First off, Sounds like clutching issues.
If you're taking belts, primary is likely slipping causing excessive heat.
Primary spring may be getting weak.
Sheaves should not be "Smokin Hot".
A kit will freshin up things and put more grab on the belt.
I used the kit from MCB Perf. Basically a Goodwyn with some small changes. Search the web, they have a good website.
You might be able to drop 1 tooth on the top and still use your 72 chain, forget how much play I had in mine.
Also, make sure of your alignments & C to C's.
and let us know how you make out.
A Motto to Live By:
Life is not a journey to the grave with the intention of arriving safely in a pretty, well preserved body,BUT rather to skid in broadside, thoroughly used up, totally worn-out and loudly proclaiming
WOW , WHAT A RIDE !