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Onan 4000 onboard Generator
#1
I had it rebuilt at the Cummins Onan facility.  I called them about my issue, they were not much help.  Now, when I run my generator it blows smoke, looks like it is ready to blow up, and exhaust is so bad I turn it off.

Onan suggested I let it run.  I don't have a place to let it run and try their theory of it will get better.  

Question:  Anyone else have an issue like or similar to this?
                What did you do about it?
CoPilots: Cleo & Joe
2000 Tioga 27' Class C
450 Ford Chassis
V-10 Triton
Onan 4000 on-board gas genny

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#2
the first thing to check is the oil and see if it is high

is it black smoke that smells like gas or blue smoke that smells like oil?
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#3
(08-23-2018, 05:48 PM)Gary Wrote: the first thing to check is the oil and see if it is high

is it black smoke that smells like gas or blue smoke that smells like oil?

White and smells like its going to blow.  Will crank her up tomorrow and check for more refined details.
CoPilots: Cleo & Joe
2000 Tioga 27' Class C
450 Ford Chassis
V-10 Triton
Onan 4000 on-board gas genny

[-] The following 1 user says Thank You to RoamingRaven for this post:
  • American Nomad Patriot (08-25-2018)
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#4
Something to read about smoke from a diesel engine.

https://dogandlemon.com/articles/ownersh...-diagnosis
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[-] The following 1 user says Thank You to Motrukdriver for this post:
  • American Nomad Patriot (08-25-2018)
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#5
Gas or diesel generator?
[-] The following 1 user says Thank You to ratfink56 for this post:
  • American Nomad Patriot (08-25-2018)
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#6
Most Onans of that size should be gas. Theres a few propane but for RVers, mostly gas...

On an Onan repair forum, I found a customer who said his was blowing white smoke, so he shut it off. He had a carb rebuild done...

Here’s the tech answer:

“The new carb will come preset from the factory, and will not need to be adjusted.

But I did just have a thought - the carb may have still had some preservative in it that will take 10-20 minutes to burn out.

Otherwise, if it is oil that is burning, you could have a bad valve stem seal or valve guide.

Let the engine run with a load for 10-15 minutes.
If it is still smoking after this long, shut it down and let it completely cool.
Pull the spark plugs and note the color.
If they are black, it may well be burning oil.”
End of quote
They say when you get older two things happen, one is you lose your memory and the other, I forget.

Organized people are simply too lazy to search for stuff.
[-] The following 2 users say Thank You to TWIH for this post:
  • RoamingRaven (08-25-2018), American Nomad Patriot (08-25-2018)
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#7
(08-24-2018, 04:21 AM)ratfink56 Wrote: Gas or diesel generator?

Gas.  

Getting the hang of what to add to the signature.  My genny infor is a good add.  Yesterday it rained all day and today I'm pulling the ark out of the shed.  Its still raining.
CoPilots: Cleo & Joe
2000 Tioga 27' Class C
450 Ford Chassis
V-10 Triton
Onan 4000 on-board gas genny

[-] The following 1 user says Thank You to RoamingRaven for this post:
  • American Nomad Patriot (08-25-2018)
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#8
Black smoke on startup with smell of oil is usually piston rings. Black smoke all the time is related to valves. White smoke all the time...Head gasket. From the information you gave here thats my best guesstimation.
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#9
When you say rebuilt, what did they do exactly? Was this a tune-up, a carb rebuild, or a complete tear-down and rebuild of the engine and the generator head?

What did they rebuild it for? Same problem or something else?

What was it doing or not doing when you brought it in?

Note to ANP: These aren't water cooled so a head gasket issue is unlikely to cause white smoke. 

I'm thinking it was overfilled with oil, but we really need more info.

If they re-bored the cylinder and she is getting continuous blueish-white or black smoke that continues for a half hour or more, we have something going on with the boring process, the rings, or maybe the valves. 

So we kinda need a few more bits of information.
Wondering about Wandering.
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#10
Agree with above...
They say when you get older two things happen, one is you lose your memory and the other, I forget.

Organized people are simply too lazy to search for stuff.
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