Onan generator

[mlh]

I have an Onan Micro Quiet 4000 with 37.1 hours on it and can't keep it running. The control board has been replaced, oil and spark plug changed. It's chilly here this morning 35 or so It starts and dies. Anyone have any experience with an Onan? Are they all junk? How I wish it was a Honda.
Lynwood

[boat391]

I have the same set up. The only time I have this same problem is when it's cold outside and my oil is a little low the low oil sensor wil shut it down. I have changed oil weight and it helped a bit in cold weather when it warms up it doesn't give me a problem. Oil must be full and clean in my case. Hope this helps with your problem. If you look to the left of your dip stick you will see the sensor I'm talking about has 2 wires hooked to it. You will see by its location the oil doesn't have to be very low for it to do it's job.

[mlh]

Thanks. I took your advice, got it warm with a portable electric heater and it fired up like it should. A generator isn't much good to you if it is only a warm weather unit. Is there anything that can be done to help get it going in cold weather?
Thanks Lynwood

[boat391]

Look in your owners manual about cold weather oils. A light weight oil such as a 5w 40 is what I use so at start up its 5weight then after it warms it gives you 40 weight protection. It seems to work for me like said in my earlier post oil level is very important too. I have 1200 hours on my generator now and keep it changed every 100 hours. Good luck hope this helps.

[K0LCB]

They are real sensitive to low oil

[mlh]

It has plenty of oil. It would start and run a few seconds quit then I would get the 3 blinking light alarm, which is Must be serviced.
Are there any carburetor adjustments or others to help with a cold weather problem?
Lynwood

[boat391]

I had a fuel pump go bad it is located below the generator. On the underside of the coach. There is a filter located at the out end of the pump. I bought the replacement at o'Rieleys.

[boat391]

I should clarify my generator is a gas run unit not LP

[mlh]

Thanks I checked the fuel pump at about 33 hours. It now has 38 hours as of this evening. It would squirt gas several feet.
Lynwood

[JandC]

There is a service code that will tell you what the problem is. If I remember correctly, after the initial 3 blinks there will be a series of other blinks, some long and some short. Record those and you can look in a service manual or a dealer can tell by that
why it shut down.

[mlh]

Originally Posted by JandC

There is a service code that will tell you what the problem is. If I remember correctly, after the initial 3 blinks there will be a series of other blinks, some long and some short. Record those and you can look in a service manual or a dealer can tell by that
why it shut down.

Thanks. When I had to replace the board because the mice had let's say ruined it I got a code telling me what the problem was but this time I just got the 3 flashes. It think it is a 3 season unit. If it had a manual choke I think I could keep it running. This is a 2007 model that only had about 30 hours when I got it. It is as clean as a new one. The camper it is in still had the tags on the furniture and the clear plastic covering on the floor with only 5000 miles on it. I call it my barn find.
Lynwood

[mlh]

Thanks for all the help. Nothing worked! I took it to a guy that does nothing but repair generators. He called Onan, Flight Systems the people who make boards for generators and every body who might be able to help. Nobody had a clue. Flight Systems almost laughed at him, just no way that could be.
He may have solved the problem. If it is under any load it may run when it's under 40 degrees. We aren't sure yet just waiting for a chilly morning.
Thanks Lynwood

[JandC]

Reference the fault codes and 3 flashes. My Onan 5500 in my MH is of course also a gaser. I am in the process of trying to figure out a problem with it. Mine will run and pull loads fine if I am stationary but after 15 to 30 minutes of highway driving it shuts down.


My fault code is an initial 3 blinks. When you get that then you push the stop just once and it will give you the actual code. Mine was 3 blinks and then 6 blinks. This fault code is the most common (36) and it just tells you that something made it shut down but does not tell you what. It is a "catch all" Onan fault code. With any luck you won't get the dreaded code 36 but will have another one.

[mlh]

Thanks. We do not get a fault code. Ain't got a clue!
Lynwood

[mlh]

I may have a solution. A man calling this afternoon. He knew all about the generator from the man that worked on it. He would like to buy it. I told him it wouldn't run when it was under 40 degrees and he has no problem with that and already knew that. He has an older camper and don't wont to put much in a generator. This one only has 38 hours on it. I'm uneasy about selling it with a problem. I worry about cheating someone. I've run my business for over 35 years by being totally honest and now it's hard to sell something I know has a problem.
Lynwood

[Wheelhouse]

I had a problem like this with my old VW Bus. When it was cold it wouldn't start until the sun shined on it or it got warmer. One morning I was running late for work and yes, it wouldn't start. Ah-Ha, I ran a piece of vent pipe from my wifes car exhaust to the engine compartment and Wha-La, it started. Sometimes you have to think outside the box, lol. It turned out to be a capacitor in the computer, that when it was cold it lost contact and when it was warm just enough contact to let it start, Hope this helpful.

[Good Life]

Originally Posted by mlh

I may have a solution. A man calling this afternoon. He knew all about the generator from the man that worked on it. He would like to buy it. I told him it wouldn't run when it was under 40 degrees and he has no problem with that and already knew that. He has an older camper and don't wont to put much in a generator. This one only has 38 hours on it. I'm uneasy about selling it with a problem. I worry about cheating someone. I've run my business for over 35 years by being totally honest and now it's hard to sell something I know has a problem.
Lynwood

Did you resolve your problem?

[JandC]

I am curious also, did you sell it or get it running? On my MH forum a few folks kept telling me to run a dose of SeaFoam through mine, 2 ounces per gallon. Since my tank is 80 gallons I had to wait until I was down to 3/8 of a tank so I could afford that much Sea Foam. I ran it a couple hours with the Sea Foam and it has worked now for months without a problem.

[mlh]

Thanks for asking. We called Flight Systems the people who make the control boards. They tried to help but didn't have a clue. We also called Onan. They are worse than our CW. If you wanted to improve mankinds IQ they would be the first to go.
We had our Onan repair business take the unit apart. What they found was:
Onan generators have a small set of brushes that excite the armature to cause it to produce power. It's low amp and the voltage can go up to 60 volts depending on how much amperage the generator needs to produce. One of these brushes was wore about 1/4 inch. The repair man took one look at it and said something in your camper is pulling too much power. It was my AC. It was making cool air but pulling 30 amps. We replaced it.
He has been working on Onan generators for 25 years. I ask what he thought of my generator. He said they have cheapen them up so much they are junk. For instance the unit this one replaces uses 4 quarts of oil. Mine uses a little over one quart.
Lynwood

[Bsorge]

Originally Posted by mlh

I have an Onan Micro Quiet 4000 with 37.1 hours on it and can't keep it running. The control board has been replaced, oil and spark plug changed. It's chilly here this morning 35 or so It starts and dies. Anyone have any experience with an Onan? Are they all junk? How I wish it was a Honda.
Lynwood

Always use a fuel additive like Stabil in you fuel. Keeps your carburetor clean. I use it every time I fill up.