Let me say up front that running a generator from a NATO fuel can is not without its risks.  The fuel line assembly running from the can to your generator is made up from a number of parts, any or all of which have the potential to fail with terrible consequences.  While every situation is unique, safety should always be your first priority and it’s up to you to learn what the best practices are and to adhere to them with near religious fervor.  

For most folks, if you’re running your generator you’re already having a bad day.  That’s not the time to rush things, take shortcuts or fail to pay close attention to what you’re doing.  You’re dealing with a significant amount of a highly flammable, potentially explosive liquid fuel.  Mistakes can cause serious injury and/or death to you and to those around you.  Know your limits.  I’m not recommending you do this and no one associated with the site is recommending you do this.  If you decide to do something like this it is entirely your responsibility to do so in a safe and responsible manner.

Now that I’ve got that out of the way, I was asked to write up what I’ve done to use a standard NATO fuel can as an auxiliary fuel tank for my Honda generator.  I work out of my home and having the generator lets me do that regardless of whether the grid is up or not.  Using an auxiliary tank allows for longer run times then the internal tank alone provides.  This allows me to manage the resource better by letting me decide when the generator goes off.  In other words, the amount of fuel available with the NATO can means the generator will run longer than a full day.  This lets me decide when to shut it down, rather than me having to stop what I’m doing to deal with a generator running out of gas at what is, inevitably, an inopportune moment.  

I also consider this to be kind of a safety issue.  I know folks who store fuel in the 20 liter NATO cans and then transfer it to a smaller can to actually fuel their generators.  This makes sense, since pouring gas from the somewhat unwieldy large fuel can into the small tank of a Honda generator is just begging to make a mess.  The problem is that every time you transfer fuel between containers you run the risk of spills and of course the EPA folks aren’t crazy about the fumes either.  I fill up the fuel cans at the gas station pump and don’t touch it at all from that point on.  When the time comes to use it I open the cap, drop the working end of the fuel line into the can and lock it in place.  No muss, no fuss.  

As well, the number of folks who admit to “hot fueling” their generator is probably only a fraction of all of those who’ve actually done it.  Swapping in a fresh fuel can has just got to be safer than doing that.

While I do this with my Honda EU2000i, the principles and most of the hardware would probably work with other generators.  

The gas cap pictured below replaces the factory gas cap that comes on the generator.  It’s pretty straight forward stuff.  As the generator runs it draws fuel from its internal fuel tank which in turn is fed by the NATO fuel can.  I raise the can above the height of the generator when it’s running so the can feeds the generator via a siphon but I’m not entirely sure this is necessary.  The fuel line assembly is air tight and there may be enough suction to empty the fuel can even if it's sitting on the ground but that’s not something I’ve tested.

I'm sorry I don't have any dynamic action photos of my generator running off of a NATO fuel can.  The generator is put away and I wasn't really inclined to drag it out just to snap a few pics.

I’ve included links at the bottom of the post for all of the components.  I don’t have any financial interest in any of this and the links are just there if you need them.  If you have any questions please feel free to ask.  

The key component of this is the Jerry can adaptor.



As you can see from the pictures, the adaptor is basically a standard fuel can cap with a tube running through it.  There’s also a small vent hole in the cap that allows air into the can as the fuel is drawn out by the running generator.  You mount this to the fuel can exactly like you lock down the cap that’s integral to the can except the “hooks” go in from the front instead of the back.  



The tube has an 8mm outside diameter and 5/16’s inside diameter fuel line works fine.  

You need to attach a length of fuel line from the end of the tube that sits inside the can that’s long enough to reach the bottom.  For a 20 liter can I used a piece that’s about 18”.  That’s longer than the can is high but allows for the fuel line to get all the way to the bottom even if it’s got a little curve to it.  I added a small brass fitting to add some weight to the end, which helps keep it on the bottom of the can drawing fuel.  

*** Added 5/6/14 - Since posting this I’ve learned that using standard fuel line for this isn’t going to work long term.  Regular fuel line will not survive being submersed in fuel (WTF?).  Since there’s no pressure in the line, I’ll be switching to clear vinyl fuel line which is submersible.  




The fuel line assembly that goes from the outside tube of the adaptor to the generator is made up of fuel line, a unidirectional hand pump, an in-line filter and a quick detach fuel coupling.  Everything is held in place by stainless steel hose clamps.  



