99% of point fired bikes use a point gap of .012 to .016 inches. You set them through the slots in the flywheel, do it by eye if you have to, just make sure they are in fact opening and closing. Those old magneto type ignitions set the timing with the point gap. Check on the flywheel for some kind of mark, typically there is a "T" for top dead center, and an "F" for a firing mark, and there will be an arrow or indicator mark on the engine case somewhere. If you have a timing light, hook it to a 12 volt battery (push bike to front of your car if you have to) then to bike plug wire. Start the bike, shine timing light on flywheel, if the "F" mark is before the indicator timing is advanced close the gap slightly. If the "F" mark is after the indicator timing is retarded open the gap slightly. If the "F" mark is aligned with indicator timing is perfect (its OK to have very slightly advanced). It takes only the slightest nudge when adjusting, if you see it move you probably moved them too far. Oh, and put some grease on the point cam part of the flywheel and your tune-up will last a long time.
