Originally Posted by Goat Herder
I can help on the piston.
As far as motor identification I feel like I am loosing track. The smaller china has a shorter stroke and the bigger china a longer one. The smaller china will rev more the bigger china seams powerful all the way around from what I hear
The 48cc has a 40 mm piston and bore
The 66 cc has a 47 mm piston and bore
therefore they have the same stroke