I was reading a post by Luther that was about Head Pipes getting cherry red. I just got a 400ex and it has about 2 1/2 hrs on it, I read the post and thought I should go and check mine, and it does the some thing! I keep my bike in a heated garage and I fired it up, revved it a little, and the pipes got so red it looked like they were going to melt! I have a dirt modified race car, and have worked in a couple of machine shops that build race motors that dynoed over 2,500 HP and I have never seen this. It seems the 400ex is at the verge of detenation from being too lean.
I called my dealer and he said just ride it, that was normal. He said he could jet it for the elevation I live in, but if I wanted it jetted and he saw nothing wrong he would have to charge me. Why did Honda build a bike that is so lean? Why could they not build a bike that would be fine in every elevation? Don't get me wrong, I love the bike, but I am afraid of it blowing up just because of jetting. Honda, please fix this! I should not have to pay to get a brand new bike rejetted. I have been around too long to hear the dealer say "say that is nomal", that is NOT normal, it is on the verge of destruction! That kind of heat will burn a hole in the piston, especially a cast piston. Why should I have to rejet a brand new bike? Anybody feel the same way?

 

every engine runs lean at different higher elevations.

The air gets thinner, and more comes on. Its just how it is!

it has nothing to do with Honda