Got the 08 YZ450F with Yoshi RS pipe. Pops as hell every time the right hand goes up. No fire though. Turned the fuel screw up to 3 turnes out - helps but only just. Serious gun fire effect is still there. Got the main jet to 170 - no effect whatsoever. Now want to order some needles to try. Anyone solved it with the needle? The manual is confusing as to the richening\leaning effects of diameter\shape options (clip positions are ok and clear). Which one(s) are the right one(s)? NFLQ NFLP NFPR NFPQ ? I know the standard is NFLR. Thanks.