I just purchased a Derbi GPR50 with supposedly a 74cc kit brand new.
1) How do I know if it is really is 74cc and not 49cc without dismantling
the engine to measurs the circumference size of the piston?
2) The top end appears to be about 102-105kmh(about 65mph). What
is the top speed for the 49cc model? What is the top speed for the
Any how, it is a great bike and fun to ride! Thanks in advance for any