I did a search but couldn't find all that I wanted and posted this in the 250 forum but got nothing. I was reading about how much it would cost to have a place rebuild the engine. We bought a 00yz426 and a 02yz250f last spring used. I have no idea about the previous owners(regret not asking the dealership we bought them from) and how hard they rode them or if they replaced anything. We ride only on trails and only get to go about once a month at the most so we are not racing these things or using them a lot. anyways what im asking is: should i think about rebuilding? I should be way over due right? what should I replace? I know nothing about the parts i need to replace How hard is it? Could I do it with little mechanical experience? I plan on doing the 03 cam swap this week. How much $$$$ am I looking at if I do it myself? if I have a shop do it? whats tools will I need to purchase besides a torque wrench and about how much $$ are they? are there any tutorials or anything out there besides the dirt rider one?=7 Thanks a ton.