I have a Toro Personal Pace mower with a 7.25 B&S 163 cc engine and run over a mole trap and the engine died and won't restart just spins over. I thought the flywheel key had sheared and pulled it apart but it is intact and not marred in any way.
What else could have happened?
Well start looking at ignition and or fuel problems, shoot a little starting fluid in the air cleaner and see if it fires off , if it does,,,it's a fuel problem , if not ----- igntion and go from there
There is undoubtedly another key on the bottom of the crankshaft, one that keys the blade flange to the motor. On most push mowers, the blade acts as a flywheel. The engine won't run at all without a blade, and if the blade is not in sync with everything else, you've got no mower. My bet is the lower key is sheared off.