| Onan Exhaust Smell [message #301367] |
Wed, 01 June 2016 12:31  |
Dan
Messages: 99
Registered: August 2014
Location: Allentown, NJ
Karma: 0
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We do not use the onan often, but I do try to keep it running. Today my wife, baby and dogs hung out in the GMC while the house was being appraised. She ran the generator and the AC. No problems there they ran fine, but the smell was starting to get into the coach even with the AC pumping air into the thing. She ran it for about 40 minutes. I've noticed that the smell is pretty horrendous outside the GMC, to the point where I do not really run the thing if Im tailgating for fear of gassing everyone hanging around. The onan seems to run well with no smoke. Any suggestions.
Dan
Dan DeLuca
1978 Eleganza II (http://imgur.com/gallery/YFHhK)
Parked at Evil Monkey Farm in
Allentown, New Jersey
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| Re: Onan Exhaust Smell [message #301371 is a reply to message #301367] |
Wed, 01 June 2016 14:03  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Never run the Onan with the left rear open.
1. Pull the Onan plugs and see what they look like. Are you running rich?
2. Find out how the fumes are getting into the coach. Do you have a leaking window?
3. Build an exhaust extension to force the exhaust farther away from the coach.
4. If you really want to get carried away, make a vertical exhaust extension that carries the exhaust up the left rear corner of the coach.
You might also look over the exhaust system before and muffler for leaks but I think you would hear any leaks there.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Onan Exhaust Smell [message #301395 is a reply to message #301367] |
Wed, 01 June 2016 19:31 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
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Propane. Read here
http://gmcws.org/blog/?p=3659
On Wednesday, June 1, 2016, Daniel DeLuca wrote:
> We do not use the onan often, but I do try to keep it running. Today my
> wife, baby and dogs hung out in the GMC while the house was being appraised.
> She ran the generator and the AC. No problems there they ran fine, but
> the smell was starting to get into the coach even with the AC pumping air
> into
> the thing. She ran it for about 40 minutes. I've noticed that the smell
> is pretty horrendous outside the GMC, to the point where I do not really
> run the thing if Im tailgating for fear of gassing everyone hanging
> around. The onan seems to run well with no smoke. Any suggestions.
>
> Dan
>
> --
> Dan DeLuca
> 1978 Eleganza II (http://imgur.com/gallery/YFHhK)
> Parked at Evil Monkey Farm in
> Allentown, New Jersey
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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| Re: Onan Exhaust Smell [message #301398 is a reply to message #301367] |
Wed, 01 June 2016 20:01 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Probably just a minor carb adjustment. Is the choke opening fully? May need to be set slightly leaner on mixture. Also roof air does not pump in fresh air. Just recirculates the fumes that are getting in.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan Exhaust Smell [message #301399 is a reply to message #301367] |
Wed, 01 June 2016 20:04 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Also air filter could be clogged. They pick up a lot of road dirt back there.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan Exhaust Smell [message #301401 is a reply to message #301367] |
Wed, 01 June 2016 20:58 |
Dan
Messages: 99
Registered: August 2014
Location: Allentown, NJ
Karma: 0
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Which adjustment screw would I use to lean the mixture?
Dan
Dan DeLuca
1978 Eleganza II (http://imgur.com/gallery/YFHhK)
Parked at Evil Monkey Farm in
Allentown, New Jersey
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| Re: [GMCnet] Onan Exhaust Smell [message #301405 is a reply to message #301401] |
Wed, 01 June 2016 21:15 |
Jim Miller
Messages: 501
Registered: March 2008
Karma: 10
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On Jun 1, 2016, at 9:58 PM, Daniel DeLuca wrote:
> Which adjustment screw would I use to lean the mixture?
The one on the bottom of the bowl. Its in the service manual. Be careful about leaning too much - its hard on the engine. Typical approach is to put it under load, take it too rich to the point that it starts to stumble…then lean it only enough for it to run smoothly. By all means follow the other suggestions about air filter and choke functionality before adjusting fuel delivery.
A gen-turi is a good idea for long-term stationary use…as in N9KB’s suggestion #4. I went a little further and fab’d up a genturi that can stay in place while in motion - it uses the trailer hitch receiver to support the vertical pipe..
Without a doubt the Onans have a smell even when they are running correctly…best approach is to work on a way to get the exhaust away from the vehicle rather than fiddle with engine controls which probably won’t make a lot of difference.
Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH
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Jim Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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| Re: Onan Exhaust Smell [message #301409 is a reply to message #301367] |
Wed, 01 June 2016 22:43 |
Darryl
Messages: 144
Registered: December 2011
Location: Northern California
Karma: 0
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I had the same problem. Complaints about the smell, not the noise. I finally used Johnny Bridges' model of a genturri to build my version of the solution. Nowhere near as elegant as Johnny's but it works, most of the time. My version is still a work in process but unless it falls apart ( which it has) it gets the exhaust up to the top of the coach where it doesn't seem to bother anyone.
Find it on the photo pages
Darryl Meyers
1978 Eleganza II
El Dorado Hills, CA
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| Re: [GMCnet] Onan Exhaust Smell [message #301417 is a reply to message #301409] |
Wed, 01 June 2016 23:50 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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The smell comes from the fact that the Onan has a very weak ignition system.
We came up with a MSD Ignition system that makes it ignite considerably
cleaner.
MSD gets it's reputation from firing twice every firing cycle. My
understanding is that the first one fires at regular time and 20 degrees
later another ignition, so if the first one did not ignite, the second one
will.
Yes, it is lot more powerful than the original.
One can play with the carb all day, but the smell will be there.
Go to our web site under ONAN.
On Wed, Jun 1, 2016 at 8:43 PM, Darryl Meyers wrote:
> I had the same problem. Complaints about the smell, not the noise. I
> finally used Johnny Bridges' model of a genturri to build my version of the
> solution. Nowhere near as elegant as Johnny's but it works, most of the
> time. My version is still a work in process but unless it falls apart (
> which it has) it gets the exhaust up to the top of the coach where it
> doesn't seem to bother anyone.
>
> Find it on the photo pages
> --
> Darryl Meyers
>
> 1978 Eleganza II
>
> El Dorado Hills, CA
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: Onan Exhaust Smell [message #301422 is a reply to message #301367] |
Thu, 02 June 2016 00:21 |
Adrien G.
Messages: 474
Registered: May 2008
Location: Burns Flat, OK 73624
Karma: 1
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Senior Member |
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Dan, Check to see how well the gen enclosure box is sealed to the body and floor.
On mine, some of the rivets where not holding anything, and the rubber gasket had long turned to dust.
It's air tight now.
But also do what other have put forth.
Adrien & Jenny Genesoto
75 Glenbrook (26-3) Mods LS3.70 FD / Reaction Sys / 80mm Front&Intermidiate / Hydroboost / 16" Tires / Frame Rebuild / Interior Rebuild
Yuba City,Ca. Text 530-nine-3-three-3-nine-nine-6
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