Ignition Solutions for Small
Engines and Garden Pulling Tractors
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Spark-ignited engines require a spark to initiate burning of the air-fuel mixture in the combustion chamber. The spark in each cylinder is provided by a spark plug and is actually a flow of electrical current through the air and fuel vapor between the closely spaced electrodes of the spark plug. The resistance of air is very high. Therefore, a 15,000- to 30,000-volt potential across the gap is used to fire the plug. Typically, the ignition system must supply this high voltage from a 12 volt power source, such as a storage battery. Moreover, the spark must begin at the proper point in the cycle and must be of sufficient duration.
Whenever a manufacturer wants to sell their latest fancy ignition system, they run a test that shows that their unit puts out more voltage than the other guy's. If you read enough ads with claims of extremely high available voltage, you may begin to think that voltage is the only thing necessary to make an ignition system the best in the world. After all, if ignition "A" puts out more voltage than ignition "B", the one you would want is "A", right? Sorry, but that isn't necessarily so. Ignition "A" may put out more voltage, but is it more mechanically dependable than ignition "B"? Did you know that 90% of ignition failures are mechanical, and not electrical? Blame burnt or dirty points, faulty condenser, bad switch(es), broken or chaffed wires, loose screws or connectors, slipped timing, etc. By the way - whenever a condenser goes bad, the engine will either: 1. Not start. 2. Start and idle fine, but when the speed increases, it'll run very erratic.
The importance of extremely high secondary voltage for more performance has been somewhat overplayed. An ignition system, regardless of type, produces only enough voltage necessary to jump the spark plug gap and ignite the air/fuel mixture. In perfect condition, a good spark plug wire and spark plug with a gap of .035" can't handle much more than 32,000 volts. If an ignition could produce more than that, then the extra voltage would escape through a leaking spark plug wire, a small crack in the coil tower, etc. Besides, an average engine simply just doesn't need that much voltage. In most cases, an average engine simply don't need a high-performance coil. If a plug requires only 10,000 volts to jump its gap, then a "Super Coil" that's advertised to produce 40,000 volts will produce just 10,000 volts for that same plug under the same conditions. An ignition advertised to produce 40,000 volts may have the potential to do it, but unless everything is in excellent condition, only a fraction of that voltage would reach the spark plug.
As a spark plug's electrodes wear, its gap increases, so more voltage is required from the ignition coil before the spark is able to jump across the gap. If uncorrected, the gap eventually increases to the point where the plug requires more voltage than the coil can produce. However, a high-performance coil would probably be able to fire the worn plug. Did you know that most stock ignition coils will produce enough voltage to jump a gap of up to 3/4 of an inch? Of course, no spark plug electrode will ever wear that wide. Therefore, the use of a high-performance coil really isn't necessary, except in extreme high compression engines.
In most cases, if an engine is kept in perfect tune, the factory stock ignition system provides more than enough voltage for the average garden pulling tractor. Most conventional stock ignitions are designed to provide a hot spark up to a relatively low engine speed. With Kohler engines running in modified form, they will get up as high as 9,000 rpm. But at higher rpm with the points system, the points open and close so quickly that the coil's primary winding has less time to absorb voltage. This means the condenser doesn't have enough time to rebuild the capacitance discharge. As a result, with the stock system, secondary voltage to the plug decreases and the engine won't run at its full potential or it may sputter just when victory is in sight. However, for most garden pulling tractors, a stock ignition system that's in good condition will provide plenty of spark.
There are 5 types of ignition systems that's used on all small gas engines, despite if it's a 2- or 4-cycle engine:
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Magneto Ignition System has breaker points, a condenser and an ignition
coil that generates it's own electrical power to produce the spark every
time a magnet in the flywheel or rotor passes the coil. Magneto ignition
coils can't be used for a battery ignition system because they must generate
their own electrical power to create the spark. The ignition timing for the
magneto ignition is the same as for the battery ignition. It's set or adjusted
by widening or narrowing the gap of the breaker points. This advances or
retards the ignition timing. Use a test light with battery power or a multimeter
set on the Ohms resistance (with the engine not running) or an inductive
or non-inductive automotive timing light (with the engine running) to set
the ignition timing on a magneto system, but a 12 volt battery must be available
to power the timing light. Because of their compactness and no need for an
outside power source, magneto ignition is very popular on virtually all small
engine equipment. Such as gas-powered string trimmers, chainsaws, lawn mowers,
garden tillers, go-karts, riding mowers, lawn tractors, lawn & garden
tractor and small construction equipment engines.
- Most cast iron block and certain [bigger] aluminum block air-cooled small gas engines having an obsolete magneto ignition system with points and condenser can be easily converted to battery ignition. All that's required is a condenser that's designed for battery ignition (automotive or Kohler), a 12 volt automotive-type ignition coil with a bracket, a ballast resistor if the coil requires one, a spark plug wire with terminals and boots, a 12 volt battery and wiring/connectors. The same ignition points and spark plug can be used. Due to the more powerful automotive coil, the spark plug gap can be set at .035" for a hotter spark. Also, the key-operated [magneto] ignition/starter switch will need to be changed to an automotive-type switch that's designed for battery ignition. Or, an OFF/ON push/pull or toggle switch to power the ignition and a push-button switch to activate the solenoid/starter motor can be used instead. And with battery ignition, the engine will need a reliable charging system to keep the battery fully charged to crank the engine and so the ignition will produce a hot spark. When converting to battery ignition, remove or disconnect the magneto coil and condenser first. Please go here if you need a kit to convert an engine to the battery ignition system.
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The reason battery ignition can't be used on the smaller aluminum block Briggs
& Stratton engines is because the [B&S] condenser is part of the
ignition points. For battery ignition to work, the wire on the [battery]
condenser must be connected to the negative post on the [battery] ignition
coil, and the body of the condenser must be grounded to the engine. Therefore,
if the condenser is separate from the points, it should work. For a hot and
reliable spark on the smaller aluminum block Briggs & Stratton engines
with the condenser as part of the points, install a
B&S's Magnetron electronic
ignition module (only for two-post coils), a NOVA 2 solid state module or
a Mega-Fire solid state module (for two or three-post coils). Please
contact me if you need a NOVA 2
or Mega-Fire solid state module.
- On engines with a magneto ignition, I believe the best thing to do is install one a NOVA 2 or Mega-Fire module and your ignition problems should be no more. Because sometimes I too, have a hard time with points and condenser trying to get a spark from certain Kohler engines with magneto ignition. Sometimes I have to set the points as close as .015" just to get a spark. But this makes the timing so retarded, the engine lacks power. So I remove the points and condenser, plug the points plunger hole, and install a NOVA 2 module. The engine then has a strong spark, starts quicker and produces a lot more power. The module puts the timing right where it needs to be. I always get a good spark with battery ignition. But magneto ignition with points and condenser can sometimes be difficult to get a spark and get the timing set right. I think it's due to a worn points lobe on the camshaft.
- Breakerless or Solid State Ignition System operates on the same general principle as the magneto system but does not use breaker points to time the spark and a conventional condenser. Instead, a trigger module containing solid state electronics performs the same function as the breaker points. Because there are no breaker points in this system, there are no requirements for ignition timing (on a small engine). Like magneto ignition, solid state ignition is self-energizing. Therefore, it does not require an outside electrical source, such as a battery. Breakerless ignition is pretty much maintenance free, with very few parts to wear out or go bad. Breakerless ignition is used on virtually all small engines built from 1982.
- Battery Ignition System uses breaker points, and a different type of condenser than magneto ignition, and an ignition coil that requires an external 12 volt source (battery) to power the system. Battery ignition is used on most all older garden tractors, farm tractors and virtually all older (pre-1974) automobiles.
- Transistorized Breaker Point Ignition System provides a hot spark, allows the ignition points to last longer, perhaps the life of the engine, and it requires no condenser. requires an external 12 volt source (battery) to power the system. Ford Motor Co. originally offered the transistorized breaker point ignition system on various Ford vehicles from 1965 to 1972. The PointSaverTM transistorized breaker point ignition unit, available from Kirk Engines, Inc. (http://www.kirkengines.com) works great for general yard use and for pulling tractors. MSD also offers a transistorized breaker point ignition module to help points last longer. Go here to construct your own transistorized point ignition module: http://www.cs.berkeley.edu/~wkahan/TransIgn.pdf. One thing to take into consideration about using a transistorized breaker point ignition system is if an engine sits for a long period of time, the point contacts may become oxidized because there's not enough "spark" or electrical current going between the contacts to burn away the oxidation. And being the transistorized breaker point ignition system requires activation of the ignition points, if the points lobe on the camshaft is worn or becomes worn, the ignition timing would be retarded.
- Crank Trigger [Electronic] Ignition System is a combination of the breakerless and battery ignition because it has no breaker points or condenser but requires a 12 volt source (battery) to power the ignition coil and control module. Virtually all large engines (farm tractors and automobiles) that's built from the mid-1970s use either crank trigger ignition, or a system similar to crank trigger. The "PointSlayer" from Overnight Solutions seems to be a good product and works somewhat like the crank trigger system. However, being it uses an electronic sensor that detects movement of the points pushrod, like the transistorized breaker point ignition system above. The only drawback with this system is if the points lobe on the camshaft is worn or becomes worn, the ignition timing would be retarded and cannot be advanced enough so the engine will run efficiently. But a true crank trigger system requires no mechanical contact to activate any moving parts. The PointSlayer kit comes with a custom pushrod and a spring that slips over it. The spring's job is to keep the rod against the cam's points lobe. The rod is stepped down, and the spring rides between the step down ledge and the back of the PointSlayer. Here's a link to PointSlayer: http://overnight-solutions.com/index_files/Page739.htm.
By the way - it's best to use a quality-made automotive battery in a pulling tractor that has no charging system. Not only because they hold a charge longer to crank the engine after several pulls, but they provide plenty of power to a battery-powered ignition system for a hotter spark.
Advertisement:
If you need any of the items listed below, please contact A-1 Miller's
Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136
USA |  Phone: 1-573-875-4033.
Please call Monday-Friday, 9am to 5pm, Central time. If no answer, please
try again later. (When speaking with Brian, please be patient because
I stutter.)  Fax: 1-573-449-7347.
 E-mail:
pullingtractor@aol.com. You can
also contact us through Yahoo! Messenger:
Convert virtually any single cylinder, air-cooled cast iron or certain aluminum block small gas engines that originally came with a magneto ignition system (having points, condenser, and ignition coil that has voltage generated by a set of permanent magnets in the flywheel, instead of being powered by a battery) into a battery ignition system. Kit includes a new automotive/canister-type ignition coil, condenser and 25-1/2" long 7mm copper-core spark plug wire. NOTE: Use the OEM points, set the gap at .020" for correct ignition timing and use the same type of spark plug, but set the gap at .035" for a hotter spark. Click here for wiring diagrams.
More of our parts & services: Conventional Ignition, Electrical and Crank Trigger Electronic Ignition Parts and Kits |
Testing for Spark -
First of all, use a fully charged 12 volt battery and not just a battery charger to test for spark. Because most battery chargers put out 2-3 volts, enough power to charge up each cell in a battery at a time until it's fully charged. With that said, a simple way to test for spark with battery ignition, having points and condenser, is to connect a jumper wire from the positive terminal on the coil to the positive post on the battery, then either crank the engine, or with the points in the closed position, open and close them manually and with the spark plug grounded on a metal part of the engine or equipment, observe for a snappy, blue spark at the spark plug's tip. If there's no spark, then either the spark plug is bad, the points are burnt or dirty, or the coil or condenser is bad. If there's a red or white spark, then the spark plug is bad. In rare cases, when cranking the engine and the points don't open and close, the points lobe on the camshaft may be severely worn.
Testing the Strength of an Ignition System -
When
testing the strength of an ignition system, it can be tested at the spark
plug's tip. Or better yet, it's best use a universal spark tester like the
ones pictured to the right. But when testing the strength of the spark with
the just the spark plug, always use a new spark plug, and the ignition must
be strong enough to produce an audible "snappy" and visible bright
blue spark at the plug's tip. A good spark
plug is supposed to produce a blue, audible
snapping sound with it placed somewhere on the engine when the engine is
cranked. (The "snapping" sound is the result of electricity breaking the
sound barrier.) If the spark is visibly white or
red in color, either the [used] spark
plug is fouled or the ignition coil is weak and needs replacing. Unlike gasoline,
alcohol fuels (ethanol and methanol) will rarely foul spark plugs.
Engines with a points/condenser magneto ignition system can be cranked over slowly to produce a spark. But most engines with a solid state ignition (B&S's Magnetron) must be cranked over quickly to produce a spark. However, on engines with battery ignition, there's really no need to crank the engine to test for spark. What can be done is momentarily and lightly connect the point contacts with a small metal object, such as the tip of a screwdriver.
