Hi guys, My bro recently bought a used 07 yz450, bike runs well and is in great shape aside from one little problem. When going slow enough, or low rpm in any gear really.... the bike will bog out, die when going from pretty much 1/8th throttle to full throttle or almost full throttle. Yet, it does not do it with the choke on.... which leads me to believe the bike would need a larger pilot jet, correct? Also thinking larger pilot because the bike pops pretty bad on deceleration. Also, the bike has a full fmf exhaust system, sunline fuel screw as well. Tuning the fuel screw has had little affect on the problem, but like I said, the problem goes away with the choke on. Thanks,Dave.