i know that this is not an atv but i need help the sled just started to backfire a little and it stalled like it fouwled a plug but it didnt and it started again but it squeaked and rattled it has compression i both cylinders and it seems like all the enternal parts move and it was running for 20 mins before this happened and by the way its a 1991 and a 440

 

I'll see if my dad, has had any similar issues. He has 2001 660 (which is basically the same thing you have, just a third cylinder, 220cc per cylinder). He also has 2 other AC sleds, but not sure what size they are. His always seem to just go though, so I'm not sure it will help to ask him.

Have you asked your dealer yet?

 

couple things you should know the 2001 660 is a four stroke the prowler 440 is a 2 stroke they are so different the only thing they have in common is they both burn gas as for the backfire and stall it may have been running hot and overheated but the rattling indicates serious problems what are your exact compression readings and have you messed with the carbs at all(could be stuck needle that caused the backfire)

 

well i know that it has sufficent compression for running it and the carbs have had old gas in them but i know that they are not my problme i think maybre crank bearings went in it and the crank wobbled and squeadke do you think the crank is bad by the eay it wasnt running hot