my 400ex runs with one exaust valve loser then he11 and wont run with it to specs... whats this mean?
*rest of valves are to spec.

 

what do you mean it won't run?

 

what i mean is... if i adjust 3 out of the 4 valves *2 intake and 1 exaust* to specification.... and leave the right exaust valve with about 1/4" of play, it will run. If i adjust all 4 to spec. it wont run at all, it will catch/turn over and then thats about as far as it'll get.... i'm thinkin that the decompression on the cam is screwed up and kickin the right front valve *exaust valve* open, and leaving it open.. so we're going to remove it from the cam and see if that works -- we're lost, we've been workin on this thing for well over 19hrs. now...

 

I bet you are right. I bet the decompression mechanism is screwing you up. Pitch it.

 

? is it a stock cam or a HOT Cam?

 

Before doing anything radical think about this. On the right exhaust valve the motor must be rotated only counter clockwise before stopping at top dead center. Even just a little clockwise can upset the correct setting of the decompression for valve adjusting. You may not even realize you have gone clockwise. It sounds to me like you are trying to adjust the right exhaust with the decompression apparatus incorrectly set. Also if it ran good before you started adjusting the valves then this should mean you have not done the adjust correctly. The easiest way for me to get the motor at TDC is with sparkplug installed and bike in high gear. Then just sit on floor and rotate rear wheel while watching timing marks. If you try to rotate motor with socket and breaker bar it is difficult to stop rotation correctly. Good luck.
Also if you tried to remove the automatic decompression system you could have real problems with using the electric starter. The starter is not designed to turn motor over with full compression.

 

STOCK