The woodruff key on the crankshaft on the starter side of the bike,that keeps the rotor lined up keeps shearing off!! I've replaced it three times already!! When I put the engine cover on and go to tighten the bolt that goes thru the manual start gear,into the end of the crank, it doesn't seem to tighten the rotor on to the tapered end of the crank. The bike will start and run fine but after about three or four electric starts the key shears and the starter just spins the rotor freely. It seem to be dependent only on the key to handle all the torque and stress.PLEASE if anyone can help or have had this same problem let me know what to do. Thanks in advance.