2001 CR250 JETTING
Jet................Stock..............Reccomended..............Altitude
Mainjet..... ...420....................430...............................400 - 420
Pilot jet........35.....................30.................................30-35
Needle.........6BEH1-73..........6BEH2-75......................Stock
Clip... .........3rd.....................2nd...............................Stock
Air screw.... 1.5 turns............1.75 ..............................Stock
Slide............4.0....................5.0................................Stock
This was suggested by everyone's favorit DB Mag, but I'm at an altitude of about 4500 ft on average and this is what I use: 390 Main, 32.5 Pilot, stock needle, 3rd clip, airscrew 1 3/4 turn, stock slide and a S-7 Jet Needle ((Sudco P/N 003-722). I'm also running a Pro-Circuit Platinum 2 pipe, Pro-Circuit shorty silencer and V-Force 2 reeds; other than that the motors stock, so far. Hope this helps.