I once ran a '50 Chevy without a voltage regulator 'cause I couldn't afford to buy a new one.((student + kids + wife) = no bucks)) This got me to school, work, and home for 3 months.
I ran a pair of wires into the cab, one from the field terminal and one that I grounded to the generator, connected a 20 ohm 50 watt rheostat between the wires (which I had from a old DC train set power supply)and hung the whole mess by the wires from the steering column.
I would set rheostat to zero ohms (shorted) to start and low speed running around town and would adjust the rheostat to keep the ammeter charging by one needle width when running on the highway.
Oh yeah, always parked it on a hill for a drift start because I couldn't afford battery either.
Conclusion: IF the generator is good it will output voltage just by grounding the field terminal - no regulator needed. Check that first. Then, if there is no output by grounding the field, check the brushes and clean the commutator as posted earlier. Probably wouldn't hurt to replace the brushes to make sure they are the correct length and don't 'hang' in the brushholders without making contact. Also check all the internal connections to make sure they are OK.
A good commmutator will be sort of a 'choclate'color, not blue, which means that it is burnt by arcing. Arcing means there is something wrong with the brush system, worn too short, bad brushholder springs, bounding from a worn commitator. etc.
If the commutator is dirty and/or worn, clean it up and make sure the mica insulation between the segments is slightly below the surface so the brushes don't 'trip' on them causing the brushes to bounce and not make good contact. This will cause arcing and burn the commutator prematurely.
You can drag the tip of a thin knife blade along the mica to scrape it away if it is too high. We would also grind the 'set' out of a hacksaw blade and use it instead.
Make sure the generator is working before you waste time and effort on the regulator.
Hope this helps,
52 Ted
