Hi all,
I have an SDMO Zephir 8000 generator. Was working fine until in the middle of a welding run, the weld turned to birdsh*t. The voltage had dropped from 240 to 155. On the 120 vac outlet, voltage is now 75v.

There is no AVR inside. Four large wires emerge from the alternator: earth, common, 110 and 220. Two pairs of smaller wires lead to two capacitors. Access to the inside of the alternator is terrible, but I can make out several diodes. Aside from this, the only other connections to the AC power are voltmeter, ammeter, circuit breaker and sockets. The voltage is regulated only by the engine speed. Running the engine flat out get the voltage up to 220v, but even then there is a loss of power when a big load comes on and the voltage drops right down, even though the engine is still turning just as fast.

I'm pretty practical, but have not had any experience with testing capacitors, windings, etc. Just wondering if these problems sound typical of anything or if there are any simple tests I can do to figure out which part is at fault.