Also, if the spark plug's tip is black and/or has wet gas on it, and if you think the problem is in the carburetor, well, the carburetor is probably working fine because the engine is obviously getting gas. As an older, experienced mechanic once told said, "Most carburetor problems are electrical." This has proven true more times than I can remember.
What is the best spark plug to run in a garden pulling tractor, stock or otherwise?
First
of all, avoid using a low cost, inferior quality or "cheapie" spark plug,
especially with the wording "LAWN MOWER" printed
on the porcelain! I never had one of these last more than 5 minutes in any
engine. Also, when I started repairing lawn mowers in 1982, I've heard great
things about NGK spark plugs, and found that they are nothing but junk! I've
had new ones foul out when priming an engine with gas just trying to get
it started! And if an engine did start, it would run for a couple of times
before the plug became fouled. I've used Champion and Autolite spark plugs
for the past 25 years and they last A LOT longer.
An OEM-type plug, Champion H-10, the one that the factory originally install in the 10-16hp Kohler engines works great for pulling. Although the AC 45 plug works great, too. From time to time I've ran various spark plugs that's designed for small engines, and I couldn't tell any difference whatsoever in the performance of our tractors. Although it's a good thing to use a non-resistor spark plug and a non-suppressor type (carbon core) spark plug wire. By doing this, more voltage will reach the spark plug's tip. The use of a "cold" or "hot" spark plug (heat range) doesn't really matter because most pulling engines have no cooling system to cool the plug. (When there's no fins on the flywheel (steel flywheel) or an electric fan running, nothing will cool the engine, but the breeze on a cool day.) And in our experience, it seems that it makes no difference of what type of spark plug works best for either gas or methanol fuel. But a wider gap (.060") works better with methanol. And gas burns just fine with a standard gap of .035". Click here for Champion Spark Plug's Numbering System.
Did you know that installing two spark plugs per cylinder doesn't help to increase the power output of an engine whatsoever? Simply because one plug will be running hot (exhaust side) and the other will be cool (intake side). Engine power is generated from the heat source, because heat is how an engine produces power. When the spark plug in the cylinder head is located over the exhaust valve, this maintains the majority of the heat in the combustion chamber in one area. When heat is maintained in one particular area in any given combustion chamber, the increase in power will be much greater, especially at high rpm. Burning fuel within a combustion chamber will "find" or locate the main heat source. The fuel will burn more thoroughly, allowing the engine to produce more power at any rpm. If the plug is located in the center of the combustion chamber, the incoming fuel could splash against the plug's tip and cause the engine to misfire or run erratic at high speed, especially when burning methanol fuel. And the plug could easily become fouled when burning gas, especially when the engine is cold. So it's best to install just one spark plug positioned over the exhaust valve with the plug gap set at .060". Because a .060" gap will simulate having two spark plugs. Use of a high-performance coil will help produce a stronger spark, too.
Indexing of the spark plug will also
help to increase engine power. This is when the open gap of the spark plug
face the center of the piston. It helps in a more thorough combustion of
the fuel so the engine will produce more power and torque at high rpm. An
indexing washer is used to index a spark plug. They're of various thicknesses,
made of copper (for heat transfer), and placed on the threads of the spark
plug. Indexing of the spark plug helps to increase the power and torque on
a high-performance engine that operates at high rpm or at wide open throttle.
It doesn't help much on a stock or low rpm engine.
Also, when the spark plug in the cylinder head is located over the exhaust valve, this maintains the majority of the heat in the combustion chamber in one area, instead of being spread throughout the combustion chamber. When heat is maintained in one particular area in any given combustion chamber, the increase in power will be much greater, especially at high rpm. Burning fuel within a combustion chamber will "find" or seek out the main heat source. The fuel will burn more thoroughly, allowing the engine to produce more power at any rpm. If the plug is located in the center of the combustion chamber, the incoming fuel could splash against the plug's tip and cause the engine to misfire or run erratic at high speed, especially when burning methanol fuel. And the plug could easily become fouled when burning gas, especially when the engine is being choked or primed with fuel to start it when it's cold. Return to previous page or paragraph.
Information about Ignition Coils -
Certain ignition coils require an
external ballast resistor (off any 1955-57 General Motors vehicle) or a
full-length resistance ignition wire (off any 1958-74 GM vehicle) to prevent
from putting too much voltage through the primary circuit and ignition points,
which could burn them up. A ballast resistor or resistance wire is basically
a voltage reducer that reduces 12 volts down to anywhere between 6-9 volts,
depending on the load. (The ballast resistor shown here is the same used
on the 1955-57 GM vehicles.) But if a coil reads "12 VOLTS" on its casing,
then it has a built-in resistor. A resistor may not be needed with many new
coils because most of them nowadays have a built-in resistor. And using a
resistor doesn't effect the voltage output of a coil. It only prevents from
burning it up, and it saves wear on the ignition points. The reason manufacturers
don't install a resistor inside some high-performance coils is because these
coils draw more amps from the battery. This causes the resistor to operate
at a higher temperature, which could overheat and damage the windings within
the coil. If you prefer to use a high-performance coil, when you purchase
one, be sure to ask the salesperson if it has a built-in resistor or if it
requires an external one. This is important for the life of the coil.
When testing a ballast resistor for voltage drop, it won't show any resistance unless there's a functioning load on it with electrical current going through it, such as the ignition coil and/or control module with the engine running.
With battery ignition, most high-performance ignition coils requires two condensers [connected to the ignition points] for quicker saturation at higher rpm but the points won't last as long because of the increased amperage that the coil draws. And a high-performance coil has no effect whatsoever with crank trigger ignition when using a Chrysler or Ford ignition control module. And most stock coils produce more than enough voltage for even the hottest high-performance engines built, especially when used with the crank trigger ignition.
And when replacing the ignition coil on a model KT17, KT19 or KT21 twin cylinder
Kohler engines, instead of using the high-dollar standard-output Kohler coil,
you can use two automotive-type canister coils with two condensers,
a 2-post Harley-Davidson coil
(this particular coil also fits Kohler engine models K482, K532, K582, K660
and K662), or a
GM DIS coil (Chevy 2 post coil) is used! The DIS coil part
numbers are AC Delco D555 or Standard Motor Products DR39X, and was used
in select GM vehicles from 1985 to the 2005, one of which is the 2005 Chevrolet
Impala. There's no certain way to connect the wires to the primary windings
in the
GM DIS coil. There is no positive or negative side. Just
connect the wires to either terminal, install a ballast resistor when using
points, and it should work great. The DIS coil is a high-output coil too,
so it'll be a good thing to use two battery ignition condensers.
What Cause Some Ignition Coils To Go Bad?
Some coils don't last forever. As the spark plug's electrode
deteriorates, the secondary windings within the coil is forced to produce
more voltage to fire the plug. Eventually, the increase in voltage will burn
out the windings, causing coil failure. This is why it's a good thing to
use quality-made spark plugs.
On the Briggs & Stratton, Kohler KT-series and Magnum
flathead and other makes of flathead twin cylinder engines that use a single
small ignition coil to fire two cylinders, after several years of use, sometimes
the coil (rather with points, Magnetron or Solid State) will fail to produce
a spark. This happens because one coil must fire two spark plugs at one time
with the plug gaps set at .030" each (factory setting). With these size of
gaps, this is the same as firing one spark plug with a gap of .060". Most
magneto coils are not designed to produce this much voltage and last a long
time. The coil is forced to produce more voltage than is necessary to fire
both plugs and this cause the secondary windings within the coil to overheat
and eventually burn out. And as the plugs deteriorate with age, the coil
is forced to produce even more voltage to make a spark through the weak plugs.
To lessen the chance of a coil going bad (again), set each plug gap at .015".
The .015" gaps will simulate having just one spark plug with a gap of .030",
and the coil will operate cooler and last much longer. The engine will still
start quickly and run the same with no loss of power whatsoever.
Or instead of doing the above, if an older Briggs & Stratton twin cylinder flathead engine has points, it can be easily converted to the more reliable and powerful battery ignition (for a hotter spark). The B&S ignition points can be still used, but two automotive canister-type ignition coils or a battery ignition coil with dual plug terminals (as described above È) with spark plug wires, and two battery ignition condensers will need to be used. The spark plug gaps can be set at .035", and the ignition timing can be set by the width of the points gap (.020") or with an inductive timing light after the flywheel is degreed in with timing marks.
And if you're wondering if rust on the flywheel magnets and/or ignition coil affects the magnetism or strength of the spark, well, this is the same as saying that pure, undiluted anti-freeze will freeze. Because I know for a fact that rust does not affect magnetism whatsoever. Don't just theorize about such things or believe what other people say, perform a scientific test to prove these kind of things to yourself. I do and I did.
And for anyone who's wondering, an ordinary automotive battery-type condenser with an automotive canister-type ignition coil will work on any one or two cylinder air-cooled engine that use the battery ignition system. But when using two automotive ignition coils on a twin or two cylinder engine with conventional points, be sure to use two condensers as well, one for each coil , only if the coil(s) requires one. Otherwise, the engine will idle, but won't rev up much. And there's a very little difference between the Kohler battery-type condenser and an automotive [Chevrolet/GM] condenser. So either can be used on a small engine.
Most
battery ignition coils will last the life of an engine. But if a quality
coil keeps going bad for no apparent reason, then there are three things
that will cause a good coil to go bad. They are:
- Lack of a ballast resistor or a resistor wire before the coil. (If the coil requires one.)
- Bad or defective voltage regulator or rectifier. If the charging system continues to charge with no "falling back" reading on the amp gauge, this will put too much voltage through the coil, eventually burning it up. If an engine has electronic ignition, this too could burn up the ignition control module, burn out light bulbs, electrical accessories and burn up a good battery by overcharging it.
-
If a garden tractor is equipped with an automotive battery,
it could have a dead cell or all the cells are weak. (Defective battery.)
Unlike in an automobile, and if the starter motor is in good condition,
a weak automotive battery will have more than enough cranking amps to crank
over a small, single- or two-cylinder engine with no problem, and a drop
in the battery's cranking amps wouldn't be that noticeable. Whether if it's
in a garden tractor or an automobile, an automotive battery with a dead cell
or weak cells will cause the charging system to continuously try to fully
recharge the battery, but instead of the battery taking full charge, the
charging system will put too much voltage through the coil for long periods
of time, causing the windings within to burn up. If an engine has a
battery-powered electronic ignition, this too, could burn up the ignition
control module, burn out light bulbs and electrical accessories. To determine
if a battery is defective, use a load tester for sealed-top batteries, and
for batteries with removable caps, test the battery's acid condition with
a hydrometer battery tester (glass tube with floating balls [pocket size]
or a floating bulb [full size]; which are available at virtually any auto
parts store).
How to Test the Strength of an Ignition Coil's Output Voltage -
The way I test a stock coil is I connect it in a circuit, like it's on an engine and if it produces a spark with at least a 3/4" wide gap, it's a good coil. A high-performance coil should produce a spark with a wider gap.
All
conventional point-type ignition systems that's installed on garden tractor
and automotive engines utilizes a standard output [20,000-30,000 volt] coil.
And all automotive electronic ignition systems utilize a high output
[40,000-60,000 volt] coil. The differences in these coils is by the height
of the center tower. The high output coil has a taller tower, to keep the
spark from shorting to the terminals. So if you want more spark, instead
of using a high dollar, aftermarket high-performance coil, you could just
use a low-cost automotive one that's designed for an automobile with electronic
ignition. (Early Chrysler and Ford products.)
On any ignition system, the voltage of the coil is the same at any rpm. The only way a coil will produce more voltage is when the spark plug gets weak or the gap on the spark plug is widened. The coil will produce less pulses of voltage at idle speeds and more pulses at higher rpm. But the amount of voltage will stay the same.
If you've ever experienced the metal strap on an ignition coil
of breaking due to normal engine vibration (especially at high rpm or
wide
open throttle) and because the metal itself is too thin, then what you
need to do is either fabricate a strap made of thicker metal, or install
two coil straps as shown in the picture to the right, and be sure to fasten
the straps securely. This will double the life of the clamps and lessen the
chances of either strap of ever breaking again.
Ever had a good run going down
the track and all of a sudden your engine dies, and then you found it was
because of a faulty ignition coil? Well, chances are it wasn't designed for
use on a garden pulling tractor. Even new oil-filled canister coils have
been known to fail in a very short time on a garden pulling tractor. The
reason some coils fail is due to single cylinder engine vibration running
at high rpm or
wide
open throttle. The tiny wires (or windings) inside the coil will vibrate
and break over time. Even the insulation on the windings themselves will
"rub" or scrape against the other internal wires, resulting in a short, and
eventual coil failure. That's why it's best to use an
epoxy-filled coil to prevent the windings from vibrating, shorting
out and/or breaking. The epoxy holds the wires solid, resulting in no vibration
of the windings whatsoever. Most epoxy-filled coils produce up to 45,000
volts, too. So for the little difference in price, accept no substitutes!
Epoxy-filled coils are most reliable for use on a garden pulling tractor.
