Generator Onan

[maggie blair]

I just bought a 2007 Fiesta Fleetwood and the generator won't stay on. It starts, but then it stops after a few minutes.

Does anyone have any suggestions?

Thanks,

Maggie

[WILDEBILL308]

You will get a lot of suggestions on this. If it hasn't ben run regularly/exercised it could be crud in the carburetor. You might look and see if there is a small fuel filter near the generator. changing this is always a good first step in trouble shooting a problem like this.

You can also make up a rich mixture of carb cleaner(at least 2X what it says on instructions) in a small (2gal)can and use a piece of fuel hose to connect it to the fuel inlet. This way you don't have to treat the whole big tank. I would also just try to start it again and see if you can keep it running longer with no load. After you get it running and warmed up put at least 50%load on it foe at least an hour this should be done once a month.

Let me know what you find out.

Bill

[wildmandmc]

oil level. i heard of ppl having problems, something like this, they changed oil an ran all the time after that. also. when it comes on , soon right after is there a load on it. let run for few minutes prior to putting a load on it.

[wildmandmc]

Forgot to add this, one time a while ago. i had a similar problem, seems after a few times my gen would shut off right after start up. after a few times it would stay running. an a few months after that i ended up changing all batteries out. eng/house. since then almost a yr now, gen comes on an stays on.

[maggie blair]

You will get a lot of suggestions on this. If it hasn't ben run regularly/exercised it could be crud in the carburetor. You might look and see if there is a small fuel filter near the generator. changing this is always a good first step in trouble shooting a problem like this.

You can also make up a rich mixture of carb cleaner(at least 2X what it says on instructions) in a small (2gal)can and use a piece of fuel hose to connect it to the fuel inlet. This way you don't have to treat the whole big tank. I would also just try to start it again and see if you can keep it running longer with no load. After you get it running and warmed up put at least 50%load on it foe at least an hour this should be done once a month.

Let me know what you find out.

Bill

Thanks so much Bill. I will follow your advice and try the things you mentioned. I appreciate your info. and hopefully this will get it up and running. I don't think it has been turned on in over a year so this sounds like it might work.

Thanks, Maggie

[maggie blair]

oil level. i heard of ppl having problems, something like this, they changed oil an ran all the time after that. also. when it comes on , soon right after is there a load on it. let run for few minutes prior to putting a load on it.

 

What does it mean when you say putting a load on it?

[jc2]

http://seafoamsales.com/ As they are meant to be used and not sit idle, we use our generator quite often when the mh is moving so our non-working/running issues are/have been minimal. With that said, I consistently run the appropriate amounts of the fuel conditioner mentioned in the link @ the beginning of this post 2-3 times a year. I use (1) 16oz can of Sea Foam per 25gals of our mh tanks capacity and have done this for many years in gas/diesel vehicles. You might give it a try as I'm sure it will help if you have gunk buildup in your fuel system. SF can be bought at Walmart, Oreilly Auto Parts and many other similar stores for $7-9 per can.

[harley-dave]

We also had one that did this and it was the fuel pump. Less than $200 for trouble shooting and replacement by tech.

 

Dave

[Kirk W]

To put a load on a generator, or to load it you turn on electrical loads to use power from it. That means to operate one or two air conditioners or 1-2 electric heaters on high. Depending upon the size of your generator in KW, you need to apply at least 1/2 the rated capacity for a half hour or so to properly exercise it.

 

It would be helpful to know what the model of Onan you have is. KW rating also plays a part in the proper answers.

 

If it starts and seems to run fine for a few minutes, but then shuts down for what seems no reason, the first thing to do is to check the oil level. I know that all Onan sets have a low oil sensor that will turn off the set if oil in the sump gets too low, so it might restart once the oil drains back and then shut down again. Too much oil can cause that same problem as the oil will foam up after a few minutes and the foam then trigger the low oil sensor, so make sure it is in the proper level range.

 

Either a dirty fuel filter or a bad fuel pump could also cause this to happen. On most Onans you can see the fuel filter when you open the access, but just how yours is mounted will play a part so if you are not sure, post a picture and we can give you directions to it.

