Briggs & Stratton 12.5 flooding
I have a 18 yr old Sears tractor w/12.5 B&S motor. It has always run well, but suddenly it wouldn't start. The air cleaner housing was filling with oily gas and the motor was clearly flooding. Long story shortened, I have replaced the plug, fuel filter, rebuilt and cleaned the carb, and changed the oil. (crankcase had filled with gas)
I can generally get the motor to turn over and catch, run poorly for a minute, then flood out. I have done this with the air cleaner off (realizing this affects the mixture) and can see that gas and some smoke are spitting out the intake side of the carb. Although I've successfully rebuilt carbs before, I can't discount the possibility that I did something wrong. The kit had minimal instructions and jets for several (Walbro) models. The one I used looked exact but....?
I'm starting to wonder if the symptoms would fit a stuck intake valve, but don't know enough to be certain. Any suggestions would be appreciated.