doc..
kevlar is improved belt and has lots to gain in high temperature.
But use only right size belt, its few cm longer then serial. Got my kevlar broken and bought multivar.
Changing belt which is only slightly used, dont make any sense. U have service manual and inspect it...
I think thats only thing ill do after tuning this slow beast is 12g sliders, for start.
Next is exaust, with changing hole size on exit gases from gy6. 125cc has 50cc exaust?