can anyone tell me what is wrong with my gilera runner sp 50?

when i was going it started making a whistling noise coming from the variator and clutch then it sounded as though the belt was rubbing and it just stopped and turned off and wouldnt start again or the kick start wouldnt move then i took the variator case off and couldnt dee anything wrong i put it back on and it started and was running a gain but still had that rubbing noise after about quarter of a mile it stopped and shut off again. can you teel me what is wrong with it? please.