Jettig 4 on a 250ex w/ WB E-Series????

[BaD_250ex]

I got me a WB E-Series last X-Mas, and its always been backfiring, and I havent thought nothing of it cause my dad told me it was supposed to. :rolleyes:

But now that I know a little more, I was wondering what size of jetting should I get for it to make it not backfire?

[rider250ex]

hey. i am running a 98 right now but i think i am goin to change it to a 106 because it is still backfiring a little. hope this helps

[GETSOME]

Try adjusting the air mixture screw on the outside of the carb. There was an acticle in ATVsport that said this fixes the problem. Come on guys, the main jet thing, backfiring or no backfiring, you know you have the proper main jet if you start large enough to where it craps out on the top end, then go down one jet size at a time until it runs smooth on the top end. I've had to do this with every mod I have made on my wife's 250EX. Recently when we did the powroll big bore kit in it, I started out with a 130 main and worked my way down to a 120 where it runs smooth on the top end without sputtering.

[mudderchic]

I had the same exact problem and then i figured out that the main jet had to be changed first. Unfortunately the 250ex seems to be VERY picky. I had to change the jetting a couple of times before riding due to the temperature outside.