If someone changed the starter, I believe they would have to change the flywheel also. Probably not. A 6V starter has heavier windings and spins better. I am not real up on AD stuff but would guess burned wire, fuse?, loose connection, Ignition switch/foot switch burned out. What do you mean "prime" first? How do you prime? That issue must be resolved also, right away. Also a "charged" battery can be real BAD when loaded. Does everything else work? lights, heater, gauges, etc.? You need to do more investigation. If you are up on electrical stuff, see if you can bypass all ignition switches/foot starters and remote start it. This eliminates most wiring and all switches.
