1989 polaris indy 500 issue

Hey guys I've been having an issue with this sled recently first it was bogging sometimes and would go and other times it ran great for a long time I cleaned the carbs after that it ran and sounded even better but I noticed the belt had alot of slack and it really sat down into the sheves on the secondary I cleaned the secondary clutch outer service when I first purchased it looked good. The belt was smoking the other day and I noticed the primary clutch had chunks taken out of the sheves that I will be fixing as soon as I can find a primary for an 89 500 indy are there other kinds that may fit it? Also I've been reading up alot on these forums and I can't find a good guide or walk through for doing the secondary clutch I'm more than confident to do it but have never done one on the skidoo my problem is my belt is too loose and needs to be tightened it's a old button style secondary any help or insight would be greatly appreciated! Also this sled has been very well taken care of not even a rip in the seat looks like new compression is good

1989 polaris indy 500 issue