Well....it WORKS!
I've completed the fabrication of my extended run fuel tanks. The first attempt was not successful. The fuel tank needed to vent. It may be possible for the generator to pull in fuel via vacuum, but I did not have any success with that. Instead I have a fuel inlet and vent outlet on the tank. Pictures of the process are available on my web site.
http://www.cptxguys.com/RV.html
The generator now runs approximately 24 hours on a tank of fuel.
Also note, that duration power is working on tanks for the EF2400is. They should be available soon....
www.durationpower.com