If you take a 1 quart canning jar.
Fill it with water.
Put three holes in the lid center.
1 hole on left side, 1 hole on right side and 1 hole in center.
take a copper rod and stick it into the jar on the outer holes being careful to insulate the rod from the lid and seal around the rod with caulk.
Fit a plastic tube to the center whole and seal also.
Attach a 12 volt battery to the two rods. The water will begin to bubble. take the other end of the tube and connect it to the mouth of you generator carbureator or fuel injector.
Start the generator and shut off the fuel supply.
Both diesel and Gas engines will run on the Hydrogen being pulled out of the water in the jar.
If water is problem you can also run that generator on gas from a wood gasifier.
Hydrogen is what deep divers use to weld ships under water. water=H2O