My Xplorer 400 starting having mid-range power issues. Everything is original and has 3-4,000 miles on it. It starts and idles great however I checked the compression and it is 85 psi. Without any know damage to the cylinder should I still get it bored or honed? Or can I just put a new piston in with oversized rings? Should I spring for the Wisco or get the cheaper Numara? Anything I should be considering replacing at the same time?

Thanks

DD

 

with 85 psi and 3to 4000mi`s the jug is out of round and needs to be re-rounded if your in no hurry take the jug to a machine shop and ask if a .5mm overbore will fix it. if they tell you yes get a new piston and rings .5mm over size, Wisco is the way to go when a redoing your motor. Once you have the new piston take it all the the same shop and have them match it up. the shop will charge (Here in Canada) around $100 and the new piston, rings, and rispin (<-however spelled) will also run you about $100. don`t forget about the gasket set you will need say another $40. I know it sounds like alot but for what the ATV is worth spending $250 and not having to worry about the top end for another 3500 miles is well worth the money spent.
just my .02cents

 

Pull the jug and send it out to Rick Ritter. polaris

For around $150-$200 you'll get a bore/hone/chamfer, new Wiseco piston and Gaskets. Done right!

Wenty