20 hp Kohler Command - fuel or fire??

16 years ago

I have a 15 yr old Kohler Command 20 hp twin cylinder that will run for a few minutes (sometimes 5, sometimes 15) and die. Sometimes it sputters like the fuel line is clogged and then runs another minute and dies. Here's what I know:

Fuel pump is good.

Carbeurator is good, bowl has been drained, float works fine.

Spark plugs are new.

Coil has fire on both sides.

Fuel filter is new.

Fuel cap is not clogged. Problem occurs with gas cap removed.

Fuel is new (93 octane).

Air filter is not dirty.

After engine cuts off it will not crank again until it's cool.

It appears to have fire all of the time but will not crank even if you pour gas directly into the carb.

Fuel filter will go completely dry but then fill up again when trying to crank.

Problem appears to be fuel, then fire, then neither, then both.

Any and all suggestions will be appreciated.

Sort by:Oldest

Comments (21)

castoff
16 years ago
It doesn't matter if the coil seems to be ok when you check it for spark, it's what happens to that coil after it gets hot. Since it seems that you have covered all the other bases, try installing another coil onto this engine. My guess is that your problem will go away just as soon as you replace the coil with a new one.
0
bill_kapaun
16 years ago
When it runs for 5-15 minutes, does it run well?
By "crank", we mean the engine will spin over from the starter motor. Is that what you mean?
"Fire" but not run means there is, at least, occasional combustion occurring in the cylinders.
We need to make sure we're on the same page with terminology-
What was the appearance of the old spark plugs?
BTW- There NO need for "premium" fuel.
0
Related Discussions
Kohler Command 20- Power Loss/Won't Throttle Up
Q
Comments (10)
On yours all you need to do is remove the entire airbox assy and you can run it easy enough to see a bit more to aid in troubleshooting. Yours won't have an accelerator pump. What you see is the fuel pump. Kohler does have sevice manuals online at no cost. When you change your fuel filter, "run" the line and catch some fuel in container so you can look for water and debris. Once that is done, run the line from the fuel pump into a container and crank the engine over to see if it is pumping a fair amount of fuel. Here is a link that might be useful: Kohler
...See More
Erratic engine speed on CC 2186...(Kohler Command 20hp)
Q
Comments (4)
Thanks for all the suggestions. Rustyj14, I have had some problems in the past with mice nesting in the shrouding of my old Cub Cadet 108. Only once have they tried to get into the new tractor. I don't think this is the case, though as I know the smell all too well after the engine is started! I've also mouse-proofed the shed since then. I'm getting ready to give the tractor a servicing, at which time I will change oil, grease everything, and clean and lubricate all the carburetor linkages and cables. TheBug
...See More
Kohler Command CV13 fuel problem
Q
Comments (8)
YOU VACUUMED THE DEBRIS OUT OF A GAS TANK! With what? I don't guess you ever heard of a vacuum cleaner turning into an air/fuel bomb from someone doing that? The vacuum cleaner motor shares some of the exhaust air that has passed through the vacuum collection canister. If the volatiles are concentrated enough and the sparks (which are always there) from the motor commutator and brushes ignite this air/fuel mixture there will be 2 explosions (at least 2). The first explosion happens in the motor compartment where the sparks are. Almost instantaneously, that small explosion will propagate back into the collection canister igniting a larger, more violent explosion. Further explosions and/or fire depend entirely on how much other flammable liquids are in close proximity to the vacuum cleaner. That's why your vacuum cleaner has a warning about not picking up flammable liquids. Most fire departments can tell a few tales of calls they have answered due to exploding vacuum cleaners caused by this. You wouldn't be the first, but it could be YOUR last.
...See More
Kohler Command 14HP Problems
Q
Comments (12)
***"If it was burning oil I'd think I'd get a consistent black smoke?"*** No. Gasoline overfuel (or excessively rich) causes black smoke because of the very "complex" way gasoline burns, or "combusts" in the combustion chamber, because of the "complex chemical make up", of gasoline. Gasoline, Diesel "fuel oil", and engine lube oil, are all in the family of chemical compounds we call Hydrocarbons. Hydro for Hydrogen and carbon for Carbon. Hydrocarbon compounds are made by combining "elemental Hydrogen" and "elemental Carbon" together. Because hydrogen and carbon can "link up" in very complex combinations (compounds), these combinations are called "chains". How many atoms of each element, and the varying ways they alternate and hook up determines the "properties" of the final compound. Some of the resulting combinations are very "stable" and DO NOT want to evaporate (or even "melt") easily. Other combinations will "flash" at low temperatures and remain "a thin liquid" at extremely low temperatures. One thing all hydrocarbon compounds share is "combustibility". The ability to combine with oxygen (or "burn"). Some hydrocarbons are eager to combust and only need to get near a "molecule" of oxygen and they just "throw open their arms" to the oxygen (very "promiscuous"). Other compounds are so reluctant to "mess around" with oxygen that they must first be heated to a high temperature before they'll have anything to do with any oxygen molecules (or oxygen atoms). You can draw your own