Post # 3
2 hands to revolve the flywheel even with the plugs out.
Bucket engine. Need to remove the blower housing and the flywheel and the other stuff on the top of the engine. Then remove the top cover and you can check everything from their.
If this is a bucket engine , closure plate on the top and no sump then you are in luck because it can stay in the mower, just slip both belts off the pulley .
Download the manual Rivets linked you to .Note Kohler fasteners are metric .
Take off the blower housing ( 4 x m 10 bolts from above ) and remove the fuel lines & dip stick, cover pulls strait up.
Then look at the 4 bolts at the front that hold the plate on.
Very good chance they have backed out and are fouling on the flywheel . Quick solution is to tighten them back up and check every season when you take that cover off to clean the cooling fins.
Slightly harder is to pull the flywheel remove the loose bolts, replace them with new ones using a dab of blue locktite .
Flywheel generally comes off easy no need for a strap wrench but a deceint rattle gun is worthwhile .
Remove the plug rotate the engine till it is at bottom dead center and the inlet valve ( one on the carb side ) is closed then feed as much nylon rope down the plug hole as you can, with at least a foot or so hanging out
Rotate the engine till the rope is compressed the engine is now locked and you can undo the flywheel.