The old gas in the oil trick again
Brand new to posting in this forum but I've read and learned a lot from all the great info here. But I've got a question puzzling me.
Recently, I purchased a walk behind mower with a 13hp Briggs Intek engine (21a907-0153-e1) for home use. Got a good deal since it wasn't running at the time and the owner wanted it gone. Got it home and ran through it and found no surprise a crankcase full of oil mixed with gas obviously from a sunk float or bad needle seat. I proceeded to remove and clean the carb. Drained the contaminated oil. Put her all back together and it fired up just fine. Cut the lawn and put it back in the shed. About a week later it had a crankcase full of gas oil again. So I thought to be sure of this I left the intake from the carb to the head disconnected overnight to see if the fuel still overflows from there. Not a drop came out?
Could this overflow happen when its running? The motor also has a vacuum fuel pump, could the fuel enter the crankcase from there if an internal diaphragm was bad? Kinda stumped...Anyone have any ideas