Generator problems

[buckeye]

Originally Posted by Kingsmen55

My Onan Generator on my 2004 Sightseer Class A won't stay running.
Fuel pump and filter replaced two years ago. I only ran it for 24 hours since then. I start it often. any ideas? Thank you

I don't know if anyone has mention the oil has to be full in the generator or it will
cut off.

[Morich]

The oil level may be one to really look over and possibly give a try as oil is a semi-critical level and the pros do not always think to spot it. I recently had a new Lawnboy that would not restart after running a short time and took it in for warranty repair where the guy told me he drained and refilled the gas tank as it had water and the oil was foamy. But the true fix was only after i drained some oil and it runs fine now without foaming the oil!
Possibly do a test run with a bit lower oil level, not enough to overheat and damage the engine but just long enough to tell if it makes it better? Those flashing lights can be a guide but not always tell the correct story.

[Rick 99037]

Originally Posted by kb2ztx

Same issue on my fathers Class C last year. Oil was overfilled. We drained some oil until it read properly and ran fine for 16 hours after that. I did alot of searching on this issue and when someone said to check the oil i thought they were nuts. Well its been over a year and he runs it all the time now with no issues.

I have an 05 Sightseer with a 4000, and was going to mention the slightly to full, not just to low issue with their sensors. That question about if it starts right up, not necessarily keeps running is important to show you hadn't run dry of fuel. Start and die could indicate start bypasses some safety sensor.
It would be nice if you could get ahold of a diagnostics testing flow chart for you to work from.

[Goodspike]

Originally Posted by Kingsmen55

Thanks we did check the oil. I appreciate your response.

The OP already indicated that he had checked the oil!

[MotoMac]

Originally Posted by creativepart

I used to own a Forest River Class C that did this exact same thing. It drove me mad. It only happened on really hot days. It would run in the morning fine but by afternoon it would stop running every 20 to 30 mins after a restart.

So, I took the RV to a Cummins Service Center - they ran it in the parking lot for 8 hours on a hot day. It never stopped once. They actually used a 1/4 of a tank of gas doing it. Charged me $250 and never touched a thing.

On my next trip it did the same thing.

I wish I could tell you how I fixed it - but I never found a fix. Ever. I traded that (lousy) FR for my Winnebago and never looked back.

When it stalls it will flash lights that give an error code. Like it will flash once, then wait and then flash 4 times. You can look up the error code on the Onan website.

But that never helped me.

They probably just let it idle without putting a large load on it. Running something like the air conditioner will consume fuel faster, and if there is a probably with the fuel system it will show up much sooner.

Modern gasoline sucks. All the additives -- especially the ethanol -- does really bad things to your fuel system. If you left the same gas in it over the past two years, a lot of it will evaporate and leave a large amount of sludge that is very difficult to remove and also blocks carburetor jets, fuel lines, filters, etc. If lines are partially blocked, you can still run it with a light load. But when you turn on the A/C in the heat of the day, it's working much hard and drinking a lot more fuel. If it can't get enough fuel through blocked lines or filters, it will die.

[losone]

Originally Posted by Kingsmen55

My Onan Generator on my 2004 Sightseer Class A won't stay running.
Fuel pump and filter replaced two years ago. I only ran it for 24 hours since then. I start it often. any ideas? Thank you

I had the same problem and found out from a very old generator tech that it could be caused by engine oil level. The oil level sensor gets quirky. When you unscrew the oil check plug, check your engine oil level by putting it back but not screwing it in. The oil level should be about mid way. If not take some out if below add some but always keep the oil level mid way. I found that I had too much oil. I took some out and now my Gen set 4KW on my 2007 Sightseer runs perfect. Good Luck, Lee from Biloxi.

[nailbender]

Our generator would only run for a minute or two,and once for about a 1/2 hour, so figured it was bad gas from the coach, got all the same suggestions you're getting, I had to take it to the dealer for an unrelated issue so I asked if they would look at it. The mechanic found the ground wire was a little corroded, cleaned it up and the generator has run great ever since. Good Luck

[DryCreek]

Originally Posted by Morich

I recently had a new Lawnboy that would not restart after running a short time and took it in for warranty repair where the guy told me he drained and refilled the gas tank as it had water and the oil was foamy. But the true fix was only after i drained some oil and it runs fine now without foaming the oil!

I remember the old days when the Lawn Boys were all smoky and loud two-strokers!

[Morich]

Yes, I had one of those which had the aluminum body and it lasted 26 years but finally got tired of replacing the wheels and it was beginning to leak oil so we went with the new one which are actually made by Toro and use a different engine. Piece of junk but may last me as long as I need for this time. With the smoke it puts out on starting it might make a good mosquito repellent if not so noisy...

[NormD]

Holding the rocker switch down on the Shutdown side is supposed to activate the fuel pump, which might be a good way to check if you can get a good flow from the pump and filter into a container. I also found by accident that if held down for about ten seconds, the Onan's computer is apparently reset. The the red light on the switch turned on and the Error 32 code I was fussing with for several weeks immediately went away. The generator started and ran immediately when I pressed the Start side of the switch.


Does your fuel line pass close to any hot exhaust pipes? This has been a cause of vapor lock in fuel lines and seems to fit your high temperature/intermittent operation scenario.

[Topsail]

Kingsmen, I suggest you go right back to square one and forget that the pump and filter(s) were replaced two years ago.

I'd change them again. Also, does your system have two filters? Mine did exactly what you describe and after I changed the pump and filter by the pump, and then did away with the filter at the carburetor my problems were resolved.

I know this may sound like good money after bad. All the other suggestions are valid and I know you won't want to throw parts at this until you know for sure what's wrong. Sometimes the simple solution is the solution. The pump and filters are not expensive.

Good luck and let us know how you get your gen going.

[Topsail]

I'd like to add that the original filters for my gen were known to leak. After I replaced my pump with filter and hooked my fuel line back to the carb it turned a little and was leaking fuel. Major fire hazard!!!

It wasn't leaking before and if I turned it a little it would stop. These were done away with by Onan when they realized these were an issue. There is a straight piece that does away with the filter (on mine). Maybe yours is similar.

[Goodspike]

Originally Posted by Topsail

Kingsmen, I suggest you go right back to square one and forget that the pump and filter(s) were replaced two years ago.

I'd change them again. Also, does your system have two filters? .

Good thought on the possibility of two filters, but I'd start with just changing the filter(s). The chance of a filter clogging again on an older motorhome is much greater than the chance of a fuel pump going bad again.

And again, I would drain the carburetor bowls, assuming it has a carburetor. They could be full of water.

[Topsail]

Originally Posted by Goodspike

Good thought on the possibility of two filters, but I'd start with just changing the filter(s). The chance of a filter clogging again on an older motorhome is much greater than the chance of a fuel pump going bad again.

And again, I would drain the carburetor bowls, assuming it has a carburetor. They could be full of water.

Yes Goodspike on just the filters, but it looks like the OP is paying a tech so the first service charge would cover the replacements and hopefully eliminate a second charge.

I'd do it myself and check the flow from the pump. Really once the demand is reduced and the carberator bowl fills then the gen will run until the bowl runs down. Hitting the start switch fills the bowl and it runs adding confusion. Just my .02...

[Topsail]

I am curious if the tech used Onan genuine replacement parts. May not matter but just a thought.