[cheapeto]

It's hard to give a certsain number to belt life, was it a good quality to start off with? Again hard to say.
Get a good quality belt, and consider roller weights, then you can dial in to your needs for where you want your power at.
Fast out of the hole, lighter weights.
More top end, is heavier.
Or you could simply drill out the ones you got, and play with them, tuning as you go.
I added sliders to my scooter, reducng from 26 gram rollers to 20 gram sliders.
Some mix up half sliders and half rollers.
While you change your belt and rollers, blow the dust and dirt from your clutch bell, it will love you for that.