I have a Wacker G2.5 120V 20Amp portable generator. I have adjusted the generator to produce 125 volts (60Hz) under no load. When I plug in a 1500w space heater the voltage drops to 108 or so and the space heater quits working but the generator is still running and producing voltage. What is the problem? I was thinking about setting the generator at a higher rpm at no load but I would hate to "fry" an appliance at initial hookup. What could be the causes and how to fix? Thanks for all the help.

The fear of "frying" came because when i started it for the first time in 2 years the throttle was stuck wide open producing 800 volts. Did not know that when I hooked up my camper and "fried" the convertor and the TV.