Hello, I'm looking at buying a 2008 wr450f from a friend of mine but first I have a question about it. I'm wondering about the maintenance on these bikes. I know the newer generation four strokes aren't reliable like the old xrs. I ride trails in which some are open, and I do a lot of messing around such as racing friends and hill climbs, ect. In which I rev the bike out, but keep up on maintenance at the same time. On average how many hours do you guys get out of a piston and rings on these bikes? Any advice, suggestions, ect is appreciated! Thanks.