I have recently jetted my 03 yz 250. At 5000ft where we ride. The people around here tend to use a generic formula of 2 sizes down on the pilot/main, and stock needle in the second clip from the top. On the yz factory spec on the air screw is 7/8 of a turn out. I've got a reed block spacer and flywheel weights. I don't know how much difference it makes, but my low end doesn't seem as crisp as it could be. I've gone as much as two full turns out on the air screw, but that was too much. I'm at 1 3/4 now. The plug reading is on the darker side of carmel, but not wet. If anyone has experience with this I'd appreciate it. thanx.
