Rode 6 hours today and picked up a noise in the top end after a serious flip. Bike ran for 5 min upside down before I could get out from under it and shut it off. I am hoping it is a wrist pin brg. Sounds like a small knock. Vitos 240 kit w/ approx 15 hours on it. Ported on race gas. Klots R50 - 32/1 Plug is actually on the dark side. It is not detonation!! Time to tear it down and check it. Any one come across brg problems