How fast do the go-karts go?
This is tough to answer as it really depends on the engine package, go-kart set-up, track configuration, and driver skill level. The go-karts are capable of 70-80+mph top speeds, but most track configurations tend to see top speeds around 55-65mph.
What are age and size requirements to drive/race the go-karts?
The driver must be at least five years old. There are classes for various ages of drivers.