Exercise the Generator or open your wallet

[Belgique]

We've be static for awhile and I failed to exercise the Onan 5.5 Marquis Gold. It would not start. Found a series of excellent You Tubes on RV maintenance by Mr. Don McAdams including one on diagnosing my problem CLICKY.

I did what he said and Sea Foamed it a lot. It got it to where it would start but then ran real rough with lots of smoke and no amout of Sea Foam made it any better. He and others (including Onan) say the only solution is to replace the carb. Rebuild is dangerous and I didn't want to take the chance. (Someone will post soon and say they did it and everything is fine. Good for them. The Gen is in a compartment under my bed and I didn't want to take the chance.)

Found a brand new one for $233 on Ebay. Watched the video and did a very simple change out. Onan purrs like a kitten.

Offered as a lesson learned. I've got computer reminders to run it under load every two weeks.

[willald]

mkane wrote:
There is one reason and one reason only for this problem! ETHANOL!

Yep, I remember a few years ago when buying a leaf blower, the tech. guy said the same thing - Most of the various small engine powered equipment he gets in for service 'cause they quit running, he finds the cause is exactly that - Ethanol in the fuel causing the carburetor to gum up. He told me to run nothing but ethanol free fuel in the (Stihl) leaf blower I was buying from him, and I'd never have a problem with it. Ever since then, thats all I've ever run in all my lawn equipment (tractor, mower, leaf blower, weed eater, etc). Never had a problem out of any of 'em since.

Its easy to only use ethanol free gasoline in small engines you use at home where you can always get your fuel for such from the same place (a convenience store nearby where they sell ethanol free gas). Howerver, it is not that easy to run strictly ethanol free with a Motorhome that you travel all over with, and have to fuel up in all different locations, where ethanol free fuel is frequently not an option. Especially at fuel stations large enough to get a Class A RV in and out of.

Sooo, we either exercise our gennys, run 'em dry on fuel before parking them, or pay the price, like noted here.

Will

[mkane]

There is one reason and one reason only for this problem! ETHANOL!

[bsinmich]

I had an Onan 5000 in my 1996 Pace Arrow, a Generac 6500 in my '03 Mountain Aire and now a Onan 2800 in the Roadtrek. I use Stabil in my tank in the fall and run the gene until I am sure Stabil has gotten there also. I store in a barn and don't have the opportunity to run it monthly. It is usually stored for 6-7 months and I have never had a problem in the Spring to get the gene running.

[Belgique]

Will: As I recall, I had not run it since Oct. I agree, $233 is cheap for a new carb and it runs much better now than it had in recent years. It wasn't bad in past years...just not as smooth as it is now. That video made it real easy to swap out. I'm told that it would have cost me about $400 at the Onan place in New Bern plus the gas to get there and back. Think I'll go exercise it right now 🙂

[willald]

Thanks for the reminder. I just exercised ours Saturday, it still runs like new. I try to run it at least once a month with one of the air conditioners on.

Did not realize that it is that dangerous to rebuild the carburetor on these generators. $233 ain't bad at all for a new one, though. You'd probably pay half that to have somebody rebuild your old carb.

Like the suggestion made earlier as well, about disconnecting the fuel pump and letting the engine run itself dry on fuel. I do this with several other small engines I have (weed eater, leaf blower). Never thought about doing it with the MH's genny, as didn't realize it was that simple. Might just try that.

[John_Joey]

Belgique wrote:
...I did what he said and Sea Foamed it a lot. It got it to where it would start but then ran real rough with lots of smoke and no amout of Sea Foam made it any better...

This usually means there is still SeaFoam in the fuel, and it should run rough and smoke. Once you get clean fuel flowing for awhile, it should have settled down. A gummed up carb does not smoke.

[Sooner_Schooner]

Good advice, I guess I just got lucky. We started our generator the other day just as we arrived in Oklahoma to visit family. I have neglected running it for quite some time, but it fired right up and ran smooth. Yes, I put it under a load running it for about 40 minutes with the air conditioner on. I must get better at running it to avoid problems.

