400ex jetting help

[Norris3710]

hi i was just wondering what other people thought i should be jetted at i am at 1060 feet above sea level i have a 400ex i have a stage 2 cam
dyna tek ignition
fcr39mm carb
curtis sparks x-4
10;1 je piston and some porting done

[Norris3710]

also i have a k$n air filter with a bunch of holes drilled in top of the air box lid

[cals400ex]

i usually start around a keihin 170 mainjet with that setup. we run a 52 pilot jet. needle clip in 3rd position from the top for starters.

[Norris3710]

yea i had a 170 main it it and thats what i rode with all winter i just dropped down to a 168 but i am not sure where my needle and pilot are at and what other little things to the honda like. i know they really like thoes denso spark plugs over the ngk`s any other little tips would be great. i had to special order thoes plugs but they really helped

[JOEX]

Originally posted by cals400ex
i usually start around a keihin 170 mainjet with that setup. we run a 52 pilot jet. needle clip in 3rd position from the top for starters.
52 Pilot? Is that a typo?

[cals400ex]

Originally posted by JOEX
52 Pilot? Is that a typo?


no it isn't. now, if you're using the fcr40 (crf 450 carb) or the fcr39 from the YFZ, the pilots should be different size. in the fcr 39's that you buy for the 400ex, we ran 52 pilot jets with good luck. that sounds big for sure. these pilot jets are a different style than the ones that come in the 400ex, YFZ, and the CRF450.

[JOEX]

Originally posted by cals400ex
no it isn't. now, if you're using the fcr40 (crf 450 carb) or the fcr39 from the YFZ, the pilots should be different size. in the fcr 39's that you buy for the 400ex, we ran 52 pilot jets with good luck. that sounds big for sure. these pilot jets are a different style than the ones that come in the 400ex, YFZ, and the CRF450.
Thanks for the info;)