Any one have Bill Boughten's # ?? In need of some tuning help... got a 09 250f 2 weeks agow and just can not get her dialed in!!

What bike?
Whats it doing?

On compresion it is poping has a flat spot or bog first starting it cold run like crap when cold. it has a ti-4r exhuast and twin air cage with out the backfier skreen. i had a 08 with the same setup and i had no problems but this 09 yz250f has been the worst running new bike iv ever had... tryed a 180 main fuel skrew turns leak jet and just cant get it good...

Go up one on the Pilot jet and go back to 2 turns on the fuel screw.

I'm with EW on this. Needs more fuel. Pre fuel-injection I always switched out low-speed fuel screw. Winter meant going out a twist and summer meant going back in. Jets seamed fine enough. No back-fires, Reasonable plug. 2006 250cc HRF was just plain bad. Wire-tied accelerator pump over-riding funky-punky-whimpy accel-pump spring. Problem fixed.