FMF power core 4 jetting Question

[redrooster]

If any body could help me that knows the jetting specs for the fmf power core 4 with power bomb header would be much apprecaited a buddy of mine has had nuthin but problems with this setup since he has had it and has sent it to twoo different shops and it still runs like crap! So thanks to everbody that can help out in advanced! :)

[cals400ex]

you could always call up fmf and ask for the jetting specs. the # is 310-631-4363. however, when i called them about jetting specs on a blaster, they jetted me a little rich. for most power, i like to lean them out a little bit. if the 400ex is all stock, airbox lid in place and factory air filter i would say: put in a 152 keihin main jet, go with a 40 or 42 pilot jet and the needle in the 3rd position(stock) or 4th position. this should get you really close.

[JD400exrider]

They have the jetting specs on their web site. It will show the dyno chart along with the recomended jetting for there pipes. You have to hunt around a little on the site but it is there. ;)

[redrooster]

Anyone else got helpful info? BUMP:confused:

I've run that exact same setup...

Pilot jet MUST be a 40 or even a 42 would work...

Needle clip 2nd from the bottom..

dynojet jet size 155-160 with the lid off.

Airscrew turned about 2.5 out from fully turned in..Might have to make it 3 turns.

This is what I used and it ran great.. Hope it helps..