Part numbers for epoxy-filled coils are: Borg Warner # BWD E81 (with an internal
resistor); OEM Kohler coil # 231281; NAPA # 7-01643; Borg Warner # BWD E40P
(requires an external resistor) and MSD 8232 coil. Most of these coils are
available on eBay, JEG'S (http://www.jegs.com),
Summit Racing
(http://www.summitracing.com), J.C. Whitney,
Inc. (http://www.jcwhitney.com) and many other sources also offers
epoxy-filled ignition coils.
All high-performance
or high-output ignition coils have more secondary windings than standard-output
coils. This is how they produce more voltage for a hotter spark. With a points
ignition system, when the energy of the primary windings within the coil
is transferred into the condenser, upon acceleration, sometimes a single
condenser isn't capable of handling the amount of electricity to fully energize
the secondary windings of a high-output coil at 100%
capacity, allowing the coil to produce a weak spark, and the engine will
fail to accelerate. The engine may idle fine, but upon acceleration, due
to the weak spark of having just one condenser, the increase of compression
within the combustion chamber when the throttle is opened will literally
"blow out the spark" at the spark plug's tip. If an engine idles fine, but
fails to accelerate or rev up successfully, and if either a high-performance
Bosch, HEI or some of type of high-output coil is being used, then perhaps
connecting a second condenser to the coil will allow the engine to rev up
with no problems. But with crank trigger ignition, if a quality control module
is used, the engine should accelerate with no problems
despite the type of coil is used.
Advertisement:
| If you need any of the items listed below, please contact
A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia,
MO 65203-9136 USA | Phone:
1-573-875-4033. Please call Monday-Friday, 9am to 5pm, Central time. If no
answer, please try again later. (When speaking with Brian, please be patient
because I stutter.) Fax:
1-573-449-7347. E-mail:
pullingtractor@aol.com. You can
also contact us through Yahoo! Messenger:
Points and Condensers |
|
 Ignition points for all
Kohler K-series single- and twin-cylinder flathead cast iron block engines.
Includes angle mounting bracket. For magneto and battery ignition systems.
Replaces Tecumseh: 32011, 32011A used on 6-20hp engine models HH80, HH100,
HH120 series with battery ignition. Fits: Clinton models 414, 418, 420, 422.
Kohler part # 47 150 03-S. NOTE: The NOVA II or Mega-Fire Solid
State Ignition Modules (below) can be substituted for the points and condenser
in a magneto ignition system.
|
 Condenser for all Kohler
K-series single- and twin-cylinder flathead cast iron block engines with
BATTERY ignition. Can be substituted for the Chevy condenser with
no problems. Wire length: approximately 4-1/2". Kohler part # 230722-S.
|
 Condenser for Kohler K-series
flathead cast iron block engines with MAGNETO ignition. (Most common.)
Body length: 33 mm, width: 17 mm. Kohler part # 47 147 01-S.
|
 Condenser for Kohler K-series
flathead cast iron block engines with MAGNETO ignition. Kohler part
# 220434-S.
|
 Complete Ignition
Tune-Up Kit for Kohler 4hp-16hp flatheads, 8hp OHV single cylinder and twin
cylinder K-series flathead cast iron block engines. Includes: points, condenser,
spark plug(s) and points cover gasket.
|
|
 Steel Points
Pushrod for K90/K91 (4hp), K141 (6¼hp), K160 (6.6hp), K161 (7hp) and
K181 (8hp) Kohler K-series flathead cast iron block engines. Made of hardened
steel. (To be no less than 1.250" in length. Measure the length of your
pushrod accurately to determine if it needs replacing.) OEM Kohler part
# 46 411 01-S. $8.80 each, plus shipping & handling.
Steel Points Pushrod for Kohler K-series models K241 (10hp), K301 (12hp), K321 (14hp), K341 (16hp) flatheads and K361 (18hp OHV) cast iron block engines. Made of hardened steel. (To be no less than 1.500" in length. Measure the length of your pushrod accurately to determine if it needs replacing.) OEM Kohler part # 47 411 04-S. $12.60 each, plus shipping & handling.  Stainless Steel Flared-End Points
Pushrod for Worn Points Lobe on Camshaft for for Kohler K-series models K241
(10hp), K301 (12hp), K321 (14hp), K341 (16hp) flatheads and K361 (18hp OHV)
cast iron block engines. Makes contact with unworn areas of points lobe on
camshaft for full advance of ignition timing. Can also be used on unworn
lobes for longer wear. NOTE: Must be installed from inside crankcase before
engine reassembly. An original concept by Brian Miller. Replaces Kohler
part # 47 411 04-S. $15.00 each, plus shipping & handling.
 |
|
 Ignition Points and Points
Cover Mounting Screw w/serrated star lock washer. Used to secure points bracket
and points cover to engine block. Size: 10-24 NC (3/16" diameter, coarse
thread). Replaces Kohler part # X-131-1-S. .50¢ each, plus shipping
& handling. |
 Grommet for ignition wire
in points cover. Fits all single cylinder K-series Kohler engines. Seals
out dust and dirt so points last longer. OEM Kohler part # 220297-S.
$3.00 each, plus shipping & handling.
 |
 Chevrolet (GM)
V8 adjustable ignition points that can be used on the Kohler K-series 10hp-16hp
and twin cylinder flathead cast iron block engines. NOTE: The "Chevrolet"
points and condenser are actually made for the 1957-1974 General Motors cars
and trucks with a V8 engine and Delco-Remy distributor. But these points
can be easily adapted for use on Kohler [pulling] engines with an adapter
bracket (see below) for easy adjustment of the ignition timing with an Allen
wrench. Has a stiff spring for quick response at high rpm. Due to
the inability to completely seal (cover) the points from dust and debris,
these are not meant for general yard use. They're for competitive pulling
only. And being the bracket for the GM points and the GM points themselves
are much larger than Kohler points and bracket, the OEM Kohler points cover
will not fit over the GM points and bracket. $10.00 each, plus
shipping & handling. |
|
  Sturdy and durable stainless steel angle bracket to mount Chevy
(GM) ignition points on a single cylinder Kohler engine. .070" thickness.
Will not rust. Very rigid and will not vibrate to fluctuate timing.
$15.00 each, plus shipping & handling.
NOTICE: The Chevy points covers for this bracket should be available soon! (The cover is only to prevent fuel from getting on points contacts, which could cause a fire.) NOTE: Being the bracket for the GM points and the GM points themselves are much larger than Kohler points and bracket, the OEM Kohler points cover will not fit over the GM points and bracket. |
|
 Solid State Ignition
Coil for Kohler Magnum models M10-M16 single cylinder flathead cast iron
block engines. Kohler part # 47 584 03-S.
|
|
Ignition Coil with
Molded-In Magnetron Module for Briggs & Stratton's horizontal and vertical
shaft models twin cylinder flathead engines. Briggs & Stratton part #'s
392329, 394891, 394988. NOTE: Set spark plug gaps at .015" for longevity
of coil.
|
|
Solid State Ignition
Coil for Kohler Magnum models M18, M20, MV16, MV18, MV20 twin cylinder flathead
engines. Kohler part # 52 584 02-S. NOTE: Set spark plug gaps at .015"
for longevity of coil.
|
|
 Ignition Coil
for Kohler flathead twin cylinder models KT17, KT17II, KT19, KT19II, KT21
engines. Kohler part # 52 755 48-S. NOTE: Set spark plug gaps at .015"
for longevity of the coil.
|
|
 Magneto coil for
Kohler engine models K161 (7hp) and K181 (8hp). Fits the U-shaped stator
under flywheel with rotating magnet on crankshaft. Spark plug wire not included.
OEM Kohler part # 231718-S.
|
|
  Magneto Ignition Coil for Clinton, Kohler K-series flathead
cast iron block and all aluminum block Tecumseh engines with point-type ignition.
Replaces Tecumseh part # 29632, 30546, 30560, 30560A, 610768, Tecnamotor
# 1633.0001, Kohler part #'s 231718-S, 232901 (obsolete), 238059 (obsolete),
47 755 20-S; Clinton # 135-13-990 and Phelon # FG-6240. Fits Clinton, early
Tecumseh and early Kohler K-series flathead cast iron block engines with
coil/stator under flywheel. Spark plug wire length: 17". Works great when
used with the NOVA II or Mega-Fire modules (see below). Dimensions: 393"
x .393" center square hole x 1.050" width x 1.62" o.d. If laminations on
stator are too big for center hole in this coil, grind or file them down
so coil will fit snug, then bend one laminate to retain coil. Coil will still
produce a hot spark. Click here
for identification and wiring diagram for this coil. How coil
produces a spark: As the magnet in the flywheel pass the laminations on the
stator, this creates a magnetic field that energizes the primary windings
within the coil. This energy (electricity) is stored in the condenser. When
the points open, the electricity from the condenser is sent to the secondary
windings in the coil & a spark is created. The coil needs to fit snug
on the laminations to receive the full effect of the magnetic field from
the magnets to energize the coil.
|
|
NOVA 2, Mega-Fire and Kohler OEM Electronic
Transistorized Solid State Ignition Modules
[Return to a previous section]
|
|
  Quality Copper Core Spark Plugs. NOTE: Listed below
are the most commonly used plugs. Other types of spark plugs are available.
When ordering, please specify make and model of engine.
|
|
 Spark Strength Tester. Handy,
easy to use, simple clamp-on style. $6.00 each, plus shipping &
handling. |
 Durable OFF/ON Toggle Switch
w/Lead Wires. Can be used for battery/magneto/crank trigger ignition, electric
cooling fan, electric fuel pump or to cut-off charging system for pulling.
$5.00 each, plus shipping & handling. |
 Heavy duty, standard output
(20,000 volts) 12 volt oil-filled canister battery ignition coil. 2" diameter.
Can be used on most garden tractors, older farm tractors, virtually all pre-1974
automobiles and crank trigger ignition systems. Requires no external ballast
resistor and can be used with one ordinary condenser. And spark plug gap
should be set at .035" with this coil. Kohler part # 41 519 21-S.
|
 Heavy duty, high output
(40,000 volts) 12 volt oil-filled canister battery ignition coil. 2" diameter.
Automotive coil. Can be used on most garden tractors, older farm tractors,
pulling tractors and with crank trigger ignition systems. Requires an
external ballast resistor and for best performance, use with two ordinary
condensers or one high-capacity condenser. And spark plug gap can be set
at .060" with this coil.
|
 Quality Black Hypolon Cover
Copper Core Spark Plug Wire. 7mm diameter, 25" long. Stranded copper wire
for more flexibility and better spark delivery. Kohler part #'s 238057-S,
25 348 01-S, 48 348 04-S.
|
New Ballast Resistor. Required
for coils that need one. Also required for the Chrysler ignition control
module. $7.00 each, plus shipping & handling. |
| Battery Ignition
System Conversion Kit.
Convert virtually any single cylinder, air-cooled cast iron or certain aluminum block small gas engines that originally came with a magneto ignition system (having points, condenser, and ignition coil that has voltage generated by a set of permanent magnets in the flywheel, instead of being powered by a battery) into a battery ignition system. Kit includes a new automotive/canister-type ignition coil, condenser and 25-1/2" long 7mm copper-core spark plug wire. NOTE: Use the OEM points, set the gap at .020" for correct ignition timing and use the same type of spark plug, but set the gap at .035" for a hotter spark. Click here for wiring diagrams.
|
|
| New points, condensers and spark plugs for other makes and models of engines are also available. Please call or email me for your needs. | |
 Dixson Precision Handheld Wireless Analog Tachometer
Accurately determine the rpm of any air-cooled small gas engine by using a quality wireless tachometer, such as the handheld tach by Dixson. This is a precision handheld solid state wireless tachometer with an analog reading. The antenna is held near the spark plug wire and it gives a correct reading rpm for all 2 and 4 cycle single and twin cylinder engines with magneto or battery ignition. Selector switch gives 0-5000 RPM low scale or 0-15000 RPM high scale. Note: Divide the reading by half on engines with camshaft operated ignition points. Works perfect when performing a tune-up, setting the rpm on all stock pulling tractors when rules require a limited rpm, and testing the rpm on high-performance engines. Uses one 9 volt battery, which is included with purchase. Manufactured by Dixson. $100.00 each, plus shipping & handling. Top of page |
|
There is absolutely no difference
how these modules work. They all work the same. Kind of like the difference
between a Chevy, a Dodge & a Ford. These are universal and high-performance.
They improve engine performance by stabilizing the spark, much like crank
trigger ignition does. The NOVA 2 & Mega-Fire have a durable die-cast
aluminum housing. They all produce a hot spark even at cranking speeds, allows
the coil to produce 100% voltage. Weather-proof and very reliable. Ignition
timing is automatically set. No kick-back and no timing adjustment required.
Works excellent with virtually any magneto ignition coil!
Typical Battery (Points and Condenser) Ignition System for a Garden Tractor
If an ignition coil has a BUILT-IN resistor, connect the wires as shown
below...
