QuestionSnapper Zero-Turn Walk Behind.The model # is PL7 H1404 KV After pulling recoil engine turns over,runs for a few seconds, spits out blue smoke and shuts off. It is getting fuel and there is oil. Need some trouble shooting advice. I do not know how old mower is, but it has some rust spots.
AnswerBlue smoke is almost always an indication of oil burning. The oil can enter the combustion chamber in a couple ways. If you have positive crankcase pressure to crankcase will be like a pump. Oil will pump up the valve train and enter the combustion chamber.
This can be caused by a failure of the crankcase gasket at the crankcase halves. The bottom oil seal, top oil, dipstick loose seal where the dipstick goes into the crankcase. Oil can also enter the combustion chamber through the carburetor. This will happen when the crankcase breather pumps oil into the air filter housing. You will find a short rubber to connected to the crankcase breather and the air filter cover base. Oil will be present inside the air filter element.
If the engine rings and cylinder has wore out. Remove, one of the heads and luck at the cylinder wall. If the crosshatch marks are totally worn away oil is coming up past the rings. I do believe that oversized rings are available for your engine, but the cylinder will have to be resized. This can be expensive, and the best way is usually installing a short block.
I hope this helps you troubleshoot your engine.
