A year ago, idiot that I was, I was practicing on the very tight circle that California DMV makes you navigate to pass your motorcycle license test. I dare say it's impossible to do on a 500, at least it was for me, but before I figured that out I must have done about an hour's worth of circling intermittently applying the rear brake. Of course, that heated up the clutch bell something fierce and the second I left the lot I heard some squealing and felt the belt slipping on takeoff. For a year I 've been disassembling the CVT, using Emory cloth to scuff the pads and the bell, only to have the squealing/ slipping disappear for 4-5 days at most. I noticed the bell was bluish in tint, knew that was bad but didn't change the bell. Well, sick of the squealing, I got my new clutch bell in today and it's a whole new bike! Much faster, smoother on takeoff, no more juddering and thank God - no more Squealing.
I don't think it was the glazing so much as that I overheated it so bad that the metal broke down and the bell probably was out of round. Regardless, if any of you have squealing, slipping issues, obviously 1) Clean your variator, check your rollers/ sliders. 2) Check that your belt is good and within wear spec. 3) Inspect your clutch pads and scuff the glaze off them making sure they are more than 1mm in thickness. Mine were 3.1mm. If yours are less than 1mm you need new pads and if all this doesn't help then inspect your bell. If it's blue or highly discolored go ahead and replace it. It's a $60 part and it will save you a ton of aggravation.
Pics of old and new bell attached. I made a video of the whole CVT assembly reassembly that I will post later on You Tube as there aren't too many around showing the intricacies of that job on our scoots. FWIW: 5,000 miles on my Dr. Pulley Sliders and they look brand new. Sliders were the best $50 investment I ever made (besides the $60 for the bell)