analogies there, but suffice it to say, these compounds are very "chaste". Ok, lets use this in a practical way now. Starting with "how come "burning oil" makes BLUE smoke. The short "answer" is: Because the oil "ain't actually burning". Some portion of the oil (in an engine that is "consuming oil") does actually burn, but the majority of THOSE hydrocarbon molecules are only "vaporized" by the heat of the combustion chamber environs. The hydrocarbon compounds that make good "lubes", are some of those "chaste", or stable ones that don't enjoy "a good combustion". The color of lube oil "vapor" in an exhaust plume is similar to to what you would see if you poured some oil on a hot exhaust manifold. Starting a Diesel engine in frigid temps will result in the following observances in the exhaust plume: First, you will see the fuel oil "vapor plume" as a white or blue/white color, because the initial heat of compression, is only hot enough to vaporize a portion of the Diesel fuel oil, but not hot enough to "ignite" (flashpoint temperature) the fuel. The next color change will be the addition of black as the combustion chamber temperature begins to reach "ignition" flashpoint. But, even though ignition has been achieved, the temperatures in the combustion chamber have not risen enough to support "complete ignition and combustion" of all the available hydrocarbon molecules. This "incomplete combustion" means that some of the hydrocarbon chains are combusting "partially" or incompletely. In this stage, some of the HYDROGEN atoms break out of the compound and unite with oxygen atoms. Some of the CARBON atoms get liberated and quickly "recombine" to form both "new hydrocarbons" and "plain carbon compounds" (soot.....black). It is the resulting carbon and new carbon compounds that give the black color to the plume. This black color only last briefly in this scenario, because the temperatures inside the engine rise rapidly now, and the combustion of the fuel is near enough to complete, that the exhaust plume will become almost clear in a "good engine". But that was in a Diesel engine having combustion chamber compression pressures of more than 500 PSI. Fuel oil can be processed (combusted) very well under those conditions, but engine lube oil would require even a greater magnitude of pressures and temperatures to "burn clean". As a result, a worn out Diesel engine throws out "blue oil smoke" too (though some of that is actually "uncombusted fuel" too, when the engine is in bad condition!). In a gasoline fueled engine, the gas is highly volatile (evaporates readily). Highly volatile compounds are also "highly combustible", and will therefore "burn" in the lower compression environs of a "gasoline engine" (though not without a well timed spark to "incite ignition and propagation"). Gasoline is a complex blend of different "complex hydrocarbons". The more volatile compounds are very eager to burn and create a fast moving flame front, or "propagation wave" that moves through the combustion chamber from the spark plug "spark gap" when the plug "fires". This combustion process is not a "homogeneous" or "simultaneous" process. The highly volatiles burn and consume oxygen first, followed by the "lesser volatile compounds" as the temperatures rise (remember it takes some heat before some of these "chaste" compounds will join in). The least volatile compounds (both of the "original hydrocarbons", the "new hydrocarbons", and the resultant carbon compounds) are faced with a problem. Most of the good looking oxygen atoms have already paired up with the more promiscuous hydrogen atoms and early carbon atoms, so there "are not enough" oxygen atoms around for everybody to find a partner. Not "everybody" will locate an oxygen partner and there will be "some wallflowers" at the end. If you make the fuel/air mix too rich with fuel, there will be even more leftover wallflowers "after the dance". These "wallflowers" end up going out the exhaust in various quantities (depending on specific criteria of fuel, air, spark, temperatures, compression, and a few etceteras). It is the carbon compound "wallflowers" (soot) that give the exhaust its black color when too much fuel is present. Lube oil, (in the same analogy) does not get heated up enough to burn, but does get hot enough to vaporize and so lends the characteristic "blue oil smoke" color to the exhaust. A term that has come up in recent years (in technical speak) is "stoichiometric combustion". That term essentially means that there are "just enough" molecules (atoms) of Oxygen to combine with the Hydrogen and Carbon atoms in the hydrocarbon fuel during combustion so that there are no atoms of any of the "original" elements remaining after combustion stops. As far as one can see into the "near future" stoichiometric combustion is unlikely to be attained in commercially available power plants (engines I mean). CLASS, DISMISSED! PS, check the "choke wizard" per tomplum's suggestion.
...See More
jmclester
Original Author
16 years ago
Yes, it runs very well for as long as it will run. The engine spins fine (no problem with the battery power or starter). If there were "fire" while the enging is trying to crank then pouring gas directly into the carb should at least get a pop or backfire or something. The old spark plugs were dark but not fouled. Replacing them was a low cost shot in the dark. So was the premium fuel.
0
bill_kapaun
16 years ago
"After engine cuts off it will not crank again until it's cool.
It appears to have fire all of the time but will not crank even if you pour gas directly into the carb."

