Just picked up this bike for $400 but it's having some issues and i don't have a clue what it could be. The bike seems to have a mind of it's own, sometimes it starts up and will run like a charm but it seems to die out if i take it through water, it starts to backfire and studder till eventually it won't start at all. Other times the bike will start but it won't move, i can hold it full throttle and it just putters for a minute then stalls. Any help would be greatly appreciated.

 

sounds like an air leak or a cracked side cover with water in the oil