Alright I'm new to the wr450 world just picked this 2003 wr450 up a few weeks ago and I'm fighting the bog. I pulled the carburetor and verified the jetting 45 pilot 165 main ncvq needle on the middle clip. I have an adjustable fuel screw set at 2 1/2 turns. Starts first kick and idles great. I get a bog 1/2 throttle at around 5-6 thousand rpm then it screams and pulls hard. Revs quick in neutral. The one thing that is puzzling me, and I've searched everywhere and can't answer my questions, is there is no leak jet. The bowl looks like it was never drilled and tapped for the jet looks made that way not like someone plugged it. Makes me think I'm getter too much fuel from the accelerator pump causing the bog. Should I buy a different fuel bowl so I can have a leak jet? Or can I fix the bog with what I have? Thanks so much for he help. I've learned a lot from this page already.