Nev, Turn you fuel screw out (found on bottom of float bowl) Turn it out 1/4 at a time until the problem goes away. If you get out to 2.75-3.0 turns, you should go up one on the pilot jet. The black on your plug is probably coming from another throttle position. Bill ------------------ 99 WR400f, YZ timed, MX-Tech suspension, Scotts steering damper, White Bros E-Series (12 discs), tapered header and a/f. Kouba T-handle for the fuel screw. Works Connection billet throttle tube and frame guards. Cycra Pro-Bend, triple clamp mount handguards. Thumper Racing rad guards, Renthal Jimmy Button highs, YZ Tank and IMS seat, YZ number plate, odo removed, de-octopussed (Thanks Clark) EKP #4, 50PJ, 175MJ, 100PAJ and 65 SJ at 500-1000' Thanks James Dean!