What went wrong?
I have a zero-turn riding mower with a Kohler 25-HP engine (vertical shaft). I was mulching some heavy leaves and the motor strained and something bad happened. The engine didn't shut off, but it lost a lot of power. It barely had enough power to drive at 1-2 MPH.
Someone said I might have broken the shaft-key under the strain and I merely need to replace that pin.
That initially made sense to me. The shaft key is designed to break under heavy strain before the engine itself is seriously harmed. The shaft-key locks the flywheel in position to the crankshaft. If the spark plug ignition timing is dependent on that, then if the shaft-key broke, the ignition timing could be way off and the engine would lose power.
But, looking at the engine, which has a vertical shaft, it looks like the pulleys that drive the hydraulic pump and mower deck are on the bottom of the shaft, and it looks like the ignition stuff is on the top. If the mower was under heavy strain, then that would come from the pulleys at the bottom of the engine. How could that possibly effect the ignition timing. Does this make any sense?