on Kohler vertical shaft engine models MV16, MV18 and MV20. 1/4" diameter hardened shaft with steel lever. Includes screws and split lock washers. No threadlocker required. Lever has a 3/16" hole for throttle bushing/linkage. NOTE: To be used with Kohler 25 146 02-S (Walbro # 34-112) throttle plate. Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth throttle operation and less wear to shaft, bushing and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off. OEM Kohler part # 52 144 25-S.

  • Used and in excellent condition. $10.00 each, plus shipping & handling. (When available.)
  • New. $21.55 each, plus shipping & handling.
Choke shaft w/remote solid wire cable-controlled lever for Carter #16, #18, #20, #22 and Walbro WHL #36, #44 carburetors used on Kohler engine models K90/K91, K141, K160/K161, K181 and M8. Steel lever with hardened shaft. Overall shaft length: 2-1/2". The 1-7/8" length choke shaft, which was made by Carter, is no longer available. L) Includes screws and split lock washers. No threadlocker required. NOTE: Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • OEM Kohler part # 41 090 22-S. $18.10 each, plus shipping & handling. Not available in aftermarket. L
Choke shaft w/hand-operated or remote solid wire cable-controlled angled lever for Carter #16, #18, #20, #22 and Walbro WHL #36, #44 carburetors used on Kohler engine models K90/K91, K141, K160/K161, K181 and M8. Steel lever with hardened shaft. Overall shaft length: 2-1/16". The 1-7/8" length choke shaft, which was made by Carter, is no longer available. L) Includes screws and split lock washers. No threadlocker required. NOTE: Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • OEM Kohler part # 41 090 20-S. $18.10 each, plus shipping & handling. Not available in aftermarket. L
Choke shaft w/remote solid wire cable-controlled, swivel screw clamp lever for Carter #16, #18, #20, #22 and Walbro WHL #36, #44 carburetors used on Kohler engine models K90/K91, K141, K160/K161, K181 and M8. Steel lever with hardened shaft. Overall shaft length: 2-1/2". (The 1-7/8" length choke shaft, which was originally made by Carter, is no longer available. L) Steel lever with hardened shaft. Includes screws and split lock washers. No threadlocker required. NOTE: Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • OEM Walbro part # 40-917-1. $17.50 each, plus shipping & handling. Not available in aftermarket. L
Choke shaft w/short, remote solid wire cable-controlled lever for Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors with the round air cleaner/filter assembly. Steel lever with hardened shaft. Overall shaft length: 2-5/8". 1/4" diameter hardened shaft with steel lever. Includes screws and split lock washers. No threadlocker required. NOTE: The choke shaft for Carter/Kohler carburetors have been discontinued. This one is made by Walbro and designed for Walbro choke plates in a Walbro carburetor. If used in a Carter/Kohler carburetor, the holes in the Carter/Kohler choke plate may need to be made elongated or oblong to align with the threaded holes in this shaft. And apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • OEM Kohler part # 47 090 35-S. $28.85 each, plus shipping & handling. Not available in aftermarket. L
Choke shaft w/short, angled, hand-operated or remote solid wire cable-controlled lever for Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors with the round air cleaner/filter assembly. 1/4" diameter hardened shaft with steel lever. Overall shaft length: 2-5/8". Includes screws and split lock washers. No threadlocker required. NOTE: The choke shaft for Carter/Kohler carburetors have been discontinued. L This one is made by Walbro and designed for Walbro choke plates in a Walbro carburetor. If used in a Carter/Kohler carburetor, the holes in the Carter/Kohler choke plate may need to be made elongated or oblong to align with the threaded holes in this shaft. And apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • OEM Kohler # 47 090 34-S. $30.30 each, plus shipping & handling. Not available in aftermarket. L
Choke shaft w/long, straight, hand-operated or remote solid wire cable-controlled lever for Kohler #26, #30 and Walbro WHG #52, #60, #64 carburetors with the AQS (Quiet Line) oblong-shaped air cleaner/filter assembly. 1/4" diameter hardened shaft with steel lever. Overall shaft length: 2-5/8". Includes screws and split lock washers. No threadlocker required. NOTE: The choke shaft for Carter/Kohler carburetors have been discontinued. L This one is made by Walbro and designed for Walbro choke plates in a Walbro carburetor. If used in a Carter/Kohler carburetor, the holes in the Carter/Kohler choke plate may need to be made elongated or oblong to align with the threaded holes in this shaft. And apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off.
  • OEM Kohler part # 47 090 38-S. $30.30 each, plus shipping & handling. Not available in aftermarket. L
Choke Shaft w/"Downward Swing" Lever (most common) for various Kohler engine models KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20, MV20 with the Kohler #26 or Walbro WHG #52 carburetor. 1/4" diameter hardened shaft with steel lever. Overall shaft length: 2-5/8". For carburetors with following numbers stamped on mounting flange: 52 053 01, 52 053 09, 52 053 20, 52 053 26, 52 053 28, 52 053 31, 52 053 36, 52 053 37, 52 053 38, 52 053 46, 52 053 50, 52 053 52, 52 053 56, 52 053 58, 52 053 63, 52 053 63, 52 053 66. Comes with screws and split lock washers. No threadlocker required. NOTE: The choke shaft for the KT-series Kohler carburetors have been discontinued from Kohler. This one is made by Walbro and designed for Walbro choke plates in a Walbro carburetor. If used in a Kohler carburetor, the holes in the Kohler choke plate may need to be made elongated or oblong to align with the threaded holes in this shaft. And Apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off. Not available in aftermarket with the long lever. L
  • Used and in excellent condition. $20.00 each, plus shipping & handling. (When available.)
  • New. OEM Kohler part # 52 090 12-S. $28.65 each, plus shipping & handling.


Choke Shaft w/"Upward Swing" Lever for various Kohler engine models KT17, KT17 Series II, KT19, KT19 Series II, MV16, M18, MV18, M20, MV20 with the Kohler #26 or Walbro WHG #52 carburetor. 1/4" diameter hardened shaft with steel lever. Overall shaft length: 2-5/8". For carburetors with following numbers stamped on mounting flange: 52 053 18, 52 053 21, 52 053 27, 52 053 32, 52 053 34, 52 053 47, 52 053 51, 52 053 54, 52 053 55, 52 053 59. Comes with screws and split lock washers. No threadlocker required. NOTE: The choke shaft for the KT-series Kohler carburetors have been discontinued from Kohler. This one is made by Walbro and designed for Walbro choke plates in a Walbro carburetor. If used in a Kohler carburetor, the holes in the Kohler choke plate may need to be made elongated or oblong to align with the threaded holes in this shaft. And apply clean motor oil, gear oil or lubricating grease on shaft before installing for smooth choke operation and less wear to shaft and/or carburetor body. Click here to learn how to professionally remove Carter/Kohler throttle or choke plate soft brass retaining screws without breaking them off. Not available in aftermarket with the long lever. L
  • Used and in excellent condition. $20.00 each, plus shipping & handling. (When available.)
  • New. OEM Kohler part # 52 090 13-S. $28.65 each, plus shipping & handling.
Choke Plate for Kohler engine models K90/K91, K141, K160/K161 and K181/M8 with the Walbro WHL #36, #44 or Carter #16, #18, #20, #22 carburetors.
  • OEM Walbro part # 62-130-1. $30.40 each, plus shipping & handling.
  • Kohler part # 41 146 16-S. (Same as above È, made by Walbro.) $7.60 each, plus shipping & handling.
IMPORTANT: For the K241/M10, K301/M12, K321/M14, K341/M16 and K361 choke plates below Ê - If the wrong choke plate is used or mismatched with any particular size engine, due to the size and number of holes in the plate, the engine may become flooded too easily, resulting in either hard starting or a fouled spark plug. Or the engine may not receive enough fuel, resulting in hard starting. (None of these will happen with my remote fuel primer system kit.) Also, Walbro and Carter/Kohler choke plates are not interchangeable.
Choke plates for Kohler engine models K241/M10, K301/M12, KT17, KT17 Series II, KT19, KT19 Series II, or MV16, M18, MV18, M20 MV20 with the Carter/Kohler #26 carburetor. Plate with spring-loaded valve was originally designed and made by the Carter Carburetor Corporation. Discontinued from Kohler many years ago. L OEM Kohler part 235422.
  • Used OEM and in good condition. $3.00 each, plus shipping & handling. (When available.)
  • New high quality aftermarket. $5.00 each, plus shipping & handling.
Choke plate for Kohler engine models K321/M14 with the Carter/Kohler #30 carburetor. No Kohler part number available; discontinued from Kohler many years ago. L
  • Used OEM and in good condition. $3.00 each, plus shipping & handling. (When available.)
  • New high quality aftermarket. $5.00 each, plus shipping & handling.
Choke plate for Kohler engine models K341/M16 and K361 with the Carter/Kohler #30 carburetor. No Kohler part number available; discontinued from Kohler many years ago. L
  • Used OEM and in good condition. $3.00 each, plus shipping & handling. (When available.)
  • New high quality aftermarket. $5.00 each, plus shipping & handling.
Choke Plate for Kohler Magnum engine models M10 and M12 with the Walbro WHG #52 carburetor. 62-129 stamped on plate.
  • Kohler part # 47 146 08-S. (Made by Walbro; available only from Kohler.) $3.35 each, plus shipping & handling.
Choke Plate for Kohler engine models K321/M14 with the Walbro WHG #60, #64 carburetors. 62-128 stamped on plate.
  • OEM Walbro part # 62-128. $1.00 each, plus shipping & handling.
  • Kohler part # 47 146 09-S. (Same as above È, made by Walbro.) $3.10 each, plus shipping & handling.
Choke Plate for Kohler engine models K341/M16 with the Walbro WHG #60, #64 carburetors. 62-124 stamped on plate.
  • OEM Walbro part # 62-124-1. $3.30 each, plus shipping & handling.
  • Kohler part # 45 146 07-S. (Same as above È, made by Walbro.) $3.50 each, plus shipping & handling.
Choke Plate for Kohler Magnum engine models MV16, M18, MV18, M20 MV20, or KT17, KT17 series 2, KT19, KT19 Series II with the Walbro WHG #52 carburetor. 62-114 stamped on plate.
  • Kohler part # 25 146 03-S. (Made by Walbro; available only from Kohler.) $16.15 each, plus shipping & handling.
1/8" Diameter Choke Friction (Detent) Ball for all Carter/Kohler #16, #18, #20, #22, #26, #28, #30 and Walbro WHL #36, #44 carburetors. NOTE: The detent ball and spring is required for hand-operation of the choke to keep it in the open position on stand-alone engines, such as a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. If choke is operated by a sliding remote wire cable control, such as in a lawn tractor, then the ball and spring isn't needed and will serve no purpose.
  • OEM Walbro part # 89-13-8. .35¢ each, plus shipping & handling.
  • Kohler part # 25 194 02-S. (Same as above È, made by Walbro.) $1.82 each, plus shipping & handling.

