Generator running two AC units, outlet appliances get hot

As others have said, you should be OK at 118 volts. If you have a microwave with a digital clock, start the generator, set the clock, and check how close it is to your watch, or clock for 10 minutes. If it is running fast or slow, load the generator with an AC and check again. If it is within a minute or two, your hertz are close enough to not cause problems.