jetting

[rrider250]

i started my 400 and was warming it up at 1/4 throtal when i looked down and the headers were glowing red. It is all stock but i don't know if it is running rich or lean. It was like 70 out.

[AtvMxRider]

If the pipes were glowing that means it's running lean which means it is running hot.

[JDiablo]

did u forget to take the choke off?that wat will happen if you have barely any air going into ur engine,just my two cents:blah:

[Aceman]

If your choke was closed it would run like crap from being way rich, not lean. Bump your pilot jet up one size.

[rrider250]

i looked and my filter was hella dirty could that be it. and it did not run long enough to get hot that is why i had to hold the throttle and i dont use the choke so i don't have to worry about leaving it on.

[Aceman]

Filter restricted=lean condition. Sounds like you figured it out:)

[rrider250]

thanks for the help. next time i wont be so retarted

[cals400ex]

i don't see how a dirty filter would cause a lean condition. you would get less air meaning a rich condition.


for your headers glowing:
if they are glowing at IDLE, turn your fuel skrew out to 3 turns from lightly seated. if they still glow at idle, you need a larger pilot jet.

if they are glowing when giving it like 1/8 throttle to 3/4 throttle, move your clip on your needle down one position.