5/32" Diameter Choke Friction (Detent) Ball for Walbro WHG #52, #60, #64 carburetors. NOTE: NOTE: The detent ball and spring is required for hand-operation of the choke to keep it in the open position on stand-alone engines, such as a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. If choke is operated by a sliding remote wire cable control, such as in a lawn tractor, then the ball and spring isn't needed and will serve no purpose.

  • OEM Walbro part # 89-29-8. .35¢ each, plus shipping & handling.
  • Kohler part # 25 194 01-S. (Same as above È, made by Walbro.) $8.02 each, plus shipping & handling.


1/8" Diameter x 5/16" length Choke Friction (Detent) Compression Spring for Walbro WHL #36, #44 carburetors. NOTE: NOTE: The detent ball and spring is required for hand-operation of the choke to keep it in the open position on stand-alone engines, such as a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. If choke is operated by a sliding remote wire cable control, such as in a lawn tractor, then the ball and spring isn't needed and will serve no purpose. Also, the 1/8" diameter x 1/2" length spring for the Carter and Kohler #16, #18, #20, #22, #26, #28, #30 carburetors have been discontinued from Kohler. L This 1/8" diameter x 5/16" length spring can be used in these carburetors with an 1/8" diameter x 3/16" length solid spacer placed under spring. (An 1/8" diameter x 3/16" length Allen set screw makes an excellent spacer.)

  • OEM Walbro part # 98-162-7. .60¢ each, plus shipping & handling.
  • Kohler part # 25 089 06-S. (Same as above È, made by Walbro.) $1.82 each, plus shipping & handling.


1/8" Diameter x 1/2" length Choke Friction (Detent) Compression Spring for Carter and Kohler #26, #28 and #30 carburetors. NOTE: The detent ball and spring is required for hand-operation of the choke to keep it in the open position on stand-alone engines, such as a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. If choke is operated by a sliding remote wire cable control, such as in a lawn tractor, then the ball and spring isn't needed and will serve no purpose.

  • Discontinued from Kohler many years ago. Used and in excellent condition. $1.00 each, plus shipping & handling. (When available.)


5/32" Diameter x 1/2" length Choke Friction (Detent) Compression Spring for Walbro WHG #52, #60, #64 carburetors. NOTE: NOTE: The detent ball and spring is required for hand-operation of the choke to keep it in the open position on stand-alone engines, such as a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. If choke is operated by a sliding remote wire cable control, such as in a lawn tractor, then the ball and spring isn't needed and will serve no purpose. Also, this spring can replace the 1/8" diameter x 1/2" length spring (discontinued from Kohler) for the Carter and Kohler #26, #28, #30 carburetors. It is to be used with the 5/32" ball. The detent hole in the carburetor will need to be drilled out to 5/32" to accommodate this bigger spring and ball. Be careful not to drill the hole deeper, just make it bigger in diameter.

  • OEM Walbro part # 98-198-7. .60¢ each, plus shipping & handling.
  • Kohler part # 25 089 03-S. (Same as above È, made by Walbro.) $8.02 each, plus shipping & handling.
Small Engine Remote Fuel Primer System Kits. Safe to use and works flawlessly! With the fuel bowl atmospheric vent opening plugged (air passageway from inside the float bowl area to outside of carburetor), then with one or two pushes of the primer bulb, air pressure within the carburetor float bowl forces fuel through the main jet and out the nozzle, creating a slight flooding condition inside the carburetor throttle bore allowing a cold engine to start quicker. With this setup installed, the choke plate and shaft can be removed. No more binding of remote solid wire choke cable and/or bent choke plate, or messy "hand choking" of carburetor. The fuel baffle splash shield is not needed with this setup. For ordinary lawn and garden tractors, garden pulling tractors or virtually any small engine lawn and garden or snow removal equipment with a choke plate on the carburetor. Works with pump gas, race gas, E-85 or alcohol fuels. Requires 1/4" mounting hole. Kit includes primer bulb assembly w/serrated mounting nut and integrated 1/8" barbed hose fitting, 1/8" i.d. x 3/16" o.d. x 3' length clear vinyl hose, loop-type clamp and 1/8" diameter x 1" length brass tube. Click here for installation instructions. An ingenious, thoroughly researched and innovative concept by Brian Miller, because nobody else advertise this kit for lawn and garden tractors or various small engines. NOTE: If an engine is hard to start, even with the choke plate fully closed and tuned correctly, then it may need a professional valve job performed and valve clearances reset. The reason some older engines is hard to start is because the valve faces, especially the intake valve, wears slightly away against the valve seat, and this causes the clearance between the valve stem and lifter to be lessened, which will prevent the valve(s) from fully closing to trap adequate compression in the combustion chamber [so the engine can start easier]. This remote fuel primer system will not fix this type of problem either. [Return to Previous Section]
  • Fuel Primer Bulb Assembly Only. Includes serrated mounting nut. $6.00 each, plus shipping.
  • High Quality Universal Complete Fuel Primer Kit. $15.00 each, plus shipping & handling.
  • XT Fuel Primer Kit. OEM Kohler part # 14 755 36-S. $13.75 each, plus shipping.
Vented Gas Caps for all IH-built Cub Cadet garden tractors with a metal fuel tank, except AQS (Quiet Line) models 800, 1000, 1200, 1250, 1450, 1650, and all spread frame models with a plastic fuel tank. Also fits larger Briggs & Stratton, Clinton, Tecumseh, Lauson, Wisconsin and other makes of engines with a 1-3/4" diameter (measured across raised threads) threaded filler neck on fuel tank.
  • Neoprene rubber O-ring for 1-3/4" gas caps. Provides a better seal which helps prevent leaks. Also helps seal against rim of a slightly damaged filler neck of gas tank to lessen chance of loss of gas when tank is full. Pry out and install under paper-like gasket material in gas cap better sealing. Small cross-sectional diameter, snug-fitting in gas cap. $1.00> each, plus shipping & handling.
  • 1-3/4" high quality aftermarket ordinary metal gas cap w/vent hole and paper-like sealing gasket material. $6.00 each, plus shipping & handling.
  • 1-3/4" ordinary metal gas cap w/vent hole and paper-like gasket sealing material. OEM Kohler part # 236655-S. $13.55 each, plus shipping & handling.
  • 1-3/4" ordinary metal gas cap w/vent hole and paper-like gasket sealing material. OEM Cub Cadet part # KH-236655. $17.89 each, plus shipping & handling.
  • 1-3/4" metal safety gas cap w/vent hole and paper-like gasket sealing material. OEM Cub Cadet part # KH-236655. $17.89 each, plus shipping & handling.
  • 1-3/4" metal safety gas cap w/vent hole and neoprene rubber sealing material. Also has baffle shield and foam rubber (reticulated polyurethane foam) to absorb and prevent fuel from spewing out of vent hole due to normal engine vibration. OEM Briggs & Stratton part #'s 69221, 297866, 297866S, 392305, 393156, 395005. $9.00 each, plus shipping & handling.

FYI - If a gas cap is missing the gasket/splash shield, this part can be made by cutting out a piece of poster board material (cereal box, etc.) so it'll fit snug inside the gas cap. Be sure to make a small pin hole (1/16") off-center in the gasket for the atmospheric vent. If fuel spews out of the vent hole in the gas cap with a full tank of gas due to normal engine vibration and to prevent a possible fire, place a small piece of foam rubber (reticulated polyurethane foam) between the gasket and vent hole in the cap. The foam will absorb the fuel and block it from being forced out the vent hole, and it'll allow incoming air to pass through it as the fuel is depleted in the tank.

Small Plastic In-Line Fuel Filter. 1/4" barbed fittings. 1-3/8" diameter x 1-3/4" length. 75 micron. For engines with gravity feed or fuel pump. Install before fuel pump to lessen wear to pump valves.
  • High quality aftermarket. Our part # 21-1022. $3.00 each, plus shipping & handling.
  • OEM Kohler part # 24 050 13-S. $8.25 each, plus shipping & handling.
Large Plastic In-Line Fuel Filter. 1/4" and 5/16" barbed fittings for 1/4" or 5/16" fuel hoses. 75 micron. For engines with gravity feed or fuel pump. Install before fuel pump to lessen wear to pump valves.
  • High quality aftermarket. Our part # 21-1008. $3.00 each, plus shipping & handling.
  • OEM Kohler part # 25 755 22-S. $37.30 each, plus shipping & handling.
Fuel Hose Clamps for 1/4" i.d. x 1/2" o.d. black neoprene rubber reinforced fuel hose. Necessary when using a fuel pump for safety.
  • Spring-Loaded Clamp. High quality aftermarket. .50¢ each, plus shipping & handling.
  • Spring-Loaded Clamp. OEM Kohler part # 25 237 37-S. $1.30 each, plus shipping & handling.
  • Stainless Steel Worm Gear Clamp. $1.00 each, plus shipping & handling.
Reinforced Black Neoprene Rubber Fuel Hose. Suitable for 100% gas, E85 or methanol fuels. Can withstand up to 15 psi of pressure. 1/4" i.d. x 1/2" o.d. size.
  • High quality aftermarket. .15¢ per inch, plus shipping & handling.
  • High quality aftermarket. $36.00 per 25 ft. roll (.12¢ per inch), plus shipping & handling.
  • OEM Kohler part # 25 111 81-S. (1/4" i.d. x 24" length.) $9.90 each, plus shipping & handling.
Straight Fuel Hose Fitting. 1/4" barbed fitting x 1/8" NPT male threads. Made of steel. Discontinued from Kohler. L Replaces Kohler part # X-495-1.
  • Used OEM Kohler fitting. $2.00 each, plus shipping & handling. (When available.)
  • New aftermarket fitting. $3.00 each, plus shipping & handling.
90º Fuel Hose Fitting. 1/4" barbed fitting x 1/8" NPT male threads. Made of steel. Kohler part # 25 155 02-S.
  • Used OEM Kohler steel fitting. $2.00 each, plus shipping & handling. (When available.)
  • New aftermarket fitting. $3.00 each, plus shipping & handling.
  • New OEM Kohler fitting. $8.10 each, plus shipping & handling.
Neoprene Rubber Compression Sleeve for Metal Fuel Line. Replace dry-rotted or deteriorated compression sleeve to prevent dangerous and hazardous fuel leak. 7/32" i.d. x .255" o.d. Other parts shown in drawing to the right have been discontinued from Kohler. Not available in aftermarket. L
  • OEM Kohler part # 220547-S. $4.92 each, plus shipping & handling.
Fuel Hose Conversion/Upgrade Kit

Do away with the old-fashioned sediment bowl/fuel filter and metal fuel line. This conversion/upgrade kit includes 1/4" i.d. x 12" length reinforced black fuel hose, small in-line fuel filter, one new straight 1/4" barbed fitting x 1/8" NPT male threads fitting (threads into fuel tank), one new 90º angled 1/4" barbed fitting x 1/8" NPT male threads fitting (threads into carburetor) and four spring-type fuel hose clamps. This kit is for Kohler engines with gravity feed and the fuel tank positioned higher than the carburetor. The fuel hose is routed in a U-shape under carburetor. Filter is to be installed just under fuel tank. An innovative concept by Brian Miller, because nobody else advertise this kit.

