Well, I raced the first race of the year last weekend, only to have my 400 start making a weird noise going up a hill 3rd gear pinned. I got scared, so I babied the engine through the end of the moto. I got back to the pits and told my dad, we both agreed it was coming from the head, and that it deffinately wasn't normal. So I pulled the valve cover off yesterday only to find that both my exhaust valves are currently measuring something like .19mm when they are supposed to be between .25-.30mm. And to make things worse they have been adjusted once before, and I had just checked them 2 rides ago (and the first ride was only about 15min long). So in about 1.5hrs they went from .27mm-.19mm. If these valves aren't shot I don't know what would be. So I have decided to bite the bullet, and completely rebuild the engine, since the last thing I want it to do is lock up on the face of a jump. So I am going to order the following parts -All 5 valves -All 5 valve springs -All 5 valve seals -All 5 valve cotters -Head gasket -Base gasket -Cam tensioner gasket -Cam chain -OEM Piston -Piston rings -Circlips -Piston pin Am I missing anything? And with the help of the TT Store, all the parts listed up come to a total of $250. Thanks, any help is greatly appreciated. Oh, and one other thing, My dad has a valve compressor that fits his Gravely L8 lawn tractors(You probably don't know what those are), and I am wondering if by some kind of miracle it would fit my 400s head? I can get a picture if you guys want.