It depends on the gearing of the gearbox and how many gears there are
a 125cc varies between 65-85mph with a four stroke engine, and 65-up to 100mph with a two stroke
real fast
55mph
about 70-75
45
125
a 125cc pit / stomp bike can reach limits of 70mph :)
40mph
50 mph
it goes up your *** belive it
Depends of the landform, how it is built, or the weight. well it really depends on the 4 wheller not just the built or the weight of the wheller
1 km