Glowing Head Pipe

[03TRX400EX]

I just purchased a 2003 400EX. Everything is stock and the bike appeared to be meticulously taken care of. When I picked it up I checked everything over and rode it a little. Seemed great. I brought it home in the back of a pickup truck 2 hour drive (it was very cold, about 15 degrees F).
When I got home and started it up it was putting out some white smoke and wouldn't idle correctly. Its around 12 degrees outside at this point, so that didn't suprise me. Next thing I know the head pipes are glowing red from the head aroung the first bend. (about 8" of pipe). I shut it off and pushed it inside. Left it cool and checked the oil. It was low but clean and smelled normal. I did not yet check the plug.
Any ideas?
I'm hoping I didn't get burnt in a bad deal.

[400exrider707]

jetting is lean

just from dealing with other bikes with the same issue.. id get a 155 main jet and that should solve your problem

Jesse

[400exrider707]

Eh 155 seems a little too big. I had a 155 on mine here in NY (03trx400ex lives in PA) with a slip on and open air box and it was rich soo I would say try a 152

[400exrider707]

You also might want to try upping the pilot jet size too

[UglyMotha™]

Originally posted by Dirt Merchant
just from dealing with other bikes with the same issue.. id get a 155 main jet and that should solve your problem

Jesse



good call??, now explain yourself........... how exactly is upping the main jet going to fix somthing that is controled by the idle jet aka pilot jet :o


only time main jet is in use is between 3/4 throttle and WFO, and he said it wouldn't idle

ahh thats because im retarded.. i totally missed that part ... my fault..

Jesse

[bone705]

dirt merchant will you answer my pms. i want to know whats going on with that case you were suppose to send. if your not going to send it then send my money back.

[Jonas]

A glowing headpipe at night is normal. Smoke is not.

[400exrider707]

Originally posted by Jonas
A glowing headpipe at night is normal. Smoke is not.

No no its not. The titanium headpipes on some race bikes like the CRF and YZF glow a little easier, but on a stock header for a 400ex:huh NO its definitely jetting.

[Chef]

Originally posted by 400exrider707
No no its not. The titanium headpipes on some race bikes like the CRF and YZF glow a little easier, but on a stock header for a 400ex:huh NO its definitely jetting.

NO Your definitely wrong. As cold as it was outside, it could have been a bit lean from the air temp. Plus, it was at night. I wouldn't worry about it to be honest. I'm amazed you even got it started in 12 degree weather.

[UglyMotha™]

any ex you let set and idle the head pipe will start to glow even if jetting is spot on

so no that deffinantly doesn't MEAN the jetting is wrong

[400exrider707]

So when I start mine up in -15 and let it warm up for 30 minutes and I dont see the head pipes glowing, then does that mean that MY jetting is wrong?????:confused:

[mojoe2878]

like most others already said, you are probably just running a tad lean with it being so cold out. either back the air/fuel screw out a little or install a 40 or 42 pilot jet and that should solve the starting and idling problems in the cold weather. as far as the head pipe glowing red, i believe it is normal because every quad and bike i have ever owend has down this, but you will get alot of mixed opinions on here about wether its normal or not. the white smoke you saw would be normal for any engine on a cold day, its from the hot exhaust mixing with the colder air and making it condensate, like when its cold out side and you can see you breath coming out and it looks like smoke but isnt.

[daryl]

I have an 02 400ex with a full yoshi pipe.I had the same problem and posted a thread about it several months ago. A couple people told me to jet it out I went up to a 150 and played with the air screw it seems to run a lot better and Ive not seen it glow anymore,but its not been under the 30 degree mark while Ive been rideing either...

[cals400ex]

if they are glowing a bit at IDLE, just turn the fuel mixture screw out a little bit. its not a hard fix.

[04EXdude]

:cool: /\ :cool:

[Plante400]

reving the bike to much at start up could cause it..


ive seen glowing beat red pipes before from idiots hammering it right at start up..

no offense to u haha

[cals400ex]

if they are glowing when you are hitting the gas, drop the needle clip one position.

[itp82001]

is u r 400ex stock if it is dont go to a 155 main it will run way to fat thats for a 440 kit and for a pilot i would run prob a 40. so u r quad worms up faster. because 400ex are known for taking a long time to worm up. i put a 40 pilot in mine and it took care of the long worm up prob and a 42 was to fat even for a 440 kit. hope that helps u out.

[Camaden]

I had the same problem with my new 04 Ex, so I talked to two dealerships and they said this is completely normal, as for any starting problems I was told to change your pilot jet to a 42

[Chef]

Originally posted by itp82001
is u r 400ex stock if it is dont go to a 155 main it will run way to fat thats for a 440 kit and for a pilot i would run prob a 40. so u r quad worms up faster. because 400ex are known for taking a long time to worm up. i put a 40 pilot in mine and it took care of the long worm up prob and a 42 was to fat even for a 440 kit. hope that helps u out.

Dont give advice if its wrong. Thanks

[itp82001]

its not u must be smoken

[AtvMxRider]

Originally posted by 400exrider707
You also might want to try upping the pilot jet size too

[AtvMxRider]

Originally posted by itp82001
is u r 400ex stock if it is dont go to a 155 main it will run way to fat thats for a 440 kit and for a pilot i would run prob a 40. so u r quad worms up faster. because 400ex are known for taking a long time to worm up. i put a 40 pilot in mine and it took care of the long worm up prob and a 42 was to fat even for a 440 kit. hope that helps u out.

[AtvMxRider]

Originally posted by itp82001
its not u must be smoken


No your smoking I ran a 160 in a my 400 with just a slip on and K&N.

[AtvMxRider]

Originally posted by Jonas
A glowing headpipe at night is normal.


No it's not

[Chef]

Wow Jerry...4 in a row. Must be a record! :chinese:

[400exrider707]

Originally posted by AtvMxRider
No it's not

Finally someone backs me up on this. Thanks man. And wait did he say 42 is too fat for a 440:huh !!!!!!! I have a 45 in my std bore w/ 11:1 piston, cam, slip on, filter w/o lid, and its never started easier!

[mmartin]

I have an HMF and a UNI filter and I run a 165 main and 42 pilot. Runs perfect