But if a coil requires a ballast resistor, connect the wires as shown
below...
How to set the points on a Kohler engine -
Adjust the points by first positioning the piston at TDC on the compression stroke. Then slightly loosen the set screw on the points and place the flat screwdriver in the slot on the upper part of the points bracket to widen and narrow the point gap. Then use a .020" feeler gauge to set the gap.
For a more accurate setting of the ignition timing, use an inductive timing light with the engine running at an idle. This cannot be done with an aftermarket steel flywheel having no timing marks.
On a Kohler engine, if the screw that fastens the points to the bracket is hard to get at with a screwdriver on the equipment, then install an Allen head screw and use an angled Allen wrench to adjust the points.
NOTE: If the ignition timing is set right and the engine kicks back when trying to start, sometimes, but not always, the compression release isn't releasing enough compression from the combustion chamber. Try setting the valve clearances to specs and see if that makes a difference. If the timing is retarded to reduce the possibility of kickback, then the engine will run sluggish and not produce enough power.
Setting the [Point] Ignition Timing on Virtually Any Small Gas Engine - Top of page
The point gap on virtually all 4-cycle small gas engines, rather if it has one or two cylinders, is set at .020" using a feeler gauge with the piston positioned at TDC on the compression stroke. This is when the valves (#1 cylinder for a twin cylinder) are fully closed. This sets the ignition timing approximately at 20° BTDC (Kohler engines), and is the most easiest and simplest way to basically set the timing. A better way is to statically set the timing. But the most accurate way is use an inductive timing light to dynamically set the timing.
To statically set the ignition timing on an engine with a stock flywheel is with a multimeter (analog or digital) set on OHMS, or with a 12 volt test light and a battery or 12 volt power source to power the light. To make this happen...
-
Connect one lead of the multimeter
or test light to the ignition points terminal screw or the points wire
(disconnect it from the ignition coil first) and the other lead to engine
or tractor ground so that the points will serve as a switch to activate the
meter or light. To test the connection, set the points gap at .020" with
a feeler gauge and then slowly rotate the crankshaft (flywheel) back and
forth when the points open and close to see if the meter is activated or
light comes on and goes off. IMPORTANT: Always clean new or used points
contacts with a wire wheel, quality steel fingernail file, a small, thin
steel "point file" or small, thin special purpose file to remove any oxidation
(light corrosion) that can form on the platinum while in storage. If this
isn't done, it could cause a faulty connection. After setting the gap, close
the gap (by rotating the crankshaft) and pull a clean piece of white lint-free
paper through the contacts to remove any oil or dirt that may not be visible
to the naked eye on them. Don't use sandpaper or emery cloth to clean the
contacts! They'll leave grit between them (which is hard to remove) and cause
a bad connection.
-
On Kohler flywheels, there should
be a T and an S stamped into the edge
of the flywheel. Place a bright colored paint mark on the S mark
[punched line] on the flywheel. The S mark is located exactly
20° BTDC (above) the T mark. S stands for Spark
Advance, which is where the timing is set if the engine is equipped with
a one-piece camshaft that has a compression release mechanism. T stands
for TDC, which is where the timing sets if the engine is equipped with an
older two-piece camshaft. The flywheel may need to be cleaned to see the
timing marks. If there is no visible S mark, then it's located exactly
1-5/8" (1.625") above the T mark. This cannot be done with an aftermarket
steel flywheel having no timing marks. Steel flywheels must be degreed-in
to create new timing marks.
- If there's a timing site hole in the rear of the bearing plate, then the timing marks are on the backside of the flywheel. If the marks can't be seen, then the flywheel will need to be cleaned off and depending on type of camshaft, a bright colored paint mark needs to placed at the T (older two-piece cam) or S mark (newer one piece cam).
- Slowly rotate the flywheel back and forth by hand when the timing marks are aligned and at the same time observe the ohmmeter or test light. The ohmmeter should show an intermittent connection or the test light should flicker. If necessary, widen or narrow the points gap until the points make contact the exact same time the timing marks are aligned. It is at this position when the ignition timing is accurately set.
- Timing for gas fuels - usually 22° (low octane) to 30° (high octane) BTDC.
- Timing for E-85 fuel - 25° BTDC.
- Timing for methanol or methanol/nitro mixture - usually 25° to 35° BTDC.
- It's a good thing to check the timing periodically as the points contacts wear.
Another simple
way to set the ignition timing is to use a dial indicator to measure the
distance of the piston from the top of the block. On the 10hp Kohler engines,
the points just begin to open when the piston is located exactly at .125"
BTDC. And on the 12, 14, 16hp flathead engines and 18hp OHV engine, the points
just begin to open when the piston is located exactly at .100" BTDC. Distances
shown is when the S mark on the flywheel is aligned with the mark on the
bearing plate. Take into consideration if the piston doesn't come flush with
the top of the block, or if it pops out of the cylinder.
EXCEPTION: When setting the ignition timing on an older
Kohler engine with the old
style two-piece camshaft, set the points so they just begin to open with
the piston positioned on the compression stroke at 0° TDC (T mark on
the flywheel). As soon as the engine starts, the points lobe rotates on the
cam pin and flyweights on the cam gear automatically advances the timing
to 20° BTDC. Don't set the initial timing at 20° BTDC (S mark)
with the old style two-piece camshaft. Due to the absence of a compression
release (these engines start under full compression), setting it at 20°
BTDC will advance the timing too much and cause the engine to "kick back"
when trying to start.
How To Read A Dial Indicator -
Each mark on the face of a dial indicator represents one thousand of an inch (.001") graduations. The marks with a number (10, 20, 30, etc.) represents every ten thousands (.010"). Depending on the size of the engine, for a reading of .050" or .070" BTDC, first, run the piston up at true TDC, then set the dial indicator at the .050" or .070" mark. Then, slowly rotate the crankshaft in opposite of normal engine rotation until the needle reads 0 degrees BTDC. The needle will move in the counterclockwise direction (back to the 0 degree mark) as the piston moves downward in the cylinder.
Where
is the Timing Site Hole in the Flywheel Shroud?
On the small [8"] flywheel without the starter ring gear and with the starter/generator, the timing site hole is on the right when facing the front of the flywheel, or on the same side as the starter/generator. But on the large [9-1/2"] flywheel with the starter ring gear and gear starter, the timing site hole is on the left when facing the front of the flywheel, or on the same side of the carburetor.
To set the ignition timing on the 7hp and 8hp Kohler engines, there's a sight hole in the backside of the bearing plate on the starter/generator side, just behind the flywheel. It has a metal hole cover plug in it. Remove the plug and then slowly rotate the flywheel by hand until you see the S mark. Place a white paint mark on the line. Now connect an inductive timing light, start the engine and then note if the mark appears midway in the sight hole. If not, adjust the points until the mark is centered in the hole. This is how you set the ignition timing with a timing light.
It is recommended that a steel
flywheel be degreed in on an engine to locate true TDC. Mark the flywheel
every 5 degrees out up to 35 degrees BTDC. Note: With a steel cam and ground-on
point lobe, do not correlate points gap with engine timing – there is
a range from approximately 10 degrees BTDC to 40 degrees BTDC! Use a continuity
tester to set points to desired ignition timing by gapping points.
Ignition timing must be properly set for any engine for it to produce full power. Ignition timing is set according to when the piston reaches its Before Top Dead Center (BTDC) position in the cylinder on the compression stroke. When measuring the piston distance, take in consideration if a piston "pops" out of the cylinder or if it doesn't come flush with the top of the block. And don't trust strange markings on the flywheel.
For precise accuracy, use an ohmmeter or a test light in the points circuit, a dial indicator to measure the distance of the piston in the cylinder, fasten a degree wheel to the crankshaft flywheel end and you'll need to fabricate a piston stop. On a flathead engine, to serve as a piston stop, a long reach spark plug can be used, and the cylinder head must be positioned so the spark plug is over the piston.
A dial indicator, degree wheel and piston stop are also used in
degreeing in the camshaft. Check your local automotive
parts supply stores for a 12 volt test light, dial indicator and degree wheel.
If they don't have them in stock, they can probably order them for you. But
a piston stop will probably have
to
be fabricated from scratch.
With an aftermarket steel flywheel or a stock flywheel with no timing marks, the most accurate way to set the ignition timing [on virtually any engine] is performed by measuring the distance of the piston before it reaches top dead center with a dial indicator in conjunction with a degree wheel fastened to the crankshaft flywheel end. To learn more, read on....
Find TRUE Top Dead Center (TDC) on an Engine with a Steel Flywheel to Accurately Set the Ignition Timing! Parts needed are a degree wheel and a piston stop. Or on a flathead engine, a long reach spark plug can be used, and the cylinder head can be positioned it so the spark plug is over the piston.
- Connect the ohm meter or test light as described above.
- Remove the cylinder head from the engine.
- Fashion a rigid pointer from stiff wire or an old coat hanger and attach it to the engine block. This pointer locates the degrees on the degree wheel.
- With a degree wheel installed on the flywheel or PTO end of the crankshaft, and with the flywheel fastened onto the crankshaft, rotate the crankshaft by hand in normal running rotation until the piston at the very top of the cylinder with both valves fully closed (this is the Top Dead Center position on the compression stroke), and then adjust the pointer to zero (0º TDC) on the degree wheel.
- Now turn the crankshaft opposite the running rotation approximately 15-20 degrees. Install a piston stop on the top of the engine block fastened in place by two head bolts. NOTE: If a piston pops out of the cylinder at TDC, then to use a piston stop, you'll need to install several flat washers or a spacer between the piston stop and engine block so the piston will clear it and go past the TDC mark.
- Continue to turn the engine in the same direction until the piston comes back up and just touches the piston stop. Make a note of the exact number on the degree wheel that the pointer is on.
- Rotate the engine in the other direction (running rotation) until the piston comes back up and touches the piston stop. Again note the number where the pointer is.
- Remove the piston stop and rotate the crankshaft to the midpoint of the two marks. At this point the piston is at the true top dead center. Loosen the degree wheel and adjust it so it will read 0º TDC at the pointer. Don't rotate the crankshaft to do this!
- Slowly rotate the engine in reverse normal rotation. The test light should be on. If not, adjust the points so it is on.
- Rotate the crankshaft by hand in its normal direction until the degree wheel is where you want the timing to be set at (20º) and then adjust the points so they just begin to open. The test light should've gone off or flickered by now. If not, set the points so they just start to open and the light flickers. Once the degree wheel is in the proper position, the breaker points should just begin to open. Or, when using Crank Trigger Ignition, check or set the initial timing by positioning the center of the magnetic pickup coil or inductive proximity sensor with the center of the trigger screw or small raised portion of the rotating disc. It is at this moment when spark occurs. And it's at this point that the ignition timing is set correctly. Mark the flywheel or front pulley where the timing marks are on the degree wheel for setting the timing with an inductive timing light in the future.
Setting the Ignition Timing with an Automotive Inductive or Non-Inductive Timing Light -
NOTE: The above method is sufficiently accurate and useful in building a fresh engine and not having to mess with adjusting the points just to get the engine started for the first time. However, after getting the engine started, it's always a good thing to use either a non-inductive or inductive timing light to check to see if the timing is truly set where it's supposed to be. This is called setting the timing dynamically. Use a timing light when the timing marks on both the bearing plate and flywheel are perfectly aligned. The ignition timing setting for Kohler engines burning GAS is 20-22° BTDC. NEVER run over-advanced timing (beyond the 22° setting) with gas just to try to get "more power" out of an engine! All that'll do is seriously overheat the engine and ruin parts. Return to previous paragraph. Ê
To use a non-inductive timing
light (these are very old and are considered obsolete), connect one lead
on the spark plug (on a twin cylinder engine, connect it on the #1 cylinder
spark plug) and the other on the coil, and then start the engine.
To use an inductive timing light, the engine can be running while connecting the clamps on the battery posts in their respective order, and then connect the inductive pickup on the spark plug wire. On a twin cylinder engine, connect it on the #1 cylinder spark plug wire. (The #1 cylinder is the one closest to the flywheel.) If using an inductive timing light with an advance adjustment, make sure it's set at 0 (zero) before checking the timing on the S mark.
If an engine has a compression release on the camshaft and the valve clearance is set right (at least for the exhaust valve), chances are the engine won't "kick back" (when the flywheel/crankshaft suddenly and violently rebounds in the opposite direction) when cranking it over to start it if the timing is set over-advanced. (This is terribly hard on the starter gear and armature shaft.) Therefore, this would be a false indication that the timing is set correctly. Always check it with a timing light to make sure!
The ignition on Kohler engines aren't like the ignition on most automotive engines. You don't dwell-in the points on a Kohler engine. Instead, you set the point gap at .020" just to get the engine running. Then you set the ignition timing by widening or narrowing the points gap until the timing is at 20° BTDC by observing the alignment timing marks on the flywheel.
