Originally Posted by red_tx
Thanks.! How do you know other that eyeballing it?
Are the 6mm head bolts the only way to tell?
The 6 mm head studs are unusual for a 66 cc as they usually are 8 mm.
That is my favorite motor made by NanTong JiaLi Gas Engine factory
The other identifying clues are the unique shape of the fins on the head
and the flat shape of the bottom of the transfer port castings.
If you still have doubts the measurement between the head studs
prove it's a 66cc too. The 50cc is smaller and no 50 cc looks like this.