  • $12.00 per kit, plus shipping & handling.
Durable Plastic In-Line Fuel Shut-Off Valve. Alcohol resistant neoprene seal. Fits 1/4" i.d. fuel hose. No filter. Lever rotates 90º OFF/ON position. Use for a leaky carburetor or long term storage, and this part is required by certain pulling associations for safety. Our part # 24-1036.
  • $3.00 each, plus shipping & handling.
Heavy Duty All Metal In-Line Fuel Shut-Off Valve. Alcohol resistant neoprene seal. Fits 1/4" i.d. fuel hose. No filter. Lever rotates 90º OFF/ON position. Use for a leaky carburetor or long term storage, and this part is required by certain pulling associations for safety. Our part # 24-1166.
  • $16.00 each, plus shipping & handling.
Fuel Tank-Mounted 90º Angle Fuel Shut-Off Valve with fine mesh screen filter. Used with metal gas tanks on various Kohler engine models CH15, CH22, CH23, CH680, ECH730, K91, K141, K161, K181, K241, K301, K341, M8, M14 and M20. Threads into bottom of fuel tank. Has 1/8" NPT mounting threads and fits 1/4" i.d. fuel hose. Use for a leaky carburetor or long term storage, and this part is required by certain pulling associations for safety. Replaces: AMF 42879; Bolens 1703896, 1718029; Briggs & Stratton 396244, 399517, 698182; Gravely 18563; John Deere AM31850, PT8655; Kohler 220764-S; Lawn Boy 677052; Noma 42879; Scag 48056; Snapper 2-4507, 3-4212, 24507, 34212, 7024507, 7034212; Tecumseh 27689, 27803, 28571, 29683, 430137, 430209; Toro 304-71.
  • High quality aftermarket. Has alcohol resistant neoprene rubber O-ring seal. Our part # 24-1037. $6.50 each, plus shipping & handling.
  • OEM Kohler part # 220764-S. $27.77 each, plus shipping & handling.

Alcohol resistant neoprene rubber O-ring seal for shut-off valve above È. Replace dry-rotted O-ring or leather packing which can cause leaking fuel. Dimensions: 3/16" i.d. x 5/16" o.d.

  • .25¢ each, plus shipping & handling.
Neoprene Rubber Gas Tank Fuel Fitting Bushing (Grommet) for Cub Cadet AQS (Quiet Line) models and Kohler Magnum engines. Replace dry-rotted, hardened and leaking bushing/grommet. Use oil or grease for easy installation into 33/64" hole on bottom of plastic fuel tank. Fuel fittings and fuel shut-off valves below Ê that plugs into this part. In addition to the fitting below Ê, for competition pulling only, this part can also be used as a fuel return system in fuel tank when burning methanol or diesel fuels. Replaces: AMF 42690; Ariens 07509300, 07511400; Bolens 1738433; Briggs Power Products 78299GS, 80269GS; Exmark 1-513645; Ferris 22151; Kohler 25 313 01-S; Lawn-Boy 104047, 708331, 46-6560; MTD 735-0149, 1738433, 935-0149, 1903198, 1902479, GW-1738433, GW-B1738433, 581615; Murray 42690; Noma 44847; Scag 48309; Simplicity 1654930; Snapper 12337, 74158, 7012337, 7074158; Tecumseh 33679; Toro 46-6560, 1-513645, E513645; Wheel Horse/Toro 104047; 104047P.
  • High quality aftermarket. Our part # 71-1028. $1.50 each, plus shipping & handling.
  • OEM Kohler part # 25 313 01-S. $1.80 each, plus shipping & handling.
L-Shaped Fuel Tank Plug-In Fitting w/o filter screen or shut-off valve for Cub Cadet "Quiet Line" models and Kohler Magnum engines. 1/2" fitting fastens in neoprene rubber bushing (above È) in bottom of plastic fuel tank. Use oil or grease for easy installation. 1/4" fuel hose fitting. require in-line fuel filter. For competition pulling only, in addition to the grommet above È, this part can also be used as a fuel return system in fuel tank when burning methanol or diesel fuels. Replaces Cub Cadet part # IH-109042-C2 (except w/o shut-off valve).
  • Our part # 751-3054. $3.50 each, plus shipping & handling.
L-Shaped Fuel Tank Plug-In Shut-Off Valve w/o filter screen for Cub Cadet AQS (Quiet Line) models and Kohler Magnum engines. Use for a leaky carburetor or long term storage, and this part is required by certain pulling associations for safety. 1/2" fitting fastens in neoprene rubber bushing (above È) in bottom of plastic fuel tank. Use oil or grease for easy installation. 1/4" fuel hose fitting. require in-line fuel filter. Replaces Cub Cadet part # IH-109042-C2 and Kohler part # 25 462 01-S (except w/o filter screen).
  • Our part # 120-253. $8.00 each, plus shipping & handling.

Alcohol resistant neoprene rubber O-ring seal for shut-off valve above È. Replace dry-rotted O-ring which cause leaking fuel. Dimensions: 3/16" i.d. x 5/16" o.d.

  • .25¢ each, plus shipping & handling.
L-Shaped Fuel Tank Plug-In Shut-Off Valve w/filter screen for Kohler Magnum Engines and Cub Cadet AQS (Quiet Line) models and Kohler Magnum engines. Use for a leaky carburetor or long term storage, and this part is required by certain pulling associations for safety. 1/2" fitting fastens in neoprene rubber bushing (above È) in bottom of plastic fuel tank. Use oil or grease for easy installation. 1/4" fuel hose fitting. In-line fuel filter not required. Replaces Cub Cadet part # IH-109042-C2 (except w/filter screen).
  • High quality aftermarket. Our part # 24-1132. $6.00 each, plus shipping & handling.
  • Kohler part # 25 462 01-S. $20.15 each, plus shipping & handling.

Alcohol-resistant neoprene rubber O-ring seal for shut-off valve above È. Replace dry-rotted O-ring which cause leaking fuel. Dimensions: 3/16" i.d. x 5/16" o.d.

  • .25¢ each, plus shipping & handling.
1/8" NPT x 1/8" NPT x 3/4" length [close] steel pipe connector. Use to fasten fuel shut-off /filter/sediment bowl assembly (listed below Ê) to fuel tank.
  • High quality aftermarket. $1.20 each, plus shipping & handling.
  • OEM Kohler part # 25 136 23-S. $1.30 each, plus shipping & handling.
Fuel Shut-Off/Filter/Sediment Bowl Assembly. Replacement for many older lawn and garden engines. Filters fuel and separates water from gas. Threads into bottom of fuel tank. Use for a leaky carburetor or long term storage, and this part is required by certain pulling associations for safety. Dimensions: Overall height: 3"; Maximum width (not including shut-off valve): 1-3/4"; Thread fittings: inlet (top) and outlet (side) are both 1/8" NPT. Complete assembly no longer available from Kohler. Use fuel hose conversion/upgrade kit (above È) instead if you wish. Fits Cub Cadet models 70, 71, 72, 73, 100, 102, 104, 105, 106, 107, 122, 123, 124, 125, 126, 127 and 147. Replaces: Kohler A-210101 (discontinued L); Briggs & Stratton 293964, 295913, 295977, 296005, 393169, 690612; Clinton 293-32-500, 293-32-5; Gravely 010313; John Deere PT4337; Tecumseh 24449, 24459, 32164, 32439, 32984, 32984A, 34279, 34279A, 34279B; Wisconsin LP43.
  • High quality aftermarket. Our part # 21-1009. $11.50 each, plus shipping & handling.
O-ring seal for shut-off valve shaft in fuel shut-off/filter/sediment bowl assembly above È. Replace dry-rotted O-ring or leather packing which can cause leaking fuel. Made of alcohol resistant neoprene rubber. Dimensions: 1/16" x 1/8" x 1/4".
  • High quality aftermarket. .25¢ each, plus shipping & handling.
Fuel Shut-Off Valve for Filter/Sediment Bowl Assembly above È. Includes alcohol resistant neoprene rubber O-ring seal.
  • OEM Kohler part # A-210480-S. $14.00 each, plus shipping & handling.
Gasket (Seal) for fuel shut-off/filter/sediment bowl assembly above È. Made of alcohol resistant neoprene rubber. Dimensions: 1-1/2" o.d. x 1-1/4" i.d. x .060" thickness.
  • High quality aftermarket. Our part # 14-1097. $1.00 each, plus shipping & handling.
  • OEM Kohler part # 210468-S. $3.40 each, plus shipping & handling.
Fine Mesh Brass Screen Filter/Strainer for Fuel Sediment Bowl Assembly above È. 1-1/4" o.d.
  • OEM Kohler part # 210479-S. $4.00 each, plus shipping & handling. Not available in aftermarket or from any other source. L
Replacement glass bowl for fuel shut-off/filter/sediment bowl assembly above È. Dimensions: 1-1/2" maximum width x 1-1/8" height. Replaces: Briggs & Stratton # 298683; John Deere # PT4271.
  • High quality aftermarket. $3.50 each, plus shipping & handling.
  • OEM Kohler part # 210467-S. $9.55 each, plus shipping & handling.

Wingnuts, Pleated Air Filters and Reticulated Foam Wraps/Prefilters -
If you need any of the parts or services listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Please click here to place an order.
Air Cleaner/Filter Assembly and Velocity Stack Mounting Screws - TIP: When installing a screw to keep it from falling out of the screwdriver, either apply a dab of grease in the head of the screw or temporarily magnetize the screwdriver by rubbing a magnet along the length of the shank.

8-32 UNC (coarse thread) x 3/8" thread length Phillips Head Screws. Use to fasten air cleaner/filter assembly base to Carter #16, #18, #20, #22 and Walbro WHL #44 carburetors.

  • High quality aftermarket. Hardened zinc-plated steel. .50¢ each, plus shipping & handling.
  • OEM Kohler part # 25 086 99-S. $1.75 each, plus shipping & handling.

10-32 UNF (fine thread) x 3/8" thread length Phillips Head Screws. Use to fasten air cleaner/filter assembly base to Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors.

  • High quality aftermarket. Hardened zinc-plated steel. .50¢ each, plus shipping & handling.
  • OEM Kohler part # X-167-2-S. $1.75 each, plus shipping & handling.

10-32 UNF (fine thread) x 1/2" thread length Stainless Steel Hex Socket (Allen) Head Screws. Use to fasten velocity stack to Carter/Kohler #26, #28, #30 or Walbro WHG #52, #60, #64 carburetors. (For competition pulling only.)

  • $8.00 per pair, plus shipping & handling.

8-32 UNF (fine thread) size. For rethreading or cutting new threads in choke flange of Carter #16, #18, #20, #22 or Walbro WHL #36, #44 carburetors for mounting of air cleaner base. $8.00 each, plus shipping & handling.

10-32 UNF (fine thread) size. For rethreading or cutting new threads in choke flange of Carter/Kohler #26, #28, #30 and Walbro WHG #52, #60, #64 carburetors for mounting of air cleaner base or velocity stack. $8.00 each, plus shipping & handling.

