Zoom, what size track are you racing on and what gears are you using? Setting your clutch is also key... If you're running the stock gears and topend is fine, change your first gear from 20 to 19 on the clutch bell... Also make sure your adjustment screw on the centax clutch didn't loose it's setting and back down on the adjustment spring to much... If you're running 20, change to 19... You won't have any problems coming out of the corners or accelerating doing that switch. Take apart the clutch and make sure everything think is ok... If your clutch is out of adjustment, you'll really have problems with accelerating and engine tuning... Goodluck and happy racing with the G4 Mongoose..
RC_Alan