# onan generator problems



## doodle (Feb 20, 2006)

Hi there 

I have an Onan Emerald 5000 generator supplying 240v to my RV. 

On the plate it states its rated as 120v and 4.8kv. 

Model No.5BGEFA26100P Serial No. B000067151 

The problem is that over a period of about two months the output of the unit has started to drop off to a point that it will only run approx 2kw of load after which the engine begins to falter and then dies. It will restart with all loads removed but once the load is put on again or increased it dies. It will run small loads but no where near its previous capacity.I have checked all serviceable items, plugs filters etc and all seems to be in order. It runs on LPG and it seems that no adjustments can be made, the tank and regulator are virtually new (less than a year old). 
Any help would be much appreciated.


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## 107088 (Sep 18, 2007)

the only suggestiion I can offer is to check the oil. I have no idea what else to do, but whenever mines being obstropppoluous, I check the oil, and it seems to placate the genney fairies.


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## b16duv (Feb 14, 2006)

Try http://www.cumminsonan.com/rv/support/faq/ to see if they have any suggestions.


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## loddy (Feb 12, 2007)

How many hours on the clock?, if its high the engine could be down on power hence struggling to spin the jenny under load.

Loddy


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## doodle (Feb 20, 2006)

*onan genny*

Hi there

thanks for taking the time to reply.

Oil level checked and ok was a little low but still on the stick........genny fairies moved onto far costlier items!

Checked Cummins website........no joy but have now emailed them.

Engine is well shall we say used at more than 1000hrs+ hmmm might be time for a rebuild!

Thanks again


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## 123243 (May 7, 2009)

*Onan*

Hi
Not quite sure of the type of speed governor the Onan you have uses. Some governors are mechanical and operate the throttle directly, others are electronic and use an actuator to operate the throttle.

Generators are required to run at a constant speed in order to produce the desired output frequency. For example it may need to rotate at 3000 RPM to get 50Hz operating frequency.

The governor senses the speed and increases or reduces fuel flow to maintain that constant speed. When the generator come on load, the amount of horsepower required increases, this results in the engine speed dropping momentarily until the governor senses this and increases the fuel flow. When the load drops off the reverse happens, and the governor will reduce fuel flow.

If you are unable to put the full rated load onto the generator without it stalling, then it will be a governor or fuel problem. I would check that the governor travel is not limited by dirt or rust. Also check the fuel filter is clean and fuel is free to flow to the pump in adequate quantity.

Hope this helps
Joe


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## firewood (Mar 17, 2009)

hi i have come across this b4 and the cure for the one i worked on was it was reving to low .
check with a volt meter to get the correct revs and output
also i do have some parts for onan gens


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## pippin (Nov 15, 2007)

Totally off ball, but I think the answer lies in the unfortunate name of the generator - ONAN.

Look it up in the dictionary or in the Bible, Genesis Ch 38 Verse 9.


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## Ozzyjohn (Sep 3, 2007)

Pippin,

:lol: 

Though I did have to use a dictionary 

Regards,
John


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