I need an opinion on the way my plug is burning. I'll try to post a picture. I have a 2001 yz426 all stock except I leaned the needle 1 clip position from stock. This is a new bike with about 10 hours on it. I did the BK mod and disconnected the neutral switch (blue wire mod). The pump duration is set for about .75 sec. Fuel screw is at 1 3/4 and I'm running Sunoco 94 pump gas. The altitude is under 1000 ft. The bike runs good, starts good, but developes a black powdery soot deposit around the insulator and the spark plug threads. There is also a sooty ring around the electrode tip. This is a new Autolite 4303 (NGK CR8E Eqiv.) plug after about 4 hrs. of riding, all first & second gear on a MX track. Do you think the fuel screw needs to be leaned out or the needle lowered another position?