QuestionThis engine is on a Craftsman rider mower and I have been having starting problems. I normally always checkthe oil but becuase of starting problems I have not done so lately. Today I decided to troubleshoot the starting problem and as battery was charging I checked the oil and found it to be way overfilled. I know I did not add any oil sine I last changed oil so I drained it and about 2 quarts poured out and was very watery and smelled of gas. I turned the engine over with the starter and it spun up much faster then before which makes sense if that much liquid was in the crankcase.
I re-serviced the crankcase with fresh oil and the engine started normally and ran well.
How did the gas get into the oil and will it probably occur again?
I read somewhere that the carb float may have a hole and leak gas into the cylinder when engine is shut off. That makes more sense to me then a cracked ring as the engine runs so well.
AnswerNot likely the float is bad but we see a lot of carb inlet needles and/or seats leak allowing gas to enter the crankcase oil.
You can do two things to solve the problem.
1) Rebuild the carb and replace the inlet needle/seat.
2) Install a fuel shut-off valve in the fuel line and shut-off the fuel when you are done using the mower.
The second option is a proven method to preventing the problem, cheap, and something you can do at home in about 5 minutes. However, you have to remember to shut-off the valve every time you finish using the mower.
You can search You Tube for Briggs carb rebuilding or inlet needle replacement as there are lot of videos for replacing the wore parts.
Eric
