There are a number of things that causes the belts to heat...or heat higher then normal. Normal being something at or under 200F let's say. Lower air flow is one, higher continuous higher speeds like running down roads at or above 45mph, higher spring resistance as in clocked to a higher setting or stouter springs in the primary, warn or binding helix in secondary, on some a mis-alignment between the two clutches, a glazed belt slipping all the time. But no transmission issue other then something that would cause increased load on the clutches would have an effect on cooling. The biggest cause on mine even with the increased clocking and other things is air flow. I run an air filter on mine and as it gets more restrictive the flow rate drops and up goes the temps. When it starts bumping upper 190s-200 I flip the helper fan on which takes it back down to the upper 170s. When that stops helping I have no choice but to pull and clean the filter. PITA but at least my clutches stopped wearing out parts from all abrasives being pumped through it. I suggest a full inspection for yours. Check the sheave condition for slippage...which is the #2 cause for unwarranted heating.