Re: Ballast resister?
You are correct about the voltages to the coil, (between 6 and 9 volts with the key in the 'Run' position, but I think you mis-spoke about the coil.
The coil doesn't care what voltage it sees (within reason), and can handle up to about 400 volts.
(400 volts in will really give the output a kick! Welcome to CDI output voltages!)
The reason the voltage is reduced is to keep from smoking the points. If you try to run a straight 12 volts to the points for very long, you will be walking shortly. The points will weld together.
Most starter solenoid have an 'I' terminal on them. The 'I' is for ignition. A wire should go from that terminal to the positive side of the coil with no resistor, so when you are trying to start the thing, you get hotter spark. When you let the key back to the 'Run' position, you should be on the resistor wire, or the ignition resisted circuit.
Check your voltage with the key in the 'Run' position, 6 to 9 volts should be the reading.
If you get 12 volts on this test, forget the resistor, and get an internally resisted coil.
Check your voltage with the key in the 'Start' position, the voltage should be 12 volts.
If you get less than 12 volts, or no volts at all, run a 12 AWG wire from the 'I' terminal on your starter solenoid to the ( ) positive side of the coil. Test again.
Check to see than the (-) negative side of the coil goes to the points.
You should be up and running.
So many cats, so few recipes...