20 year old Onan Generator: 2 hours on it, not starting - '90 Fleetwood Flair

[duprester]

Hi,

We are looking at purchasing an 1990 Fleetwood Flair, that's in beautiful shape, that sat for 3 years with fuel in it. The seller replaced the gas tank and all the fuel lines. I test drove it and it ran great.

But, we may have an issue with the Onan Generator that has less approximately 2 hours on it over the past 20 years. The seller has tried to start it (it did crank) without luck but neither of us are mechanically inclined.

What is the worst case scenario? Replace the whole generator? How much would/could that run us?

Or, could it be as simple as the carburetor or that the fuel needs to be drained?

Thanks and I appreciate any help/answers,
Mike

 

[Water Dog]

Does it start and run as long as you hold the start button down, but quit when you release the button, or does it just crank over and never really start at all?

 

[duprester]

Hi Water Dog,

Thanks for your help. He only pressed the start button, a few times, for about 10/15 seconds and it only cranked. I assume that's probably not long enough but we were too worried about messing up the generator. It never ran.

 

[Mavarick]

Mike, there are quite a few older gensets still running simply because most don't get used that often. It really depends how well they were taken care of and gensets typically get forgotton about. If the rig is in that nice of shape chances are the genset is too. It might just need a new carb and some TLC. Before you do too much experimenting check fluids etc to make sure you don't do any unintentional damage. Worst case you can always replace the unit. Google Onan and you can find units that are app. 5500w for under $5k so research based on what the rig has in it. Don't forget to add in for labor also. If you like the rig that much I wouldn't let the genset stop the sale but you might get a little more $ leverage because it don't run.

 

[Water Dog]

My guess would be that you are probably right about either bad gas in the line, filter, and carburator, and/or a gummed up carb. If the total hours are only 2 in 20 years, there is a possibility that once you get the engine to fire it may not stay running once you release the start switch. If that happens, it would most likely be due to slip rings that are oxidized due to so much time sitting idle. That's a pretty easy fix with a $20 tool and no disassembly if it's similar to a 4.0 Onan Emerald. Onan parts are available through Cummins dealers

 

[gwcowgill]

More than likely the Carb can be removed, cleaned and the genset should start. It is recommended that gensets be started at least once a month and ran under a load. If it is an old cast iron  genset you may need to free up valves but I would try the carb first and if not sure do a compression check.

 

[duprester]

Thanks everyone, I really appreciate your help!

 

[spoonef]

Hi guys, can i jump in here. Wow I have a 30ft 1990 fleetwood flair  doing the same thing. Plus a battery issue.  When I press the start button on the geni it just turns over and never starts. my motorhome has been sitting for over 10 years with 35 total hours on the gen. I have changed 2 spark plugs and oil. I'm on the 3rd tank of gas thru the motorhome. Could it be a gummed carb. How do you get it off? It looks like a specialized tool needs to be involved.  Any help would be awesome. 

 

[boatbuilder]

One quick way to check the generator is to spray some WD-40(NO JOKES HERE) in the air intake, take the filter off first, while cranking it.  If the generator fires then you know it is a fuel issue.  WD40 works better than starting fluid because it doesn't wash the oil off the cylinders.
It is a good thing that the generator cranks over.  It means that the engine side is not locked up.

 

[reeltime]

Mike,

You have gotten some good information here. The worst-case scenario would be is to replace the generator and the 5K range pretty accurate. I have a 1990 Rockwood class C with an Onan Emerald 4Kw generator. It was in storage for nine years prior to my purchase. The generator would crank but not start so good fuel delivery was the prime suspect and the easiest thing to check. Remove the air filter from the front of the Carburetor; get a can of starting fluid (WD40 may work, never tried it) while cranking the generator spray starting fluid in the carburetor opening. It will only take 6 or 7 seconds to see if will try to start. If it does then your cost to fix it just went way down. The carburetor will need to be cleaned or rebuilt and there is a small in line fuel filter that must be changed and change the oil.
There is no special tool needed to remove the carburetor just a tight space to work in.  You stated you are not mechanically inclined so take it to a professional for work.

 

[duprester]

Thanks everyone! We just settled on a price and I'm gonna pick it up Saturday. This our first RV and my family and I are really looking forward to the experience. Thanks for your help!

 

[Water Dog]

What part of the country are you in duprester?

 

[duprester]

Hi Water Dog,

We live in Virginia.

 

[Water Dog]

Thanks everyone! We just settled on a price and I'm gonna pick it up Saturday. This our first RV and my family and I are really looking forward to the experience. Thanks for your help!

Congrats on the new to you MH. I'm sure you will enjoy it even though there will be challenges. We bought our "94" Flair about a year ago with a non-running generator (long story) now it works great. Even worst case, if it isn't worth fixing and you don't want to spend thousands for a new one, I see used 4-5.5KW's on Craigslist fairly often for from about $400 to about $800. Once you get it and can play with it take boatbuilder's advice and spray a little WD in there and see if it will fire. It's probably not in too bad shape. Be sure and write down the model name and complete model # of the generator .... you will need it.

 

[Honest John]

My guess is that the folks suggesting fuel clogging up is correct.  Be sure to check (and maybe change) the generator oil and filter.  If that unit has been setting for 20 years you don't really know the condition of the oil.  Also, if the oil is low the generator will not start due to a safety feature in the unit to keep if from damage due to lack of oil.

 

[duprester]

Again, thanks everyone. The rest of the rig is immaculate. The previous owners really took good care of it. We have been looking for months and this is by far the best we have found. So I am hoping that there isn't much to it.... but even if there is, this thing is in such good shape that I am willing to sink a bit more cash into it.

 

[tvman44]

1st think I would look for is a gummed up carburetor.

 

[dog_soldier]

when we first bought our 84 coachmen it had the same problem. genset would crank but not run. what i did was take the fuel line off at the fuel pump and spray some pb blaster in the line. then i cranked it and then sprayed more in it and let it sit for a couple days. when i tried again it fired up.
if your unsure what the pump looks like ill take a pic of mine and point to where i took the line off

 

[carson]

My thoughts:  We are taking a lot for granted here on the info provided.

approximately 2 hours on it over the past 20 years.

  2 hours seems to be hard to believe. In what year did this operation take place? If 18 years ago, all bets are off.

  Perhaps the hour meter is on repeat mode.. i.e. turned to zero hrs at the max reading level.

  I would go to an independent ONAN shop and get an estimate before spending hours of fruitless trouble shooting.

  I have an old ONAN...good engines--direct drive, but 2 hours in 20 years??

Just my opinion.
carson FL  81.1?

 

[cmc222]

I have a 1991 flair that had the same problem would try to start but wood not. Ordered the manuals From onan followed the trouble shooting guides found that the brushes where dirty from not being used cleaned them and it runs great.