As some of you know, i just jetted my 00' 400ex. I have a stock exhaust, and i already did the stage 1 jet. I also drilled 8 1 inch holes in the airbox lid. The dynojet instructions says to use a 165 main with the airbox lid off (stage 2 instructions). right now i have the 142 main in. so what do i do? help would be appreciated.

'00 4ooex 142 main (dynojet), holes in airbox lid, K&N'd with precharger

 

did you run it with the air box lid on it first
(with out the holes). how did it run then.

 

at least go to a 152 main...stock main in a 400ex is a 148, and you don't want to go leaner than stock...

 

i misunderstood the direction. but it runs and starts good now. Do you think it it totally neccessary for the 165? will it give me more power?

Dill: this is a dynojet kit, if you look at previous posts, i am pretty sure that dynojet uses it's own numbers

 

yes chuck they use there own #'s. you day it runs good now with the 142?. they will run really good
when there lean put a new plug in it and check it.
you are probaly running lean.

 

ok... i don't have a spare plug laying around, but i did check my plug that i have in it now, and it's all black, and it looks like it's filed. does that mean it's running lean? if it is running lean, and i go to a 165 main will that help?

'00 4ooex K&N filter, precharger, airbox lid has 8, 1 inch holes in it. I am currently running a 142 main.

 

black means rich, but that was the old plug, you need to put in a new one to get a true reading.
does it run good or what????

 

ok... i am gonna have to find some time to get this plug, i'll definatly have it tomorrow morning, then i'll post results. thanks : )

 

hey, in the mean time, could you give me further instructions so i know what to do. like how do i tell if i am running lean, or rich? and what do i do if i am running lean or rich? do i go up another jet size (165 main).