Wheel Horse riding mower, 250 hours
Engine is Kohler
Model CV15S-41550 (Command Vertical-shaft 15HP Electric-Start)
Family: SKH426U1G2RB
Spec No. 41550
Engine size 426 cc
Serial 2812823131

Has always started right up with a touch of choke. Still does, when it's cold. Runs for about five minutes, and shuts off until it cools down again.

When this started, it was only occasionally. So I changed the oil, oil filter, spark plug, air filter. Used 10-30W oil Put in fresh gas, and changed inline gas filter. It just got more and more common, until now it won't stay running five minutes.

Tested spark plug by cranking while it was out and grounded to the engine block. No spark -- but it starts right up when it's cold. Spark plug has a lot of carbon on it, black and sooty.

It does not drip oil, and it does not smoke at all when running, but it has started to sip oil where it never used to want any.

Any advice?

Thanks,

Antifa

 

It sure sounds like a bad coil. I assume you checked for spark after it was warmed and would not run, and that's when you found no spark? If so, I'd say you have a bad coil.

BTW: Thanks for posting the pertinent information for your engine. Hardly anyone does that anymore. It makes things so much easier sometimes.

 

Sounds like the diagnosis I'd make and to rule out any peripheral trouble, you need to disconnect the ground (kill) wire at the ignition coil and then test run and see if any failure occurs. Bear in mind that all safety features as well as the ability to shut the engine down will be null requiring utmost safety in mind when operating the machine as such. You will need to carry an insulated pliers with you in order to pull the spark plug wire off the spark plug to shut the engine down. If failure occurs at this point, replace the coil, part number 12 584 04S. If no failure...post back.

 

Thank you both for your help.

You know, a couple weeks ago I tested the spark plug against the engine, and got a big blue spark, so I'd just figured I wasn't grounding it properly on these last couple of tests.

I downloaded the Repair Manual for this engine model, and it gives an ohmeter test for the ignition coil. But, as you say, a quick test on flat ground will be to disconnect the ground lead off the coil and see what happens.

Looks like I have to pull the blower housing to get at it. Will advise when I get the new coil in.

Thanks again!

Antifa

 

Hopefully you didn't misunderstand us. Try the kill wire trick before ordering a new coil. You may not need the coil and as most dealers have a no-return policy on electrical/ignition parts, you will be stuck with it if you buy it without first knowing if you, in fact, need it.

 

Hello, Puey61;

I did the disconnect of the ground or 'kill' wire right at the ignition coil. The engine started right up, ran beautifully for five minutes, and turned itself off like a lamb.

Damn. Or damb. It's the coil.

It is nice to find that the blower housing comes off and goes back on without a great deal of trouble.

Thanks again for your help. I will update this post when I have put a new ignition coil in place.

Regards,

Antifa

 

I just went through this this weekend - same problem, stalling after 5 minutes of mowing. Replaced fuel filter, spark plug, etc. same as you. The problem is the coil, which could be called an "ignition module" on your engine. Mine was a 14 CV Kohler, your sounds similar.

You need to get a new coil, cost is around $40. When you install it, make sure you "gap it" as in leave a gap between the coil and the flywheel - I was told to put a regular business card between the flywheel and the coil to get the correct gap. I did this today, and mowed for over an hour, no stalling. Good luck

 

I put a new ignition module in today. Used a .010 feeler gauge to set the gap, per the repair manual.

Runs like it always did.

Thanks once again to cheese and Puey61 for setting me in the right direction.

Antifa

 

Great! Glad we could help, and thanks for the update!

 

I think this is the problem i am having. Seems the mower loses power the longer it runs and then sputters and dies. It cranks back up and runs for 4-5 minute or so... then gradually dies. It is a gradual loss of power the longer the mower runs. The mower seems to run best beyond the standard full throttle and will not run at all in partial throttle. Are these the same symptoms?

 

I've had the same problem with this engine and it turned out being a carburetor issue. I took apart the carb and cleaned it and reassembled it and that was the end of the issue. Beer 4U2

Its possible that any subsystem of the engine could fail, so I check them all. I will also note that there was junk in the fuel bowl. All I can say is Thank God for carb cleaner and Armor All LOL! Armor All comes in handy when you have rubber hoses that won't twist off of a fitting, give it a shot sometime and let me know what you think.

