I bought a stock '03 Raptor on ebay for $3900. I finally got it after about a month of hassle w/ the shipping and rode it for about 10 mins. before it broke down. Turns out the starter clutch failed and it cost me about $450 to repeir w/ all the parts needed to fix the problem. After that the compression was around 115 and I was told it should be no less than 165. The idiot that I bought it from didn't have the K&N air filter mounted to anything so it sucked in a bunch of crap. Now I need to get the top end rebuilt. That's were I need a little help. I don't want to go extreme yet so I am going with a 100.5mm 11:1 Wiseco piston, Pro Design/K&N air filter combo with the K&N Power lid, Hot Cams Stage 1 cam and DMC Alien complete exhaust. They also are replacing the exhaust valves. Any opinions on what I plan to do? And will I need to run race gas or will pump premium be OK? Any input would be great. Thanks!

P.S. Avoid buying ATVs on ebay unless they come with some sort of warranty. The shop where my Raptor is now said the person I bought the Raptor from had to have known there was a major problem and that's why I got it so cheap.

Nathan

 

Sounds like you have got a good plan. You will be fine with premium gasoline in the raptor and that piston. I have a 100mm set up like that and love it.