red hot headers....

[buster024]

On start-up my buddies brand new 05's headpipes are glowing bright red. Everything is bone stock. They quit glowing after warm-up, but is this normal? Does this mean it's running rich from the factory (or lean)?

[CarGuy7a]

the only way they will glow red is if you let it set and idle really high for a long time before riding it.

how long is he letting it sit and idle before he rides it?

when you ride it the air keeps them cool so they won't glow red.

[CarGuy7a]

the only time mine have ever glowed red was when i put my stage 1 cam in and let it idle at 3000 rpm for like 5 minutes when i was breaking it in. but that's only because i forgot to put a fan in front of it to keep it cool but when they got red i rode it and they cooled off.

[JW450R1]

Bump up the slow jet 1 size.That seems to help some

[400exrider707]

Try adjusting your fuel screw a little first, and if that doesn't work go up one pilot jet size. This is a lean condition. This is sometimes common and you will hear people say its ok to run like this, but you shouldn't see this from stock headpipes, maybe a super thin titanium headpipe, but not stock 400ex head pipes.

[CDCHONDAS]

air flow itself is not going to make the temperature change if they are really glowing, I've seen alot do that, to lean they will really do it but its definatly not uncommon

[underpowered]

Originally posted by 400exrider707
Try adjusting your fuel screw a little first, and if that doesn't work go up one pilot jet size. This is a lean condition. This is sometimes common and you will hear people say its ok to run like this, but you shouldn't see this from stock headpipes, maybe a super thin titanium headpipe, but not stock 400ex head pipes.



well actually a properly jetted 4 stroke, you should be able to see a glow in the dark, not during the day though. on my 400, with stock header the head pipe glows at night, as it should.

but yours does sound lean, try adjusting the fuel screw first.

[400exrider707]

Originally posted by underpowered
well actually a properly jetted 4 stroke, you should be able to see a glow in the dark, not during the day though. on my 400, with stock header the head pipe glows at night, as it should.

but yours does sound lean, try adjusting the fuel screw first.

I disagree, but to each his own.

[REDRIDDER]

orange glow = lean condition

[mcleod]

mine too glow at night, almost not visible in day...

tuned my atv with a wideband aem sensor btw! so i really know if im lean or not :P

[underpowered]

Originally posted by 400exrider707
I disagree, but to each his own.


well it is a common mis-conception that glowing is always bad/lean. with proper jetting, and low light they should glow. even headers on a car will glow at night if you rev it hard. (notice, Headers, not manifolds) mot people run their bikes rich because they think that th eglow at night is wrong. but they could lean out a bit fro better performance, but a little rich won't hurt em

[mcleod]

Originally posted by underpowered
well it is a common mis-conception that glowing is always bad/lean. with proper jetting, and low light they should glow. even headers on a car will glow at night if you rev it hard. (notice, Headers, not manifolds) mot people run their bikes rich because they think that th eglow at night is wrong. but they could lean out a bit fro better performance, but a little rich won't hurt em

just can say better then that.