Small Engines (Lawn Mowers, etc.): gas in oil tank of b&s mower, vertical engine, oil tank

Question
i have a 2yr old murry riding mower with a b&s 12.5
vertical engine. ran fine until today with sputtering and was hard to start. checked the oil dip stick and smelled gas. opened the drain plug and
i have gas in the oil. broken piston? bad o-ring?
please help.
b&s model 28v707
thank you
ken

Answer
Hi Ken,

I would suspect a fuel logged carb float or a bad float needle and seat.  The fuel is probably leaking into the crankcase while the engine sits.  An alternative to doing the carb work would be to add a fuel shut off to the fuel line.

Let me know how you make out.
Michael