Home » Public Forums » GMCnet » Major Gas Leak at Onan, Help Me Stop It
| Major Gas Leak at Onan, Help Me Stop It [message #105697] |
Thu, 11 November 2010 14:32  |
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WD0AFQ
Messages: 7111
Registered: November 2004
Location: Dexter, Mo.
Karma: 207
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Senior Member |
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Onan fired then stopped. I went around and gas draining out of carb air entry. I can not stop it. Finally took gas line off the fuel pump and plugged it. How is the gas draining up thru a fuel pump that is turned off? I got a real mess here.
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
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| Re: Major Gas Leak at Onan, Help Me Stop It [message #105699 is a reply to message #105697] |
Thu, 11 November 2010 14:38  |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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| WD0AFQ wrote on Thu, 11 November 2010 12:32 |
Onan fired then stopped. I went around and gas draining out of carb air entry. I can not stop it. Finally took gas line off the fuel pump and plugged it. How is the gas draining up thru a fuel pump that is turned off? I got a real mess here.
Dan
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With the Onan not running, I would think you would have heard the pump clicking. We no gas does not run up hill... unless, you had pressure in your tanks at the time and it was enough to lift as high as the Onan carburator.
For sure, your needle valve or float is bad in the carburator. Usually, we rap on those, back in the day, to try to get the needle to seat.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105702 is a reply to message #105700] |
Thu, 11 November 2010 14:44 |
Sandra Price
Messages: 709
Registered: May 2006
Karma: 1
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Hey Dan and others, if the needle and seat has a rubber end on the needle,
the alcohol may have damaged the rubber...
Bob Price
On Thu, Nov 11, 2010 at 2:39 PM, Kosier <gkosier@roadrunner.com> wrote:
> It almost has to be the float has sunk or the needle is not
> seating, cause that should stop any flow.
>
> Gary Kosier
> 77EII & 77PB
> Newark, Ohio
>
> ----- Original Message -----
> From: "Dan Gregg" <gregg_dan@hotmail.com>
> To: <gmclist@temp.gmcnet.org>
> Sent: Thursday, November 11, 2010 3:32 PM
> Subject: [GMCnet] Major Gas Leak at Onan, Help Me Stop It
>
>
> >
> >
> > Onan fired then stopped. I went around and gas draining out of
> > carb air entry. I can not stop it. Finally took gas line off
> > the fuel pump and plugged it. How is the gas draining up thru a
> > fuel pump that is turned off? I got a real mess here.
> > Dan
> > --
> > Dan & Teri Gregg
> >
> > http://danandteri.blogspot.com/
> >
> >
> >
> >
> > _______________________________________________
> > GMCnet mailing list
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--
IN GOD WE TRUST!
Sandra and Bob in the 52nd Year of our State of Marriage
“Life’s a Trip” in “The Roadhouse”
’73 Painted Desert
Huntsville, TX
Finally, all of you, live in harmony with one another, be sympathetic, love
as brothers, be compassionate and humble. Do not repay evil with evil or
insult with insult, but with blessing, because to this you were called so
that you may inherit a blessing. --1 Peter 3:8-9
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105709 is a reply to message #105703] |
Thu, 11 November 2010 16:24 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| WD0AFQ wrote on Thu, 11 November 2010 16:22 |
Ok, I just did not think the gas would flow thru the elec pump when it is off. My first thought was the float in carb also. So, gas will flow through the pump? I had Teri take cap off the fill up and it still flowed. It is a steady flow but not like when the pump is pumping, maybe 1/8th that size flow. I am glad it did it in my driveway and not on the road. I am thinking tomorrow the carb will come off. The Onan is higher than the dang tanks, that made me figure there must be pressure in the tank. I have both tanks full of fuel.
Thanks,
Dan, who is glad Teri handed me a spark plug to stick in hose and clamp tight.
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Dan,
Those of us that are very familiar with Bendix "Clicker" pumps can tell you that they are little impediment to flow in the flow direction. This is why Onan included a solenoid valve to stop the fuel flow as a standard part.
For the case you have here, there must be two (2 - dos) failures.
The first is the needle and seat must have a problem. That had better get fixed soon.
Next is that you must have too much pressure building up in your fuel tank(s). This means that the silly little vent valve in the left rear wheel well isn't working. Either get it repaired or switch off to a vented fuel cap. And, don't pull out the golf tee until you do.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105718 is a reply to message #105713] |
Thu, 11 November 2010 17:22 |
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ljdavick
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
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Senior Member |
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Dan,
Will you be changing all of your soft lines when you install the in-tank fuel pumps?
Larry Davick
Fremont, California
The Mystery Machine
'76 (ish) Palm Beach
----- Original Message -----
From: "Dan Gregg" <gregg_dan@hotmail.com>
To: gmclist@temp.gmcnet.org
Sent: Thursday, November 11, 2010 2:58:09 PM
Subject: Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It
Wow, thanks Matt. I know exactly why my venting is not working...
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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105732 is a reply to message #105709] |
Thu, 11 November 2010 19:41 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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| mcolie wrote on Thu, 11 November 2010 14:24 |
| WD0AFQ wrote on Thu, 11 November 2010 16:22 |
Ok, I just did not think the gas would flow thru the elec pump when it is off. ...
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...
