Purchased not running 2155 for $100 for mower deck. Has the usual starting/20 min quitting issues. However took off starter/removed spark plug. Tried to turn hand-turn flywheel. Flywheel will turn about 1/4 turn or so and easily turn back but it stops. Something is stopping the flywheel from completely rotating Only has 450 hours showing and seems to be correct. Any ideas? Wife would like it for her kwork yard. Thanks.