OK, Neal, old thread resurrected! Does your Honda pull from the fuel tank? The outboard fuel pumps are much different than the small vacuum operated pump on the Honda generator. Joe got his to work on a 22, with the generator on top of a cooler inside the boat (not a good place because of CO issues). The top of a fuel tank on a 22 is only a few inches below the top of the splash well pan. We know that the Honda EU series will pull fuel about 2 feet, but it is rumored to pull up to 6 feet. The issue in the standard 25 is much different than in the standard 22. (The 25 has the fuel tank under the cockpit soul, the 22 the fuel tanks are much higher.).
We run our EU 1000 2 to 4 hours daily when using the freezer and refer. 90% of the time we put the generator on shore, some distance from the boat. It takes less than a tank of fuel to charge up our batteries, etc, so we don't need an aux fuel tank.
Why is the generator off the boat? Noise, and exhaust fumes are the main reasons. On the Tom Cat we used the EU 2000 on the swim step, and had the fuel tank at about the same level. There were no problems.
Be safe--CO, fumes, fire and gas hazards. Let us know how the fuel pump pulls the fuel up from the tank on the 25.