Well, my PMR generator had gotten weaker and weaker , down to about 1.5 volts , and It would just barely operate anything. I took off the brush end frame , and after an inspection, cleaned the commutator and brushes , paying special attention to the grooves between the commutator segments . There was a big buildup of crud in those grooves , so I think that was the problem . Anyway , it seems to be back up to operating potential. I haven't tested it with a volt meter, but it really does power my electrical accessories like it should. If it works with the PMR , I think a good cleaning might possibly rejuvenate any weak , small generator that has brushes .
D. E. Jones