Many other small screw sizes and taps available at reasonable prices.

Wingnuts. Each wingnut below recommended for side-mounted air cleaner covers or battery hold-down studs. Do not use on top-mounted air cleaner covers due to rain water may seep into intake. 1/4-20 UNC (coarse thread) threads.
  • Heavy Gauge Plain Stamped Steel Wingnut. .25¢ each, plus shipping & handling.
  • Bright Cadmium-Plated Aluminum Wingnut with Self-Locking Nylon Insert. $1.00 each, plus shipping & handling.


Heavy Gauge Stamped Steel Wingnuts with Rubber Seal. Recommended for top-mounted air cleaner covers to prevent rain water from seeping into intake. Also, rubber seal prevents wingnut from loosening. 1/4-20 UNC (coarse thread) threads.
  • High quality aftermarket. $2.00 each, plus shipping & handling.
  • OEM Kohler part # 25 100 15-S. $3.16 each, plus shipping & handling.
Pleated Air Filter Elements and Reticulated Foam Wraps/Prefilters for certain Kohler K-series engine models K91, K141, K161 and K181. Non-restricting flame retardant filter. Performance engineered for increased breathing. Air filter: Kohler 230840-S; Cub Cadet 385163R2; Clinton 002-0233-00; Gravely 20299; John Deere AM31034; Massey 1035-991-M1; Tecumseh 30804. Foam Wrap/Prefilter: Kohler 234870-S; John Deere AM31034; Massey Ferguson 1035-991. Air filter element dimensions (±): 4-3/8" o.d. x 3" i.d. x 1-1/2" overall height.
  • High quality aftermarket air filter. $4.00 each, plus shipping & handling.
    • High quality aftermarket foam wrap/prefilter. $3.00 each, plus shipping & handling.
  • OEM Kohler air filter. $18.50 each, plus shipping & handling.
    • OEM Kohler foam wrap/prefilter. $6.20 each, plus shipping & handling.

NOTE: To clean the foam wrap/prefilter, use cleaning solvent (paint thinner) and 150± psi compressed air, allow to thoroughly dry, but do not add oil in an attempt to trap the dust and dirt. Oil is not recommended because some of the oil could get drawn into the paper element while the engine is running, partially clogging it.

Pleated Air Filters and Reticulated Foam Wraps/Prefilters for certain Kohler K-series engine model K181. Non-restricting flame retardant filter. Performance engineered for increased breathing. Air filter: Kohler 231847-S; Cub Cadet 548436R1; Gravely 15373; John Deere AM30800; Tecumseh 31925; Onan 140-1188, 140-188; Rol Air 431. Foam Wrap/Prefilter: Kohler 234869-S (K-series), 41 083 04-S (Magnum). Air filter element dimensions (±): 4-3/8" o.d. x 3" i.d. x 2-5/16" overall height.
  • High quality aftermarket air filter. $5.00 each, plus shipping & handling.
    • High quality aftermarket foam wrap/prefilter. $3.00 each, plus shipping & handling.
  • OEM Kohler air filter. $11.10 each, plus shipping & handling.
    • OEM Kohler foam wrap/prefilter. $6.20 each, plus shipping & handling.

NOTE: To clean the foam wrap/prefilter, use cleaning solvent (paint thinner) and 150± psi compressed air, allow to thoroughly dry, but do not add oil in an attempt to trap the dust and dirt. Oil is not recommended because some of the oil could get drawn into the paper element while the engine is running, partially clogging it.

Pleated Air Filter Elements and Reticulated Foam Wraps/Prefilters for various Kohler engine models K141, K161, K181/M8, K241/M10, K301/M12 and K321/M14 with the short round air cleaner/filter assembly. Non-restricting flame retardant filter. Performance engineered for increased breathing. Air filter: Kohler 235116-S, 25 883 03-S1 (kit); Cub Cadet 385168R2. Foam Wrap/Prefilter: Kohler 237421-S (K-series), 45 083 01-S (Magnum). Air filter element dimensions (±): 6" o.d. x 4-11/16" i.d. x 1-7/8" overall height.
  • High quality aftermarket air filter. $6.00 each, plus shipping & handling.
    • High quality aftermarket foam wrap/prefilter. $3.00 each, plus shipping & handling.
  • OEM Kohler air filter w/prefilter kit. $11.60 each plus shipping & handling.
    • OEM Kohler air filter. $9.75 each, plus shipping & handling.
      • OEM Kohler foam wrap/prefilter. $3.75 each, plus shipping & handling.

NOTE: To clean the foam wrap/prefilter, use cleaning solvent (paint thinner) and 150± psi compressed air, allow to thoroughly dry, but do not add oil in an attempt to trap the dust and dirt. Oil is not recommended because some of the oil could get drawn into the paper element while the engine is running, partially clogging it.

Pleated Air Filter Elements and Reticulated Foam Wraps/Prefilters for certain Kohler and Magnum engine models K241, K301, K321, K341, CH11-15, KT17, KT19, and M18-20 engines with the oblong-shaped air cleaner/filter assembly. Fits Kohler AQS (Quiet Line) series engines in Cub Cadet models 680, 1000, 1050, 1200, 1204, 1211, 1250, 1282, 1450 and 1650. Non-restricting flame retardant filter. Performance engineered for increased breathing. Air filter: Kohler 47 083 01-S, 47 883 01-S1 (kit); Cub Cadet 117210-C1, 759-3547, 959-3547; Gravely 032494, John Deere M83646, Lesco 012596. Foam Wrap/Prefilter: Kohler 52 083 01-S. Air filter element dimensions (±): 7" o.d. x 5-1/2" i.d. x 1-3/4" overall height.
  • High quality aftermarket air filter. $6.00 each, plus shipping & handling.
    • High quality aftermarket foam wrap/prefilter. $3.00 each, plus shipping & handling.
  • OEM Kohler air filter w/prefilter kit. $11.60 each, plus shipping & handling.
    • OEM Kohler air filter. $9.50 each, plus shipping & handling.
      • OEM Kohler foam wrap/prefilter. $3.75 each, plus shipping & handling.

NOTE: To clean the foam wrap/prefilter, use cleaning solvent (paint thinner) and 150± psi compressed air, allow to thoroughly dry, but do not add oil in an attempt to trap the dust and dirt. Oil is not recommended because some of the oil could get drawn into the paper element while the engine is running, partially clogging it.

Pleated Air Filter Elements and Reticulated Foam Wraps/Prefilters for Kohler engine models K341, CH18-25, CV18-22, KT17 Series II, KT19 Series II and M18-20 engines with the oblong-shaped air cleaner/filter assembly. Fits Kohler AQS (Quiet Line) series engines. Non-restricting flame retardant filter. Performance engineered for increased breathing. Air filter: Kohler 47 083 03-S, 47 883 03-S1 (kit); John Deere M47494 (fits JD models 200, 210, 212, 214, 216, 300, 312, 314, 316, 400); Woods 71803. Foam Wrap/Prefilter: Kohler 41 083 04-S. Air filter element dimensions (±): 7" o.d. x 5-1/2" i.d. x 2-7/16" overall height.
  • High quality aftermarket air filter. $6.00 each, plus shipping & handling.
    • High quality aftermarket foam wrap/prefilter. $3.00 each, plus shipping & handling.
  • OEM Kohler air filter w/prefilter kit. $11.45 each, plus shipping & handling.
    • OEM Kohler air filter. $9.30 each, plus shipping & handling.
      • OEM Kohler foam wrap/prefilter. $3.75 each, plus shipping & handling.

NOTE: To clean the foam wrap/prefilter, use cleaning solvent (paint thinner) and 150± psi compressed air, allow to thoroughly dry, but do not add oil in an attempt to trap the dust and dirt. Oil is not recommended because some of the oil could get drawn into the paper element while the engine is running, partially clogging it.

Neoprene Rubber Seal for Air Cleaner Cover to Base. Reduces air intake noise. For following Kohler AQS (Quiet Line) engine models K181, K241/M10, K301/M12, K321/M14, K341/M16, K532 and K582. 28-1/4" length x 1/2" wide. NOTE: A 3/16" i.d. automotive vacuum hose or fuel hose can be split open lengthways and be used instead. OEM Kohler part # 47 032 03-S.
  • Used and in excellent condition. $3.50 each, plus shipping & handling. (When available.)
  • New. $7.30 each, plus shipping & handling.
Neoprene Rubber Tube for Air Cleaner Base to Flywheel Housing. Reduces air intake noise. For following Kohler AQS (Quiet Line) engine models K241/M10, K301/M12, K321/M14, K341/M16, KT17, M18, M20, K532 and K582. OEM Kohler part # 47 134 02-S.
  • Used and in excellent condition. $14.00 each, plus shipping & handling. (When available.)
  • New. $27.40 each, plus shipping & handling.
Pleated Air Filter Elements and Reticulated Foam Wraps/Prefilters for certain Kohler engine models M8, K321/M14, K341/M16, MV16, M18, MV18, M20 and MV20 with the tall round air cleaner/filter assembly. Can also be used on a garden pulling tractor, mini rods, hot rods, race cars, etc. with an automotive engine. Non-restricting flame retardant filter. Performance engineered for increased breathing. Air filter: Kohler 45 083 02-S, 45 883 02-S1 (kit); Cub Cadet 759-3359. Foam Wrap/Prefilter: Kohler 45 083 01-S. Air filter element dimensions (±): 6" o.d. x 4-11/16" i.d. x 3" overall height.
  • High quality aftermarket air filter. $6.00 each, plus shipping & handling.
    • High quality aftermarket foam wrap/prefilter. $3.00 each, plus shipping & handling.
  • OEM Kohler air filter w/prefilter kit. $11.90 each, plus shipping & handling.
    • OEM Kohler air filter. $10.00 each, plus shipping & handling.
      • OEM Kohler foam wrap/prefilter. $3.75 each, plus shipping & handling.

NOTE: To clean the foam wrap/prefilter, use cleaning solvent (paint thinner) and 150± psi compressed air, allow to thoroughly dry, but do not add oil in an attempt to trap the dust and dirt. Oil is not recommended because some of the oil could get drawn into the paper element while the engine is running, partially clogging it.

Pleated Air Filter Elements and Reticulated Foam Wraps/Prefilters for certain Kohler engine models K241, K301, K341, K482, K532 and K582 with the tall round air cleaner/filter assembly. Can also be used on mini rods, hot rods, race cars, etc. with an automotive engine. Non-restricting flame retardant filter. Performance engineered for increased breathing. Air filter: Kohler 277138-S. Foam Wrap/Prefilter: Kohler 277593-S. Air filter element dimensions (±): 6" o.d. x 4-3/4" i.d. x 4" overall height.
  • High quality aftermarket air filter. $5.50 each, plus shipping & handling.
    • High quality aftermarket foam wrap/prefilter. $3.00 each, plus shipping & handling.
  • OEM Kohler air filter. $18.60 each, plus shipping & handling.
    • OEM Kohler foam wrap/prefilter. $14.50 each, plus shipping & handling.

