Hello peoples. I bought an 07 KXF 250 about six months ago with "low" hours on it. Its my first bike so I'm kind of clueless with the major maintenance schedule. I dont know for sure that the bike has the stock chain and tires on it so maybe that gives some idea of usage. I put approximately 30 hours on the bike this past summer. My question is... at what point should I be cracking the cylinder open? What is replaced during this interval and is there anything else major I should be watching for? I've already checked valve clearances multiple times and all was good. I have alot of experience building high hp turbo cars but this is my first run at a bike motor. Any help would be greatly appreciated.