I have a 07 klx 250s, I purchased the bike used, with some small mods done, air box lid removed, an oem adjustable needle in the carb, slide drilled out, im thinking a 130 main jet, baffle drilled out of oem muffler. I installed a Muzzys complete exhaust, header and muffler, But I havent rejetted yet, still snowing here. Already having an adjustable needle and slide drilled, I was thinking i would change the main to a 132, a 40 pilot ,needle clip in the 3rd position, and adjust fuel screw as needed. Im use to jetting 2 stroke snowmobiles, never any 4 stroke bikes, actually never drove a bike until last summer. Any info would be great, Im at sea level.

 

Try a #138 main jet (Kehein OE) anda #38 pilot (Kehein OE). You have all the other parts you need to make her get up.D (Needle/adjustable FS.)