pipe glowing red hot

[400exrider26400]

why does my pipe glows red hot when i do only 2 doghtnuts ?
my friend has a 400ex too and it doesnt do that

[brewster426]

its leaning out...try a bigger jet

[katch26]

open airbox? jetting?

[400exrider26400]

Originally posted by brewster426
its leaning out...try a bigger jet


its stock

[400exrider26400]

Originally posted by katch26
open airbox? jetting?

no the air box lid is on
and its stock

[katch26]

youre in canada on stock jetting. Mystery solved lol. Its cold...cold air = denser air= more of it to the same amount of fuel you were putting into it during summer.

[heebs12]

Saying his jetting is wrong because he is "in Canada" and its cold is a stereotypical response. I am also in Canada and today it was far from cold lol! Has been high 50's all week and i'm running great on a stock jet with a stock 400ex. It all depends where in Canada he lives!

His buddy's 400ex (which I assume is also stock) is running fine. The problem must be something else.

[Pipeless416]

check for air leaks..

[katch26]

Originally posted by heebs12

His buddy's 400ex (which I assume is also stock) is running fine. The problem must be something else.

it was just a joke buddy.....take it easy. Biased is most certainly the wrong word though, maybe I stereotyped a little but it was just in fun. However assuming his buddy is stock is the same as me assuming it was cold. If absolutely nothing (including the weather) has changed then youre looking for an air leak.

[heebs12]

I had already edited it just after. I didn't mean anything by it though. I was kidding too. sorry for sounding harsh lol

[katch26]

Originally posted by heebs12
I had already edited it just after. I didn't mean anything by it though. I was kidding too. sorry for sounding harsh lol

no worries bud!......

[dankbud42o]

I just bought an 07 and the header pipes glow cherry red also, all stock...

Originally posted by dankbud42o
I just bought an 07 and the header pipes glow cherry red also, all stock...

My 400ex headers glow red as well...just noticed it today while i was riding. Ever since i changed my headers. Can someone please helps us??

Thanks in advance, Nick.

[MidnightBlade]

the stock pipes still have the packing in them wait a few years and they quit glowing i got my 05 this year and it still want broke in so i broke it in( run it like ou stole it) and mine dont glow anymore and it runs awesome but i just got a used slip on so ill see what that does

Originally posted by MidnightBlade
the stock pipes still have the packing in them wait a few years and they quit glowing i got my 05 this year and it still want broke in so i broke it in( run it like ou stole it) and mine dont glow anymore and it runs awesome but i just got a used slip on so ill see what that does

I have my fmf headers...its my first day using them. When i turned it off they were red for a few seconds and then i heard a weird noise...very low almost as if a turbo was spooling down..but it went away after a little. COuld that be a reason? should i change my jetting?

[MidnightBlade]

yea any change in backpressure needs rejetting and i they are brank new hey will still have a substance in the header that will make it get hotter and also the need for jets too

[siggy konowaluk]

my brothers 450r goes that too, i think its running too lean or someting.

Originally posted by MidnightBlade
yea any change in backpressure needs rejetting and i they are brank new hey will still have a substance in the header that will make it get hotter and also the need for jets too

I dont think i needa rejet it tho because it runs fine and only badkfires while cold.

[Muddinguy]

spray Carb clean around the intake boots and if the motor changes tone you've found your air leak

at least that works on cars

[400exrider26400]

well ive heard that the stock 400ex and any other atv's comes extremely lean from the factory to pass emission test.
Could it be that my problem ?

dont think so...i rejett it...thanks tho.