Hey guys today me and my friends were ridin and my chain popped off at a high speed the chain then got wedged beetween the shifter nnd engine case real tight so we tried to pull it out but itn nwouldnt budge so we took the front sprocket offf and were able to pull the chain out freely. so we put the sprocket and chain back on and tightened the chain up. So i pulled it out of the garage and tryed starting it up, and it made a wierd different than normal sound and started for about 2-3 seconds and then it stalled so i tried to kick it again and it wouldnt start back up and it kept makin that wierd sound. my friends told me they thought the piston ring was broke or cracked because it had no compression so i tore apart the top end and the ring was fine and everything else looked fine. So i do not know what i should do any body no what it could be??? Ohh yeah my bikes a 125 PLEAZE hELP!!!!