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n0arp's avatar
n0arp
Explorer
Feb 25, 2017

Convert Onan QG5500 LP to Gas

Safely carrying around enough fuel for our generator to boondock with is an issue I haven't quite solved yet.

We have an Onan 5.5HGJAB-1119 genset which runs on LP, and I am considering converting it to gas. Using gas, I could get an appropriately shaped fuel cell to fit in a recess under the RV, and run a filler neck to the outside. Additionally, gasoline is easier to get with just a couple jerry cans and any corner station.

The big dilemma is how to convert it to gas. It lists the same engine, EH65V, for both the LP and gas versions. I know that I will at least need the carb from the gas model, part number 5410765, fuel filter 149234101, fuel pump 541-1002, and however much fuel line I need. Has anyone done this conversion, or can anyone on here verify those are the parts required?
  • DrewE's avatar
    DrewE
    Explorer II
    Feb 25, 2017
    You may need some different control board too, and perhaps some bits and pieces for the choke linkage. Maybe you could get parts manuals for both variants and see what the differences are that way.

    Have you tried contacting Cummins (or an area Cummins repair center)? I don't know if they'd be any help or not, but it never hurts to enquire.
  • Rvpapa's avatar
    Rvpapa
    Explorer
    Feb 25, 2017
    Check the cylinder head part numbers. Don't really know Onan but Kohler used a higher compresion head for many propane single fuel units.
    Art.
  • n0arp's avatar
    n0arp
    Explorer
    Feb 25, 2017
    I contacted a dealer earlier this morning and they're going to go work with me this week to figure out the part #s. Hopefully it'll be somewhat practical/reasonable to do, or else I'll try to find someone willing to trade.
  • mwachel's avatar
    mwachel
    Explorer
    Jan 11, 2021
    jshupe wrote:
    I contacted a dealer earlier this morning and they're going to go work with me this week to figure out the part #s. Hopefully it'll be somewhat practical/reasonable to do, or else I'll try to find someone willing to trade.


    Old thread...but did this ever work?
  • n0arp's avatar
    n0arp
    Explorer
    Jan 11, 2021
    mwachel wrote:
    jshupe wrote:
    I contacted a dealer earlier this morning and they're going to go work with me this week to figure out the part #s. Hopefully it'll be somewhat practical/reasonable to do, or else I'll try to find someone willing to trade.


    Old thread...but did this ever work?


    It did - I don't have the part numbers on hand (or in my email) because it was all handled via phone. The Cummins/Onan dealer was super helpful and even delivered the parts to my house. I used a marine fuel tank and fuel pump sourced from Amazon and a bunch of misc fittings from auto parts stores.

    I ultimately converted it back to LP because I wanted the space from the fuel tank back for my solar equipment. Generators aren't for me.

    Edit: it looks like I posted the part numbers above, but if I recall correctly, the ones posted weren't correct. Or maybe they were - it's an old thread, unfortunately, as you said.

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