one of my obsessed favourites is building motorized bikes/bicycles and up to my third in a year...I usually start with rebuilding the MTB or even respraying it if needed! I have a allot of information about this subject, especially rebuilding the clutch-assembly. The biggest probs with these is ordinary steel used in there making causing everything to bend or move-out-of-place and adjustments should be done in-reverse until no slippage or sticky-clutch. 3turncarby. Mine has been blinged-out with atv-tank 3.2-litres...chromed side-engine panels-cheap kit 66cc/70cc, engine sprayed red and the blackhawk frame will be upgraded to chromolly-shogun frame. Been on net for ten-years.