Pit Bike Problems! Motorcycle moves forward while the motor is running on 1st and 2nd gears?

Not being familiar with your actual bike-a centrifugal clutch has counterweight gripping shoes inside that are held by a spring.The springs are supposed to hold the clutch open until you twist the throttle and the engine spins fast enough to throw the counterweight shoes in an outward direction to grab the outer bell and turn the drive train.So is your idle speed to fast-are the springs in the clutch getting weaker and throwing out to easily?I have never seen an adjustable one,but if you can adjust it,then yes remove that cover and adjust it so that the rotating shoes do not come in contact with the bell until you raise the rpm's.