in the yamaha manual that i have, the one the dealer gave me with the bike, it seems to leave some little steps out with the timing chain tesioner. like i said im kind of paranoid about messing something up and doing some damage. i found some info on thumper talk last night that does a way better job of expaining things step by step with pics. also another thing, i went down to a local parts shop where i buy most of my parts and i was talking with the one guy who works there, he has a yz 426f and he said i shouldnt have to mess with the valves yet. im not quit sure what he is talking about but he had me completly lost and he said something about there is something in the back of the motor and said something about the valves are self adjusting. i have no clue what he was talking about, he does know quit a bit about bikes though, he said his friend has an 02 250f and he has never been inside the engine yet.