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[GMCnet] Onan Troubles [message #55681] Fri, 04 September 2009 19:29 Go to next message
George Zhookoff is currently offline  George Zhookoff   United States
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Registered: December 2004
Location: Snellville, GA
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Well we're here at the Atlanta NASCAR track, infield Flock space 766. If you're here stop by.
I promised myself after the spring motorcycle race I'd work on the Onan. Oh well. It starts when cold runs 10-15 minutes under load. Then starts to hunt still the low end of the hunt is so low it shuts down.
So any advice while sitting here?
George Zhookoff
78 El II
Hampton, Ga
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Re: [GMCnet] Onan Troubles [message #55700 is a reply to message #55681] Fri, 04 September 2009 21:40 Go to previous messageGo to next message
klassic kampers is currently offline  klassic kampers   United States
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hard to fix not being there.............normally a gasoline engine tht runs well cold but then runs bad when warm is too rich(on fuel)..........if that's the case here, you can check the adjustment screw in the side of the float bowl to see if it has backed out which would fatten up the mixture......be sure the air filter is clean...........
...the other end of this is the engine could be starving for fuel with the situation being enough fuel can flow for 15 minutes and then a foreign substance( trash) begins to block the fuel supply.....to check for that situation you can slightly close the choke when the engine begins to hunt and if runs better then you are experiencing a fuel restriction.........unscrew the bottom of the fuel pump and check for junk.......if the fuel line from the tank or the actual fuel pick up in the tank is suspect you can hook up an auxillary tank( like off a lawn mower or motorboat) and run the onan.......this is just the possible engine problems and not an actual 120V generator diagnosis.......

good luck, mike stewart, greer.s.c.


Mike Stewart 1973 GMC 26' Canyonlands / 1973 B.S.A. B50 street tracker----- Greer,S.C/Ellijay,Ga
Re: [GMCnet] Onan Troubles [message #55710 is a reply to message #55681] Fri, 04 September 2009 23:25 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
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George, Great advice from Mike. If that does not work, slip over and plug into your neighbor.
Dan
wish I was there


3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer
Re: [GMCnet] Onan Troubles [message #55728 is a reply to message #55700] Sat, 05 September 2009 07:24 Go to previous messageGo to next message
mike miller   United States
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klassic kampers wrote on Fri, 04 September 2009 19:40

... you can check the adjustment screw in the side of the float bowl to see if it has backed out which would fatten up the mixture ...
I had one that would "adjust" itself with the vibrations. (6k in the '73) I was always having to readjust it. I replaced the o-ring on the needle like adjusting screw. Now it stays adjusted.


Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo' http://m000035.blogspot.com
Re: [GMCnet] Onan Troubles [message #55733 is a reply to message #55681] Sat, 05 September 2009 07:51 Go to previous messageGo to next message
Larry is currently offline  Larry   United States
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I had much the same problem and cured it by loosening the gas cap. The valve in the wheel well was plugged tight and the gas cap was bad not letting any air in to replace the gas being used. The fuel pump on the Onan was not strong enough to pump against the vacuum created by the gas being burned by the Onan. When the fuel pump couldn't pump against the vacuum, it eventually starved itself out. Take a close look at your tank venting system,,,might be there. JWID

Larry Smile
78 Royale w/500 Caddy
Menomonie, WI.
Re: [GMCnet] Onan Troubles [message #55752 is a reply to message #55728] Sat, 05 September 2009 10:24 Go to previous messageGo to next message
emerystora is currently offline  emerystora   United States
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Registered: January 2004
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On Sep 5, 2009, at 6:24 AM, Mike Miller wrote:

>
>
> klassic kampers wrote on Fri, 04 September 2009 19:40
>> ... you can check the adjustment screw in the side of the float
>> bowl to see if it has backed out which would fatten up the
>> mixture ...
> I had one that would "adjust" itself with the vibrations. (6k in the
> '73) I was always having to readjust it. I replaced the o-ring on
> the needle like adjusting screw. Now it stays adjusted.
> --
> Mike Miller
> `73 26' X Painted D.
> `78 23' Birchaven
> Hillsboro, OR


The original O ring on that high speed jet in the carb bowl was a
square shouldered one. I found many years ago that a 1/4" OD x 1/8"
ID regular O ring would work fine.
I carry a package of them in my GMC and have used them on many peoples
Onans when I have helped them tune up their Onans.
I is very common for the original one to crack and allow air to lean
out the mixture too much. It them becomes impossible to get the Onan
to run properly.

Emery Stora
77 Kingsley
Santa Fe, NM


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Re: [GMCnet] Onan Troubles [message #55756 is a reply to message #55681] Sat, 05 September 2009 12:07 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
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George, I will be looking for you tonight and tomorrow night on ESPN.
Dan


3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer
Re: [GMCnet] Onan Troubles [message #55757 is a reply to message #55681] Sat, 05 September 2009 12:23 Go to previous messageGo to next message
George Zhookoff is currently offline  George Zhookoff   United States
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Registered: December 2004
Location: Snellville, GA
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We"re betweeen turns 3&4. Surrounded by GIANT SOBs.
George


----- Original Message -----
From: gmclist-bounces@temp.gmcnet.org <gmclist-bounces@temp.gmcnet.org>
To: gmclist@temp.gmcnet.org <gmclist@temp.gmcnet.org>
Sent: Sat Sep 05 13:07:05 2009
Subject: Re: [GMCnet] Onan Troubles



George, I will be looking for you tonight and tomorrow night on ESPN.
Dan
--
Dan & Teri Gregg

danandteri.blogspot.com



///Halon Automatic Fire Extinguishers
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[GMCnet] Onan Troubles [message #60959 is a reply to message #55681] Wed, 21 October 2009 12:52 Go to previous message
George Zhookoff is currently offline  George Zhookoff   United States
Messages: 398
Registered: December 2004
Location: Snellville, GA
Karma: 6
Senior Member
Subject: Onan Troubles Labor Day Weekend

Well we're here at the Atlanta NASCAR track, infield Flock space 766. If you're here stop by.
I promised myself after the spring motorcycle race I'd work on the Onan. Oh well. It starts when cold runs 10-15 minutes under load. Then starts to hunt still the low end of the hunt is so low it shuts down.
So any advice while sitting here?
George Zhookoff
78 El II
Hampton, Ga


UPDATE:
New air filter, oil change & filter, new plugs, new mounts, pulled heads and blasted them. Bought EZ Kill a Watt and installed.

Read and acted upon Emery's advice.

"The original O ring on that high speed jet in the carb bowl was a
square shouldered one. I found many years ago that a 1/4" OD x 1/8"
ID regular O ring would work fine.
<<>>

Emery Stora
77 Kingsley
Santa Fe, NM

Watched the Mr. Onan DVD several times.

Cranked it up volts +/- 131. Adjusted carb to where it runs smooth. Then adjusted volts to 125 +/- a touch.

New o ring replaced cut and damaged older ring.
It all works like a champ now. I'm looking for more AC appliances to plug in to task the output. Right now 2 ACs, Microwave, PD, and coffee pot have little impact on the output.

Thanks to all that responded to my email question.


George Zhookoff, PMP
78 EL II
Snellville, GA


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