"If there were "fire" while the enging is trying to crank then pouring gas directly into the carb should at least get a pop or backfire or something"

I'd agree that if you have a GOOD spark, you should get something by priming the carb, UNLESS the engine quit because it flooded out.
When it quits are you getting a lot of black smoke?
If so, I would clean the needle/seat on the carb.

If not, I say the ignition is failing.
If you still have one of your old spark plugs, open up the gap to about 3/16" and use that for a spark tester immediately when the engine quits.
A weak coil COULD provide enough spark when there is no pressure on the plug, but fail under compression.
I'd also look for a bad connection on any primary ignition wiring. maybe a contact/terminal is a bit "flaky" and heat causes it to it to move just enough...? (probably unlikely, but??)
0
jmclester
Original Author
16 years ago
Popular opinion is the ignition coil so I have ordered one. Should have it in about 2 days and we'll see if that is the problem.
0
jimc_vt
16 years ago
Well, afetr you replace the coil ,if it runs fine disregard my post ,if not, check for a wire that is chafed and grounding out your ignition .....I have seen this in the past where as the motor warms,and vibration changes the wire will hit metal creating a ground from the coil killing the spark,then when the engine cools the wire no longer makes contact and it starts all over again....also vibration at different frequecies (sp) will vibrate a wire to ground and again kill the engine ....it's a shot in the dark but worth looking into.Good Luck Jim
0
fisher40037
16 years ago
You ordered 1 coil? Post your engine's model numbers so we
know what you have. You might have an engine with smartspark, and that would change things a bit.
We need model and spec numbers.

Fish
0
davidld
16 years ago
If the coil doesnt fix it, I think you have problems with sticky valves or improper valve clearance which manifests itself when the engine gets hot. Easiest first try for sticky valves: Put marvel mystery oil in the fuel and go for a drive. More difficulcult if that doesnt do it is check valve clearances. I think they are being held open when hot prohititing compression and startiung

Richard Debertin
(DavidLD's older Brother)
David would recommend some Seafoam mixed in the gas along with the marvel mystery oil.
0
jmclester
Original Author
16 years ago
Fish, My tech says that the actual part name is an ignition module, not a coil. I should have an answer on whether it fixes the problem today. The engine is about 15 yrs old so I don't know about the smartspark thing. I don't have the model numbers with me but I can get them tonight.
Richard, how much marvel should I put in a 3 gal tank full of gas? What is Seafoam?
0
fisher40037
16 years ago
Do not waste time with the miracle crap, there is no adjusting valve lash on a Kohler Command, they have hydraulic lifters. The Spark Advance Module, or Smartspark
could be the problem, but I doubt it. Otherwise, your engine has two ignition modules [coils]. More than likely,
you will find you have a corroded terminal somewhere, like the keyswitch, that is giving intermittant, or weak
voltage to the SAM, or spark advance module, giving you a
wide array of symptoms. If your tech wants to, have him e-mail me direct at Fisher40037@peoplepc.com, and maybe we
can resolve this and save you some money. I will make a guess, is this on a Craftsman?

