Jetin

[400ex men]

ok i need kno what you think think i need to go with? its got a 180 in it now ATV ZONE did that and i kno its to big. all its got is a x-6 and a k-n with kno lid on what do think i need to use? im thinkin about a 155

[TRXRacer1]

No matter what someone will say you still should do your own plug checks. Mine runs great with a 148 with a similar set-up but I recomend the 155 as a starting point.

[400ex men]

Sparks told me to go with the 155 with the 180 my plug dont look to good.

[400ex men]

come on some 1 pez

[sickmojave]

with my mods I run a #155 k. ;)

my airbox has 4 - 1 inch holes in the lid

[400ex men]

so a #155 wood be about right for me thin?

[sickmojave]

that is where I would start ;)

[cals400ex]

i usually set up with 1 size larger than sparks recommends. but, i would say their jetting specs are closer than most other companies that i have checked with. a Keihin 155-158 should be good depending on your elevation and temperature you ride in.