Originally Posted by JonnyR
there is only one or two engines you "may get away with calling a 49cc and its the honda GX100 and the lifan 98cc because they "look" like the HS 49cc with a little effort
What about that 66cc?
Either way, 49 cc is already an ample base to start with. A GX100 is very expensive and I dislike flatheads.