tubby, you need to rotate the blades by hand, not under engine power. Of course you must not touch the blade plate until you first make very sure the engine can't start or run, so you disconnect the spark plug lead before you go anywhere near the blade plate. Tuck the plug lead somewhere so the end of it can't flop back onto the spark plug through sheer habit.
With the deck raised so the belts are slack, turn the blade plate by hand and see how it feels. It should spin freely with no rough feel and no noises. If it passes that test, we can eliminate the spindle bearings as a possible problem, and move forward.