The quick detach coupling attaches to a gas cap fitting which sits in a replacement fuel cap on the Honda generator.  The fitting is brass and I used Teflon tape to get a good air tight seal and to orient the fitting in the cap.  The fuel cap is aluminum and they’re available from a number of sources.  




The large white hose looking thing coming out of the top of the can is just that, a short piece of fiber re-enforced hose.  It’s big enough that the fuel line slides up easily inside of it and I think it cost me a dollar at the local hardware store.  I added it because I had a concern that the fuel line coming up out of the adaptor might kink.  As you can see from the picture the short portion of hose acts like a guide and gives the fuel line a gentle curve up and away from the can.  



NATO fuel can adaptor
http://lexingtoncontainercompanysonlinestore.mybigcommerce.com/jerry-can-adapter-1-tube/

Fuel line
http://www.amazon.com/dp/B000VZJH6W/ref=pe_175190_21431760_M3T1_ST1_dp_1

Unidirectional hand pump
http://www.iboats.com/Primer-Bulb-5-16-Hose-Barbs-Moeller/dm/cart_id.763413551--session_id.369120842--view_id.887136

In line filter
http://www.iboats.com/Moeller-Clear-View-In-Line-Fuel-Filter/dm/cart_id.477752708--session_id.681536570--view_id.391050

Quick detach fuel coupling.  
http://www.iboats.com/5-16-Barb-Female-Fuel-Line-Engine-and-Tank-Connector-for-Johnson-Evinrude-Moeller/dm/view_id.373481

Stainless steel hose clamps.  
http://www.amazon.com/dp/B001HWGMBG/ref=pe_175190_21431760_M3T1_ST1_dp_2

Fuel line hose barb
http://www.amazon.com/dp/B000MTB7TW/ref=pe_175190_21431760_M3T1_ST1_dp_3

Gas cap fitting
http://www.iboats.com/FUEL-TANK-FITTING-1-4IN-JE-OMC-Attwood/dm/cart_id.763413551--session_id.369120842--view_id.927829

Replacement Honda gas cap
http://www.amazon.com/dp/B004BJ5YKM/ref=pe_175190_21431760_3p_M3T1_ST1_dp_1

Awesome. Thanks for posting this; it is directly related to my current baffled, vented, plumbed enclosure build!  I'd love to use a pair of my NATO fuel cans in parallel rather than my current BERGS setup, as it would allow for 10gallons, 100 hours of run time on a single generator, rather than my current ~70 hour BERGS setup.

Was the priming bulb necessary for your setup?  I have not spec'd one into my current fuel configuration; I was assuming that the fuel pump would pull fuel through the fuel line, as it does with the BERGS setup...

The US Army uses a tripod stand for the Scepter MFC's that turns them into gravity-fed fuel tanks for tent heaters. I'd imagine it could be used for other equipment like generators pretty easily.

This setup looks great, thanks for the post.  One big question I have is the fuel line being submerged.  I was working on a marine gas tank and had to replace the fuel line inside the tank.  I used what looks like the same type of fuel line you are showing and the gas ate up the exterior of the fuel line turning the gas black.  I know the inside "flow" part of the gas line is fine, I am just questioning the exterior of the gas line that is sitting in the gas.  I ended up having to put a more ridged plastic gas tube for inside the tank.  Let me know your thoughts.
Thanks

I added it because it seemed like a good idea to get the fuel flowing but I don't know if it's required.  The line is air tight and it would probably work fine without it.  My only concern might be with the height of the lift required for the fuel.  The highest point at the top of the arc of the fuel line as it comes out of the can is almost two feet off the ground.

Thanks for taking the time to post this.  I only have about 20 hours running with this and have no idea if what you describe is going to become a problem.  Nothing seems to have degraded yet ( the white writing on the outside of the line is still perfectly legible) but I'll keep an eye on it from now on.  Any chance you have a link to the ridge tube you ended up using?  Has it held up?

I ended up going to a Mercury dealer and he had a used one in the back of his shop.  I went to an automotive shop and got the black gas tube "that looks like yours" and that is what I used as the first replacement that turned the gas black and made the tube feel like rubber and very slick.  The gas was obviously degrading the tube.  Now the outboard I had it hooked up to was a two stroke that I added oil in with the gas maybe causing the tube to be slippery and slick, but I do think it was the gas that was eating up the tube.  Just be aware and maybe do an experiment with a section of that type of tube sitting in some gas for a period of time and see what happens.  I like your concept and hope I am wrong with your gas line as I would also like to do the same setup.  I just don't know if that type of gas line is meant to be submerged.

