Was recently given a Polaris 425 magnum. I think it is a 1995 model? It does run, but idles rough. The carburetor needs to be replaced because it has a crack in the top. Also the rear brake disc needs replaced as well. One question though, when I start it in gear it wants to go....I have to be careful which direction it is pointed. How do you fix this?

 

Used carbs are on Ebay, plus sounds like you either have some clutch wear or possible a wrong size belt if it's creeping or going in gear or even a separated motor mount can do this by having the clutches out of alignment. This model also fell in the year models with soft cam lobes,especially the exhaust lobe.(cams have been updated) Check if it appears worn compared to the intake valves on either side of it. Valves set at .006 intake and exhaust. Look at this pdf manual to get an idea of the carb,clutches,cam and valves,clutch parts and other services like oil and filter change that may be needed.Index of /ORV Manuals/Polaris/1985-1995 - All Models