I have an 02 400ex with full curtis sparks exhaust high compression piston bored to a 426 with stage 2 hot cams. I have the keihin flat slide carb off of a crf 450. I just put a 190 main and a 55 slow jet in it with the needle 3rd notch down from the top fuel screw 3 turns out. From an idle it bogs down after about a 1/4 throttleIt. It will do fine if you ease into it. And on deceleration it will not throttle back down all the way. It is like it sticks at 1/4 throttle for just a few seconds. Any help would be appreciated I want to fix it so I can ride this weekend.