Fish
0
jmclester
Original Author
16 years ago
Not a Craftsman, but probably the same mower in effect. It is a Yard Pro made by CYP (Carolina Yard Products). The coil that I ordered has the plug wires built into it. It is being installed as we speak. It wasn't terribly expensive but it will be if that does not fix the problem. Stand by.
0
tmajor
16 years ago
I had a tractor with a 16hp Kohler Magnum engine. It was fine when it was running, but it wouldn't start hot. Everything seemed to be in order ... spark/fuel. The dealer wanted to do a valve job, rebuild the motor and whatever else. He said the compressions were low and unequal on the cylinders and got worse as it warmed up. Right! Plus, he couldn't duplicate the problem. The first time I ran it, after getting it back, it did the same thing.

I changed the ignition module/coil and never had another problem. It has been sold to a friend and is still mowing grass.
0
fisher40037
16 years ago
My point is, the Command has 2 "coils" or "modules, one for
each cylinder. The liklihood that both of them "go out"
at the same time is not very high, as the engine will run
on 1 cylinder. A wiring problem grounding out both coils
is possible, if it has a sam module, that would be the the
most likely trouble spot.
The ignition coil has but 1 spark plug wire, and no other wires on it, just spade terminals. If you have
a different looking ignition coil, then you do not have a Kohler Command.
Fish
0
jmclester
Original Author
16 years ago
I meant to say American Yard Products not CYP. The engine is a Kohler Command MV20. It is a single ignition module with two spark plug cables attached. My tech installed it and says the mower is running like new. Many thanks to all who responded to my question. Without so many concurring opinions I would have been reluctant to invest in the coil/ignition module. Thanks again!!
0
bill_kapaun
16 years ago
An MV20 is a Magnum, not a Command! Totally different engines!
Kind of makes troubleshooting a moot point.
0
fisher40037
16 years ago
Now that is some funny ####

Those pesky MV20 Commands..........................................

I wonder if he even read my last post......................

Bill, we do not get paid enough for this..............

Fish

CV20=Command Vertical 20 HP
MV20=Magnum Vertical 20 HP
0
fisher40037
16 years ago
Now if you would have took the old coil, and holding it by the spark plug wires, dipped it into a cup of Marvel Mystery Oil, that would have fixed it too......

But now, since the mower is fixed, and the problem was
the coil, on the MAGNUM,....

Did he check for voltage on the kill wire circuit, which would have damaged the old coil, and WILL damage the
new one?

That is the $100 question.

Coils do go out, but many times, if not most, they are
damaged by stray voltage that gets into the kill wire
circuit. Partial voltage damage, then the coil comes and
goes out when hot. Full 12 volts, it goes real quick.....

That is the question now.......

Fish
0
jmclester
Original Author
16 years ago
Apologies with thanks again to all. Engine is a Magnum.
0
fisher40037
16 years ago
What about the stray voltage possibility?

Fish

I take paypal.................. my new suffix for my
signature here....................
0
fisher40037
16 years ago
What about the stray voltage possibility?

Fish

I take paypal.................. my new suffix for my
signature here....................
0
PRO
RCC
last year
Broken Flywheel
0

20 hp Kohler Command - fuel or fire??

Comments (21)

castoff

bill_kapaun

Related Discussions

jmclester
Original Author

bill_kapaun

jmclester
Original Author

jimc_vt

fisher40037

davidld

jmclester
Original Author

fisher40037

jmclester
Original Author

tmajor

fisher40037

jmclester
Original Author

bill_kapaun

fisher40037

fisher40037

jmclester
Original Author

fisher40037

fisher40037

RCC

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

20 hp Kohler Command - fuel or fire??

Comments (21)

Related Discussions

jmclesterOriginal Author

jmclesterOriginal Author

jmclesterOriginal Author

jmclesterOriginal Author

jmclesterOriginal Author

jmclesterOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

jmclester
Original Author

jmclester
Original Author

jmclester
Original Author

jmclester
Original Author

jmclester
Original Author

jmclester
Original Author