Running both A/Cs

I would first make sure that the generator is getting enough gas. You might have a problem with the fuel lines or fuel pump. Try running the fuel pump into a gas can to make sure that there is no crud in the line. Swap it out with a new one and see what happens. (You should always keep a new one on hand anyway.) Try running it out of a gas can. Check the air filter and air intake.

Then try a different load as was suggested. Add together some electric heaters. You may have a problem with one or both of the AC's. Good luck with your repairs.

Miles