Finding a 6 Volt ring gear can be a project. But..the ring gear can be gently removed, flipped over and re-indexed and re- installed. I did this to mine. It takes a shop with patience and care but it can be done. Disconnect the battery. Work the linkage by hand. With the cover removed from the bottom of the bell housing you can see just how and when the bendix drive meets the flywheel ring teeth. If the bendix engages before the switch, Good. If the switch engages before the bendix, Bad. The link arm that pushes the switch can be modified with a bit of weld(switch never contacts) or a bit of filing(if the switch contacts before the bendix and ring) The contacts on the starter can be replaced, turned around, and cleaned with a file to get a good connection. Lots of things can be done to this system. The engine tends to stop in one position(just the nature of the beast) moving the ring gear to another spot can reposition those worn teeth out of the most common starting spot. Like putting a new one on without a new one..:)