Those of us that are very familiar with Bendix "Clicker" pumps can tell you that they are little impediment to flow in the flow direction. This is why Onan included a solenoid valve to stop the fuel flow as a standard part.
...
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The solenoid valve is the valve that many say "Isn't needed in our application." (Even I have said it.) BUT it was installed there for this very reason. It is for both safety and emission concerns.
Many have removed it. (One of three of mine has been removed.) It does take several different conditions to be met before there is a problem... but as we see here, it CAN happen.
Something to think about.
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
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105737 is a reply to message #105703] |
Thu, 11 November 2010 20:20 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Dan,
Disclaimer: this is a SWAG!
I'm wondering if both tanks are FULL it is possible that the vent lines to
the float valve in the wheel well are FULL, the vent line up to the filler
neck is FULL, and the fill line is also FULL. This would mean that the tanks
were NOT vented. The gas will cool overnight and I would suggest you wander
outside as soon as you get out of your jammies and take the spark plug out
of the fuel line to the Onan. If nothing comes out I'd say you answered your
question the cold night caused the gas to "contract" and so no fuel flow. If
fuel flows . . . . hmmm?
Regards,
Rob M.
USAussie
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Dan Gregg
Sent: Thursday, November 11, 2010 3:23 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It
Ok, I just did not think the gas would flow thru the elec pump when it is
off. My first thought was the float in carb also. So, gas will flow through
the pump? I had Teri take cap off the fill up and it still flowed. It is a
steady flow but not like when the pump is pumping, maybe 1/8th that size
flow. I am glad it did it in my driveway and not on the road. I am thinking
tomorrow the carb will come off. The Onan is higher than the dang tanks,
that made me figure there must be pressure in the tank. I have both tanks
full of fuel.
Thanks,
Dan, who is glad Teri handed me a spark plug to stick in hose and clamp
tight.
--
Dan & Teri Gregg
http://danandteri.blogspot.com/
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_______________________________________________
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105743 is a reply to message #105713] |
Thu, 11 November 2010 21:39 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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| WD0AFQ wrote on Thu, 11 November 2010 17:58 |
Wow, thanks Matt. I know exactly why my venting is not working. I will have that fixed in the morning. I pulled the carb and cleaned it good. Sprayed both jets with cleaner and screwed them back in where they were. Washed the gas off the concrete, hit my prime button. Fired and ran better than it has been running. Ran the a/c for a while then killed the thing. No gas. So, thanks to all. I have to believe the float was stuck. I had beat the fire out of it before I came in to ask for help but no luck. Teri gave me a spark plug and I plugged the line. I need a new rubber hose to the filter now. Mine is eaten up with gasoline. Guess I had been having a problem and did not know it. I will fix the vent line first thing in morning. Too tired now, I been polishing on the beast.
Dan
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Dan: You need to pull the onan oil dipstick and see if it is overfull and smells like gas. If it was running out the air filter it could fill the cyl and into the crankcase. You might need to change the oil and filter??
C. Boyd
76 Crestmont
East Tennessee
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105745 is a reply to message #105744] |
Thu, 11 November 2010 22:22 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| WD0AFQ wrote on Thu, 11 November 2010 23:05 |
Thanks Chuck, that is my plan for in the morning. Do you recall how many qts of oil for the 6k Onan?
Dan
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nope.. sorry, I got a 34 year old Generac. It has a side tank reservoir that I keep full. I think it is a total loss system?
C. Boyd
76 Crestmont
East Tennessee
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| Re: [GMCnet] Major Gas Leak at Onan, Help Me Stop It [message #105748 is a reply to message #105733] |
Fri, 12 November 2010 00:42 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Dan,
I'm just now reading this after the fact. There is no reason for gas to be running up hill. You had to have some pressure in the tank system. That electric fuel pump is the same one used on my airplane as a boost pump. It is there just in case the mechanical one quits. The engine is normally run with the electric pump off and gasoline runs right through it.
The normal procedure is to turn it on before starting the engine and read the gas line pressure. Then shut it off and start the engine. Leave it off during taxi to make sure the mechanical pump runs at the correct pressure. Before take off it is turned on again. Once you are off the ground to 2,000 feet or so the electric pump is shut off for the rest of the flight until just before landing.
It is obvious that the needle valve stuck. You got it freed up but I would take it out and look at the tip. I'm concerned with the condition of the rubber tip on the needle valve. Is it clean and is it swollen or deformed?
Ken B.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Major Gas Leak at Onan, Help Me Stop It [message #105818 is a reply to message #105697] |
Fri, 12 November 2010 22:32 |
Luvn737s
Messages: 1106
Registered: June 2007
Karma: 2
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Senior Member |
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I just went through a similar problem with my Kohler. It would start okay, but choke out. The choke wasn't the problem, but I didn't know what was.
Until I checked the oil. The oil level was about 1/3 higher than the top of the dipstick and it was pitch black. There was no reason for there to be excessive oil other than it wasn't all oil. It was gas mixed with oil. The float needle has allowed excessive fuel to run past the rings until it get so bad that it finally got so rich it quit (which probably saved the generator). I replace the needle and seat along with all the other seals and put it back together and it leaked like a sieve. I replaced the float and all was right.
Now where you are getting fuel under pressure without a pump? Maybe a clogged vent and warming of the tank?
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
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