dealership won't help you, as its probably changed hands quite a few times!
Contact your licensing officials first... At least in the states, the DMV's are the ones to talk to. If the bill of sale isn't in the same name as what the current title shows up to, you will have a problem as there is no way to verify the sled was actually sold by the titled owner and not stolen.
the absolute easiest would be to give the kid you bought it from $20/$50/$100 to get a copy of the title...
(i'm personally going through this with a sled right now, had I known I wouldn't have gotten a title with it, I would have never gotten close to the sled, its been a pain!)