I'm new on here and barely know what I'm doing, so here is what came out of my upgrades to my '78 Puch from last night. I put on an Athena 60cc piston set and a BiTurbo exhaust, it runs, sounds decent except for a slight putter noise that I can't tell if it should be there. Also if I don't feed gas the engine just slows and dies. Do I need to do something with the timing? Cause I have no idea where to start with that. Anyway I can recover the low end speed that I lost? Would a new rear sprocket work?