Gentlemen, I rode my 2001 yz426 last weekend (7 days ago) and it ran fine. Tried starting it last night and it wouldn't start at all. Not even a sputter. This is odd because mine is one of the lucky 426's that is really easy to start. I have stock cams and use the stock de-compression lever. Normally there is a point in the piston stroke that i can't push past when using the kick start lever, then i use the decomp lever to get past that point and start it up. As it sits now i can kick the bike all the way through the piston stroke without ever using the decomp lever. I'm going to tear into it today. I guess I just wanted to know where to start, and if anyone has any helpful tips. I've never done anything with a 4-stroke top-end. I am pretty handy with a wrench, and have done plenty of 2-stroke top ends (haven't we all ) Thanks in advance, and please let me know if anyone knows what my problem may be, or if you see any flaws in my plan of attack. Plan: check spark Get valve cover off, check valve clearances (re-shim if out of spec) start ordering a top-end kit if the valves look good. should i replace the cam chain while doing the top end?