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Talley

Onan Microquiet Won't Stay Running

11 posts in this topic

I have an Onan Microquiet 4K genny that will not stay running. The tank is full, I have verified fuel in the fuel line and the bowl is full of fuel. I replaced the carb thinking it was gummed up and the genny will still not stay running. I have "jumped" the positive side of the fuel pump and get a clicking sound but I never hear the clicking sound when it is plugged in normally, even when I hold the button on "stop" which should prime it. What is wrong with this thing? When it runs it runs smoothly and generates power to run the motor home but it will only run for 5 minutes or so then stops and re-starting takes many tries. Any ideas are much appreciated.

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Will it start when it is cold and only hard to start after it runs for 5 minutes and stops? If yes, and you let it cool down will it start easy again?

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Have you verified that it is not shutting down due to low oil level or oil pressure?

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Tally, first post mentions you have a 1997 model year coach. The information I have mentions Microprocessor Control with Diagnostics.

With the owners manual there should be tests that you could run and get information like fault codes from the processor.

I will look and see if I can find a manual on line that I can read in the meantime.

Manual link. http://www.cumminson...s/981-0159D.pdf

Check section #4 trouble shooting, reading fault codes.

Oil pressure was mentioned and heat could be an issue that would shut down the unit.

There are others issues like the line voltage and frequency that cause a microprocessor to shut down the unit to protect your 110 volt equipment.

Also check the Ground cable between the generator and the Chassis.

I also see you had a battery issue, with one exploding . Not good !!! Wash things down with water and then mix up some baking soda and water,about 1 tablespoon to 8 to 10 oz. of water is a good mix.

Use ti ti wash down the area may need more then one glass of the mix.

Make SURE the battery caps are on, it can be a little like a volcano if the two mix in large quantities !!

Did the battery fail after the generator issue? ( after it shut down,, after running for 5 min. or so ??)

Rich.

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Thanks all. Rich, I have not seen any control board with any blinking lights. Where would that be located? This genny does not have an oil filter (splash lubircation) so don't think oil pressure is even measured.

I have changed the oil and it is full.

Battery issue (blowing up) happened after the problems with the genny and don't think it is related as the genny had not been run for over a week when it happened..

It never starts easy either hot or cold.

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If it has repeated the 5+/- minute shut down several times, it may be related to the automatic choke system. If it is stuck (mechanically or electrcially) partially closed could make it hard to start, allow it to run fine and then shut down when it warms up and it would be hard to restart because it would have choked down. If the engine slows a little before it dies that would fit. If it dies like you hit the kill switch, maybe not.

BH

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Tally ! When you got the new carburetor,you needed engine information. Could you post that info. so we can look to see if an engine manual can be located.

You mentioned smelling fuel ,installed a new carb. and the unit starts hard. Will run for 5 plus min. then shuts down. Got to have spark, because it runs well after it starts.

The hard starting sounds like a fuel problem and you have replaced the carburetor. That leaves the fuel delivery system. Fuel line and pump.

When you start the unit from outside using the switch under the access panel, do you see the LED light they mention in the manual? It should blink.

My old Onan Generator had a mechanical governor link to control the engine speed,this was prior to the computer systems on the newer units.

I need to find some more information about the engine, as it should have a fuel pump and fuel filter in the line somewhere. Also wondering if you may have a bad fuel line,that has a small pin hole(s) that is allowing air into the fuel supply line. This would starve the unit for fuel under load.

It wants to run, we are just missing a piece of the puzzle.

Think I found the manual for your model generator. Try this link.

http://www.0y7.net/g...y1QYXJ0cy5wZGY=

It mentions fuel pump and electrical troubleshooting info. on page 11.

Rich.

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Thanks Rich but that is not the genny either. I am wondering if I have some weird version or if something is missing as I do not see any LED light near the Start/Stop switch.

Model is 4KYFA26100E and S/N is F963541420

Next time I am out at the ranch I will bypass the fuel filter and run directly to the carb to at least eliminate one question. Note that I did replace the spark plug and have verified it is getting spark. Also, it is a mechanical control or governer link...definitely not electrically controlled.

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Its a Model KY spec E. I was able to locate the manual number for a spec E thru Quickserve. These appear to be the same but available thru the public site. See if they look like the right manuals.

Owner manual link: http://www.cumminson...ls/981-0155.pdf

Service manual link: http://www.cumminson...ls/981-0503.pdf

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The service manual is it! Thanks. I could not find this on Onan's website??? The owner's manual appears to be a bit different variant but is close.

Thanks for all the help.

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Tally. sounds like you got one of the first models made in Canada when Linamar took over Onan.

Glad you found some useful information.

Rich.

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