Surging at high speed

[skyrider]

Hey guys, my 10,000mi quinqui with new belt and rollers, runs great except for a slight surging at 2/3 to full throttle. The surging is similar to going against the wind and at one point I thought my new belt was tearing so pulled the cover and the belt is fine. The surging feels like its actually in the front part of the motor, but a young 12yr old mini-biker kid said it could be the gears slipping so I ordered a new clutch yesterday(origional clutch still on) But increasing speed I don't notice slippage, yet if the clutch goes I thought I'd be stranded and it was a long walk a few months ago when my belt broke, LOL!!!
Any thoughts???:hmm: