Originally Posted by Dan
Cool, Lud! TY. One pic shows the, I think brake assembly, can be removed so the engine could be close if not centered. And the shaft could be adapted to receive a sprocket. Or replaced.
2nd & 3rd pic of GY6 pictures
The output shaft is splined on all of them so all that would be needed is a rear wheel to remove the splined insert from and then weld the desired sprocket on to that spline is what I would be doing I think.
Here is a pic of the little 50cc version