need help with bogging and backfiring

[remix92]

I have a 400ex with a full pro circuit pipe and k and n filter and when i go to start it, it will only idle with the choke on, then when i turn the choke off it wants to die and when i hit the gas it will either bog or back fire really bad. im guessing this is a jetting issue but am not totally sure. any help would be great . thanks

[hondaguy20]

well if it runs good with the choke on it must mean that it needs more fuel than gas... so i would jet it richer and go from there... go about 10 or 15 units larger then if it does run better.. back down on the jet size until it doesnt run good then go one size larger... hope that makes sense..

[remix92]

alright i kind of understand, but if i did jet it and it was running good why would i have to go back down then one size up again :confused: thanks

[Eviltanker]

Have you rejetted since the pipe and filter? If not you need to jet it accordingly. Whats your elevation and approx. temps? that has to be figured in to selecting jets.

[CarGuy7a]

sounds like you may have a plugged pilot jet. your main jet only controls 1/2 to full throttle.

or your fuel screw may be out of adjustment.

how long has it been since the carb was taken off and cleaned?

[remix92]

i just rejetted like a half hour ago with a 40 pilot and a 155 main and i put it back together and it started right up but the idle was way to high, i could get out of gear without even giving it gas. and suggestions?i also turned the idle screw but the idle didnt change at all so idk what was going on with that. thanks

[Eviltanker]

Not to be a hammerhead but, are you sure your going the right way with the idle adjustment? also make sure the cable for the adjustment isn't binding.

[400exrapes]

its 42 pilotadn 155 keihin jet we put in a little bit ago. The idle screw is broken which happened with my 400 and were curious how to fix it now because the idle is set at the maximum idle and is way to high to ride with. Remix092 has no lid, k&n filter full pro circuit pipe and 416 with stage 2 hotcams. What should the jetting be the temperatures are between 50-0 degrees farenheight right now and were 300feet above sea level. The 42 pilot is fine but were curious on the 155 which was the only jet we had the other ones are dyno jets.

[drew416ex]

check to see if the airbox boot is secure on the back of the carb. Same thing was wrong with mine and the boot had come off a little.