Snowmobile tech: Ask the experts

I have a 2002 polaris 800xcsp i was just wondering about these engines mine seems to run loud like it has and seems like piston slap i had the dealer look at it because i bought it from them and they say its all normal the 800 engine is loud well i listen to other ones and there alot quieter than mine so i dont know what to do with this replace pistons?

Without listening to it, I couldn’t say for sure what is causing the sound you are hearing. The dealer is correct when he says that the 800 has more noise coming from the internal engine than some other models. You could also be hearing a clutch with worn parts. Sometimes that noise can resonate through the whole engine. How many miles does this engine have on it? Have you done a compression check? Has the crankshaft run-out been checked? If you pull the pipe off of the engine, you can look in at the exhaust side of the pistons, you may see something wrong there like a cracked skirt or something. If you pull the spark plugs out of it, you can inspect the tops of the pistons for abnormal markings. These would be the first things I would do. If the engine has a lot of miles on it, I would pull it down, inspect it and rebuild it with whatever new parts are required. And if he has it apart, you should have the crankshaft trued. Ultimately, you will have to be the one who decides what needs to be done.

 Thanks,

Jerry Mattews

Starting Line Products
 

Thanks for responding the engine has 3131 for miles and compression is 125 per side cluthes have been gone through. Im thinking of doing a new top end what do you think? Thanks Don