 

If you have not done so, check the air cleaner while you are in there as a very dirty one will cause the generator problems as it accepts a load even when it may start fine. The Onan is designed to where it runs for a short period before it starts to send out power to the RV in order to allow it to come fully up to speed and stabilize first.

 

When it starts, does the engine run very rough and seem to shake, or does it settle into a nice steady operation sounding smooth and even after only a few seconds? Surging is a pretty good indication of a dirty carburetor or sticking float. Cleaner used as Wild Bill suggests, mixed up in a small fuel can and using a short length of rubber fuel line is a trick that I have used to correct this problem and is pretty easy to do if you have good access to the suction side of the fuel pump. The Onan has its pump mounted on the side of the set and it uses an electric one but access to it and to the fuel lines will depend upon the way the RV builder mounted it into the RV.

 

How comfortable are you with mechanic work? You may need to remove and clean the spark plug or even replace it. Do you have an owner's manual for the generator? Most of them list a number of operator maintenance tips that help to keep the set purring along.

[maggie blair]

To put a load on a generator, or to load it you turn on electrical loads to use power from it. That means to operate one or two air conditioners or 1-2 electric heaters on high. Depending upon the size of your generator in KW, you need to apply at least 1/2 the rated capacity for a half hour or so to properly exercise it.

 

It would be helpful to know what the model of Onan you have is. KW rating also plays a part in the proper answers.

 

If it starts and seems to run fine for a few minutes, but then shuts down for what seems no reason, the first thing to do is to check the oil level. I know that all Onan sets have a low oil sensor that will turn off the set if oil in the sump gets too low, so it might restart once the oil drains back and then shut down again. Too much oil can cause that same problem as the oil will foam up after a few minutes and the foam then trigger the low oil sensor, so make sure it is in the proper level range.

 

Either a dirty fuel filter or a bad fuel pump could also cause this to happen. On most Onans you can see the fuel filter when you open the access, but just how yours is mounted will play a part so if you are not sure, post a picture and we can give you directions to it.

 

If you have not done so, check the air cleaner while you are in there as a very dirty one will cause the generator problems as it accepts a load even when it may start fine. The Onan is designed to where it runs for a short period before it starts to send out power to the RV in order to allow it to come fully up to speed and stabilize first.

 

When it starts, does the engine run very rough and seem to shake, or does it settle into a nice steady operation sounding smooth and even after only a few seconds? Surging is a pretty good indication of a dirty carburetor or sticking float. Cleaner used as Wild Bill suggests, mixed up in a small fuel can and using a short length of rubber fuel line is a trick that I have used to correct this problem and is pretty easy to do if you have good access to the suction side of the fuel pump. The Onan has its pump mounted on the side of the set and it uses an electric one but access to it and to the fuel lines will depend upon the way the RV builder mounted it into the RV.

 

How comfortable are you with mechanic work? You may need to remove and clean the spark plug or even replace it. Do you have an owner's manual for the generator? Most of them list a number of operator maintenance tips that help to keep the set purring along.

Thanks Kirk. I sure appreciate your input. No, I am not very mechanical but I'm willing to try the ideas to save some money. New tires on the list this morning and I will read the manual while waiting. The ONAN is a 4000 UltraQuiet model.

[maggie blair]

We also had one that did this and it was the fuel pump. Less than $200 for trouble shooting and replacement by tech.

 

Dave

 

Thanks Dave. I may have to open my wallet again and just go to the RV shop.

[Kirk W]

At least check the oil level as I'm sure that you can do that much. If you do have it serviced, make sure that they change the oil and filter on it at that time and also the fuel filter. My last Onan called for an oil change either annually or every 50 hours of run time.

[maggie blair]

http://seafoamsales.com/ As they are meant to be used and not sit idle, we use our generator quite often when the mh is moving so our non-working/running issues are/have been minimal. With that said, I consistently run the appropriate amounts of the fuel conditioner mentioned in the link @ the beginning of this post 2-3 times a year. I use (1) 16oz can of Sea Foam per 25gals of our mh tanks capacity and have done this for many years in gas/diesel vehicles. You might give it a try as I'm sure it will help if you have gunk buildup in your fuel system. SF can be bought at Walmart, Oreilly Auto Parts and many other similar stores for $7-9 per can.

