Try this. Remove the spark plug. Disconnect all the wires from the stator to the rest of the bike. Take the black wire from the stator coil and hook one end to a VOM (volt ohm meter) and the other end to any metal part on the motor. Use an electric drill and spin the crank shaft. You should get a 6 volt reading on the meter. If not then look into slot on magneto coil and gently turn the coil with your hand and see if the points are opening and closing. Then report back.