Kohler ch25 shuts off after 5 05 10 minutes-restarts fine but shuts off again in abou

[hutch1917]

model # is CH25S/ Family SKH725U1G2RA SER # 2829418121/SPEC#68613, 1998 model. replaced fuel line s, filter, plugs, checked all connections for ignition . Checked fuel solenoid. It shuts under load or not and wether I'm on mower or not. Its a scag turf tiger. engine does not smoke. Any ideas?

 

[Fish]

Thanks for the engine numbers, your engine has a Speed Advance Module, or S.A.M., also know as Smartspark, which is a real troublemaker for folks trying to diagnose engine problems. Many times the trouble is just corroded terminals on the back of the keyswitch, or other places, take a quick look and see. And let us know, if not we can go a little deeper.

 

[hutch1917]

ignition switch looks good and all other connections look good under dash

 

[Fish]

Well, it is a quick thing to look at. You need to determine what is at fault when it shuts down, spark, fuel or compression.
We can rule out compression, as it runs fine when it runs, but you need to see if it is fuel or ignition related, so keep with you an extra plug and a can of carb cleaner, and when it shuts down, see if will restart with a squirt of carb cleaner,


and pop on the spare plug, lay it against the block, and check for spark. See what that tells you.

 

[hutch1917]

It starts right back up, so its getting spark and fuel. Runs great until it warms up.

 

[rrussell14]

You're describing my mower to a T new coil pack, plug, carb is clean??? I read somewhere that muffler might be clogged or shear pin damaged if you find a solution, please post, this has been the hardest troubleshoot ive had in a while.THANK YOU:frown:

 

[gregjo1948]

I wouldn't say it's a coil because, I think it would have to be both failing at the same time. Sounds like a fuel restriction. Fuel filter or maybe carb float. gregjo1948

 

[reynoldston]

Do a leak-down test to check for bad head gaskets.

 

[Rivets]

If you have the SAM system, don't replace the coil. Replace the SAM module with the kit, which contains a new coil and module together in one unit,

 

[reynoldston]

If you have the SAM system, don't replace the coil. Replace the SAM module with the kit, which contains a new coil and module together in one unit,

Not saying not to do this if it's your problem. I have one in my shop doing the same thing. I went nuts trying everything to cure the problem. I finely did a leak down test and found a left side bad head gasket. The part that had me stumped and still dose is the shutting down.