Worn and defective flywheels can often result in high repair cost and expensive down time. Starters can be ruined by worn flywheel teeth. Clutches can chatter due to worn and uneven clutch surfaces. Crankshafts and dowel pins often leak oil due to loose dowel pin holes. Crankshafts have even broken due to misfit of defective flywheels. If you are in doubt replace your old unit with a factory fresh flywheel.