This is how to set the [point] ignition timing on older Tecumseh engines - Top of page
First of all, on virtually any spark-ignition engine, advancing or
retarding of the ignition timing is performed by widening (advancing) or
narrowing (retarding) the ignition point gap, and on Tecumseh engines, it's
also performed by rotating the stator. (The thing the points, condenser
and coil are fastened to.) On a Tecumseh engine, the points gap is supposed
to be set on the high spot of the rubbing block or points lobe that's on
the crankshaft, located underneath the flywheel. There are no points lobe
on the camshaft.
NOTE: If the ignition timing is set right and the engine kicks back, sometimes, but not always, then the compression release isn't releasing enough compression. Try setting the valve clearances to specs and see if that makes a difference. If the timing is retarded to reduce the possibility of kickback, then the engine will run sluggish and not produce enough power. |
The timing also greatly depends on where the spark plug is located in the combustion chamber. Most plugs are centered in the combustion chamber. But if it's closer to the exhaust valve, the timing must be advanced slightly more.
For METHANOL fuel, if the spark plug is positioned in the center of the combustion chamber, set the timing at 24-26° BTDC. If the plug is located closer to the exhaust valve, the timing needs to be set to about 30°. If the plug is directly over the exhaust valve, the timing needs to be at 38° to obtain full power. 38 degrees is the maximum setting for methanol fuel. Location of the spark plug in the combustion chamber and proper ignition timing are two things that's very important in engine performance. Actually, it's best to set the timing with some test pulls or with the engine connected to a dynamometer or "engine dyno." Return to a previous page or paragraph. Return Ê
Isn't it a pain having to constantly adjust or set the ignition timing on a Kohler pulling engine? To fix this problem, the best type of ignition points to use for pulling are ordinary Kohler points. The spring on Kohler points is much stiffer than the one on Chevrolet (GM) V8 points. And because the clamping screw locks in position, the adjustment won't slip with Kohler points due to normal engine vibration. Chevy points are fancy to show off and convenient because they make it so much easier to adjust the ignition timing. But they will sometimes get out of adjustment because it's difficult (if at all possible) to lock the adjusting screw in position.
How to Fix the Problem with a Worn Points Lobe on the Camshaft -
Sometimes the points lobe on a single cylinder Kohler camshaft will become worn or have a groove worn into it so badly that the ignition timing can't be advanced enough to get adequate power out of the engine. There's a way to fix this, and there's no need to purchase another camshaft or do welding on the points lobe. Simply install a nut on the pushrod. The nut will make contact with the outer unworn areas of the lobe, allowing full advancement of the timing as if the lobe wasn't worn at all. To fix the problem with a worn points lobe...
- Completely disassemble the engine and remove everything from inside the crankcase.
- Acquire a hardened steel 10-24 NC or 10-32 NF (thread size) x 3/8" (wrench size) hex nut.
- Cut very short threads perpendicular on one end of the pushrod. To maintain correct pushrod length, cut the length of the threads the same thickness of the nut.
-
Install the nut on the
rod. The nut is threaded onto the pushrod and jammed where the threads
end. And if you're concerned about the nut coming off the pushrod while in
use, well, it'll be impossible for it to come off because for one thing,
the nut will be jammed tight against the short threads on the pushrod. And
when
Loctite® Threadlocker Red 271™ or
Permatex® Red Threadlocker is applied, this will secure
the nut even better.
The minimum length of the Kohler 10-16hp
flatheads and 18hp OHV engines points pushrod is 1.500" and the maximum length
is 1.600". And the minimum length of the Kohler 7hp and 8hp engines points
pushrod is 1.250" and the maximum length is 1.260". If it's too long, the
points' contacts won't touch and the rod will need to be shortened. But if
the rod is too short, the contacts won't open enough or at all and the rod
will need to be replaced with a longer one. So measure accurately before
(re)installing! The minimum diameter of each pushrod is .184".
- On the 7hp and 8hp Kohler engines, the nut will need to be reduced in diameter (in a small metal lathe), and the inside of the block will need to be ground away for clearance of the nut.
- Remember that the pushrod must be inserted from inside the block before the camshaft is reinstalled!
- This can also be done for an unworn lobe, to keep it from wearing later.
- See image below for a better understanding. Ê
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| If you need a part listed below, please contact A-1 Miller's Performance
Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday, 9am to 5pm, Central time. If no answer, please try again
later. (When speaking with Brian, please be patient because I stutter.)
Fax: 1-573-449-7347.
E-mail:
pullingtractor@aol.com. You can
also contact us through Yahoo! Messenger:
Steel Points Pushrod for K90/K91
(4hp), K141 (6¼hp), K160 (6.6hp), K161 (7hp) and K181 (8hp) Kohler K-series
flathead cast iron block engines. Made of hardened steel. (To be no less
than 1.250" in length. Measure the length of your pushrod accurately to determine
if it needs replacing.) OEM Kohler part # 46 411 01-S. $8.80 each,
plus shipping & handling.
Steel Points Pushrod for Kohler K-series models K241 (10hp), K301 (12hp), K321 (14hp), K341 (16hp) flatheads and K361 (18hp OHV) cast iron block engines. Made of hardened steel. (To be no less than 1.500" in length. Measure the length of your pushrod accurately to determine if it needs replacing.) OEM Kohler part # 47 411 04-S. $12.60 each, plus shipping & handling. Stainless Steel Flared-End Points
Pushrod for Worn Points Lobe on Camshaft for for Kohler K-series models K241
(10hp), K301 (12hp), K321 (14hp), K341 (16hp) flatheads and K361 (18hp OHV)
cast iron block engines. Makes contact with unworn areas of points lobe on
camshaft for full advance of ignition timing. Can also be used on unworn
lobes for longer wear. NOTE: Must be installed from inside crankcase before
engine reassembly. An original concept by Brian Miller. Replaces Kohler
part # 47 411 04-S. $15.00 each, plus shipping & handling.
More of our parts & services: Conventional Ignition, Electrical and Crank Trigger Electronic Ignition Parts and Kits |
If
doing the above doesn't help to advance the timing quite far enough (for
gas and especially methanol fuel), grinding (and polishing) of the lobe may
need to be done. Grind about .050" deep into the surface just before the
lobe (see drawing to the right) and about 1/2" from the lobe to right
next to the lobe, but not on the lobe itself! A die grinder with a porting
stone works excellent for doing this. After doing this, the timing can then
be advanced as far as 50º BTDC!
By the way - to keep crankcase oil from getting on the ignition
points on a Kohler engine, install a new [hardened steel] points pushrod
and/or if the hole is worn in the block, install a small snug-fitting
rubber/neoprene O-ring on the points pushrod. Place the O-ring on the outside
and close to the engine block. The oil will travel out to the O-ring and
drip off, staying off the points. But if the hole for the points pushrod
is excessively worn, the block will need to be machined for installation
of a bronze sleeve bushing. FYI - Bearing bronze is porous, very
hard, and lasts a long time when lubricated and used as a bushing. Brass,
on the other hand, is soft, non-porous and wears quickly when used as a
bushing.
Be Professional With Your Wiring!
When connecting the wires for
an electrical system, don't just make a connection by twisting the wires
together by hand and then taping them up. All this does is allow moisture
between the wires and in time, lets corrosion set in, causing a faulty
connection. Instead, solder the wires together, then tape them up electrical
tape or use heat-shrink wrap of the correct size. Or use "crimp" style wire
connectors to connect the wires together or to connect a wire onto a coil,
switch or terminal. Route the wiring along the inside of the frame in a safe
manner, away from any rotating parts, hot exhaust areas and for a "clean"
and professional look.
And if using an automatic reset
circuit breaker instead of an in-line fuse holder, don't fasten the circuit
breaker to anything solid, such as the steering column or metal part of the
tractor! Allow it to dangle free, but wrap some electrical tape around it
so the terminals won't short out against any metal part of the tractor. The
reason it shouldn't be mounted solid is because at high rpm, normal engine
vibrations will momentarily cause the "flapper" or contact spring inside
the breaker to become disconnected, causing the engine to run erratic, misfire
or "cut out" while going down the track.
Ignition System Options - Top of page
If a Kohler K-series engine originally came with points and condenser ignition, and you're looking for a more reliable and maintenance-free ignition system, well, you have these options...
- If the engine has magneto ignition, do away with the points and condenser, and install a NOVA 2 solid state ignition module, like the one I sell.
- If the engine has battery-powered ignition, do away with the condenser, and install the PointsSaverTM from Kirk Engines (http://www.kirkengines.com) for longer points life.
- Install the ignition and related components off of a Magnum engine. The parts needed are: Magnum bearing plate, starter motor, flywheel w/fins, flywheel shroud and solid state ignition coil (the Magnum ignition system is very similar to Briggs & Stratton's Magnetron ignition). If the engine has battery ignition, a different ignition switch will be required, one that's for magneto/solid state ignition because the Magnum ignition coil needs to be grounded to shut off the engine, and is not powered by the battery/electrical system.
-
Install the crank trigger ignition
setup as described in this web site. Install a small "bump" on the edge of
the flywheel to trigger the ignition. On a K-series flywheel, the "bump",
for the detection of the sensor, will need to be a 3/8" (wrench size) x 3/16"
thread diameter hardened steel hex head bolt (screw), and must be set at
20° BTDC for correct ignition timing (for gas). Use the two mounting
hole bosses that's at the 10:00 position in the bearing plate
(originally for mounting of Kohler's
Breakerless Trigger unit) to fasten a fabricated steel bracket to mount the
sensor. You'll also need a battery/electrical system to power this type of
ignition.
If a Kohler K-series engine originally came with breakerless ignition and it quit functioning, and you're looking for an alternative ignition system, well, you have these options...
- Install points, condenser and battery coil to convert it to battery ignition.
- Install the ignition and related components off of a Magnum engine. The parts needed are: Magnum bearing plate, starter motor, flywheel w/fins, flywheel shroud and solid state ignition coil (the Magnum ignition system is very similar to Briggs & Stratton's Magnetron ignition). If the engine has battery ignition, a different ignition switch will be required, one that's for magneto/solid state ignition because the Magnum ignition coil needs to be grounded to shut off the engine, and is not powered by the battery/electrical system.
- Install the crank trigger ignition setup as described in this web site. Install a small "bump" on the edge of the flywheel to trigger the ignition. On a K-series flywheel, the "bump", for the detection of the sensor, will need to be a 3/8" (wrench size) x 3/16" thread diameter hardened steel hex head bolt (screw), and must be set at 20° BTDC for correct ignition timing (for gas). Use the two mounting hole bosses that's at the 10:00 position in the bearing plate (originally for mounting of Kohler's Breakerless Trigger unit) to fasten a fabricated steel bracket to mount the sensor. You'll also need a battery/electrical system to power this type of ignition.
If the solid state ignition on a Kohler Magnum engine quit functioning, and you're looking for an alternative ignition system, well, you have these options...
- Purchase a new high-dollar solid state module and put it back the way the factory intended. (If part is available.)
- Drill new holes and cut threads in the side of the block to mount ignition points, install a condenser and a battery ignition coil. You'll also need a battery/electrical system to power the ignition.
- Install the crank trigger ignition setup as described in this web site. Install a small "bump" on the edge of the flywheel to trigger the ignition. On a K-series flywheel, the "bump", for the detection of the sensor, will need to be a 3/8" (wrench size) x 3/16" thread diameter hardened steel hex head bolt (screw), and must be set at 20° BTDC for correct ignition timing (for gas). Use the two mounting hole bosses that's at the 10:00 position in the bearing plate (originally for mounting of Kohler's Breakerless Trigger unit) to fasten a fabricated steel bracket to mount the sensor. You'll also need a battery/electrical system to power this type of ignition.
Crank Trigger Electronic Ignition Section - Top of page
Okay, so you've got a fancy carburetor or fuel injection, custom-machined billet cylinder head, larger valves, high-performance camshaft, forged piston, billet connecting rod, steel crankshaft, etc., but you're still running the old-fashioned points and condenser ignition system? Use the latest state-of-art technology! Upgrade to Crank Trigger Electronic Ignition for durability and to be truly competitive on the track!
This is the era of modern wonders, where everything is transistorized, digitized and miniaturized. Yet even today, many garden tractor pullers still use breaker point ignitions on their garden pulling tractors. For other people, the frustration of attempting to keep a breaker point-fired tractor in peak running condition has been enough of a reason to join the electronic era. Breaker point systems do have some positives, though. Points are cheap and somewhat easy to install. And many pullers are comfortable with setting-up their points. But for the utmost precision ignition timing and maintenance-free convenience, crank trigger electronic ignition is the way to go!
Tired of changing or constantly adjusting the ignition points? Convert to electronic ignition! For improved performance, easier starting, and less moving parts to leave your tractor dead on the track. Shock and moisture resistant, and all it takes is a few simple hand tools to install. In my opinion, getting rid of the points and condenser has been the best advance ever in engine technology.
