400ex jetting question

[nissanraceboy]

I just installed a k&n filter with a dynojet Brand kit. I followed the instructions which told me the following settings (stage 1 settings):

Needle position at #3 setting

146 main jet (for aftermarket exhaust and air box lid on)

pilot jet is still stock

Does this sound correct? I am new to the whole jetting thing and don't want to run into problems (to rich/ to lean).

My 400 has a fmf slip on pipe and the air box top is still installed. Everything seams to run fine, and has seemed to gain a few extra ponies.

[nosliw]

wait let me get this straight, you added a highflow filter, a highflow exhaust and you went DOWN on your mainjet (148 being stock)?

[nissanraceboy]

The dyno jet kit said to use those settings.

[nissanraceboy]

also is there any tool you can buy to see if you are rich/lean. I know you can read the spark plugs, but this seems like more of a guess method...

[AtvMxRider]

Originally posted by nosliw
wait let me get this straight, you added a highflow filter, a highflow exhaust and you went DOWN on your mainjet (148 being stock)?


Dynojet numbers thier jets differently. It is not the same as the stock jet #'s