We have two eu2000i hooked to a 12 gallon marine tank on our motorhome. I found this information from another site:
Ok, kiddos. Today I did some goofing with external Fuel tanks and the Honda EU2000i. Interesting results!
Background: I coupled an Atwood 12 gallon marine tank to an EU2000i. At the loads we typically run, this means about 4 days of non-stop fuel (3 GPD). But because this rig will be trailer mounted I wanted to see how much vertical distance the EU2000 could suck fuel out of the aux tank and into the genny tank at sea level. My goofings gave some interesting answers:
NOTE: the measurements given below are from the surface of the fuel level in the aux tank to the top of the generators gas cap. The bulk tank is at atmospheric pressure and no pressure or vacuum is allowed. Ambient temp was 93F at 23 feet above MSL. The generator tank was pre-filled to within 1/4 inch of the topmost thread on the cap (ie, nearly "full to the brim")
Results:
0 to 30 inches: ran fine for all loads up to and including 1600 watts
30 to 34 inches: ran ok, with the occasional miss, at loads up to 1000 watts.
>36 inches: Nada. Full stop after 10 mins or so. Repeated tries could not cure this and the genny can not overcome this lift. Anything over 36 inches kills the genny after a minute or two.
So at sea level, the safe "do not exceed" differential level should be 30 inches. Running the numbers for elevations of 4500 feet and a 105F ambient temperature shows you can safely and reliably run up to 26 inches of draw on the playa. If you are the conservative type, make this number 20 inches and you should be absolutely golden up to 7000 feet MSL.
So now we know.
NEXT UP: I want to investigate the effects of installing a fuel demand regulator and allowing the aux tank to operate in "California SCAQMD mode" (ie, the tank can pressurize up to 5 psi to keep fuel vapor emissions at nil levels)
Parts list:
Fuel cap: Great River:
http://www.amazon.com/EXTENDED-FUEL-HON ... B004BJ5YKM
Fuel Tank: Atwood:
http://www.attwoodmarine.com/store/prod ... fuel-tanks
Fuel Line and primer bulb: Atwood:
http://www.amazon.com/Attwood-CARB-Univ ... B009RJK532
Final note: the right way to feed the EU2000 is from a tank located at the same level, or slightly higher. In a perfect world, this is what you SHOULD do. Unfortunately I am constrained to a less-than-perfect world and the tank will be slightly lower than the genny. If you can get the tank slightly higher, do it. It works better that way!