I recently purchased a '03 WR250 with the following mods:
Yoshi pipe/header, YZ exhaust cam, Barnum airbox mod, p-38 and Zip-ty pilot screw.
my settings are: Main jet-#185, Pilot jet-#40, Leak jet-#90, Stock needle (groove #4)
I ride at 0-500 foot elevation @ 60 to 70 degrees. Could you recommend a good jetting set-up? Also, I checked the pilot screw and found the o-ring, washer & spring missing. The screw was only 3/4 turns out. Can you recommend a starting point (turns out)? Thanks for your help.