You said the voltage dropped from 130V to 116V with everything except the AC on. How much load is "everything except the AC"? Do you have a way to measure frequency? Is that stable?
When you "crank up the voltage to 130V", how did you do that? Is there a voltage regulator
, or did you speed up the generator
, which by the way would impact the frequency?
Assuming your load isn't real big, I think the voltage sag you describe will lead you back to the source of your problem. Voltage regulator
, brushes, or other parts
related to voltage regulation depending on the type of regulator.