[Canadian_Rainbi]

koda55 wrote:
There are two reasons to run your generator every month.
1. To get fresh fuel through the system.
2. You run it under load so that the generator runs the stators so they do not rust.

AND to bring the alternator up to a decent temperature for long enough to drive out any moisture.

[koda55]

There are two reasons to run your generator every month.
1. To get fresh fuel through the system.
2. You run it under load so that the generator runs the stators so they do not rust.

[Jagtech]

10forty2 wrote:

RLS7201 wrote:
Interesting. For many years people used to take carburetors apart and clean and repair them. Now were told we can't do that and it's dangerous. Why is that?

Richard

Because that doesn't sell new carbs.....

I took my carb apart (Onan 5.5 Marquis Gold)...cleaned the components with Sea Foam and stiff brush, and low and behold after about an hour it ran like a charm and still is. It can be done safely and effectively, but they want to sell more new parts rather than let people keep their money.

Absolutely right. There is a higher risk of fire from that cra**y fuel line to the Onan than a rebuilt carb. Any rebuild, done correctly, is as good as new.

[ferndaleflyer]

Mine has over 3000 hours on it. I think it gets run enough.

[Belgique]

Tony: I like your option 2 also. Which is the fuel pump wire to undo? I.e., where is it? Thanks!

[CallThisCamping]

I also had to recently replace my carb. The carb. CANNOT be rebuilt or effectively cleaned as the parts are pressed together, not bolted or screwed. I have an inverter and battery bank that we use mostly, or we usually have full hook ups. So I don't use the generator unless we're dry camping and it's hot, or we want to use the microwave.
This cost be a shade over $300. The cause is said to be the high ethanol content in gas, which evaporates and leaves behind the 'varnish' that gums up the works.
I was given 2 options by the very good mobile RV tech who changed it out. 1) exercise the generator under load 1 hour every 30 days. I asked 'why under load' and was told it was solely to increase the volume of gas going through the carb.
OR 2) (my preferred method) Pull one wire from the generator fuel pump and run it till it stops. Then open the small screw on the bottom of the float tank and drain it completely. This is only about 4 drops of gas. Then plug the fuel pump back in. Good to go. Now I do this when we get home if we've used the generator.

The fuel pump is a small cylinder looking device under the generator base on the left side. It has a small wiring harness that has 2 wires that go from the pump up to the control electronics (where the start switch and breakers are). On my MH, there is an insulated spade lug connector on each wire, I guess so the pump can be changed without going into the black box. It's a very simple matter to unplug one of the wires. Just pull it apart. Doesn't matter which one. Then start 'til it stops, drain the float tank, done. (really, it's about 4 drops of gas after the generator stops)

[Belgique]

Ed: we stayed in one place without running the Gen from Oct-Jan. Then we came home and didn't start it until early April and found the problem. Did a lot of research and these have a tendency to do that, thus Onan's recommendation to run them under load monthly. It is an 2088 rig. In the past we used it a lot and ran the gen a lot for AC on the road. I know better. Was into boating for decades and they start having problems if you let them sit.

Appreciate the other comments about fire extinguishers. I negligent in that area too.

[Ed_Gee]

Belgique wrote:
We've be static for awhile and I failed to exercise the Onan 5.5 Marquis Gold. It would not start. Found a series of excellent You Tubes on RV maintenance by Mr. Don McAdams including one on diagnosing my problem CLICKY.

I did what he said and Sea Foamed it a lot. It got it to where it would start but then ran real rough with lots of smoke and no amout of Sea Foam made it any better. He and others (including Onan) say the only solution is to replace the carb. Rebuild is dangerous and I didn't want to take the chance. (Someone will post soon and say they did it and everything is fine. Good for them. The Gen is in a compartment under my bed and I didn't want to take the chance.)

Found a brand new one for $233 on Ebay. Watched the video and did a very simple change out. Onan purrs like a kitten.

Offered as a lesson learned. I've got computer reminders to run it under load every two weeks.

I am somewhat curious on your situation. You did not say how old your rig is, nor did you say how long you failed to run your generator. I'd be curious to know both details.