My boy was all freaked out thinking we seized up the quad this weekend but turns out the belt broke and locked up the front pulley.

Is there a better belt to use then the stock one or is this something that happens. The bike is mildly sup'd up and doesn't have a rev limiter on it. Thinking the higfher than stock rpms might of caused it.

 

IMO: you had a bad belt.
They do make other belts for them.
www.maximumrpm.com.