250 X jetting question

I have an 1987 250 X with White brothers E Series Pro Meg, k & N filter, and a Web All-Around Cam. I was wondering if anyone has any jetting specs for the set-up? It loads up some when it idles-may be bad float needle and seat? When I rev it up, and let off of the gas, it backfires a lot. Any help would be appreciated. Thanks.

get a bunch of jets, im thinkin u is lean if it pops

Sorry I can't help much but try turning in your mixture screw half or a full turn and see if that helps the idle. Frequently, when an engine backfires (or pops) when you let off the throttle, than there is an air leak into the exhaust system allowing fresh oxygen into the hot exhaust stream inside the pipe to mix with the unburned gasses and causing a popping or backfire sound. Check the pipe at the head and at all joints for an air leak. You did use a new exhaust manifold gasket, didn't you? If everything checks out, then you can work on jetting and such. It may also be something as simple as the valves out of adjustment. :cool:

Hey 250 rider
what kind of pipe do you have?
i have a 87' 250X too with a cobra pip and i hate it,i want white brothers one and i see you have one.

THink you could tell me hwo mcuh it was and if you like the power change, what about the sound......it is loud??
well any info on it would help


thanks man