with only a 4 to 12 hour run-time, there's a bit of an issue dealing with running the generator all night at burningman. i don't want to have to run back to camp just to make sure power is up, make sure the generator is purring along.
somewhere along the way i stumbled upon the other posts talking about using an external fuel tank, with certain model yamaha or honda (inverter class) generators.
some of these new models use fuel pumps (fuel sits lower than the carburetor)... so you can close off the cap, feed an external fuel line through it. suction will pull fuel from an external (and generally much bigger) tank. letting you go out and wander about, no having to worry 'bout power back at camp.
you can make your honda eu2000 run for days, not hours...
my first stab at this was to just buy the 'Duration Power' tank, all-in-one solution. but at $110 that was pretty steep for all parts, which probably add up to $40 tops. they use tubing, a thru-hull barb connector (replaces the vent the eu2000 gas cap), and a few connectors to a six gallon tank (on the tank end there's one just to weigh down the line, help it drop low in the tank, to suck up the gas). simple, done. probably should have just stuck with it.
duration power, gas line parts.
if you already have some similar parts --like a suitable gas tank, you can fashion up something for considerably less money.
i had time, and the inclination. so i returned my un-used tank. (though, i would recommend it to anyone who needs a preset no fuss solution, just pay the money, it does work).
like i said, i had the summer to work this out, i went the route of using external gas tank connections, for marine outboard engines. after eyeing my neighbors tank (just lying around), noticing it had the kind of connector i was looking for --he actually just donated it me. one piece down, and for free!
johnson/evinrude tank, three prong connector.
i also read up on marine gear (tanks for fishing boats), naturally they've got a ton of stuff in this department already sorted out. the gas tank was a johnson/evinrude. i took my new tank to a local supply shop to start sizing up phe gear and to get advice.
i was led slightly astray by the knowledgeable but incorrect staff at the local shop. the tank had a three prong connector. true. even though i told him i was not connecting to a boat engine at all (i guess he just didn't get the concept. too much gas fumes or something) i had to explain this several times... he made me second guess myself. he told me the tank would not work, it mixes the air (third prong). that i would need to spend $70 on a mod to convert the tank into a two prong connector.
and he was wrong. i had to take the damn assembly off the tank to prove it (i guess to myself really). a two prong johnson connector would sit on the tank fine. the built in fuel pump would suck gas right through the gas line and into the honda tank/carb like a champ! i'm still not even sure it's a real three pronger (1st prong is the locking stand-off post, to the right is the gas line, and the third, well doesn't appear to have a slot for air at all... could be tiny, but i just don't see it) --eh, no matter, the more modern two prong fits on the three pronger using the top two posts, johnson/evinrude kept the standard measure there. good.... oh, note: one way to test if this works (without taking apart) is just to connect it and blow bubbles into the tank. remember to open the vent cap first!
on the generator side, i bought a spare gas cap i could drill a suitable hole through. most people usually drill a hole in order to place a through-hull-prong-barb of some type. i started with this in mind. but i didn't have the right size drill, or the barb connector. couldn't find the right drill bit without investing in some more gear (i just use a skill power screwdriver with hex bits).
so, i started filling. after a few minutes i thought, i had really just made a task out for myself --yikes, this would take a while. but a few minutes later, i stopped when i realized i could just barely fit the 1/4" hose in. and that worked. made a nice tight fit. saved one part... one less thing to deal with. definitely worth trying. (now i'm wondering if you need to file/drill at all!)
this presented a new problem. i couldn't find the right connectors between the gennie and the tank, since i could only find the tank connectors in a 3/8" size. i guess i could special order one? oy --getting more complicated here. i could widen the hole on the cap, but that would require a lot more filing, or a proper drill, and i didn't feel like asking for help, just yet anyway. i really discovered here, just how many different kinds of connectors there are (different vendors e.g. honda, yamaha, mercury, johnson/evinrude, different barb sizes, it goes on). just one of those things i guess. if you already know this, it's no big deal. but it's all new to me, and still doesn't make getting all the right connectors easy.
well, after some more fussing around, and in a moment of using some pure f'ing magic... i discovered i can place 1/4" tube directly into 3/8" -- has a nice tight fit. hold that firmly in place by a clamping a hose ring there. brilliant. no barb, one less parts! (i'm sure others have done this, but no one seems to talk about it). well, this only works when the thickness of the 1/4" tubing itself is 1/16", yielding an extra 1/8" in total diameter, thus bringing the total diameter up to 3/8"!
shown here with a tempo 6 gallon tank.
i got everything working fine, gas flowing. success! well kinda. it took a really long time for gas to flow, mostly was just vapor at first. seemed the line was just too long...the long line of 3/8" tubing is too much for the fuel pump. i had to shorten that up.
close up, of the connector.
with a shorter line of just 1/4" tubing, the gas flowed faster, like a drinking with a thin straw. that worked like a champ. i put the section of 3/8" right on the end of the johnson/evinrude connector, just enough to catch the 1/4" tube. i even decided to splice in a fuel filter for good measure, now that i had a good working prototype.
finished prototype, using the tempo brand tank.
whole thing even worked for two days on the playa... but then something gave out --it didn't have the proper flow anymore. i think the heat loosened/warped some of the vinyl, right at the gas cap, creating a gap for air, no more vacuum -- so the fuel didn't flow.
so, on the down side i had to refuel the generator everyday. not the worst thing in the world. plus running out, allowed for a measured, or timed shutoff control. (good thing i got the honda, because at 1.1 gallons it lasts 50% longer than 0.6 gallon yamaha eu1000, a few hours makes a real difference here).
i still need to do a post mortem on it, and prep for next year. i think it's a minor issue just getting the seal right on the gas cap. i just need to plug up the cap better, guess i had whittled away too much there. it's all still packed away right now.
note: if you shop for standard fuel line, it's dark and rated for pressure. whenever i asked for fuel line, the shop would point to this stuff. that's all the marine shop carried. but this system doesn't place the fuel under any pressure (or really just minimal pressure). so the clear vinyl is perfect. my local auto store stocked the clear vinyl. it's cheaper, lighter, and more flexible. plus, you can see the fuel.
update: i've got a working model again, just need to test out. there was a pretty tiny but visible gap at the cap where the vinyl shrank a bit (from heat?), and was loose too. i put a rubber washer and a pile of o-rings on each side, with a hose clamp on top to keep it in place. should do the trick. if that doesn't work i'll go for the gusto, tap it, and put a proper hose barb on top.
generator part 1, backstory.
generator part 3, to the rescue!
follow up's:
external tank v2.
external fuel tank v2+.