NOTE: To clean the foam wrap/prefilter, use cleaning solvent (paint thinner) and 150± psi compressed air, allow to thoroughly dry, but do not add oil in an attempt to trap the dust and dirt. Oil is not recommended because some of the oil could get drawn into the paper element while the engine is running, partially clogging it.

NOTE: Air filters and foam wraps/prefilters are available for many other makes and models of engines. If you need something that's not listed here, please contact me with your engine model and specification numbers and I'll see if I can get it for you at a reasonable price.


How To Convert a Carter/Kohler Carburetor For High Performance Use At Any Engine RPM -

By boring out the venturi (the smallest part of a throttle bore) and reworking the Carter/Kohler carburetor, this will "open up the carburetor" and allow the engine to draw more air into the combustion chamber so it can build up more compression, which will allow it to produce more power. (It'll be like going from a small 2-barrel carburetor to a large 4-barrel carburetor on a V8 automotive engine.) Although the below Ê method is considered "Old School" by today's standards, it has been proven to help the engine produce more horsepower and torque on the dynamometer (dyno), and allow the tractor to pull much stronger on the track, and it equals the performance of the popular and high dollar recast (Kohler) carburetors.

  1. Completely disassemble carburetor, including removal of the throttle shaft/plate and main jet/nozzle (emulsion tube), except for removal of the choke shaft/plate if it's required in the rules to be intact, and clean the carburetor body and metal parts with an ultrasonic cleaning machine, Berryman® Chem-Dip® Carburetor and Parts Cleaner or Purple Power Cleaner Degreaser to dissolve or loosen any dried gas deposits, crud and debris.
  2. Resurface the choke flange on a wide, flat belt- or disc-sander to remove any gasket material and ensure proper alignment when boring the throttle bore, and resurface the mounting flange to remove warpage and restore flatness, and to prevent a vacuum leak. (I use the side of the cutting wheel on my 14" electric chop saw with a metal cut-off wheel. Works great! Be sure to use eye protection!)
  3. Clamp the carburetor body securely on the table of a milling machine and center the throttle bore with the spindle with use of a centering indicator. Clamp down the table. If intact, be sure the choke plate is in the closed position!
  4. Use a reamer or large drill bit of a specific diameter to bore the venturi. Enlarge the venturi to either a limit of .995" or 1", make it a straight-through design (to match the diameter of the throttle bore) or enlarge it to whatever your club's sanctioning rules allow. Turn the cutting tool at a slow speed, and apply a continuous spray of WD-40 while boring the venturi to create a smooth, slick surface in the throttle bore.
  5. Soak the carburetor body and all related parts (except rubber-like parts) in carburetor cleaner overnight. Then clean the carburetor with solvent (paint thinner) and use [150± psi] compressed air to thoroughly clear out all fuel and air passageways.
  6. Grind an angle on the end of the main jet/nozzle (emulsion tube). To do this correctly so the engine will accelerate with no hesitation whatsoever...
  7. Reinstall the main jet/nozzle in the carburetor body and tighten it down.
  8. Use a permanent ink felt-tip marker (Sharpie, Magic Marker) or a center punch to locate where to grind the angle on the end of the main jet/nozzle:
    • For a K241-K341 Kohler engine with a stock size intake valve, go through the throttle plate end of the carburetor and place a mark on the center of the exposed end of the nozzle.
    • For a K241-K341 Kohler engine with an oversize intake valve (larger than stock), go through the choke end of the carburetor and place a mark on the center of the exposed end of the nozzle.
  9. The mark will be reference where to grind the angle when the main jet/nozzle is removed from the carburetor. See animated photo below Ê.
  10. Remove the main jet/nozzle (emulsion tube), then carefully and gently grind a 60º angle where the mark (Sharpie, Magic Marker or center punch) is made. Use a bench grinder, belt- or disc-sander, or the side of an electric chop saw with a metal cut-off wheel to better see the angle. NOTE: When grinding the 60º angle, carefully grind away 3/4 of the tip, but leave 1/4 of the end of the tip flat. Be careful not to shorten the nozzle when grinding the angle, and make sure the angle is centered with the mark. If the tip is ground too short or not centered with the mark (throttle bore), the engine may hesitate or need to be "hand choked" upon acceleration. See drawing to the upper right. ä
  11. After grinding the angle, use a deburring tool or drill bit (that fits the hole) to remove the burr from the nozzle. The end of the nozzle must be fully open. Then use [150± psi] compressed air to clear out any metal fragments from inside the nozzle.
  12. Reinstall the nozzle in the carburetor and check that the angle is in perfect center alignment with the throttle bore.
  13. Due to normal engine vibration at high RPM, plug the original atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor) and then drill a 3/32" hole on the side of the carburetor body in alignment with the atmospheric vent opening (air passageway from inside the float bowl area to outside of carburetor) in case of gas overflow and/or so the engine won't possibly run erratically rich on fuel. Or for safety and convenience, leave out the choke shaft and plate, plug the choke shaft holes, and install my remote fuel primer system kit as described further down in this website.
  14. With a bored-out venturi, the engine will obviously draw more air and require more fuel. To prevent the engine from starving for fuel at high RPM, offset the level of the float upward. To adjust it correctly, with the carburetor body turned upside-down, set the float so it will be downward. This will permit the float to drop down more as fuel level decreases, allowing the float valve to open further so more fuel will enter the float bowl. See the drawing to the right. à
  15. Idle Fuel Passageway: For 4,000± RPM operation, enlarge the lower hole in the high speed air/fuel mixture needle with .a .039" / #60 / 1mm diameter drill bit clamped in a mini micro pin vise hand drill chuck. This is the perfect size to enlarge lower the hole on high speed needle adjusters so the engine will start quicker and idle smoother. Be careful when handling any tiny drill bit because they can break easily. Anyway, make sure the idle fuel passageways are clear of debris, too. Leave the expansion/welch plug intact, or if necessary, remove it only to clear out any debris from the factory-drilled idle holes next to the throttle plate. If performed correctly, the carburetor should idle just fine and accelerate with no hesitation whatsoever as described in this section. If the engine is going to run at high RPM or wide open throttle, it is recommended that the carburetor be converted for use with the bottom high speed air/fuel adjuster as described further down in this website.
  16. On the throttle shaft, grind the area opposite the throttle plate until the shaft is about 1/16" thickness so more air can pass around the shaft at high RPM, but leave the screw holes "lumped up" to prevent stripping the threads and to maintain strength in the shaft. See photo to the right. à
  17. Reassemble the carburetor using a new overhaul/rebuild kit and install a bronze throttle shaft bushing if it needs one, set the idle air/fuel mixture screw at 1-1/2 turns from lightly bottoming out, and set the high speed needle adjuster at 6 turns from lightly bottoming out against the main jet hole, and that's it! Make final air/fuel adjustments until the engine idles smooth and revs smoothly. If done correctly, this carburetor modification will perform with any "high performance" carburetor on the market. FYI - Bearing bronze is very hard, porous, absorbs oil and lasts a long time when lubricated regularly and used as a bushing. Brass, on the other hand, is soft, non-porous and wears quickly when used as a load-bearing bushing.


How to Easily Convert the Carter/Kohler #26, #28 or #30 Carburetors to the Bottom High Speed Air/Fuel Adjuster - An ingenious and innovative concept by Brian Miller, because nobody else advertise this type of foolproof conversion. Top of page

This conversion has been proven many times to function flawlessly for a high RPM or wide open throttle competition pulling engine. The bottom high speed air/fuel adjuster is not an OEM Kohler part and not a modification by Kohler. It provides no high-performance enhancements or "added horsepower" to the engine whatsoever. This part is an absolute must for a competition pulling engine that runs at very high RPM or wide open throttle. It provides no high-performance engine enhancements whatsoever. It's an add-on feature that replaces the OEM float bowl retaining bolt only to prevent wearing or enlarging the fuel suction hole (orifice) in the main jet by the OEM high speed needle adjuster due to normal engine vibration at very high RPM or wide open throttle engine operations. (Whoever says that the use of this part will increase the performance of an engine obviously do not know what they are talking about, or they are in the business of selling new main jet/nozzles, which can be very difficult to remove.) Rather the main jet/nozzle can be easily removed with a screwdriver or drilled into and chiseled out. (If not done carefully, damage to the carburetor could result, rendering it useless.) Also, with a bored-out venturi, a 60º angle would need to be precisely ground on the end of the nozzle in exact alignment with the centerline of the throttle bore so engine vacuum will draw fuel through the main jet/nozzle immediately upon acceleration.

Due to normal engine vibration at high RPM or wide open throttle operation, the pointed tip on the OEM top high speed air/fuel needle adjuster will "severely vibrate around" inside the lower hole (orifice) in the main jet/nozzle. The tip of the flexible brass needle adjuster will wear the main jet hole (orifice) larger, eventually causing the engine to run rich on fuel, and over time as the hole (orifice) wears even larger, will make further lean adjustments impossible. This will happen with gas or alcohol fuels. There is no way to prevent this from happening except convert the carburetor to the bottom high speed air/fuel adjuster. And when the carburetor is reworked with the venturi bored-out (straight-through throttle bore design) for high performance use, it equals the performance of the popular "Super Carb" carburetor. (Which I think is a very fine performance carburetor.) Also, if you're wondering if the presence of the OEM high speed adjuster tube will slow the incoming airflow through the "straight through" throttle bore, well, the throttle plate and shaft are about 30% wider than the high speed adjuster tube, even with the throttle shaft ground or machined thin to increase the air flow.

How to Convert a Carburetor to the Bottom High Speed Air/Fuel Adjuster:

  1. Break off the tip on the top OEM high speed needle adjuster at the lower idle fuel feed hole (orifice) with pliers. Make sure inside the tube is open and not clogged with dried gas or debris to allow fuel to still be drawn through the tube so the engine will idle). And bevel the end of the tube so fuel can flow past it smoothly at high RPM. Preferably use an OEM adjuster with a damaged tip for this conversion. There's no need to ruin a good adjuster for this.
  2. Remove the OEM compression pressure spring from the high speed adjuster and install a spacer or stack of flat washers measuring approximately 9/32" in height in place of the spring. The 9/32" height positions the end of the high speed adjuster tube about midway in the float bowl and about 3/16" above the main jet hole (orifice) so fuel will be drawn through the tube so the engine will idle.
  3. Reinstall the top OEM high speed needle adjuster in the carburetor body with the spacer or washers and tighten it in place, making it fixed in place and non-adjustable.
  4. Reinstall the float, bowl, etc., and install the bottom high speed air/fuel adjuster (instead of the OEM float bowl retaining bolt), and tighten the adjuster. IMPORTANT - Before tightening the bottom adjuster, back off the needle (in the adjuster) to keep it from jamming into the main jet hole, possibly causing damage or stripping the threads in the carburetor body!
  5. Install the carburetor on the engine, linkages and fuel hose on the carburetor, start the engine, and adjust the idle air/fuel mixture screw and the high speed air/fuel mixture bottom adjuster until the engine runs smooth at idle and at high RPM or wide open throttle. NOTE: Absolutely nothing needs to be done to the idle fuel passageways or the idle fuel mixture adjusting screw. Just leave them alone. The engine should idle fine after the conversion. And there's no need to install a small brass tube next to the float for the idle fuel passageway. The tube could interfere with the operation of the float.


