Just take the thin shim out of the secondary to tighten the belt and leave averything else alone.

 

andy the 650 cat sits up so high that a radial tire just doesn't seem to work at all you need a really stiff sidewalled tire that is a 6-ply. and i need to take out my remaining shim and put in a thinner one i think it is .08 mm i need to get a .06 i think and put in still not as tight as i want it.

 

Does a Bighorn not have a stiff sidewall? I wouldn't think that it would make any difference with tires on a quad sitting up high. What PSI are you running in the stock tires?