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Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits


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  #1  
Old 09-10-2017, 11:08:29 AM
mfergu7392 mfergu7392 is offline
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Default Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

Model 4KYFA-6747P / Serial number B160921647
email address is markatpinnacle@gmail.com

Unit has 60 hours on it - last time it ran was in Sept 2016 - went out in June 2017 and did an oil change on the unit - tried to start and it would not start.

I read about using Gumout Carb Cleaner to see if that would help. I took off the air filter and sprayed the cleaner into the carb. The unit would try to start and would start just because the cleaner was in there and quickly died.

I then took off the fuel hose to the carb and hit the prime and saw that it pushed fuel through the line (I assume that means that the fuel pump works?)

I put Sea Foam (a 1/3 of a bottle) into a gallon of gas. I took off the fuel line before it goes into the fuel pump and replaced that line with a fuel line that went directly into the gallon of gas. I drained the carb of gas in it and ran the prime for a while to ensure that the only fuel that was in the line was the gas with the Sea Foam.

I then replaced the spark plug with a new one.

I put back on the fuel hose to the carb and primed the unit. The unit will start but will die in 5 seconds.

I have attached a video of what is happening in this link...

https://www.dropbox.com/s/apk71b3rbj...14618.mp4?dl=0

Not sure what is going on. This is a pretty new unit - so, I hope that there is not something that is expensive wrong. Oh, also the unit gives the 3 blinks of the light after I try to start - meaning that it needs service.

Any ideas would be greatly appreciated.

Thanks

Mark
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Old 09-10-2017, 12:59:45 PM
len k len k is offline
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Default Re: Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

Your gen is spec P, made Fed of 2016

Typical for ethanol in gasoline to plug up carb from sitting more than ~ 30 days without stabilizer in gasoline. I'ld pull and clean carb. Don't remember if this one has riveted carb. Looks like it has fuel cut off solenoid on carb,

My 7NHM will run for ~ 10-15 sec with pump off, just on gas left in carb bowel.

3 blinks is telling you the computer has issued an error code. Manual tells how to get it to spit out the rest of code and interpret it. Codes are in back of service manual

Manual number and link to it
ky---SERVICE--(1-06)--( J - )--981-0530C.pdf
http://www.twinslan.net/~n0nas/manuals/onan/

Link has been down past few days, server issues. They are working on getting it back up. Might get manuals here
https://www.smokstak.com/forum/showthread.php?t=155507

Last edited by len k; 09-10-2017 at 01:29:13 PM.
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Old 09-10-2017, 01:26:57 PM
KPack KPack is offline
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Default Re: Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

Should be under warranty use it.
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Old 09-10-2017, 01:42:37 PM
mfergu7392 mfergu7392 is offline
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Default Re: Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

Len K - thanks for your quick response. I will definately go out and check the fault codes - I was able to get the manual based on your help - that is awesome.

one question - i was looking on youtube and they said that cleaning the carb is problematic and they suggest replacing the carb. I would like to try cleaning the carb as you have suggested - can you provide me with some info on how to do that?

Thanks so much

Mark
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Old 09-10-2017, 02:43:01 PM
mfergu7392 mfergu7392 is offline
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Default Re: Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

Thanks, KPack

I will definitely look into that

Mark
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Old 09-10-2017, 03:36:45 PM
KPack KPack is offline
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Default Re: Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

I don't know what they'll say on warranty if you work on it. If you take the carb off make a mark on the pointer and count the turns on the main jet so you'll know where you started when adjusting. If you pull the bowl off the carb there's a small washer on the inside that will drop and you'll lose it if you don't know it's there. I would take it in stuff is easy to break on the carb and choke lever.
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Old 09-10-2017, 03:55:38 PM
len k len k is offline
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Default Re: Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

On the old carbs ( other engines) you just take carb off and take bolt off bottom of bowl and it comes apart. Then have to unscrew a few parts to get jets out, disassemble the main jet on bottom of bowl to clean it. Blow passageways out with compressed air.

Seems yours has a fuel solenoid on bowel bottom , I've never worked on those .Some people say they are riveted on or have to break them off, might not be able to reassemble. I'ld either look it over well and be very carefull or wait for advice from others first.
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Old 09-10-2017, 07:41:16 PM
KPack KPack is offline
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Default Re: Onan generator - 4000 - model 4KYFA-6747P - starts but immediately quits

Takes a thin wrench between the solenoid and the bowl. You have to undo the wires to the solenoid it's a lot easier with the carb off with the carb on your going to say some bad words to get the bowl off.
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