Information About the Carburetor Extension, Intake Tube, Manifold, Spacer, Stand-Off (or whatever it may be called) and Fuel Atomization - (Updated 3/20/17)

Spacing the carburetor away from the engine block allows the fuel to atomize better (break down into a fine mist) so the engine will produce more power and torque at higher RPM. The further the carburetor is spaced, the better the fuel will atomize.

When choosing the length of an intake tube, it seems that a 3" length works best for gas, and 5" length works best for E85 or methanol. Because gas runs more lean than E85 or methanol, it require less space or distance to fully atomize, and being E85 and methanol fuels run richer, they need more space or distance to fully atomize before they enter the combustion chamber.

For competition pulling, if no [long] intake tube is to be used with the carburetor, a heat isolator gasket will work great. (Manufactured of heat-resistant phenolic resin.) The heat isolator gasket isolates the carburetor from engine heat so the fuel will atomize better (break down into smaller particles) before it enters the combustion chamber, which will help the engine produce more power and torque.

In addition, "roughing up" the inside of the carburetor extension will help create turbulence to "break up" and atomize the fuel better and should help a Kohler engine produce a few more ponies. This works for automotive engines, and it should work for Kohler engines, too.

Also for competition pulling, with a carburetor extension in use, mounting gaskets are not necessary. Just resurface the ends of the extension (if needed) and carburetor mounting flange on a wide, flat belt- or disc-sander to remove warpage and restore flatness (use eye protection!), and then apply a thin bead of Clear RTV Silicone Adhesive Sealant with no gasket. When the bolts or nuts (on studs) are tightened, the softness of a gasket could cause the carburetor flange to warp and possibly break. With no gasket, there will be metal to metal contact with the silicone filling in the open gaps between the two metals, and there is NO WAY the flange can warp or possibly break! By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for three reasons: Gaskets don't always seal the irregularities between mating metals, especially thin metal covers; being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean and professional-looking repair job. When applied sparingly, it can't be easily seen or noticed between the parts. Return To Previous Paragraph


Use a Bigger Air Filter on a Pulling Engine -

If an engine has a carburetor with a bored-out venturi, bigger ports, bigger valves, a big cam and it runs at wide open throttle, then it will definitely benefit from use of a bigger air filter. All of these things will undoubtedly allow an engine to draw in a lot more air at high RPM. If rules require that the engine must have an air filter, stack two air filters on top of each other (install a longer mounting stud, too), or use an OEM K341/K361 or opposed (flathead) twin cylinder air cleaner/filter assembly (they're twice as tall than the K241, K301 and K321 air filter) or install a velocity stack and use an aftermarket K&N air filter. The bigger air filter is so free-flowing and less restrictive, using an air filter this size would the same as not using an air filter all. The shorter K241, K301 and K321 air cleaner/filter assembly is too restrictive for wide open throttle operation. But if it's a basically stock engine with a stock carburetor, stock size ports and valves, and a stock cam, there'll be very little gained with a bigger air filter. If you pull on a lot of dusty tracks, then it would be worth investing in an air filter to save wear on the engine.


How to repair stripped air cleaner base mounting screw holes in a Carter, Kohler #26, #28, #30 or Walbro WHG #52, #60, #64 carburetor. - An ingenious and innovative concept by Brian Miller, because nobody else advertise these repair procedures. (Updated 5/5/17)

Method #1: On a Kohler #26 or #30 carburetor with five air cleaner base mounting screw holes (AQS [Quiet Line] models), if the two lower holes (located at the 4:00 and 8:00 positions) are stripped out but not overly enlarged, drill all the way through these two holes, and if the threads in the upper hole (12:00 position) is also stripped, drill about 3/4" deeper in this hole, then cut new 10-32 UNF (fine thread) threads deep in the drilled holes, and then use longer 10-32 UNF (fine thread) screws with lock washers to fasten the air cleaner base to the carburetor.

Method #2: Do this when the holes are too big for 10-32 UNF (fine thread) screws are described above, Heli-Coil thread inserts, or even 12-24 UNC (coarse thread) screws will not fix the problem. It takes expert mechanical skills to make the method below Ê work. I have done this many times and it works great.

  1. Parts needed:
    • Several inches of 1/4-20 UNC mild steel threaded rod. If the holes in the carburetor body are already 1/4", then use 5/16-18 UNC (coarse thread) mild steel threaded rod. (All Thread, long threaded rod or long threaded bolt.) NOTE: 5/16" is the maximum that can fit.
    • 1/4" x 2"+ long solid aluminum rod.
  2. Remove the choke plate and shaft from the carburetor body. When removing the choke shaft, there's a tiny (1/8" or 5/32") steel ball and small compression spring located at the 9:00 position when facing the choke end with the float area down. When the choke shaft is removed, hold one finger over the screw hole and end of the choke shaft hole to prevent the ball and spring from popping out and possibly getting lost. By the way - the ball and spring is required only for hand-operation of the choke to keep it in the open position on stand-alone engines, such as on a garden tiller, portable generator/welder, portable air compressor, portable water pump, etc. The ball and spring is not needed if the choke is remotely operated with a choke cable, such as in a tractor, etc.
  3. For 1/4" thread insert, enlarge the stripped hole(s) in the carburetor body with a 13/64" drill bit, or for 5/16" thread insert, use a 17/64" drill bit.
  4. Cut threads all the way through in the drilled hole(s) with a 1/4-20 UNC or 5/6-18 UNC (coarse thread) plug hand tap.
  5. Apply high strength liquid threadlocker in the threaded hole(s), insert the 1/4" solid aluminum rod through the choke shaft holes, and install a minimum 1/4" length of 1/4" or 5/16" threaded rod in the hole(s) until they bottom out against the aluminum rod, creating thread inserts. Remove the rod immediately to prevent the threadlocker from sealing it in place.
  6. When the high strength liquid threadlocker has fully cured (usually takes 24 hours at room temperature), cut off or grind the threaded rod(s) flush with the choke flange. If a choke plate is going to be used, make sure the end of the insert(s) will not to interfere with movement of the choke shaft. If necessary, grind interference of the insert with a Dremel or equivalent small rotary grinder chucked with either a very small grinding stone (chainsaw sharpening stone) or an 1/8" high speed steel end mill.
  7. Resurface the choke flange on a wide, flat belt- or disc-sander so any protruding part of the insert(s) are flush with the carburetor body.
  8. Carefully locate the dead center and place a punch mark in each insert.
  9. Drill an 11/64" hole through the insert(s). For accuracy, it's best to use a drill press or milling machine to do this. Heat from the drilling process may cause the threadlocker material to loosen, which could cause the insert to thread down in the choke shaft hole. To prevent the insert from unthreading, insert the 1/4" aluminum rod through the choke shaft holes so the insert will bottom out against the aluminum. Allow the drill bit to penetrate the aluminum slightly to go the full length of the insert. And to lessen the chance of overheating the threadlocker material when drilling the hole, use plenty of cutting oil, and drill slowly into hole(s) with a 5/32" drill bit, then finish with the 11/64" bit. Use sharp (preferably new) drill bits, too.
  10. Allow the inserts to thoroughly cool after the drilling process (dip in cold water), then use a 10-32 UNF TAPER hand tap to initially cut new threads through the insert(s), then finish cutting the threads all the way through the insert(s) with a PLUG tap. Again, as a precaution to prevent the insert from threading into the choke shaft hole, insert the 1/4" aluminum rod through the choke shaft holes, and allow the plug tap to cut threads into the rod so the threads will go the full length of the insert. Click here to learn how to cut new threads, the professional way
  11. With the 1/4" aluminum rod in the choke shaft holes, use a 1/4" drill bit to lightly chamfer or bevel the threaded hole in the insert(s).
  12. Apply motor oil in the threaded holes, and then the choke shaft/plate can be reinstalled, and the air cleaner base or a velocity stack can now be securely fastened to the carburetor.

Advertisement:
If you need the air cleaner mounting threads repaired in your carburetor, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Go here for more parts: Carburetor, Fuel System Parts & Machine Shop Services | Please click here to place an order.
Repair stripped 10-32 UNF (fine thread) air filter housing mounting threaded hole(s). $10.00 - $20.00 for parts and labor. An ingenious and innovative concept by Brian Miller, because nobody else advertise this repair service.


Never Over-Tighten the Mounting Bolts or Use Multiple Gaskets When Fastening the Carburetor to the Engine! (Updated 11/26/16)

When installing the carburetor to an engine, the use of two or more gaskets and then torquing the mounting bolts to specs, or just over-tightening the bolts will severely warp the mounting flange on a carburetor, causing it to bend, which will create a vacuum leak, or worse yet, being cast aluminum don't bend or flex too easily, the flange could break. So remember, before installing any carburetor, first resurface the mounting flange on a wide, flat belt- or disc-sander to remove warpage and restore flatness, and for general lawn and garden use, install just one thin (.030" thickness) gasket or one (3/16" thickness) heat isolator gasket. And use the "two-bolt torque" procedure! To do this, lightly tighten the first bolt, then lightly tighten the second bolt. And tighten the first bolt securely, and then tighten the second bolt securely. Or a shallow, narrow groove can be machined in the mounting flange of the carburetor for a reusable small cross-sectional neoprene rubber O-ring. No gasket or silicone will be needed. The same can be done to the end of a carburetor extension, intake tube, manifold, spacer, stand-off (or whatever it may be called) that fastens to the engine block.

If a Carter/Kohler or Walbro carburetor body is broken and/or damaged beyond repair, the carburetor body is 100% scrap metal. (If the threads for the float bowl retaining bolt are stripped, read below Ê.) But the parts on the carburetor body are considered valuable and can be used on another carburetor body that's in good condition (if some of the parts are in fact reusable). Parts such as: throttle and choke shafts and plates, choke friction (detent) ball and spring, idle speed adjusting screw and spring, idle fuel mixture screw and spring, high speed air/fuel needle adjuster and spring, main jet/nozzle (emulsion tube), fuel inlet valve and seat (if not worn and leaks fuel), float, float pin, float bowl, neoprene rubber O-ring seal, fuel baffle/splash shield, bowl retaining screw, and fuel hose fitting. The OEM (US) manufacturers are phasing out many parts for flathead engines due to EPA smog emissions. But some parts may still be available in aftermarket.

How to Repair Stripped Float Bowl Retaining Bolt Threads in a Carter/Kohler or Walbro Carburetor - An ingenious and innovative concept by Brian Miller, because nobody else mentions these type of repairs.

