Buddy of mines got a 95 xlt indy 600, He's got a new belt but it still slips, we were wondering how you tighten up the clutch. Old belt was replaced with the factory polaris belt made for his sled. First belt got burnt up towing another sled.
Take a look at where the belt makes contact in the primary. Most times, if you burn a belt up, there will be a black ring of rubber residue in the clutch. Clean that off and scuff the area with sandpaper or a green scotchbrite pad and the clutch will engage a bit easier without slipping.
Adjust as bigbear said, trying for about 1/8" of belt riding out of the secondary.
2007 Dragon RMK 700 155", 2008 RMK 600 155", 95 Prowler 550 2-up, Really OLD AC Cheetah