I've been fighting an issue for a couple of years now with this engine. It started burning oil really bad so I tore it down to check the rings. They seemed fine but I replaced them anyway, along with a new crankcase breather. This did not change a thing. I thought maybe the bores were slightly egg shaped so I bored it .020" over with another set of rings (gapped .009") and obviously new pistons. The guides appear to be fine and the valves were lapped in. I continue to have the same problem. I use as much as half a quart of oil in a 20-30 minute time frame.
I installed a pcv valve inline with the breather and ran a tube to a water bottle to see if oil was really being pumped into the intake. Sure enough, I could fill 8oz in the same time as mentioned above.
Next I installed a fuel shutoff valve and looked into replacing the fuel shutoff solenoid. It was about 75% of the cost of a new carburetor so I went ahead and replaced that too. At this point, literally everything is brand new and the tractor still smokes like crazy. The oil is surprisingly clean. My lash was slightly off but the motor did not turn over hard. It's almost as if I have extreme crankcase pressure. A local small engine guy has looked it over and is completely stumped as well. What's left that we're missing?
I installed a pcv valve inline with the breather and ran a tube to a water bottle to see if oil was really being pumped into the intake. Sure enough, I could fill 8oz in the same time as mentioned above.
Next I installed a fuel shutoff valve and looked into replacing the fuel shutoff solenoid. It was about 75% of the cost of a new carburetor so I went ahead and replaced that too. At this point, literally everything is brand new and the tractor still smokes like crazy. The oil is surprisingly clean. My lash was slightly off but the motor did not turn over hard. It's almost as if I have extreme crankcase pressure. A local small engine guy has looked it over and is completely stumped as well. What's left that we're missing?