View Full Version : Kohler 25-One Cyclinder Fouling Plug

06-19-2007, 01:26 AM
I have a Kohler 25 that bent a push rod and was burning oil and fouling plug on one cylinder. So far we have replaced push rod/rocker assembly and replaced head gasket. It is still doing the same thing, fouling the plug and burning oil in one cylinder.

Any Kohler experts have any idea what else it could be? I would still think it is something in the top end as I don't see why one cylinder would wear out faster than the other. The motor only has 2 1/2-3 seasons on it.

Any thoughts?

Thanks in advance.


06-19-2007, 09:30 AM
What cylinder - 1 or 2?

Did you check the reed on the one cylinder when you had the head off (vertical crankshaft) or is it a horizontal?

I would do a leak down and crankcase vacuum test.

06-21-2007, 12:24 AM
Its the #1 cylinder(left side looking at muffler) and it is a horizontal on a John Deere zero turn rider.

I did not check the reed. Where is it located? I'm assuming this vents the crank case and can become clogged or stuck?

Thanks for your reply.


06-22-2007, 11:38 AM
The reed is under the breather cover between the cylinders. If it is broken, there will be crankcase pressure and both plugs should foul from oil passing the rings.

Do a leak down and compression test, as well as crankcase vac.