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Topic: Onan Emerald Plus not running. (Read 1162 times) previous topic - next topic
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Onan Emerald Plus not running.
I'm sure this has been covered here ad nauseam.

My Emerald Plus wouldn't start the other day and had been running fine.
Now, it will only stay running with the starter pushed, as soon as I let it go, it stops.
Oil level is good and there is plenty of fuel.
It's had a fair amount of work over the years and has an updated board and some newer parts.

any help would be appreciated.

Jota
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #1 –
Sounds like the fuel  pump is failing, common in older rigs.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Onan Emerald Plus not running.
Reply #2 –
Quote from: Larry W  - 
Sounds like the fuel  pump is failing, common in older rigs.

Larry
It will run with the start switch kept in. I didn't want to keep it in long, but I did for at least 20 seconds.
I put a new fuel pump in it back in 2016 when I took it out of the RV and did a bunch of work to it.
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #3 –
Hi Jota; IIRC ( big if! ) there is a resistor to decrease spark while it is running, that is switched out to give it more spark (richer mixture) when starting. Could be burned out. I think it is a nichrome wire wrapped around a ceramic form. Our low tech old generators! RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Onan Emerald Plus not running.
Reply #4 –
A youtube video, "Daves RV Life",   found a chewed wire on the running circuit, that was bypassed while starting. As he stated the starter motor disengages and shuts off, but generator runs as long as the switch is held down. Lots of rodent damage this time of year. RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Onan Emerald Plus not running.
Reply #6 –
Back in 2016 I removed the generator from the coach to work on it.
It had been not working for about 2 years as I tried to figure it out.
I replaced the board, the fuel pump, starter and finally the voltage regulator.
It was the voltage regulator that was keeping it from working.
Now, it seems a bit different, and will look for chewed wires or other obvious things.
I will also look at the brushes, something that hasn't been replaced yet.
Thanks for the help.


PS, I travel with a buddy who has a Honda 2000 that I can use in the mean time.
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #7 –
Quote from: RonB link=m[quote author=RonB  - 
A YouTube, Daves RV Life, found a chewed wire on the running circuit, that was bypassed while starting. As he stated the starter motor disengages and shuts off, but the generator runs as long as the switch is held down.

Good to know, the newer Microquiet 4000 does not appear to use an ignition resistor, something that was common before electronic ignition became prevalent.

Larry

Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Onan Emerald Plus not running.
Reply #8 –
To add. This generator now has 2712 hours on it.
So it gets used regularly, when I bought it, it had 200 hours.
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #9 –
Jota,
I think,
Compression, probably OK, Runs for 20 seconds or so.
Ignition, sounds like this is OK, runs for 20 seconds or so
Fuel, Will it run from a one gallon gas can? Yes. Suction line to fuel tank: No, its the generator.

Now to the Flight systems Checklist.
I missed a monthly run, and the Carb was all varnished up the next time. float stuck open actually flooded out( wet black exhaust and in oil.
Rodney
1988 Mid Bath
Re: Onan Emerald Plus not running.
Reply #10 –
Update!

I pulled the brush block and the brushes look good. One a little more worn than the other.
I'm told that is normal.
Went to Flag Tool in Flagstaff to ask for assistance and maybe diagnosis.
The guy thought it was the voltage regulator and said he has a tool to check it.
So, I'm going to remove the regulator and have it checked.
If it is bad a new one is about $600.
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #11 –
Mine had the same symptoms as yours, it was the fuel pump.

Jon
1994 MB
Re: Onan Emerald Plus not running.
Reply #12 –
Final update.
Pulled voltage regulator and took it to shop for checking.
Voltage regulator was bad.
Could not find Onan replacement so looked at aftermarket ones.
Parts for Techs had an updated one that was a direct replacement for $370.
Got the replacement and installed it this morning.
Generator fired right up and is producing power again.

Glad to have it back in operation.

Jota
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #13 –
I’m having the same issue but with my Onan Microquiet 4000. Never thought of the voltage regulator. I may give that a shot cause God knows I’ve replaced most of the other parts over the past few years!
Joe B.
2008 26ft  grey/white Rear Bath
NE88 caravan club
Re: Onan Emerald Plus not running.
Reply #14 –
There is a good small engine repair facility in Flagstaff.
They have a tool from Onan that you plug the voltage regulator into.
It tests to see if it is working.
They did it for free for me, takes a few minutes.
I wanted to give them my business for the new regulator but they couldn't compete with
the place I bought it from online. I understand they needed to mark it up a bit, but adding an
addition fee of $20 on top of that and also having to charge sales tax made it about $100 more.
I live on a very low fixed income so the difference was enough to go online.

I try very hard to use and keep small businesses going when possible.

Maybe you can find a place that can check the regulator in your Microquiet to make sure.
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #15 –
Jota, we have a similar Situation with our generator, It is not producing voltage and may be the Voltage regulator also.  Where did you purchase the regulator online? I will have mine tested and may have to do the same.   Thanks

      Karen~Liam
         98 ~ MB
            NinA
1998 ~ MB  WanderDaze
previously a 1984 Winnebago itaska- The Road Warrior, before that several VW Buses and before that a 1965 Chrysler Convertible Newport or our 1969 Chrysler La Barron with an ice box and a couple sleeping bags
Re: Onan Emerald Plus not running.
Reply #16 –
There were two places that I found helpful.
First was Flight Systems, they had some You Tube videos that helped me diagnose the issue.
For my model, they wanted $390 for the regulator. They have a page for Onan generators that you look up
your model and spec number to get the parts you need, very helpful. Mine is a BGE and M spec.
Also is Parts for Techs, who had what seems to be the exact same regulator for $370.
The new regulator is an improved design, it now contains the round thing that sat on top of the original.
When installing, I had to remove the old one and tape off the wires to it.
Also, this one is repairable in the future if it fails.

Generator issues are very tricky.
Hope this helps.
Jota
96 23.5 FL
Re: Onan Emerald Plus not running.
Reply #17 –
Thanks, we don't use our gen a lot maybe a couple hours a year but at this time we want it working.

     Karen~Liam
        98 ~ MB
           NinA
1998 ~ MB  WanderDaze
previously a 1984 Winnebago itaska- The Road Warrior, before that several VW Buses and before that a 1965 Chrysler Convertible Newport or our 1969 Chrysler La Barron with an ice box and a couple sleeping bags
Re: Onan Emerald Plus not running.
Reply #18 –
Quote from: Jota  - 
Final update.
Pulled voltage regulator and took it to shop for checking.
Voltage regulator was bad.
Could not find Onan replacement so looked at aftermarket ones.
Parts for Techs had an updated one that was a direct replacement for $370.
Got the replacement and installed it this morning.
Generator fired right up and is producing power again.

Glad to have it back in operation.

Jota
If I remember correctly, there’s a web site called Flight Systems that sells all related Onan parts for a real reasonable price. I bought a voltage regulator there about ten years ago and was amazed how much money I saved.
Dale from Downey 27’ 2012 RB,”Casa Verde”, 2000 Jeep Wrangler. Formerly1991 RB & 1990 Jeep Wrangler.
 
Re: Onan Emerald Plus not running.
Reply #19 –
Here's the web address for Flight Systems.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"