I worked on my jetting for a year and some time and it is best to start with the pilot jet, find the best idle within' the air jet, if you have to turn past 2 turns to get the smoothest highest idle, then you need to go down a turn on the pilot, if you get best idle results within' 1 turn of the air screw, you need to install a richer air screw. Next is your needle, lift/drop a notch at a time. They make BIG diffrences in changes. Then the main jet which you can only do by plug chops in my oppinion, cause the big KX is always going to run powerful in the WFO range.