Re: Engine and Bike Suggestions
cc stands for cubic centimeters. It is the displacement of the engine.
The difference between the engines is that the 49cc has a bore diameter of 40mm and the 66/80 has a bore diameter about 47mm. The bore refers roughly to the size of the piston.
I do not have a personal comparison of the different sizes but have read (from many threads) that top speed is roughly the same. The larger displacement has more torque.
Search the threads here. There are several vendors and reviews. There seems to be alot of variations between motors. Not necessarily between brands or vendors but literally each motor has its own quirks and personality.