But if the threads for the float bowl retaining bolt are stripped in a Carter #16, #18, #20, #22 carburetor, an 8mm fine thread (M8 x 1.25 pitch) metric bolt can be used. But if the metric threads become stripped, then a 3/8-24 UNF (fine thread) bowl retaining bolt (for the Carter/Kohler #26, #28, #30 or Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors) can be used. For the 8mm metric bolt, an 8mm x 1.25 bottom hand tap will need to be used. But for a 3/8-24 bolt, the stripped hole will need to be enlarged with a 21/64" drill bit (be careful not to drill into the main jet; there's no need to remove the main jet/nozzle), and new threads will need to be cut perpendicular to the carburetor body with a 3/8-24 UNF bottom hand tap. A bottom tap cuts the threads deeper with very little taper at the end. Do not complete the tapping process with just a taper or plug tap because the threads may not go deep enough for the bigger bolt. However, the threads can be started with a taper or plug tap, but will need to be finished with the bottom tap. Then use [150± psi] compressed air to thoroughly clear out the metal drilling/cuttings from the main jet/nozzle (emulsion tube) and entire carburetor! A 3/8" i.d. fiber washer will need to be used with the 3/8" bolt, and the hole in the float bowl will need to be drilled out to 3/8" to match the bolt in the carburetor, or use a float bowl with a 3/8" hole. And do not over-tighten the metric bolt to prevent from stripping the new threads. If the metric threads strips out, the carburetor body is scrap metal.

If the threads for the float bowl retaining bolt are stripped in a Carter/Kohler #26, #28, #30, Walbro WHL #36, #44 and WHG #52, #60, #64 or virtually any other carburetor that use a 3/8"-24 UNF (fine thread) float bowl retaining bolt, a 10mm fine thread (M10 x 1.25 pitch) x 3/8" thread length bolt can be used. If a 3/8" length metric bolt can't be found, a longer bolt that's made of mild steel can be machined down (shortened) in a metal lathe. Being the stripped hole is already large enough for the M10 x 1.25 threads to be cut, so it won't need to be drilled out. But if it does need drilling out (enlarging), use an 8.8 mm or 11/32" drill bit (be careful not to drill into the main jet; there's no need to remove the main jet/nozzle), then new threads will need to be cut perpendicular to the carburetor body with a M10 x 1.25 bottom hand tap. A bottom tap cuts the threads deeper with very little taper at the end. Do not complete the tapping process with just a taper or plug tap because the threads may not go deep enough for the metric bolt. However, the threads can be started with a taper or plug tap, but will need to be finished with the bottom tap. Then use [150± psi] compressed air to thoroughly clear out the metal drilling/cuttings from the main jet/nozzle and entire carburetor! Also, the holes in the fiber washer and in the float bowl for the retaining bolt will need to be enlarged to 13/32" to match the bolt in the carburetor. And do not over-tighten the metric bolt to prevent from stripping the new threads. If the metric threads strips out, the carburetor body is scrap metal. But save everything off of it because they can be used on another carburetor body that's in good condition.

On a used (and supposedly clean) carburetor, if the float bowl retaining bolt will not effortlessly tighten against the float bowl to secure it in place, DO NOT FORCE THE BOLT TO TIGHTEN! Doing this may cause the thin-wall metal to split, possibly rendering the carburetor useless. The resistance in threading the bolt in the hole is caused by debris "gumming up" the threads in the carburetor body (or in the threads of the bolt). Instead, clean the threads in the carburetor body with a 3/8-24 UNF (fine thread) BOTTOM hand tap, then use 150± psi compressed air to clear out the debris. With a bottom tap, there's no need to remove the main jet/nozzle (emulsion tube). But if the protruding part where the float bowl bolt threads into is previously cracked or does split, a spring-loaded 1/2" fuel hose clamp can be installed over the protruding part with the opening in the clamp opposite the crack. This will reinforce the aluminum, squeeze the tube back to its original size and prevent the crack from spreading when the bolt is tightened. After the clamp is installed, grind the protruding tangs flush with the clamp so they will not make contact with and interfere with the operation of the float. The clamp will then become a permanent part of the carburetor. And if any part of the clamp blocks off the fuel feed holes, a new 3/32" fuel feed hole will need to be drilled through the opening in the clamp so fuel from the float bowl can reach the main jet/nozzle. This size hole should be big enough to allow plenty of fuel to enter through the main jet. An ingenious and innovative concept by Brian Miller, because nobody else advertise this type of repair.

Advertisement:
If you need the repair service provided below Ê , please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Go here for more parts: Carburetor, Fuel System Parts & Machine Shop Services | Please click here to place an order.
Repair stripped threads in float bowl retaining bolt hole for Carter #16, #18, #20, #22, Carter/Kohler #26, #28, #30 or Walbro WHL #36, #44 and WHG #52, #60, #64 carburetors. An ingenious and innovative concept by Brian Miller, because nobody else advertise this repair service.
  • $10.00 each for parts and labor, plus return shipping & handling.


Fabricate a Foolproof Type of Foot-Operated Spring-Loaded Throttle Return Control Setup on a Pulling Tractor - Top of page

For a fancy and noticeable gas pedal, install a chrome-plated, die-cast aluminum "barefoot" pedal. These were popular in the late '60s to early '70s as a nostalgic item used mainly on street rod and hot rod vehicles. They're available on eBay. Use a medium size household brass door hinge to fasten the pedal to the foot rest on the tractor.

When using a Carter or Kohler carburetor, a spring-loaded throttle control is a safety feature because the engine will idle down as soon as the driver lets off the gas pedal, just like in an automobile. But with the OEM-type, manually-operated sliding solid wire throttle control, the driver must quickly reach for the throttle lever to idle down the engine. Many pulling association's/club's rules state that a spring-loaded throttle control must be used for safety, either hand- or foot-operated (hand lever or foot pedal). All Mikuni carburetors have a built-in spring-loaded throttle return.

When using the sliding stranded cable housing to operate the throttle, for the cable to slide back and forth in the housing with less friction, pull the inner cable from the housing (with one end [ball] cut off), and use a chainsaw bar tip grease gun to pump a small amount of lubricant inside the housing so the inner cable will operate much smoother and last longer. But before reinstalling the cable in the housing, to prevent the end of the cable from unraveling, singe the end of the cable with a propane torch or an oxy-acetylene torch with a small, blue flame, or use electrical solder and soldering gun to bind the wires together (make sure the cable is absolutely clean), and then grind down the lump [of metal or solder] so the cable can be inserted in the housing and wire swivel easier.

To fabricate the steel rod throttle linkage and levers, run a 3/16" diameter steel rod from the pedal, up to a bell crank (lever), then fasten the lever to a 5/16" diameter steel rod. Run the rod through the steering column support and then fabricate another bell crank (lever) on the other end of the 5/16" rod (other side of the tractor), and connect that to another 3/16" diameter steel rod which goes forward and attaches to the throttle lever on the carburetor.

I made our own bell cranks (or levers) from 1/2" x 1/8" x about 2" length mild steel. I simply drilled a hole in each end (3/16" and 5/16") and clamped one end of the lever with a locknut on the 5/16" rod so I can loosen the nuts to make adjustments as necessary, and the other hole in the lever is for the 3/16" rod. Install a lightweight return spring from the pedal to the tractor frame. And look your tractor over to determine where the holes should be drilled through the steering column support. Just don't drill the holes where the steering column will be in the way. This setup cannot be used with Mikuni carburetors because Mikuni carburetors are operated by a stranded wire throttle cable only.

If fabricated correctly, and properly installed and adjusted, I believe that this type of throttle control is absolutely the best design. There's very little wear to the moving parts and it will never fail on virtually any tractor. It works much better and with less friction than the stranded cable design. There's no sliding stranded cable that can bind, fray and eventually break, causing one to lose a good pull. And being virtually all tractors are different in design, I offer no kits for these. You'll have to fabricate your own. And the reason foot pedals are more popular than hand throttles is because both hands are needed on the steering wheel to control the tractor as it's going down the track.

Oh, and if you've ever wondered what a "dead man's throttle" is, it's a spring-loaded hand lever or foot pedal throttle control that automatically returns the throttle plate to the idle position when the pressure is released. It works the same as the gas pedal in a car.

Wide Open Throttle Sliding Stranded Cable Control Setup for K241-K341 Kohler Engines - (Changed 5/29/16)

This proven and well thought-out design allows the sliding stranded cable to be connected to the carburetor from the exhaust end of the engine, with the cable housing mounted well above the hot header pipe. This design places less pressure and friction on the throttle shaft/bushing, which reduce wear. NOTE: Remove the inner stranded cable from the housing, and use a chainsaw bar tip grease gun to pump a small amount of lubricant inside housing so the cable will slide easier with less friction. Return To Previous Paragraph or Section | Top of page


How to Repair the Vacu-Jet (3hp) and Pulsa-Jet (3.5 or 4hp) Automatic Choke Carburetor on a Vertical Shaft Briggs & Stratton Flathead Engine - Top of page

First of all, don't believe all factory-trained, brain-washed technicians. Because sometimes one must improvise to make something work. And despite what the service manual says, using a large, flat file to make the warped surface of a carburetor and/or fuel tank flat again will not hurt anything if a skillful person does it and if he/she knows what they're doing. B&S wants to make more money by selling new parts. That's why they write their manuals the way they do. Remember the old saying: "A fool and their money are soon parted." B&S probably laugh all the way to the bank after making a sale, too.

The Vacu-Jet carburetor operates off of engine vacuum to delivery fuel to the engine. (The very first Vacu-Jet carburetors have a manual choke, and no diaphragm. The second design Vacu-Jet carburetor uses a diaphragm, and have a manual choke. The third design Vacu-Jet uses a diaphragm and has an automatic choke.) And the Pulsa-Jet has a built-in fuel pump to delivery fuel to the engine. Both of the [newest design] Vacu-Jet and Pulsa-Jet carburetors have an automatic choke. If either of these carburetors run rich on fuel, and the choke will not open after starting, what has happened is where the carburetor is fastened to the fuel tank, these two "mating surfaces" has become warped. This is caused by over-tightening of the air filter housing screw. To fix this...

