was this the drive chain or the pedal chain? yoru problem could be that your chain is all strectched out and not happy. if that is the case then get a new one. they run like 15 to 20 from the moped shop here in kzoo. their number is (269)344-1977. how does yoru chain tension look? sit on your bike and touch the chain. you should have about 1 cm of play in the chain with your butt on the seat and the bike off of the stand.