My gy6 Var kept coming loose no matter how tight I made it so Blue lock tite did it so far. I had the same issue with the flywheel. It actually wallowed the key, and slot so bad I had to spray the inside of the flywheel, and bed it on the shaft with wet JB weld to get it all back in shape. The flywheel pulled right off after the jb cured, and its held up about 5 months so far of EVERY day. I have a 150 bike I can get for a transplant engine and I do plan to build a monster gy6.