I have the same problem, but mine is worse. I read the post someone else wrote, I tried to reply there but it wasn't working.

Anyway, I have a 2001 400ex that doesn't have even the 2nd tank of gas out of it and mine does the same thing. I called 4 local dealers, and they all told my that was normal. They all told me because of the bike being rich, and the thin walls on the pipes, they just do that.

They also said it was because the bike is air cooled and the bike at an idle has no air on it. It just seems to me that it would cause problems later on. The one dealer I talked to is the biggest in Ohio, and they said they only have had one 400ex have motor trouble and it was from a bad oil pump.

One service guy at the Honda dealer said my car does the same thing also, if I look at it at night, he says the manifolds on my car would glow. I have a 600 hp dirt modified race car and I have never seen such a thing.

Obviously they are not going to fix it. So what does everyone suggest I do about it?

 

Thin pipes and glowing red. Normal? That is exactly what the dealer told me too when I dropped it off yesterday. I'm not satified with that answer yet either. I'll call Honda Corp. this morning to hear what they got to say about it. They were glowing red hot all the way back to behind the heat shield after idling 5-7 minutes after a cold start in a cold garage during 40 degree air temperatures the first night I ran it. I have been following the various manufacturer forums in this site for about 8 months now and have not read of others mentioning this condition as normal for factory pipes as apparently some of the dealers are claiming. Couple guys that responded to the other post suggested it may be a jetting problem. I tend to agree with them that could be a posibility at this point in time. Is this a normal condition for you other EX owners???????

 

I'm still saying this isn't normal.

You are definently running lean! I'm sure it won't be a problem in the summer. Since the air gets thinner when its colder out

 

My stock 400EX had 38 pilot jet and a 148 main jet with pilot screw turned 3.5 out from seat per Honda Service Manual.

I'd try the pilot screw first before changing jets (Clockwise=richen, Counter Clockwise=lean). If that doesn't work try going up to a 40 or 42 pilot jet. This should take care of glowing pipes at idle.

 

Guys,

There has been ample discussion on this in the past, in many of the brand areas. Start by doing a search for "glowing" or "glowing red" in the Honda area and you will find plenty of reading.

"Thin head pipe, glowing is normal" ... hate to say I would agree. I have an '87 350 4-Trax that has a billion (or close!) miles on it. It is driven hard summer (up to 100 F and winter (down to -40F). The head pipe glows red in the dark. Never an engine problem in all these years.

My '98 Sportsman 500 does the same thing. My log splitter (3 cyl from a Firefly) does the same thing. So does the snowblower (actually the whole muffler glows).

If I am moving (on the ATVs!) and there is sufficient airflow, or there is daylight, the red is not noticable. At night, idling, it certainly is noticable.

Is it a problem? Not on my machines. Read the plug to determine correct jetting, don't read the color of the head pipe at night, with no air flow.

Dwight

 

Racer18J,
Have your dealer check it anyhow. I had them pull the carb apart to look and they claim they did find a parcial jet obstruction problem.
Whatever they did corrected the problem. I understand that they will glow to a point if running long enough but the glow problem I had was excessive compared to a couple other new machines my buddies have.

 

If your carb is jetted too lean your exhaust gas temperature will go up. If you fatten up the jetting a little it should lower the exhaust gas temperature. '99 400EXs were jetted too lean from the factory. If you have done any intake or exhaust mods but never changed your jetting, you are likely to be too lean.

 

I noticed this occurance on my EX when I started it in extreme cold. I opened up the pilot jet about 1/2 - 3/4 to improve my cold weather starting and haven't noticed it glowing since.

 

I have a 2000 400EX Stock, I noticed my pipes glowing red the first day I got it. I bought it in January of 2001. I dealer said this has happened on all 400ex's since they were first released. Now nobody said it wasn't a problem Honda plans to fix, but I is normal for all 400ex's. The summer air should help but the glow of the sun will also mask the red glowing pipes, so don't be deceived.