Help Please-plug Keeps Fouling

[tahoe97]

Here recently i would say after i ride for about 30 minutes or so my plug fouls and the bike starts acting funny then as i ride more it dies and wont start.. When i take the plugs out they are solid black which means i think i am getting too much gas.. But the thing is i am running factory jets.. No jetting has been done.. I have a pro circuit pipe on it and a few uni filter vents in the air box.. i would think this would make it run lean if anything.. Does anyone have any idea whatsoever that could be making my bike do what its doing..

thanks in advance for the help guys

[ridesa02400EX]

is it a dry black or is it really wet?

[Cody_300ex]

Sounds Like your running rich. Might want to mess with the air-fuel mixture screw or the pilot screw.

[Dienamo111]

You could try these things.....

Try running with a modded air box lid or no lid at all , this will lean out the bike some. Also making minor adjustments on the air/fuel screw can help too.

[400extracc]

k, i have a pro circuit pipe as well. just installed in last week, with stock filter and holes in the air box. the pipe came with a 160 main jet and a 55 pilot. i installed all that and the quad was running like crap. i then went back to the stock pilot, 155 main jet, lowered the jet needle clip one notch and the air fuel screw
1 1/2 turns from closed.

it now seems to run fine. i did notice that the idle rpm was low, so i just adjusted it.

hope this helps:macho