My son and I just spent allot of time; top end rebuild,forks,plastic,seals,carb ect. on his project bike..he took it out today and he said it started to knock then stall. I tore the top end down now the rod bearing is gone and new piston is done. I give up on this bike! He is heartbroken as most of his summer job $ is gone. Oh well..at least he wasn't hurt..only the wallet. Parting it out to re-coup some of the cost.