I recently had an inquiry about trying to time a Harley Davidson (mid-seventies) 2 stroke so that it will run well in both forward and reverse. I had worked on one recently so I offered this:
The model I was working on had no service manual available for it. However, I did come up with a copy of the procedure for similar models and it was close enough. There was no advance mechanism on the one I was working on. You had to “split” the timing adjustment between forward and reverse rotation of the crankshaft, and with each change of the timing, the point gap had to be readjusted.
The following are some pages that I scanned out of a manual I found for some similar models (there was no manual available for the model I had).
Ron Staley has published the following books, and you can get more information about them by just clicking on each title below:
Electric Golf Cart Repair 101 (and a half)
Techniques, Tips, Tools and Tales
Gas Golf Cart Repair 101 (and a half)
Techniques, Tips, Tools and Tales
4-Stroke Golf Cart Engines Explored
What Makes Them Tick
By an old Slot Machine Mechanic