Do I just pour the Sea foam into the gas tank?

[Kirk W]

Do I just pour the Sea foam into the gas tank?

Doing it that way isn't going to solve the problem that you have at present, but the regular use of a fuel system cleaning product one or two times per year is a good preventative for future problems. It might help now if you can get it to keep running but it will mean several hours of run time in order to get enough of the fuel, cleaner mixture through the generator fuel system to do much good. If it won't stay running, you probably won't be able to get enough through the engine to help.

 

When you treat a tank of fuel the proper way to do so is to pour the cleaner into the tank just before you add gasoline and then fill the tank completely to get them to mix.

[Dreed917]

Because of the pickup location in the gas tank, my generator won't run unless I have at least 1/4 tank full of gas in the motorhome. Something else to check.

 

Dave

[AlCherry]

Maggie, do you have a operator manual? Is the genset throwing a code? The Prime/start button on the genset has a light in it. When there is a fault, it will flash a sequence of codes, and you can reference them in your manual. You didn't mention which genset it was.

[maggie blair]

You will get a lot of suggestions on this. If it hasn't ben run regularly/exercised it could be crud in the carburetor. You might look and see if there is a small fuel filter near the generator. changing this is always a good first step in trouble shooting a problem like this.

You can also make up a rich mixture of carb cleaner(at least 2X what it says on instructions) in a small (2gal)can and use a piece of fuel hose to connect it to the fuel inlet. This way you don't have to treat the whole big tank. I would also just try to start it again and see if you can keep it running longer with no load. After you get it running and warmed up put at least 50%load on it foe at least an hour this should be done once a month.

Let me know what you find out.

Bill

Thanks Bill. I am very leery of any mechanical stuff so will probably have to bite the bullet and take it in. Thanks, again.

[maggie blair]

Doing it that way isn't going to solve the problem that you have at present, but the regular use of a fuel system cleaning product one or two times per year is a good preventative for future problems. It might help now if you can get it to keep running but it will mean several hours of run time in order to get enough of the fuel, cleaner mixture through the generator fuel system to do much good. If it won't stay running, you probably won't be able to get enough through the engine to help.

 

When you treat a tank of fuel the proper way to do so is to pour the cleaner into the tank just before you add gasoline and then fill the tank completely to get them to mix.

 

Thanks Kirk. I will remember this the next time I pour the fuel cleaner in.

[maggie blair]

Maggie, do you have a operator manual? Is the genset throwing a code? The Prime/start button on the genset has a light in it. When there is a fault, it will flash a sequence of codes, and you can reference them in your manual. You didn't mention which genset it was.

 

It says 4000 Onan on the generator and the light flashes red. I don't see a code.

[maggie blair]

At least check the oil level as I'm sure that you can do that much. If you do have it serviced, make sure that they change the oil and filter on it at that time and also the fuel filter. My last Onan called for an oil change either annually or every 50 hours of run time.

 

Yes, I checked the oil and it was good. The previous owner said everything was changed last May when he bought the RV. He said it ran fine then. I doubt it's been started since last May so probably needs some attention. This is probably something I need a professional to look at and fix. Thanks for your info.

[chuckbear]

maggie, Many times it is the number of flashes per second that indicates the fault code. Check your manual. Chuck

[maggie blair]

Maggie, do you have a operator manual? Is the genset throwing a code? The Prime/start button on the genset has a light in it. When there is a fault, it will flash a sequence of codes, and you can reference them in your manual. You didn't mention which genset it was.

Yes, and the light flashes red three times. I looked in the manual says that means it needs serviced. The man I bought it from purchased it last May from a dealer and he said they did all of that. Could it need serviced this soon?

[chuckbear]

It's possible. The Need Service code can mean a lot of things, even a problem that a service department needs to correct and not necessarily just an oil change or maintenance item. Chuck

[Kirk W]

The man I bought it from purchased it last May from a dealer and he said they did all of that. Could it need serviced this soon?

The "need service" light on an Onan is the equivalent of the "check engine" light in an auto. It basically means that something is wrong which has no specific flash code. It could be any of the various issues that have been discussed up to now, but it might be anything. It is not saying that the oil needs to be changed or that it is due for routine maintenance.