  1. Remove the carburetor/fuel tank assembly from the engine.
  2. Remove the choke rod cover from the carburetor and the carburetor from the fuel tank.
  3. Completely disassemble the carburetor, except for the throttle shaft and choke plate. Gently remove the fuel pickup tubes with a 3/8" and 9/16" 6-point socket. Be careful not to twist them off in the carburetor!
  4. Use a carburetor jet cleaner wire set or an oxy-acetylene welding torch tip cleaner to clear out the dried gas and/or dirt/debris from the idle and main nozzle holes. Be careful not to enlarge the holes, or the engine will run rich on fuel!
  5. Resurface the carburetor's diaphragm surface on a wide, flat belt or disc sander to remove any warpage and restore flatness. (Be sure to use eye protection!) If the carburetor is warped, the sander will make contact where the screw holes are, but not between the screw holes.
  6. With the gas tank lightly clamped in a large bench vise, resurface the diaphragm surface with a large, wide, flat file to remove any warpage and restore flatness. Use caution! Do not "rock the file" when resurfacing the mating surface of the tank! Use diagonal and swirling motions of the file so the diaphragm surface will be more or less even across the gas tank, or very little will be gained.
  7. After resurfacing, use a hacksaw blade to recut (or deepen) the shallow groove from the choke bellow well to the vacuum port. Doing this will allow the choke plate to open immediately when the engine starts. Failure to do this will allow the choke plate to open very slowly or not open at all, which will cause the engine to flood out and die.
  8. Use [150± psi] compressed air to clear out the metal filings and any dirt or debris from the air and fuel passageways in the carburetor, screens on the fuel pickup tubes, and entire fuel tank.
  9. Reinstall the fuel pickup tubes in the carburetor with the 3/8" and 9/16" 6-point socket. Be careful not to twist them off in the carburetor!
  10. A new diaphragm should be installed. When reinstalling the carburetor with the diaphragm on the tank, make sure the fuel pump flapper valves are properly in place, then start the mounting screws in the threads.
  11. Insert the choke rod in the choke shaft and flip the choke plate over of normal operation. This preloads the bellow in the diaphragm, making it flex easier and allows the choke plate open easier when the engine starts.
  12. If it's a Pulsa-Jet carburetor, invert the carburetor (turn upside down) and place the fuel pump spring in first with the protective cap on the spring. Place the spring and cap in the carburetor recess, and not in the fuel tank recess. With the carburetor still upside down, install the diaphragm on the carburetor, place the tank on the carburetor, then flip them over to loosely install the mounting screws.
  13. Connect the choke rod to the choke lever, and flip the choke plate over in the reverse rotation with the lever facing downward. Doing this places pressure on the bellow of the diaphragm so the choke plate can open more freely without binding when the engine starts.
  14. Tighten the carburetor mounting screws, reinstall the choke rod cover with a new gasket and that's it!


How to Repair the Pulsa-Jet Carburetor on a Vertical or Horizontal Shaft 5hp Briggs & Stratton Flathead Engine -

If a 5hp B&S engine has excellent spark and adequate compression, but doesn't run right, then the problem is obviously in the carburetor. To fix the problem...

  1. Remove the carburetor from the engine and fuel tank, completely disassemble, and clean the carburetor body and metal parts with an ultrasonic cleaning machine, Berryman® Chem-Dip® Carburetor and Parts Cleaner or Purple Power Cleaner Degreaser to dissolve or loosen any dried gas deposits, crud and debris.
  2. Use a carburetor jet cleaner wire set or an oxy-acetylene welding torch tip cleaner to clear out the dried gas and/or dirt/debris from the idle and main nozzle holes. Be careful not to enlarge the holes, or the engine will run rich on fuel!
  3. Use [150± psi] compressed air to clear the debris from the nozzle holes, entire carburetor and fuel tank.
  4. Clean the screens on the pickup tubes.
  5. When the carburetor-to-block mounting screws are tightened for the first time, this causes the carburetor mounting flange to warp, which allows for a vacuum leak. To fix this, resurface the carburetor flange on a wide, flat belt or disc sander to remove any warpage and restore flatness. (Be sure to use eye protection!) If the flange is warped, the sander will make contact where the bolt holes are, but not between the bolt holes.
  6. Again, when the fuel pump cover mounting screws are tightened for the first time, this causes the cover to warp, which causes a vacuum leak, and the pump will not produce full flow and pressure to the reservoir bowl. To fix this, resurface the cover with a large flat file or on the sanding belt or disc sander (be careful!) to remove warpage and restore flatness. (Sometimes I use the side of the abrasive cutting wheel on my 14" electric chop saw with a metal cut-off wheel. Works great! Extreme care is recommended and be sure to use eye protection!)
  7. Install a new fuel pump diaphragm, carburetor to tank gasket and carburetor to block gasket, set the fuel mixture adjustment screw about 1-½ turns out, and make the final adjustment after the engine runs.
  8. If the throttle shaft needs to be removed for whatever reason, first pull the sheet metal spiral from the throttle bore with large pliers or long/needle-nose Vise-Grips locking pliers. Then access to the throttle plate retaining screw can be gained with a long slender screwdriver. Repair as needed.
  9. Your engine should run like new afterwards!


How to clean the main jet in a 16hp/18hp flathead opposed (flathead) twin cylinder Briggs & Stratton engine -

The main jet is located in the float bowl of the carburetor. To access and clean it...

  1. If equipped, remove the hood of the tractor (they're easy to remove).
  2. Remove the air cleaner/filter assembly. Be careful not to drop the screws down inside the carburetor!
  3. Remove the choke cable from the carburetor.
  4. Remove the top of the carburetor.
  5. Remove the hex plug on the side of the carburetor.
  6. Use a carburetor jet cleaner wire set or an oxy-acetylene welding torch tip cleaner to clean out the hole (orifice) in the main jet. The hole (orifice) in the main jet is accessed through where the hex plug is. Be careful not to enlarge the hole (orifice) in the main jet, or the engine will run rich on fuel!
  7. Use [150± psi] compressed air to clear out the hole (orifice) in the main jet and dirt/debris from the float bowl area.
  8. Reinstall everything in reverse order of removal.

Your engine should rev up without using the choke afterwards! This may have to be done every few years because these type of carburetors are notorious for having tiny particles of dirt/debris that passes through the fuel filter settle at the bottom of the float bowl. The main jet is real close to the bottom of the float bowl too, which allows dirt/debris to clog it over time.


Advertisement:
If you wish to have your Kohler stock or pulling engine tested on a dynamometer (dyno), please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday, except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends, except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest.

A-1 Miller's Fully Computerized Stuska Water Brake Engine Dynamometer (Dyno) Service with DPM Data Logger Software!

For performance testing engines up to 200hp at speeds up to 12,000 RPM. The only engine dyno service in Missouri for Kohler pulling engines! Now set up and fully operational, customers can rent dyno time, fine tune and make adjustments or changes to their engines for maximum horsepower and torque, and print-out the results so their tractor(s) will be truly competitive on the track.

Engine Dyno Rental Fee: $30.00 per hour run time from the moment the engine is started. No setup fee for Cub Cadet engines with a 3- or 6-pin/stud clutch driver. An adapter may need to be needed or fabricated for other makes and models of engines. Only engines with the narrow base oil pan can be tested. Engines with the wide base (tall) oil pan cannot be tested at this time.


To place an order and/or for technical assistance, please contact:

A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO (Missouri) 65203-9136 USA | Phone: 1-573-256-0313 (shop) | 1-573-881-7229 (cell). Please call Monday-Friday , except holidays, 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) A-1 Miller's shop is open to the public from 9am to 5pm, including weekends , except holidays. Please call before coming so I'll be here waiting for your arrival. Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Directions to our shop | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. If you're the kind of person who don't trust delivery/shipping companies (mis)handling your high-dollar and fragile merchandise, you can always make the long drive to A-1 Miller's shop to personally drop off and/or pick up your engine, transaxle, tractor, etc. "The road to a friend's house (or shop) is never long."

To place an order, please call the number below Ê or send an email with your name, complete and correct postal address and phone number and so I can figure the total with shipping cost and USPS Tracking. For payment options for parts ordered or services performed, or to make a donation to my websites, I accept cash (in person), USPS Postal Money Orders, cashier's checks, business checks, MasterCard, VISA, Discover, American Express (please add 2.5% to the total for the credit/debit card processor's surcharge), Western Union Money Transfer, MoneyGram Money Transfers or Popmoney. (If a part for a specific purpose is special ordered, your debit/credit card may be charged for the full amount or as a deposit right after your order is placed; please do not send your debit/credit card information in email!) Or you can pay me through PayPal. (My PayPal account name is my email address. And be sure to mention in PayPal a description of what the payment is for.) If sending a money order, please include a note in the envelope with your name, complete and correct postal address, phone number and a description of what the payment is for. My mailing address and phone number are below Ê . I'll make a note of your order, and I may have to order some of the parts, which should take a few days to come in, but I will send the parts to you as soon as I have everything in stock after I receive your payment.

IMPORTANT - When sending your part(s) to me for rebuilding or repair, package everything securely so the item(s) won't get damaged in shipping and please include a note in the box with your name, mailing address, phone number (in case I have any questions) and a description of what you want done. When shipping heavy parts, it's best to put a slightly smaller box inside a larger box, to double the strength and integrity of the package. Because the clumsy "gorillas" or incompetent and uncaring workers that work for certain delivery services mishandle the heavy packages and don't care. And when the work is completed, I'll either call or email you an invoice with the total including shipping & handling.

To figure the shipping cost, I weigh the package with the parts, then I go online to the USPS Postage Rate Calculator website. I type in the weight, my zip code and your zip code, then it shows me the prices for various ways to ship the package. I always choose US Postal Service because I believe that's the most fastest, economical and reliable method.

Shipping: (United States and it's territories)
To save you shipping charges, item(s) in a package or cushioned envelope weighing less than 13 oz. is sent by First Class Mail for a 2-6 day delivery. Most packaged item(s) weighing over 13 oz. is sent by US Priority Mail for a 2-3 day delivery. To save you even more on shipping heavy items, I always try to use the US Postal Services' Flat Rate Priority Mail envelope and boxes (if the item(s) can fit inside the envelope or boxes). Some heavy items weighing no more than 70 lbs. is sent by US Mail Parcel Post. Item(s) weighing over 70 lbs. is sent by FedEx Ground. Again, if you're the kind of person who don't trust delivery/shipping companies (mis)handling your high-dollar and fragile merchandise, you can always make the long drive to A-1 Miller's shop to personally drop off and/or pick up your engine, transaxle, tractor, etc.

We Ship to Canada and Worldwide -
Item(s) in a package or cushioned envelope weighing less than 1 lb. is sent by US Postal Service Airmail Letter Post for a 4-7 days delivery. Packaged item(s) weighing over 1 lb. and up to 66 lb. is sent by US Postal Service Airmail Parcel Post for a 4-10 days delivery. I cannot use the US Postal Services' Flat Rate Priority Mail envelopes and boxes to ship outside U.S. territories. Item(s) weighing over 67 lbs. or more is sent by FedEx Ground or equivalent services.


We Accept PayPal, Visa, MasterCard, American Express & Discover Credit & Debit Cards
(When placing an order through PayPal, please provide a list of which parts you need.)

To make a payment to me through PayPal, go to PayPal's secure website ( https://www.paypal.com/ ) and click on Send and Request -> Pay for goods or services. Type in my email address, or copy and paste this: pullingtractor@aol.com, the amount and follow the directions. Be sure to mention in PayPal a description of what the payment is for. After you've finished, PayPal will send me an email notifying me that you have made a payment to me for the product(s) or services and amount entered. Then I go to their website and direct PayPal to deposit the money in my bank account. And I will send the parts to you as soon as I receive your payment. But I may have to order some of the parts if they're not in stock, which should take a few days. In that case, I will send you the parts as soon as they come in. PayPal protects your financial privacy and security. With PayPal, privacy is built in. It's a way for you to pay without exposing their financial information.


à Return to Main Pulling Tips Page | Return To Previous Page | Reputable Garden Pulling Tractor Engine Builders, Parts Suppliers and Service Providers | Hot Links to Reputable Garden Tractor Pulling Clubs and Associations | Top of Page

Copyright © 1996-Present. This website created, designed and maintained by Brian Miller.