The previous owner of our house left a North Star 13000 generator that he used when the power went out. It looks like a nice unit with a Honda engine which starts right up each time but was probably stored, unloved for a time. https://www.northerntool.com/shop/tools/product_200467368_200467368
The issue is that the power output never seemed to match the expectations. The 120/240 outlet is putting out 139V and the 120 outlets are reading 66V on a multimeter. The engine seems to be running okay by ear and there isn't a throttle to adjust (that I can find).
I plan on calling Northern Tool this week but figured the hive knows all... Is there something simple I am missing? Something I should be checking?
Have you tried putting a load on it and see if it reacts appropriately, which is to say, it throttles up the engine to maintain a constant RPM? These things try to maintain a constant RPM as that is what determines the AC frequency. There won't be a throttle adjustment per-se, it is all controlled though the governor. Put a fairly heavy load on it, almost anything that has an electrical heating element like a toaster oven or an electric grill and see if the governor responds. Measure the voltage with the load attached.
RPM wont affect output voltage in that if it sounds good, its got enough RPM to make reasonable volts but it will affect the hz output unless its an inverter unit. Unit was left behind because one of the windings is gone in the generator and thats why you are only getting half voltage. If you hook it up to a scope you will only see half of a sine wave. Sadly unless you can trace back to a disconnected or damaged external wire on the generator side its done for. Good for parts.
Keep in mind AC power is not like DC power where there is a constant potential difference, the potential on AC switches back and forth between hot and neutral (120V) and hot and the other hot thats out of phase (240V)
One last thing, if you put a load on it make sure its a "dumb" load. IE Not anything computerized. A nice toaster oven as suggested with a mechanical timer is a good load, cant really hurt those. I wouldnt even use an electric motor like a saw or grinder, too much risk of burning it out.
It's broken. One bad winding or rectifier or something.
