I'm living off grid, but I seldom have to use a gasoline powered generator, since I have a solar panel. But I do have tools and some devices which require more than just battery power. On the rare occasions when I need to fire up the generator, I often find that it's been setting so long the gas has gone bad and the generator won't work. I've found the solution to be very simple: I just blow a little propane into the carburetor, with the choke wide open, making sure the propane isn't set too high. With this approach, the generator runs just fine, and I can use up the bad gas.
Next, I'm going to try using HHO with Henry Paine's special fuel vaporizer bubbler, which his very short patent says makes the HHO non explosive.