Apparently we didn't change the flywheel in time after the stage one upgrade and Mikuni addition because we keep finding the flywheel loose after a hard ride. The key, flywheel and shaft all looked good so we applied red lock tight and torqued the flywheel nut. The next ride caused the flywheel to come loose again and upon closer inspection we found the flywheel key slot on the crankshaft taper was damaged. Should we replace the flywheel key and try again or wait to get a lighter flywheel? I may even have to buy another engine if this shaft is the problem- $99 and in stock at this time.
Thanks and have a great day!