Just adding info here so someone can find it later...
My 2009 Kymco Super 8 150 has 13 gram rollers.
Since I broke my belt this morning, I'm grabbing a Kevlar belt and some Dr. Pulley sliders, also in 13 grams because I like the amount of torque it has already. I may put in a 2000 rpm clutch spring while it's apart. I'll post back the results.