FYI: The crank trigger ignition isn't my idea or my "product". Like most of my other pulling tips & tricks, it's something that I presented to the public, made them aware of it. - Brian Miller
Virtually Any Engine Can Be Converted To Crank Trigger Ignition!
If an engine is connected to a battery (and if it has a charging system to keep the battery fully charged for prolong use), and if there's room on the PTO end of the crankshaft for the trigger disc, and a place to mount the bracket for the magnetic pickup coil or inductive proximity sensor, then the engine can be converted to crank trigger ignition!
Stable ignition timing is a necessity in high-performance engines. In most cases, a points ignition will do just fine, but when you start making big time horsepower with extreme cylinder pressures and higher rpm, the timing is critical to both the performance and life of the engine. The ignition must be triggered at a precise time in relation to the position of the piston during the compression stroke. However, the timing can get erratic or fluctuate at higher rpm with the points system, due to camshaft end play, clearance in both the crank and cam gears and mechanical flexing that takes place through the camshaft support pin, especially when using a high lift cam with very stiff valve springs. In fact, if you ever checked the timing on an engine with camshaft-operated points using an inductive timing light, you may have noticed that the timing marks will fluctuate or "jump up and down" a few degrees. And it'll fluctuate more as the engine rpm increases. This won't happen with crank trigger ignition. It totally eliminates spark scatter or fluctuations and erratic timing problems common with point ignitions. With crank trigger ignition, the "tighter" the main bearings are, the more stable the timing is.
When checking the timing with an inductive timing light on an engine with crank trigger and main ball bearings, it's best to run the engine until it reaches normal operating temperature. The reason for this is the free play in the ball bearings is lessened as the bearings get warm, providing a more stable spark.
The crankshaft knows exactly where the piston is, plus it is the most stable component in an engine in relation to piston position. That's why a crank trigger ignition is so important in high-horsepower/high rpm engine applications. With this ignition, you get absolutely stable timing with ± 1/10th of a degree of accuracy from 0 to 15,000+ rpm without missing a beat (depending on the size of the transistor in the control module). The ± 1/10th of a degree is the result of the clearances in the main bearings. With a quality electronic ignition control module, the crank trigger ignition system will work flawlessly without missing a hit even if an engine can turn up to 100,000 rpm! Because it works as fast as electricity can travel. As long as it's installed and adjusted correctly, it'll help an engine scream down the track. Also, with the crank trigger ignition system, you can set the ignition timing and forget it!
Crank trigger ignition is when the mechanical breaker points and condenser are totally eliminated and replaced by solid state transistorized circuitry. Actually, it works on the same principle as the electronic ignition that's used in the older automobiles (before computerized ignition systems). The conventional points ignition system is considered as old-fashioned technology by today's standards. Even the [high dollar] aftermarket adjustable ignition plate that's made for Chevy points is considered old-fashioned by today's standards!
Using points versus crank trigger is up to you. Personally, I prefer the
crank trigger setup because it's very reliable and virtually maintenance
free. With conventional ignition, the points will ALWAYS go bad or wear out.
The contacts on points can get dirty, worn, burnt, oily (oil seepage from
the crankcase), out of adjustment, wet (whenever the tractor is washed off
or rained upon) or even oxidized (light corrosion). The use of a high-performance
(high output) ignition coil can also shorten the life of points. And the
condenser can go bad. Because a high-performance ignition coil draws more
amps from the battery, they will sometimes burn a good set of ignition points
in a short time. But high-performance ignition coils have no effect whatsoever
on the GM, Chrysler or Ford electronic ignition control module (ECU), even
if two automotive-type canister coils,
a
2-post Harley-Davidson coil
(this particular coil also fits Kohler engine models K482, K532, K582, K660
and K662), or a
GM DIS coil (Chevy 2 post coil) is used! The DIS coil part
numbers are AC Delco D555 or Standard Motor Products DR39X, and was used
in select GM vehicles from 1985 to the 2005, one of which is the 2005 Chevrolet
Impala. There's no certain way to connect the wires to the primary windings
in the
GM DIS coil. There is no positive or negative side. Just
connect the wires to either terminal, install a ballast resistor when using
points, and it should work great. The DIS coil is a high-output coil, too.
And crank trigger ignition is much safer than points. Because ignition points
creates a spark (which is normal), there's always danger of a fire if there's
ever a fuel leak. The only spark that occurs with crank trigger ignition
is at the spark plug's tip.
At
very high rpm (well above 4,000 rpm), with conventional points and condenser
ignition, the ignition coil operates at about 80% efficiency. The same is
true with high-performance coils because they require more amps. But with
crank trigger ignition using the Chrysler or Ford electronic ignition control
module, any type of coil operates at 100% efficiency at any
rpm, which produces a much hotter spark. This is why General Motors refers
to their 1974-'86 electronic ignition as HEI, or High Energy Ignition. The
reason there's a hotter spark is because at higher rpm, there's no condenser
to break down the voltage in the primary circuit in the coil.
When a magnetic pickup coil is used with crank trigger ignition, the duration of each spark lasts about twice as long than with points and condenser ignition. And when an inductive proximity sensor is used with crank trigger ignition, the spark duration is about 4 times longer than with points and condenser ignition, because an inductive proximity sensor can detect the trigger screw at the farther distance than a magnetic pickup coil. A longer spark duration burns the fuel more thoroughly, especially at very high rpm, resulting in more power. Although an inductive proximity sensor can be used on a stock engine running at around 4,000 rpm with no problems, it's more suited for a high-performance engine (than the magnetic pickup coil) due to its longer spark duration. In other words, a stock engine with limited rpm will not benefit from the longer spark duration. Also, the closer the magnetic pickup coil or inductive proximity sensor is set to the trigger screw, the longer the duration will be.
Items needed and details on how to install a Crank Trigger Electronic Ignition System (on virtually any engine) are listed below Ê Top of page
ü A Universal Magnetic Pickup Coil,
Crankshaft Position Sensor, Tach/Speed Sensor or an Inductive Proximity
Sensor. Virtually any automotive engine speed sensor or
crank position sensor will work for this system. These all work the same.
These sensors require no power from the battery or module because they
self-generate an AC signal. Be sure to use a magnetic one that produces
a small electrical current whenever a small steel (nonmagnetic) object is
passed quickly over the end of it. Also, there needs to be a way to mount
it on the engine so the air gap and ignition timing can be set and/or adjusted.
A universal magnetic pickup coil is most common for this application. It's
an engine speed sensor (Tach Sensor) that threads into the bellhousing of
a late model truck with a Diesel engine for activation of the tachometer.
A crank position sensor is an automotive unit that threads into the engine
block and reads off a cogged wheel mounted on the crankshaft. It's for a
crank trigger ignition system that's on an automobile with a computer-controlled
engine that has electronic fuel injection.
Some GM crank position sensors have three or more wires, but are activated by just two wires. The third (or other) wire(s) is a ground or neutral and really have no purpose. When you buy a sensor, test it to see which wires produce the electrical current, then just snip off the other wire(s). And a used sensor can be easily tested by connecting it to a voltmeter that's set on the lowest AC scale and then quickly pass the head of a small steel bolt or nail back and forth close to the end of the sensor. If the reading (digital type) or needle (analog type) fluctuates each time the metal object passes it, the sensor is good. Also, the more voltage a sensor produces, the hotter the spark. I sell 3/8" diameter universal magnetic pickup coils further down in this web site.
ü A Chrysler, Dodge or Plymouth (MOPAR) Electronic Ignition Control Module (ECU). The stock Chrysler module works great on a garden pulling tractor for durability and all-out performance. Plus they're vibration-proof because the internal electronic components are sealed in epoxy. This means there's no internal wires to vibrate and break due to normal engine vibration. This type of module was used from 1972 through 1992, except on vehicles with the "lean burn" ignition. Also, tests has proven that an OEM/stock Chrysler module performs just as well as an after-market high-performance [Mopar] modules when used on a garden pulling tractor. And the ignition timing stays constant with the Chrysler electronic ignition control module. Which means it doesn't advance or retard the timing at any rpm. I sell Chrysler modules further down in this web site.
The control module
or magnetic pickup coil could burn up (possibly instantly) if the wires aren't
connected to the right terminals! When connecting the wires, take your time
and make sure to use different colored wires to avoid confusion. And be sure
to fasten all wiring securely to avoid breakage or loose connections from
normal engine or tractor vibration.
When mounting the Chrysler module, mount it away from excessive heat and remember that the exposed power transistor is electrically hot while the power is on. The unit should be mounted in an area which minimizes the possibility of shorting the transistor when working in the engine area. Shorting the power transistor to the heat sink or any ground could damage the unit.
Virtually any automotive parts supply store carries the stock type Chrysler electronic ignition control module. They retail for about $21.00 and up. Various manufacturer's part numbers are: EL110 (G.P. SORENSEN, available at Advance Auto Parts stores); MPETP50SB (NAPA); LX101 (STANDARD); CBE14 (Borg-Warner); AL403 (NIEH); TP51 (ECHLIN, available at NAPA Auto Parts stores); CH301 (FILK); CR109 (WELLS); E106 (KEM); C1900Z (AC DELCO) and AL-401 (NIEHOFF IGNITION). Or just tell the counter person it's for a 1972 Chrysler Imperial. And being a new Chrysler electronic ignition control module wiring harness cost about $20.00-$45.00, I recommend getting the connector w/wire leads off a 1972-1992 Chrysler, Dodge or Plymouth vehicle that's in a salvage yard. But if you want to get a new one, the part number is Standard S-516. For accurate and detailed wiring information and diagrams, please click here or scroll down further in this web page.
ü A Ballast Resister or a Full-Length
Resistance Ignition Wire.
The Chrysler electronic ignition control module (off any 1972-85 Chrysler,
Dodge or Plymouth vehicle), whether if it's a stock or a high-performance
one, require a ballast resistor (off any 1955-57 GM vehicle) or a full-length
resistance ignition wire (off any 1958-74 GM vehicle) to prevent from putting
too much voltage into it and burning it up. A ballast resistor or resistance
wire is basically a voltage reducer that reduces 12 volts down to anywhere
between 6-9 volts, depending on the load. (The ballast resistor shown here
is the same used on the 1955-57 GM vehicles.) The reason the Chrysler module
doesn't have a built-in resistor is because as the resistor heats up while
the module is in operation, the heat from the resistor could travel to and
damage other sensitive internal electronic components within the module.
And if you've ever wondered about this, there's very little difference in the "ohms (d) resistance" of various automotive ballast resistors. So it really doesn't matter which one to use with the Chrysler module. The "ohms resistance" is just the amount of load or amps that a resistor can handle. And the stock Chrysler module draws very few amps.
ü Another type of electronic ignition control module that works great for crank trigger ignition is one that's made for certain domestic Ford, Lincoln and Mercury vehicles. This type of unit operates off of full 12 volts, which means it does not require a ballast resistor. The correct module to use has a blue grommet and comes with its own wiring harness. Here's a list of Ford and Motorcraft Numbers for the Ford Blue Grommet Ignition Control Module:
| Auto Parts Stores Cross Reference - FF402 (NIEHOFF); MF-481 (Mitech); F0306 (Filko); F102 (AmpcoWells); E302 (Kem); EL107M (G.P. SORENSEN, available at Advance Auto Parts stores); LX203 (STANDARD); F1910 (AC DELCO), ECHTP36 or ECHTP40 (ECHLIN, available at NAPA auto parts stores); F100 (Duralast).
Ford -
Motorcraft - |
Donor Vehicles - American Motors: AMX 78-80; Concord 78-81,83; Eagle 80-81, 83-87; Gremlin 77-78; Hornet 77; Matador 77-78; Pacer 77-80; Spirit 79-81,83. Ford: Bronco 76-87; Custom 75-77; E Van 89-89,95; Elite 75-76; Escort 81-82; EXP 82; F Pickup 76-87,97; Fairmont 78-83; Fiesta 78-80; Gran Torino 75-76; Granada 75-82; LTD 75-86; LTD II 77-79; Maverick 76-77; Mustang 79-85; Mustang II 76-78; P Series 76-77; Pinto 76-80; Ranchero 76-79; Ranger 83-88; Tempo 84-87; Thunderbird 75-83; Torino 75-76. Jeep: Cherokee 77-85; CJ5 77-83; CJ7 77-86; Grand Wagoneer 84-87; J Series 77-87; Scrambler 81-85; Wagoneer 77-85. Lincoln: Continental 76-80, 83-85; Mark IV 76; Mark V 77-79; Mark VI 80,82-83; Town Car 82-83; Versailles 77-80. Mercury: Bobcat 76-80; Capri 77-76,79-86; Comet 76-77; Cougar 76-84; Grand Marquis 76-83; LN7 82; Lynx 81-82; Marquis 76-85; Monarch 76-80; Montego 76; Topaz 84-87; Zephyr 78-83. |
The control module
or magnetic pickup coil could burn up (possibly instantly) if the wires aren't
connected to the right terminals! When connecting the wires, take your time
and make sure to use different colored wires to avoid confusion. And be sure
to fasten all wiring securely to avoid breakage or loose connections from
normal engine or tractor vibration.
