convert gas generator to propane

[johntank]

Has anyone done this conversion on a Onan 4K and what was the cost and where did you find the best price on parts needed.

Thanks John

[bobsallyh]

MrWizard, they simply tap into the onboard low pressure system. Most fivers have either 30's or 40's. I didn't want propane on our worthless Onan, but instead have an 18 gallon onboard gasoline tank. But I sure would like to have a dual fuel system set-up, just for choice. LP sure isn't as efficient running a generator nor is it as readily available as gasoline as you stated.

[MrWizard]

bobsallyh wrote:
Mr. Wizard, there are numerous 5vers with Onan propane fueled generators in the U.S. No telling how many are sitting in Quartzsite, AZ.as I type this.

do these 5evers use 20# portable cylinders/bottles

or do they have frame mounted tanks ?

class A , i have seen with LP gennys, all have frame mounted tanks, so they more fuel capacity, my DP carried over 100# of LP, that is still only 20+ gallons and not as quick and easy to come by as gasoline
and 3 days of 100+ temps required an LP refill

apparently this is NOT the OPs concern, but it is for many other people

Of course wintering in Q, Az one does not really Need A/C
just the ability to use cooking appliances and recharge batteries

it helps to keep things in perspective
as for the OP, it seems his main concern was in NOT using his genny,
and the carb being gummed up and the fuel going bad, when he did want to use it
(2) things that are fairly easy to avoid, without changing over to LP

i hope smokestack provides him the info he is seeking

[nightshift]

If you're going to convert to propane, get an extand-a-stay kit. Propane gennys suck fuel like there's no tomorrow.

[bobsallyh]

Mr. Wizard, there are numerous 5vers with Onan propane fueled generators in the U.S. No telling how many are sitting in Quartzsite, AZ.as I type this.

[road-runner]

OP, I actually do have something possibly helpful. Try your question in the Smokstak Onan forum. This is the biggest repository of Onan information I'm aware of, and it's definitely more propane friendly.
https://www.smokstak.com/forum/forumdisplay.php?f=1

If I were doing this my instinct to use the actual Onan propane carburetor and associated parts. There's a greater possibility of finding some actual experience over at Smokstak than there is here.

[MrWizard]

Most homes provide low pressure natural gas or low pressure propane. This kit does not support high pressure propane that comes from a tank. Adapters will mix the Propane or Natural Gas into the air stream above the gasoline carburetor. The gasoline carburetor remains basically untouched.

going to need a regulator between the LP tank and this KIT

[Chum_lee]

This isn't that hard. Google is your friend. First hit on Google searching for:

"converting an Onan 4000 gas to propane"

https://centuryfuelproducts.com/onan-microquiet-4000-df

A veritable plethora of information, none of which I have tried, but hey, if Onan can do it both ways from the factory, how hard can it be?


Chum lee

[MrWizard]

RVs with propane generators, have frame mounted tanks
I have never seen an RV with portable cylinders and a propane powered built in Onan generator

We had a DP with a propane Onan generator, as dry campers, propane is costly and a hassle

The OP stated his generator is used infrequently, he believes the conversion to be worth while, I think it would cost less and be more efficient, to just exercise his Onan once a month and keep stabilizer in his fuel

He thinks he did not get any helpful info
He did not get change over conversion info, because nobody here has done what he wants to do
He got lots of helpful info, but not the info he wanted
Sometimes learning that what you want to do, is not very feasible, is helpful info

Like our parents telling us not to do things we wanted to do when we were children

This doesn't fall in the same category, as riding the bicycle down the barn roof into the snow drift

But the concept is the same,
Don't get offended because you don't get the consensus and info you want
Maybe what you want isn't the best way

If the OP pursues this and finds the way
I hope he comes back with pictures and detailed info on the how-to

[road-runner]

johntank wrote:
Moderator please lock or delete this thread as I have not gotten any real useful answers.

Thank You

johntank

You asked 3 very specific questions, and from 23 prior responses, none have been answered. Of those 23 responses, about 14 of them have stated to some degree that you shouldn't make the conversion. Not knowing how you use your generator I won't assume to know what's best for you, but will say it all depends on your usage model. I have a propane 4k Onan, and it's a good choice for the way I use it. In 10 years, I've needed it for the air conditioner about 2 times. I don't use it to charge the battery because it's so darn noisy, using a small portable generator instead. The Onan gets used infrequently for short periods of time, more often than not for running the microwave. Having to top off the propane a bit more often is a lot easier for me than worrying about old fuel and/or a gummed up carburetor.

And I just made it worse with another post that doesn't answer your questions.

[bobsallyh]

It just fascinates me that so many genny manufactures now have dual fuel setups, by just throwing a switch, while Onan just keeps plugging along with old style technology.

[joebedford]

johntank wrote:
Moderator please lock or delet this thread as I have not gotten any real useful answers.

Thank You

johntank

You're welcome. Bibi.

[JaxDad]

johntank wrote:
Moderator please lock or delet this thread as I have not gotten any real useful answers.

Thank You

johntank

It that’s your thoughts why did you even start here?

There’s plenty of online info, Google IS your friend. It’s dead simple, you need a vapourizer, regulator, tank(s), lines and some form of carb adapter plate, or a new carb altogether.

The chances of finding someone who’s done this anywhere is slim, on a single forum? Buy a PowerBall ticket, I think the odds are better.

Realistically however, unless you remove the fuel tank and replace it with a ASME type permanent tank you’re going to stuck with 20 or 30 pounders for a fuel source, read ‘very expensive’.

[philh]

Pure gas is good

Aviation gas is better

[fj12ryder]

You're welcome, come back anytime.