Need Help With 400ex

[315thrider11]

Ok i have my 400ex running rich

i have a whitebrothers e series complete

and k&n airfilter with the lid off

it runs good it just has some black

stuff on the end of the pipe after a good ride


can any one tell me what is causing this

or what it is?
THanks Jim

[miller821]

Sounds like your jetting is to rich.. Try going down a little bit..
Whats your main jet set at now?

[Halter]

might just be blowing out some carbon

[315thrider11]

My jets are 170 main

and 45 pilot

and it runs good

i dont know if I should

move the air fuel mixture screw or

im not sure

but every time i ride it

it has black on the end of the pipe

and it just puzzles me.
THanks for the help =]

[boricua]

sounds a tad on the rich side with just the mods you mentioned.
45 pilot jet:huh
i could be wrong.

[JOEX]

I had the same set up with the lid on and 150 main (pilot and needle stock) and it ran great with ZERO problems from sea level to over 3000'.

[krt400ex]

is the black stuff wet or dry? if it's dry it's just carbon. that would mean that your jetting is too rich. if it's wet then you could have blown rings, bad piston, cylinder could be worn(is thats th problem then you would need to rebore it), or something in the valve system.

[jsmith2232]

I would run a 160 and a 42 pilot, I ran a similar setup for a year and a half and had very good results but with the 38 pilot but after running the 42 i'd never go back to the 38

[quadrider400]

Originally posted by boricua
sounds a tad on the rich side with just the mods you mentioned.
45 pilot jet:huh
i could be wrong.

Not if choke has been removed...