red hot pipe

[daryl]

Ive got a 02 400ex with a full yoshi exhast and a uni filter.Ive not had time to jet it out yet though it seems to run fine like it is.I only rode it for about 10 minutes last night and when I stoped the two header pipes were bright red hot from the head to about 5 inches out. Is this normal for an aftermarket pipe.Any information on this would be greatly apreciated.....

[400EX QUADER]

it needs to be jetted! It's way too lean!

[dirt308]

This could be from not jetting it. When a motor is running real lean it gets very hot.

[PIMP]

or maybe its for the cold wheather. that makes it get hot real easy.

[400exrider707]

Originally posted by PIMP
or maybe its for the cold wheather. that makes it get hot real easy.

No its definitely jetting. And anybody tells you that this is normal is lying

[daryl]

Thanks for replying.Iam going to order me a jet kit for it. I checked the plug it was black not white like you would think it was if it was real lean.. Do you think it hurt my pipe or engine running like that..

[PIMP]

Originally posted by 400exrider707
No its definitely jetting. And anybody tells you that this is normal is lying

i'm not saying its normal its cause i seen this happen even if the bike is stock.
ppl that ride in the snow know what i'm talking about

[cals400ex]

i have seen this on many stock bikes including the new 450's. i usually richen up the jetting a tad and it fixes the problem. here is what i would do:

if they are glowing at idle, turn the fuel screw out a 1/2 turn or so.

if they glow from 1/16-3/4 throttle, drop the clip on the needle one position.

if they glow from 3/4-full throttle, raise the mainjet up a size or two.


this will fix your problem. good luck

[quad_400ex]

i have the full yoshi system and jetted mine fairly rich to take care it but if i ride hard on the road or anything that pulls the engine hard it still glows

[daryl]

Thanks for the info. The first time I noticed it I just got back from giving it all it had going down the road and back.And the next time a couple of days later I was checking every thing over while letting it idle (It was running for about 10 minutes)and I noticed the pipes starting to get red. this weekend I should have my larger jets and I will try to find out just when it is doing it and try what you said. Iam glad other people has seen this hapen before.