I started all my toys today (since they've mostly sat this winter) and noticed my 400EX had red hot exhaust manifolds at about 1/3 throttle. I've heard people posting this problem in the past and couldn't believe it's normal. The machine is fresh from the dealers 1st service (and was jetted by the dealer for Denver when purchased new). Is the engine running too lean or is this normal?

 

how long did you leave it set to idle? My 220 will even do that if I leave it sitting there idle for more than about 5 minutes after It's been ran for a while.

 

Mine does the same thing, and so does every other 400ex I have seen. I talked to 5 dealers and they all told me it IS normal. It was hard for me to believe, but it must be true, I even read it in the tech departments service manual. They all told me it was a combination of no air to cool the motor, lean condition and the head pipes being very thin. This does bother me, but my bike runs perfect.

 

Hey my son,
Next time you notice your header getting red hot.
Put your tongue on it to find out the actual temperature. LOL!!!
Later I no you told me not to reply to you but I just had too.