By
SShields27
I am rebuilding a Kohler 12hp, k301. The tractor had been sitting for about 20 years. When I first got it I thought maybe it just needed some run time, possible a stuck ring. I've had it for a couple months and there has been no change. I have recently took the engine apart and can't find a definite reason for the smoking. Piston and ring appear to be in good condition. The cylinder is very clean and is not really worn. It does measure 3.377" at top of bore, and right on size at bottom, but not egg shaped at all. It does not smoke too bad at an idle or at a constant rpm, but when the rpms ramp up, or tractor gets under a load, it smokes like a train. It will occasionally backfire at an idle and blow a little puff of smoke but not a lot. If anybody has a bit of advice on where to look, I would love to hear it. I do not know a lot about the valve guides, if they are worn, could this cause this issue?