Do you drain the gas out of your Onan Carb?

[RambleOnNW]

Recently noticed in the Onan 4000 manual that it has a carburetor gas drain valve below the front of the carburetor. The valve is adjusted using a phillips or slotted screwdriver. The gas drains on the front of the generator, but I found that a 1/4" rubber hose fits the drain port. I used a 1 foot hose to drain however an 18" hose would have allowed draining to a container on the ground. I got 1-2 oz of gas out.

I had not been doing this before without issue. I run the gen once a month though and put Stabil in the gas.. Now I plan to drain the carb when not using it for awhile as further insurance against getting varnished.

Any long term MH storers drain it also?

[IAMICHABOD]

the trippers wrote:
Where or how would I find a gas station that pumps non-ethanol blended gasoline? Didn't know stations were allowed to do that. In Utah or the Southwest somewhere? I would like to try pure gasoline in all my vehicles.

Hey neighbor try This site

[the_trippers]

Where or how would I find a gas station that pumps non-ethanol blended gasoline? Didn't know stations were allowed to do that. In Utah or the Southwest somewhere? I would like to try pure gasoline in all my vehicles.

[the_trippers]

ajriding wrote:
First, if you want to store the gen for more than, say 2 months, then use non-ethanol gasoline with Stabil. The so-called ethanol fuel stabilizers will not stabilize ethanol to the degree you need it to. The ethanol will break down and turn everything gummy. The ethanol is water based and the water that is left behind will rust or corrode the carburetor parts.
Second, and this all depends on your generator fuel pump, if left in a dry state some things can dry out and crack/rot. I personally have a mechanical pump and the paper element/diaphragm dried out as well as some of the rubber o-rings. Some generators need to have gas in there to keep things wet.
Run the generator with non-ethanol gas for 10 minutes (or until it is purged of ethanol). You can simply move the fuel hose to a container with the gas in it, or you can purge your RV gas tank by running real gas for a while. I have an old push mower gas tank that I use to feed the generator gas when I will store it.
All said, the generator head unit also needs to be run regularly, so it is not ideal to store the generator for too long.

Where would I find a gas station that pumps non-ethanol gasoline?
Seems like they would be fined by the State EPA. I would like to run it in all my vehicles, pure gasoline no ethanol.

[RambleOnNW]

Good feedback all, thanks. I am going to stick with the draining unless short on time but am neutral on the topic. Much like blowing out lines vs using pink antifreeze for winterizing. Have been running monthly without draining gas from the carb with no issues.

[tpi]

I've extended stored ATVs in extremely hot desert conditions by draining fuel bowl without incident. I personally would never leave fuel in a carb I expected to completely go dry-even treated high quality fuel.

These carbs have no accelerator pump. Perhaps if concerned about that or something drying out in other carbs run a bit of premix through it at the end before layup.

[ajriding]

First, if you want to store the gen for more than, say 2 months, then use non-ethanol gasoline with Stabil. The so-called ethanol fuel stabilizers will not stabilize ethanol to the degree you need it to. The ethanol will break down and turn everything gummy. The ethanol is water based and the water that is left behind will rust or corrode the carburetor parts.
Second, and this all depends on your generator fuel pump, if left in a dry state some things can dry out and crack/rot. I personally have a mechanical pump and the paper element/diaphragm dried out as well as some of the rubber o-rings. Some generators need to have gas in there to keep things wet.
Run the generator with non-ethanol gas for 10 minutes (or until it is purged of ethanol). You can simply move the fuel hose to a container with the gas in it, or you can purge your RV gas tank by running real gas for a while. I have an old push mower gas tank that I use to feed the generator gas when I will store it.
All said, the generator head unit also needs to be run regularly, so it is not ideal to store the generator for too long.

[tpi]

I'd drain mine if I expected to lay it up for more than a month or so. It's evaporating an entire bowl of fuel that reduces down to these flaky deposits.

[jjrbus]

The Logans wrote:
It has to be run once a month with a load on it (we use the AC or the hot water heater for the load). We run it for about 20 minutes. The monthly exercise eliminates the need to use a fuel conditioner or drain the carburetor.

If the genset is not run monthly, it can dramatically shorten the life of the Onan.

That is what I was taught. Jim

[jjrbus]

Cobra21 wrote:
I don't think the fuel evaporates very fast during a Minnesota winter, but Florida is most likely a different story. I don' drain.
Brian

Or does it evaporate faster because of different formulation/additives and lower humidity?

Expiring minds need to know. Jim

[The_Logans]

It has to be run once a month with a load on it (we use the AC or the hot water heater for the load). We run it for about 20 minutes. The monthly exercise eliminates the need to use a fuel conditioner or drain the carburetor.

If the genset is not run monthly, it can dramatically shorten the life of the Onan.

[Dusty_R]

Thirteen years ago we bought a new mh with the 4000 watt generator. I located the electric fuel on it and put a switch ahead of the pump. So then come fall when I used the generator for the last time, I would turn the pump off and let the generator burn all the fuel in the carburetor.
I like the idea of the drain on the carburetor but will the gas in the jets drain? If not will that very small amount of gas gum up the jet?
We just replaced that 2003 mh for a new 2015, and it also has the carburetor drain. How long has Onan been putting that drain on the carburetor?

Dusty

[Cobra21]

I don't think the fuel evaporates very fast during a Minnesota winter, but Florida is most likely a different story. I don' drain.
Brian

[jjrbus]

If using stabil and running occasionally no need to drain. If not using and you want, take a small amount of gas with Stabil in it in an open container and see how long it takes to evaporate. Then look at the film that is left in the container.

Next check and see how much it will cost to clean/rebuild your Onan carburetor. Your choice weather to drain or not.

I drain for storage. Jim

[Robocop]

j-d wrote:
Exercise, StaBil, No Draining.

X2.

Going on 5 years no issues.