NOTE: Not all automotive electronic ignition control modules will work adequately for the crank trigger ignition system! Because some modules have a small transistor, which can't react quick enough to the increased rpm when triggered directly off the crankshaft. They're made to operate off the magnetic pickup coil that's positioned inside the distributor in an automotive engine that rotates half the speed of the crankshaft, which fires every other revolution per piston travel. So when choosing a module, make sure that it can handle increased rpm, at least up to 4,000 rpm (for a stock engine) and 15,000 rpm for a fully modified engine. And for stable ignition timing, the triggering device must operate directly off the crankshaft. And although the MSD control box will work excellent for the crank trigger ignition, it's not a good thing to use it on a garden pulling tractor because the wires inside the box have been known to break due to normal engine/tractor vibration. When using any type of module, make sure the internal wires and components are epoxy sealed to prevent vibration and breakage.
If you have doubts that an ignition control module is defective, you can have it tested (usually free of charge) at virtually any auto parts store.
The only reason any engine would need the ignition timing retarded or a spark advance system is so the piston won't "kick back" (when the flywheel/crankshaft suddenly and violently rotates in the opposite direction) when cranking over to start it. (That's when the crankshaft momentarily rotates or rebounds in the opposite direction.) All small gas engines nowadays have a compression relief mechanism on the camshaft (that opens the exhaust valve slightly halfway on the compression stroke), which allows the engine to crank over easily without kicking back. And most pulling engines have a long duration camshaft with the compression relief mechanism (if using a cast cam) and a heavier-than-stock [steel] flywheel. Which will also allow an engine to crank over easily without kicking back when starting. So you see, a spark advance really isn't necessary.
Set the air gap (clearance) between the
magnetic pickup coil or inductive proximity sensor and trigger screw (in
the disc below) at a minimum of .025" and no more than .25" (1/4") with a
brass, plastic or paper (anything non-magnetic) feeler gauge. If the gap
is wider than .25", the engine could misfire at high rpm due to normal engine
vibration. And of course, direct metal contact will damage either unit. If
the gap is closer than .025", due to normal engine vibration, the magnetic
pickup coil or inductive proximity sensor could strike the trigger screw
(or disc) and damage could occur, rendering either one useless.
Wiring diagrams for a Magnetic Pickup Coil (Scroll down for the Inductive Proximity Sensor wiring diagrams.)
NOTE: Magnetic Pickup Coils are magnetic, self generating (requires no outside power) and functions with two wires: black and white.
GM HEI ignition control module wiring connections for an ignition
coil that does NOT require a ballast resistor:
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GM HEI ignition control module wiring connections for an ignition
coil that does NOT require a ballast resistor:
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Chrysler ignition control module wiring connections for an
ignition coil that does NOT require a ballast resistor:
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Chrysler ignition control module wiring connections for an
ignition coil that DOES require a ballast resistor:
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Ford ignition control module wiring connections for an ignition
coil that does NOT require a ballast resistor:
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Ford ignition control module wiring connections for an ignition
coil that DOES require a ballast resistor:
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Wiring Diagrams for a Normally Open Inductive Proximity Sensor
-
NOTE: Inductive Proximity Sensors requires external power and functions
with three wires: blue, brown and black. A Normally Open sensor produce
electrical current when it passes or comes close to a steel object. But a
Normally Closed sensor produce electrical current except when in close proximity
of a steel object.
GM HEI ignition control module wiring connections for an ignition
coil that does NOT require a ballast resistor.
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GM HEI ignition control module wiring connections for an ignition
coil that does NOT require a ballast resistor:
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Chrysler ignition control module wiring connections for an
ignition coil that does NOT require a ballast resistor:
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Chrysler ignition control module wiring connections for an
ignition coil that DOES require a ballast resistor:
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Ford ignition control module wiring connections for an ignition
coil that does NOT require a ballast resistor:
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Ford ignition control module wiring connections for an ignition
coil that DOES require a ballast resistor:
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Crank trigger ignition will work on virtually any single or multiple cylinder gas engine.
- For a two cylinder engine, two trigger screws will need to be installed exactly 180° apart in the trigger disc (or flywheel, etc.).
- For a three cylinder engine, three trigger screws will need to be installed exactly 120° apart in the trigger disc.
- For a four cylinder engine, four trigger screws will need to be installed exactly 90° apart in the trigger disc.
- For a six cylinder engine, six trigger screws will need to be installed exactly 60° apart in the trigger disc.
- For an eight cylinder engine, eight trigger screws will need to be installed exactly 45° apart in the trigger disc.
- For a ten cylinder engine, ten trigger screws will need to be installed exactly 36° apart in the trigger disc.
- For a twelve cylinder engine, twelve trigger screws will need to be installed exactly 45° apart in the trigger disc.
- The trigger screws will need to be set so the ignition timing will be properly advanced at all times so the engine will produce full power.
- And for all of these engines, one magnetic pickup coil or inductive proximity sensor, one ignition control module and an ignition coil for each cylinder or one GM DIS coil (Chevy 2 post coil) for every two cylinders will need to be used. Connect the wires for multiple coils (for a multi-cylinder engine) as follows: Connect the battery (+) positive wire to the (+) terminal on each coil, and then the coil's negative terminal to the specified terminal or wire on the module.
Degree Increments for a Super Spacer or Indexing Fixture with a 3-Jaw Self-Centering Scroll Chuck -
The chart below is for installing multiple trigger screws in the trigger disc for crank trigger ignition on a multi-cylinder engine. NOTE: The degrees shown is not for the spark to occur at 0º TDC for each cylinder. They are so each cylinder will have equal timing or distance of spark between them. [Print this chart]
| Number of trigger screws to be installed -> | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | 9th | 10th |
| For a 2 cylinder engine -> | 0º | 180º | ||||||||
| For a 3 cylinder engine -> | 0º | 120º | 240º | |||||||
| For a 4 cylinder engine -> | 0º | 90º | 180º | 270º | ||||||
| For a 6 cylinder engine -> | 0º | 60º | 120º | 180º | 240º | 300º | ||||
| For an 8 cylinder engine -> | 0º | 45º | 90º | 135º | 180º | 225º | 270º | 315º | ||
| For a 10 cylinder engine -> | 0º | 36º | 72º | 108º | 144º | 180º | 216º | 252º | 288º | 324º |
| For a 12 cylinder engine -> | 0º | 30º | 60º | 90º | 120º | 150º | 180º | 210º | 240º | 330º |
Crank Trigger will spark on the compression stroke for each piston when used
on a multiple cylinder engine. It'll also work excellent on any 2-cycle engine,
because it fires on every stroke of the piston. On a twin or two cylinder
engine, use just one Chrysler or Ford electronic ignition control module,
one magnetic pickup coil or inductive proximity sensor, one trigger screw
in the trigger disc located at approximately 20º BTDC on the compression
for the #1 cylinder. It'll spark for the #2 cylinder at 20º BTDC on
the compression stroke, too. And you could install two ordinary automotive
ignition coils, one for each cylinder. Wire them together as you would for
one coil. As the trigger screw passes the pickup coil, a spark will be produced
for each cylinder, one piston being on the compression stroke and the other
on the exhaust stroke and vice-versa. It'll work identically the same as
Briggs & Stratton's Magnetron ignition on their twin cylinder flathead
(valves in block) engines. Because the flathead Briggs twins use a single
ignition coil. By the way, the stock timing on Briggs engines for gas is
set at 11º BTDC.
To advance the timing for methanol fuel, a special-made flywheel
key must be used. They come in 2º, 4º, 6º and 8º increments.
Use the 6º one for a setting of 17º BTDC. These flywheel keys are
used mostly in racing go-karts and Junior Dragsters. You can get offset flywheel
keys from Russell Karting
Specialties (http://www.russellkarting.com/), 500 S. Lincoln, Raymore,
Missouri 64083, Phone: 1-816-322-3330, Fax: 1-816-322-2860, Email:
sales@russellkarting.com.
And an offset flywheel key can be used in a Kohler Magnum engine that has solid state ignition to advance the ignition timing when burning either E-85 or methanol fuels. Have an offset steel key machined, like the ones that Briggs & Stratton racing go-kart engines use.
For crank trigger to work on a V-twin small gas engine (B&S Vanguard, Honda, Kawasaki, Kohler Command, etc.), one magnetic pickup coil will need to be used per cylinder and use one control module with dual coils or a GM DIS coil. Position each pickup coil in place where the original ignition coils. And because of the magnet in the flywheel, a different [steel] flywheel will need to used, or replace the magnet with a piece of secured steel weighing the same as the magnet or have the flywheel rebalanced. Then install one trigger screw in the flywheel where the magnet was so the ignition will be in time with each magnetic pickup coil.
If installed correctly, nothing could possibly go wrong with the crank trigger ignition system. Mainly because everything is totally sealed. There's no moving parts to wear and it could very well outlast the life of a typical tractor, even when used in high-performance conditions! It's virtually maintenance free, extremely reliable. That's why auto manufacturers, virtually all small engine manufacturers (Kohler's Magnum engines ignition system operates much like crank trigger ignition) and most high-performance/racing vehicles nowadays use electronic [or better yet, computerized] ignition. Plus it's something fancy to show off. It's powered by full 12 volts and features a more stable spark than the convention point ignition. You can also use your existing standard ignition coil or you can get a high vibration one from JEG'S or Summit Racing. And remember, a high-performance coil will draw more amps from the battery.
Crank trigger ignition will work on virtually any small engine, but only if there's room on the crankshaft (preferably the PTO end, which is opposite the flywheel end) for mounting of the rotating disc that contains the trigger screw (see below Ê). The trigger screw(s) can also be installed in the factory flywheel. Be sure to allow the head of [each] screw extend approximately 1/8" above the circumference of the flywheel to prevent false triggering. And when mounting the magnetic pickup coil or inductive proximity sensor, make sure it's mounted solid and stable to prevent erratic timing fluctuations.
On a single cylinder engine, this type of ignition will produce a spark on both the compression and exhaust strokes, which is harmless. Camshaft driven point ignitions only spark during the compression stroke. By the way, Kohler engine is mentioned here only as an example, because they're most common in garden tractor pulling.
The crank trigger ignition system is nothing to be afraid of. Once you understand how it works, it's actually quite simple and you'd feel more confident using it. Also, once you've tried this type of ignition, you'd be reluctant to go back to points. If the crank trigger is installed correctly on an engine and the timing is set right, it'll bring a pulling tractor to life and help it scream down the track! But if an engine already have a factory-installed solid state ignition that is triggered off the flywheel, you really don't need crank trigger ignition. Factory-installed flywheel-triggered electronic ignitions are very stable, reliable and they produce a strong spark. But if you're installing a machined steel flywheel with no trigger magnets or pins on an engine that originally came with solid state ignition and/or there's no provisions (no threaded bolt holes present) on the block to install points, you will need the crank trigger ignition system.
 Degreeing the Trigger
Disc -
To simplify degreeing the trigger disc, after finding true TDC on the disc, use a 6" protractor to make timing degree marks on the disc. Refer to the animated drawing to the right for identification. Hold the protractor on the disc, align the TDC zero on the disc with the zero on the protractor and then, facing the disc as if it were mounted on the PTO end of the engine, and with the magnetic pickup coil or inductive proximity sensor mounted either above the disc or on the side of the engine block, make the marks on the disc going counter-clockwise of the TDC mark. Going counter-clockwise of the TDC mark would be advancing the ignition timing, and clockwise of the TDC mark would be retarding it. Degree it as shown in the drawing below. But make sure that the marks on the disc are according to how the disc is going to be mounted on the crankshaft, with the center protruding hub facing toward the engine or away from it. Otherwise, the marks could be on the wrong side of the disc. (Most of the time, the protruding part of the hub faces away from the engine.) |
Set the ignition timing according to piston travel in the cylinder,
as mentioned earlier in this web
page. Install a timing degree indicator mark (with a felt marker) on
the disc and a mark on the engine block and then make a final check of the
ignition timing with engine running using an inductive timing light.
How it works: The magnetic pickup coil or inductive proximity sensor is able to detect the presence of the trigger screw object without any physical contact. Each time the trigger screw in the rotating disc pass the magnetic pickup coil or inductive proximity sensor, this generates a small electrical current within the pickup coil or sensor. This current is sent in the form of a signal to the electronic ignition control module; within, a transistor opens the primary circuit in the ignition coil and the spark occurs. All this happens at the speed of electricity, which is 95 to 97% that of the speed of light. The conventional ignition points and condenser ignition system is much less responsive. |
Checking for Spark -
Because this system produces a spark at very low cranking speeds, once installed, you can check for spark simply by rotating the crankshaft (rotating disc) back and forth by hand so the steel trigger screw passes the magnetic pickup coil or inductive proximity sensor. But turn the ignition switch on first. Also, after the engine has been ran, and because there may be some raw fuel remaining in the combustion chamber, crank trigger ignition will produce a spark once each time the ignition switch is turned on. Sometimes this single spark will make an engine go "poof!" which is harmless in most cases.
