I don't know about this particular motor, but if the float in the
carburetor hangs up, the gas runs into the piston and down the gap in the
rings to the oil pan.

Wow... Thanks Ralph. I hadn't thought about that. I did ponder
" carburetor " for a moment, but not the float valve. In my paranoia
I immediately suspected foul play. I changed out the oil and did
my mow job, parked the mower. Then ran a length of black thread
across the garage opening ( no doors ) and check it periodically
to see if anyone had 'tripped' it. My next move was to be a trip to
Harbor Freight and buy a motion detect alert gizmo ($16.95).
Then I'd fill my S&W 357 with 38 Sp shot shells and wait for my
queue...

Would it help to burn some kind of carburetor cleaner stuff ?

It's a 2006 Super Bronco w/B&S 19 hp if'n that makes any dif.

Thanks again ... ( them shot shells are $15 a box of ten ... too
much to waste ..)

Ima ... ( actually Paul .. ).


Adding a fuel shutoff would help. You could run it out of gas before
putting it away.