Correct Jetting 02 YZ125

May 7, 2003
I recently bought a 02 yz125. The bike is really rich down low. If you back the air bleed screw out things improve somewhat but then the bike won't start, (2 1/2 turns) starts good at 1 1/2 turns but fouls the plug in 2 rides. I saw some recommended settings for the 02 on the Bill's Pipes site, they keep the stock pilot and main, back the air screw to 2 3/4 and use a different needle, one that I haven't been able to find on earth.
Anybody found something that works? I dropped the needle one spot, little effect, except it scared the willys out of me when I saw the 3 diameters separated by tapers of various lengths…. Mayday..mayday..mayday


02 YZ125
01 YZ125
99 KX100