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TechWriter's avatar
TechWriter
Explorer
Sep 04, 2023

External Fuel Tank for Generator

Several months ago I found out that the fuel line to my Generac Q-55G was clogged. I've looked into replacing the fuel line, but it would involve dropped the RV's gas tank. My local service guy (who has done this on other RVs) looked into dropping the gas tank on my 2001 SeaView, but gave up. Apparently, it's an "over-engineered" RV. Too complicated and labor intense.

Anyway, I nearly gave up fixing the generator until we crossed the Southwest this summer. Just let me say that my RV's dash air wasn't up to that cooling task. Never again.

So I think I'm going to install a 5 gal external gas tank for my generator. Anyone else done this?
  • Grit_dog's avatar
    Grit_dog
    Navigator
    Sep 04, 2023
    I have no idea how your rv is configured but it’s not unreasonable to think you could plumb in an outboard motor tank or any suitable tank really.
  • JoeH's avatar
    JoeH
    Explorer III
    Sep 04, 2023
    Find a different service guy... sounds like he just didn't want to do the work or maybe look into taping into the chassis motor fuel line. Just make sure if you do that, when running the genset, you don't completely drain the fuel tank , leaving you stranded.
    I've also read where some folks have accessed the fuel tank by cutting a hole in the floor of the coach... could be an option , depending on your floor plan.
  • enblethen's avatar
    enblethen
    Nomad
    Sep 04, 2023
    Some manufacturers install copper/steel rigid tubing out of fuel and then transitions to rubber tubing then back to rigid.
    Find someone willing to crawl under rig to follow line.
    Which rig are you dealing with? Diesel coach with gas genset?
  • Dusty_R's avatar
    Dusty_R
    Explorer
    Sep 04, 2023
    Some MH's have two fuel lines into the gas tank, one goes to the bottom of tank, the other goes down only 3/4's of the way down for the onboard generator, so the generator cannot use-up all the gas in the tank.
  • okhmbldr1's avatar
    okhmbldr1
    Explorer
    Sep 04, 2023
    If you can't do this test yourself, find a mechanic who will locate the line from the gas tank to the generator. Disconnect line at the generator, then have him cut the line close to the gas tank. Use about 40 lbs. of air and blow through the line towards the generator, if stuff comes out then the line is clear. If it wasn't clogged in that section of line, then blow the line into the tank. Then use a union and hose clamps to join the two lines together. They should be clear, so hook up the line to the generator and give it a try.
  • jjrbus's avatar
    jjrbus
    Explorer
    Sep 06, 2023
    I have an external extended run fuel tank for my Honda 2200. I see no reason you can't do one with an Onan.
  • Bobbo's avatar
    Bobbo
    Explorer II
    Sep 06, 2023
    jjrbus wrote:
    I have an external extended run fuel tank for my Honda 2200. I see no reason you can't do one with an Onan.

    The ONAN doesn't have a fuel cap to remove. It has a hose running into the RV's main fuel tank. He would have to:

    1. cut the fuel supply line
    2. put a shutoff valve in the side going to the fuel tank
    3. put a "Y" connector between the shut-off and the ONAN
    4. Put a shutoff valve in the hose going to the external tank
    5. Run that hose to the external tank.

    You would have to close the shutoff valve to the line not being used, or the generator would just suck air.
  • Grit_dog's avatar
    Grit_dog
    Navigator
    Sep 06, 2023
    It would take like 10 minutes to plumb it to an outboard motor boat gas tank provided there’s an adjacent compartment to put the tank in and able to drill an access through or out to the generator enclosure.

    Sounds like OP doesn’t know anymore than one mechanic is telling him though and unable to discern what the problem (s) or legit permanent solution requires though. So I’d suggest a second opinion.
  • TechWriter's avatar
    TechWriter
    Explorer
    Sep 12, 2023
    okhmbldr1 wrote:
    If you can't do this test yourself, find a mechanic who will locate the line from the gas tank to the generator. Disconnect line at the generator, then have him cut the line close to the gas tank. Use about 40 lbs. of air and blow through the line towards the generator, if stuff comes out then the line is clear. If it wasn't clogged in that section of line, then blow the line into the tank. Then use a union and hose clamps to join the two lines together. They should be clear, so hook up the line to the generator and give it a try.

    Tried this, but no dice. External fuel tank on order.

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