Check this out. I found some info on some Lifan engine swappers that put them in CT and it looks like a guy did a CL as well. He bought the 140cc it looks like.
http://lilhonda.com/webboard/f35/1972-cl70-11309/
"Installing the lifan 140cc went fairly easy, but I did had to grind down the engine a bit where it slides into the frame.
Converting the 12 volt engine volts back to 6 volts went faily easy also. All had to buy was a 20.00 buck rectifier and a wire harness.
I strained my back trying to start the sucker one day. The new 140cc is hard to kick over and sometimes kicks back at you.
I have run about 300 miles on it so far and the engine seems to run better with time and it seems it is getting easier to kick over.
I'm happy"