Help jetting 40mm CRF

[Unicam450r]

I was wondering what would be a good setup for jetting with the 40mm FCR carb off the dirtbike? I have 2004 trx450r it has an '03 CRF cam, 03' CRF450 40mm FCR carb, 13.5:1 piston and sparks full exhaust system. I left the stock 170 main jet in it. The bike falls on it's face when you punch in first gear off an idle and just has a hesitation. Any help would be appericated.

[cals400ex]

from what i have seen, that hesitation is hard to get rid of with that carb. people have went from putting on new needles, mainjets, pilot jets, leak jets, boysen quick shots, etc. some never totally even fixed the problem. i had that problem with my 400ex. i have one of those carbs sitting in my basement with the noss adaptor already installed but i am afraid i will either get no performance gains or i will have a hesitation and i really don't feel like messing with it. the stock carb makes the same horsepower on a dyno. the fcr should give better throttle response if you can get it dialed in...

[RedRacer44]

Jetting for the main jet is anywhere from 165-175, depending on location, etc. The hesitation off idle is just part of the FCR carb. There really isnt much to totally fix it, you can make it better by getting the pilot jet more "spot on".

You learn to ride with the hesitation.....I mean, if you really think about it...you dont pin the throttle from dead idle/dead stop very often at all. When you're riding, you're using the clutch and reving the bike. At least thats how I ride...

I used the stock carb on my '04 for 2 seaons of MX and then got my '06 with the FCR....I havent had any problems at all with the whole "hesitation" thing. But I also upped my pilot jet and I keep my idle turned up pretty high.....