i had a post on this exact same thing a month back. vforce made my jetting go berserk on the same bike. leaning the main from 420 to 400 made it run acceptable. then i put the #70 needle on the first clip, and fatten the pilot to 32.5. back to running perfect now. make sure you set the air screw properly with the bike warmed up and running at 1/4 throttle. don't just pull a number out of a hat.