Most 2 cycle chassis will not accept a 4 cycle engine because the tube behind the seat does not allow for enough room for the sprocket hub and gear.

To cure this problem, I remove the tube, fabricate a new tube and weld it in giving more room for the sprocket. Also the seat strut has to be moved and re-welded.

The pictures came out backwards. The second picture shows before, and the first picture shows after, with new tube in place and ready to weld in.

Butch