Red Glow Header

[iamabowler]

ok i just got my 400 and i already got a question. My header glows red right where it comes out of the engine. I dont know i look about the motor but the guy i got it from said he thought it had a 165 main jet , not sure of the jet, in the carb. It has the stock exhaust and a k&N filter with no lid. i just really need a few ideas of where to start. thanks

[400exstud]

First off, a glowing header at night is not a real big problem.

Second, a 165K is a HUGE jet to have for those mods. That jet belongs in a built 416ex. I would check to see what really is in there and what mods your bike has.

[cals400ex]

is it a keihin or dynojet? a glowing header is not a huge deal probably. i would take the carb out and check the jets. look at the needle and its clip position, mainjet, and pilot jet. then see how many turns out from lightly seated your fuel screw is.

[iamabowler]

what are the stock setting on the carb suppose to be? also should i be able the feel the heat coming from the motor when i stand beside it.

[motox450]

If it is glowing red at the day time and you can see it right off you are running lean. It depends on if you are letting it sit as well they will turn red after awhile and at night it is far more noticable. I would probably up your pilot one size and try that. If it glows red while idling its lean in the pilot circuit, the size of the main jet will not effect the idle circuit and you can't tell if you have a rich or lean main with it just sitting there. The main jet only comes into plat from about 3/4 to full throttle. It goes idle jet(if applicable) 0-1/8 throtte, 1/8-1/4 throttle is pilot jet,1/4-1/2 throttle is the tapered part of the needle 1/2-3/4 is the flat section of the needle and then 3/4- full throttle is the main jet. Hope this helps

[GPracer2500]

stock jetting is

148 main
38 pilot
needle clip middle (3rd from top) postion

05/06 400EX needles have only one needle clip postion.