To test if a control module
is working or not, connect a fully charged 1.5 volt [flashlight] battery
to the two terminals on the module (it doesn't matter which of the two terminals
is connected to the battery) that connects to the magnetic pickup coil or
inductive proximity sensor (but disconnect the pickup coil first!) and connect
the other terminals/wires on the module as usual. With the battery connected,
a continuous spark should result at the spark plug's tip. Don't connect
the battery to the magnetic pickup coil! It'll burn it up! This test
only proves if the module is working or not. It won't show if it's defective.
And don't use an automotive portable battery charger alone to supply the
power to check for spark or test a module. A fully charged 12 volt battery
should be used. If a battery charger is used, the crank trigger system may
produce a continuous spark at the spark plug's tip even when the magnetic
pickup coil or inductive proximity sensor (or 1.5 volt battery) isn't connected.
By the way - I have not received any complaints from our customers or the readers of this web site concerning the crank trigger ignition about their engine(s) running erratic or cutting out at high rpm, unless of course, they installed a defective module.
Advertisement: (Updated 2/25/11)
| If you need any
of the items listed below, please contact A-1 Miller's Performance Enterprises
| 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday, 9am to 5pm, Central time. If no answer, please try again
later. (When speaking with Brian, please be patient because I stutter.)
Fax: 1-573-449-7347. E-mail:
pullingtractor@aol.com. You can
also contact us through Yahoo! Messenger:
|
|
 Three Wire Normally
Open Inductive Proximity Sensor. 12mm (15/32") diameter x 1-3/8" thread length.
Requires 6-36 volts of external power. Durable metal shielded threads with
two jam nuts, and 10 foot long lead wires. End will illuminate when activated.
Click here
for wiring diagrams.
Two Wire Magnetic Pickup Coil. Self-generating power. Durable metal shielded threads with two jam nuts, two wires and 10 foot long lead wires. Click here for wiring diagrams.
|
|
 Aluminum trigger
disc fastened to keyed steel hub. A 1/4" square key and trigger screw are
included, but not installed. Dimensions: Approximately 6" diameter x 3/8"
wide disc x 1-3/8" hub width. $75.00 each, plus shipping & handling.
NOTE: All trigger discs are made to order. When placing an order, please specify diameter of PTO shaft on crankshaft so the correct size hub will be installed. |
|
| Ignition Control Modules:
|
|
| Precision Handheld Tachometer
The best way to determine the rpm of an air-cooled small gas engine is by using a wireless tachometer, such as the handheld tach by Dixson. This is a precision handheld solid state wireless tachometer with an analog reading. The antenna is held near the spark plug wire and it gives the correct reading rpm for all 2 and 4 cycle single and twin cylinder engines with magneto or battery ignition. Reads 0 to 15,000 rpm in two scales. Works perfect when performing a tune-up, setting the rpm on all stock pulling tractors when rules require a limited rpm, and testing the rpm on high-performance engines. Uses one 9 volt battery, which is included with purchase. Manufactured by Dixson. $100.00 each, plus shipping & handling. |
New Chrysler ignition control
module. $22.00 each, plus shipping & handling.
New Ford ignition control module.
$28.00 each, plus shipping & handling.
Using Crank Trigger Ignition
on a Cast Iron Block Briggs & Stratton or Tecumseh Engine -
Top of page
For a specifically designed kit to convert a cast iron block Tecumseh
engine for use with crank trigger ignition, contact Ed Stoller at 1-203-746-3800
or Mike Brooks at 1-585-243-7765. Their web site is:
http://enginesandmagnets.com.
 For emission purposes, Briggs
& Stratton and Tecumseh has phased out their old cast iron flathead engines
to get people to buy their new [EPA-approved] OHV aluminum block engines.
Tecumseh also discontinued their solid state electronic ignition module for
their cast iron flathead engines several years ago. And magneto
points/condenser/coil ignition parts for the old B&S cast iron block
engines are getting hard to find and they're very expensive. The cast iron
block B&S and Tecumseh engines are well-built and reliable engines, and
when their OEM ignition parts quit functioning, the only alternative is to
install a crank trigger electronic ignition system.
Crank trigger ignition will work on all cast iron block Briggs & Stratton and Tecumseh engines. And the early models don't have a compression release mechanism built into the camshaft. Instead, they start under full compression. The way Tecumseh engines start is their OEM solid state ignition module has a built-in ignition timing retard that automatically advances as soon as the engine starts. And the B&S engines have an extremely heavy flywheel to prevent "kick back" (when the flywheel/crankshaft suddenly and violently rotates or rebounds in the opposite direction of normal rotation) when trying to start the engine. If crank trigger ignition were installed on either of these engines, the ignition timing would have full spark advance at all times and if the engine has a lot of compression, the flywheel/crankshaft will probably "kick back" every time the engine tries to start.
An Easy Way to Start an Engine with Crank Trigger Ignition Having Full Advanced Ignition Timing With No Automatic Compression Release to Prevent "Kick Back": With crank trigger ignition, and without a way to retard or advance the ignition timing automatically, the timing will need to be set in the advanced position permanently, and two separate electric switches will need to be used - one being a push button to crank the engine with a gear starter, and the other being an ordinary OFF/ON toggle switch to power the ignition. To make this work, first crank the engine to get it spinning over, choke it and then flip the ignition switch to "put the spark to it." Doing this will allow it to start every time. Because the spinning weight of the heavy flywheel makes it impossible for it to momentarily kick back against the full compression with advanced spark. This starting method is also recommended for pulling engines (with points or crank trigger ignition) having a high-performance camshaft and no compression release. An engine with a fixed advanced and non-adjustable ignition timing uses either a mechanical timing retard, which is manually operated or automatic, an electronically-controlled timing retard, a compression release mechanism on the camshaft or a very small hole drilled in the seat next to the exhaust valve to relieve about half the compression at cranking speed. If a camshaft doesn't have a compression release, then a .050" "hump" of weld can be placed on the base circle of the exhaust lobe on the camshaft just before the piston reaches TDC to relieve half the compression in the combustion chamber on the compression stroke.
No other ignition system will work on these engines. Also, being crank trigger uses a battery ignition coil, this produces a hotter spark than any solid state or magneto ignition system. By the way - the OEM B&S or Tecumseh coil can't be used with crank trigger ignition. A battery ignition coil must be used instead. And a magnetic pickup coil or inductive proximity sensor with an automotive ignition control module must also be used. A special bracket must also be fabricated for the pickup coil or sensor. For a specifically designed kit to convert a cast iron block Tecumseh engine for use with crank trigger ignition, contact Ed Stoller at 1-203-746-3800 or Mike Brooks at 1-585-243-7765. Their web site is: http://enginesandmagnets.com. |
Using a Late Model Automotive Electronic Ignition Distributor on Older Automotive-Type Engines - Top of page.
If
you have an automotive-type gas engine in an old car, truck, farm tractor,
forklift, construction equipment, boat motor, etc., with a worn out or
troublesome point ignition distributor, and/or parts are no longer available
or if you want to upgrade it to the modern, more powerful, trouble- and
maintenance-free electronic ignition system, then all the engine will need
is a battery-powered, non-computer controlled GM HEI [High Energy Ignition]
distributor (with the 4-pin control module) and spark plug wires from a 1975-84
General Motors vehicle (Chevrolet, Pontiac, Oldsmobile, Buick, Cadillac or
GMC truck) with an L4, L6, V6 or V8 engine. These type of distributors are
considered high-performance because they produce a hot spark (about 40,000
volts to the spark plugs) for quicker starts, smooth idle and more engine
power, and is ideal for use in other makes of engines because the ignition
parts are self-contained; the coil is located in the distributor cap and
the control module is located in the distributor itself. And there's only
one 12 volt wire to power the HEI distributor. A Chevy V8 HEI distributor
is shown to the right. The 4 and 6 cylinder ones are similar.
But if there's not enough room or clearance on an engine for the HEI distributor, a smaller diameter non-computer controlled electronic ignition distributor from a Ford, Mercury or Lincoln, or Chrysler, Plymouth or Dodge (MOPAR) vehicle can be used instead. The Ford or MOPAR control module and ignition coil would need to be mounted elsewhere on the vehicle or equipment. And the spark plug wires that's made for these distributors will be needed. These type of distributors and ignition systems are also considered high-performance.
How To Convert It:
- Cut off the upper half of the old distributor housing and shaft (discard the upper half). Be sure to cut it close to the distributor head.
- Cut off the lower half of the HEI, Ford or MOPAR distributor housing and shaft (discard the lower half). Be sure to cut it far from the distributor head.
- Machine and adapt the shafts and housings of the lower part of the old distributor onto the upper half of the modern distributor head, and pin the two shafts together (like for shortened automotive axles). Scroll down for information on how to securely pin two shafts together.
- Connect just one 12 volt wire from the ignition switch to the HEI distributor. And for the Ford or MOPAR ignition systems, connect the wiring as shown above in this web site for the control module and ignition coil.
- The firing order and ignition timing are set the same as for the old distributor/engine.
- It'll probably be a lot of work setting it all up, but it'll be worth it in the long run.
How To Securely "Pin" Two Shafts Together:
-
Carefully measure each shaft
to the length they need to be, then cut each in half.
- In a small metal lathe (with a self-centering 3-jaw chuck), in one of the shafts, bore a hole .625" (5/8") deep in the end of the shaft that needs to be joined to the other shaft. The diameter of the hole is to be determined by the outside diameter of the shaft.
- In the lathe, and on the other shaft, turn down a stub that's in .750" (3/4") in length. Be sure to machine the stub .003" larger so it'll be a press fit for the shaft with the hole. Bevel the stub so it'll press in straight and easy.
- Using a hydraulic press, carefully press the two shafts together, leaving an 1/8" gap for a bead of weld. But first align the shafts so the rotor will point to the # 1 cylinder on the distributor cap when the distributor is installed in the engine.
- Thoroughly weld the two shafts together, and grind away any lumps of weld so the shaft will slide in the distributor housing(s) (that has been joined together also) with no problems.
Fabricating a Killswitch - Top of page
The
easiest way to fabricate a killswitch circuit for a battery-ignition garden
tractor is to use a heavy-duty electrical (120v) 3-prong plug and a matching
3-prong receptacle, like the ones shown to the right. You'll also need about
4' of 14 gauge 2-wire double-insulated electrical wire. Although ordinary
lightweight "lamp cord" will work, double-insulated wire would be more durable
to prevent a short. Connect the wires so the ignition and electric fuel pump
circuits will be broken when the plug is pulled from the receptacle.
Here's
how to connect the wires:
- Inside the plug, connect the two flat terminals together with a short wire. Don't run any wires outside of it.
- Securely fasten a steel loop on the end of the plug. (A key ring works perfect.)
- On one of the [flat] terminals in the receptacle, connect the wire that comes from the ignition switch (positive side of the battery).
- On the other [flat] terminal in the receptacle, connect another wire that goes to the ignition system and electric fuel pump.
- Do not use the grounding terminal on the receptacle or plug. It's only purpose (as a killswitch) is to secure the plug in the receptacle and keep it from falling out when pulling.
- Fabricate a bracket to mount the receptacle on the rear of the tractor, just above the hitch.
- Route the wire in a safe manner so it will not get pinched or make contact with the ground or chassis of the tractor.
- Install the killswitch conveniently located just above to the pulling hitch within easy reach.
To fabricate a fool-proof killswitch for either a battery or magneto ignition system, fabricate one like what's in the drawing on the right.
-
For BATTERY ignition, use MTD's
safety switch part # 925-0268 or 725-0268 (normally open/black plunger).
Connect one terminal of the switch to the positive (+) ignition switch and
the other terminal to the positive (+) ignition coil terminal and electric
fuel pump (if equipped).
-
For MAGNETO ignition, use MTD's
safety switch part # 925-0269 or 725-0269 (normally
closed/red plunger). Connect one terminal
of the switch to the ground of the tractor and the other terminal to the
ground wire or terminal on the ignition coil or solid state ignition unit
on the engine.
-
If
you have a magneto ignition and an electric fuel pump, install two
separate switches in-line. A red switch to kill the engine (ground the ignition)
and a black switch to disable the fuel pump.
- Mount the switch(es) upside-down to prevent water and dust from entering into it/them.
- Use a long 1/8" diameter hairpin clip to hold the plunger(s) down. Return to top of page. È
And for a magneto ignition system, the grounding type of kill switch, which is a trailer break-away safety switch, can be used. These can be found on eBay.
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Enterprises |
Engine Rebuild Parts, Engine Rebuilds, Build-ups, Exhaust Header Pipe Kits & Machine Shop Services |
Transmission, Transaxle Parts, Rebuilds & Machine Shop Services |
|
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