 

i have a cv22s-67522 SKH624U1G2R8
2626305427
The mower was quiting after short periods of time.
I have replaced spark plug fuel filter both coils and ignition switch and put in a fuel shut off.
After replacing all that it seemed to run really good until about an hour or hour and a half mowing it started to sputter then died. At that point it would not turn over or do anything. After it sat and cooled down awhile i went over and it started right away and i finished mowing.

 

So when it quits, there is no power, the engine doesn't turn, no click sound, no nothing? Like the battery is dead?

 

I have a Kohler Command 15 hp OHV engine that has recently exhibited some of the same symptoms as described in these threads. However, my symptoms include the engine exhibiting what appears to be a timing issue: That is, regardless of cold or warm, when the engine load increases (indeed, if I move the throttle from Slow to Fast), the governor tries to compensate, but the engine coughs and wheezes as if the timing is off - or the carburetor is flooding the cylinder. Can bring it back to idling smoothly, but only upon forcing the governor to an almost stall position, then letting it find an equilibrium. I note that AT IDLE I can allow the engine to run, engage blades, and travel at any speed while cutting the lawn. Not a very efficient way of mowing, however...

I discount the coil solution because I tested the spark plug outside of the cylinder, and spark across plug seemed strong and consistent. I suppose at higher rpms than that achieved by starter motor the coil may show a problem. I did replace fuel shutoff solenoid, plug and changed oil/filter, and disassembled and cleaned the carburetor fully. Could not, however, find any fuel mixture needle valve that was indicated in Owner's Manual - had to assume the carb is a "set at factory; no adjustments allowed" variety.

Any feedback would be appreciated.

Joe

 

Sounds like your carburetor has a blockage.

 

Cheese,

I suspected carb blockage also, until I tested for that by putting engine into "cough and wheeze mode" at full throttle, then spraying some accelerant into carb throat. If not enough natural fuel were getting through, the engine should have at least tried to recover for some short period of time. If too much natural fuel were getting through, the engine should REALLY flood and die. It died instantaneously.

Can you tell me if the Stator assembly under the flywheel has any tendency to fail over time, or is this pretty much a fairly long-lived component of the electrical system?

Lastly, would you mind explaining why you/the group suggested disconnecting the "kill" switch of the ignition system, to prove What? Didn't follow. Thanks.

Joe

 

When you disconnect the wire to the coil that eliminates the safety devices that could be bad. Eg seat safety switch. deck safety switch etc.

If the engine starts then coil is good, but after time it can breakdown and get weak or quit altogether. Then coil must be changed.

If your engine starts with the wire attached then your switches are fine. Your coil can breakdown if the wire is on or off the coil.

Hope this helps.

 

That's not really an accurate test especially depending on what "accelerate" was used. Better test would be to apply partial choke and see if it helps.

 

Thank you, BoudreauxEunice. Checked all safety switches manually, but forgot to mention this. I now understand why the suggestion to remove kill-circuit was made.

And, thank you, BFHFixit. The "accellerant" used was aerosol ether - it should have combusted quite nicely, I believe. I did, however, also try manually "choking" the carb while it was in its "cough and wheeze mode". Response was approximately the same - the engine died upon choke application.

As you suggest, I shouldn't discount the coil just because spark is strong at low rpm (with no combustion or heating of engine during turnover while plug is removed). Suppose there's a possibility of a heat-induced open or short in the coil windings. Unless someone can tell me what a good coil's Resistance range should be, guess I'll have to spend the $40 or so on a new coil to find out.

Thanks, all, again.

Joe

 

With your engine and symptoms and no help from partial choke, I'd suspect either spark plug, flywheel key, or coil.

 

I have a 20 HP Kohler in a Simplicity Sunstar that liked to shut down after an hour of Mowing, Turned out to be a plugged metal filter that protects the air entering the flywheel fan fins. I don't think this engine has a high temp shut down system so you tell me. If I keep that filter clean it will run all day.

 

It's not uncommon for an engine that's overheating to shut down even though it doesn't have a specific system designed to do so.

A lot of diesels have shutdowns either to total kill or limp modes. One of those systems responds to low coolant/high temp.