I got this fine motor horse trading, well the guy said it had not run in years. upon inspection under the flywheel I found a sheared key and a cracked cam, so I found a used key and ordered a cam and the motor ran fine after a tune up & new coils. well went to start it and the plastic paw on the recoil starter flew out, so I new something was not right, pulled the flywheel to find the key sheared again, so I dug around and found a key in its original package (p/n 120395). can some one confirm this to be the correct flywheel key for this motor mod#181025-E05541 I may have put the wrong key in or not tightened the flywheel nut to proper toque, or something else ?? might be going on. thanks