Go to your local NAPA parts store. Ask for fuel line designed to be submerged in fuel tank. Common among fuel injected vehicles with in tank fuel pumps.

6 months from now normal hose will be dissolved


Edited here is what you want.
Napa sells the SAE 30R10 submersible fuel hose. The SAE number is the clue.

I’m far more interested in doing this right then doing it cheap so if I end up having to replace the fuel line with something better I’m not opposed to that at all.  I gave it a good look this morning after reading your original post and the portion that was submerged is indistinguishable from the rest of the line.  Of course, 20 hours probably isn’t much of a test.  Leaving a portion in a jar full of gas is probably the only way to be sure so I’ll see what I can do about that.  Thanks again for the reply.

Here is a known good online source for in tank hose. They also offer a corrugated no kink hose for less money.
The SAE is $20/foot
http://autoperformanceengineering.com/html/kits.html

Thanks for the reply.  I don't think I'm going to need anything that nice.  Real fuel line like that is designed to deal with a pressurized system, right?  All I need is a fuel pickup line, there's no pressure involved.  Hopefully there's something out there that isn't quite that expensive.

It is not so much the pressure as it is the make up of the materials of the hose.

They do offer a much cheaper option with the corrugated hose but it is only 14 inches long.

Regular fuel rated hose from any auto place or cheaper off ebay will do fine up to maybe 10 psi.

Regular fuel rated hose will not work in a submerged type of application. It will dissolve the outer jacket. Sucking that crap into a carburetor will lead to a terminal failure.
Hoses are made with different layers. To save cost the outside jacket of a normal fuel rated hose is not made of the same material as the inside. Yes it can stand having some fuel on the outside as in some spilled on it but where it can evaporate. Submerged in constant contact with fuel will dissolve the jacket.

Why risk damaging and losing use of something as important as a generator over something less than $100.

Thanks again for the reply.  I mean real fuel lines are built like they are to deal with the stresses of a pressurized system.  Wouldn't something like this work?

http://www.amazon.com/Motion-Pro-Clear-Vinyl-Fuel/dp/B000UKM4GI

This isn't multilayer fuel line but I don't think it needs to be.

In your application that might work. Now I will put two kinks in it. Depends on how much ethanol you gas contains. E10 it should work E85 NO WAY Second kink is a kink. That hose tends to kink easy just becareful when you install it. I don't think it will loop across the narrow width of the can. Try it and see.

It says any type of fuel but I'll look around and see what else is out there.  I'm not worried about this kinking, I'd only need to change the part that's actually in the can.  That's just a more or less straight drop into the can.  Thanks for the help.  

Thanks for the writeup OP.



Anyone know an alternate source for the fuel cap that fits on the generator?  Amazon says they're out...

They're on EBay.  If this link doesn't work google "eu2000i extended run fuel cap" and it should come up.
http://www.ebay.com/itm/like/150946859975?lpid=82

Thanks Beo. I appreciate the time and effort it took you to put this together.

just get this

Yep, I've got a couple dozen of the MFC adaptors to run the fuel lines. Nice little system, and works on other stuff than heaters too.



 

describe please?

thanks
ar-jedi

It's in the picture I posted, it's not easy to see though. It's a standard Scepter MFC cap, but it's got a port for a hose.

It's been ten years since I used one, but they're pretty cool. They're gravity fed, IIRC.

Just a thought, $122 in parts from the list, plus the price of a quality 5 gal can.




$120 will buy this.

 

not as sophisticated as the OP, but another advantage...I use a 5/16" line with a siphon bulb to a hose barb brass coupling then to a 1/4" feed line to the carb inlet... this allows me to run the fuel bowl dry for storage without having to remove the carb inlet line...



this offers some flexibility in source containers

I think you can probably put this together for a bit less if you shop around.  I didn't look for best price, I just provided the links to show what I used.  As well, you don't need 25 feet of fuel line.

If you buy the Bergs you still need to store you're supply of gas in something, right?  I really like the NATO cans for this and a lot of folks on this site seem to agree.  As I mentioned in my OP I also like the idea of minimizing transferring fuel between containers.