The clutch buttons in the secondary clutch are worn out, not hard to replace if you are mechanicly inclined.

 

It could be that you need a shim that moves the top part of ur clutch in to engage the belt properly, im haven the same problem, my scrambler just went through 2 belts in the last month and im gettin sick of this. lol. Was wonderin if you need a clutch tool for this?