I've been jetting mine recently, been doing constant arse dynos in a disused quarry, in England, at sea level, airbox lid off, 48 pilot (45 only worked at half a screw out) CEL needle @ 3rd from top, and currently a 162 main jet, I tried 170 and it worked better but jumped from 160, going to fit 165 on the next ride, running fully synthetic oil at 32:1.
My bike is an SR model, but with pwk measured at 36mm inlet side, fibreglass reeds, proskill exhaust pipe and standard can. Rings are in tolerance, bore in good condition, KIPS working fine and lubricated, there is nothing wrong with this bike. Current temperature is about 5 celcius, that and sea level is the only reason I can find why mine is running better with larger jets. But I would expect it to need larger jets with the box and expansion chamber mods anyway... so why is the KDX so special that it constantly needs to be made leaner the more you tune it
seems like absolute madness to me!
