OK, check the output voltage, if it reads something like 1-3 VAC L-N and 3-6 VAC L-L (Line to Neutral , Line to Line) proceed. Pull the rear end cover off the generator end. Look at the slip rings. If they are dark looking, what I have done in the past, is pull the brush block out, marking or noting wire/terminal position, cranks and run the generator and use a pair of needle nose pliers and a FINE scothchbrite pad to clean the slip rings. check with a DVM the resistance though the rotor across the slip rings and then check from the slip rings to chassis ground. you should have an open circuit to ground and some resistance through the rotor. Then reinstall the brush block. Then take a volt/ohms meter and see which of the wires going to the brush block is going to ground, one should read high resistance, the other fairly low. Leave the one going to ground connected, unhook the (+) going to the brushblock. The one reading low Ohms should be the ground. Connect your meter to the AC output (120/240) like you're checking the voltage. Then with the generator running, take a 6-12VDC battery, connect the (-) to chassis ground and the touch the (+) to the brush block for a second or two. This will flash the rotor. It should put out unregulated AC Voltage, note the voltage on the 120/240 output your meter is hooked to. it should rise well above what it is reading before you flash the field. If it does, put the (+) wire to the brushblock back on after shutting it off, reinstall everything and then try it as normal. If when you flash it, the voltage does not rise, you probaly have a good parts engine. As the crankshaft is a tapered end, not straight. It cost so much to replace a rotor or stator it's as cheap to go buy another generator. If after flashing, the voltage does rise, but after installing back to normal it does not work, you have a voltage regulation problem. Depending on how it regulates, some have a regulator, some capicator, it may worth fixing.
