After reconnecting chain and placing clutch pin back in bike was riding fine for 20km. Then I noticed the screw tightening the clutch string was loose and not allowing clutch to fully pull in (hence not being able to peddle while motor was turned off)....so I tightened the clutch string by adjusting the screw clamp further up (tighter) and the clutch is working fine, just that the clutch pin keeps coming loose while riding it (it comes up a quarter inch just enough that it wont clutch). Did I tighten the clutch line to much? I see a bolt on the top of the clutch but does not seem to help make it more snug. Any ideas ? Thanks