| Onan Hydrolocked? [message #313821] |
Sun, 26 February 2017 12:38  |
Palmerdad
Messages: 60
Registered: August 2016
Location: Traverse City
Karma: 0
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So I was giving the Onan a Sea Foam treatment through the carb and gave it a bit too much of a spurt and it bogged down and stalled and now won't restart. I pulled the plugs and engaged the starter several times. It coughed out some liquid from one of the plug ports but once the plugs were reinstalled it still won't start. Anyone have thoughts on what I should try next? I didn't want to try anything else until I got some different opinions as I don't want to make it worse and I've never dealt with this before.
-James Palmer, Traverse City, MI
1976 Eleganza
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| Re: [GMCnet] Onan Hydrolocked? [message #313823 is a reply to message #313821] |
Sun, 26 February 2017 13:01  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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And you were giving it a Sea Foam treatment because? Was it running
incorrectly when you decided to affect it by spraying something other than
motor fuel into the carb throat? I suspect that you fouled the plugs. Clean
them thoroughly with carb cleaner, re gap them to what the onan manual
calls for,or replace them and regap the new plugs to spec, reinstall, and
see what happens. If it does not run after this, check for spark to rule
out ignition related problems. If you have spark, likely that you have fuel
delivery or carb adjustment issues.
Jim Hupy
Salem, Or
78 GMC Royale 403
On Sun, Feb 26, 2017 at 10:38 AM, James Palmer wrote:
> So I was giving the Onan a Sea Foam treatment through the carb and gave it
> a bit too much of a spurt and it bogged down and stalled and now won't
> restart. I pulled the plugs and engaged the starter several times. It
> coughed out some liquid from one of the plug ports but once the plugs were
> reinstalled it still won't start. Anyone have thoughts on what I should
> try next? I didn't want to try anything else until I got some different
> opinions as I don't want to make it worse and I've never dealt with this
> before.
> --
> -James Palmer, Traverse City, MI
> 1976 Eleganza
>
> _______________________________________________
> GMCnet mailing list
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| Re: Onan Hydrolocked? [message #313824 is a reply to message #313821] |
Sun, 26 February 2017 13:18 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Uh how much did you pour in when it quit? "It coughed out some liquid".. how much? If you hydraulic locked it you may of done damage to it. I suspect it would take a pretty good shot of liquid to do this though. If the above suggestions don't produce results, check the compression on each cylinder.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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| Re: Onan Hydrolocked? [message #313830 is a reply to message #313821] |
Sun, 26 February 2017 15:46 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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I would never ever use that stuff in any engine. Reminds me of the elixer traveling salesmen from the wild west. Except more dangerous.
I would crank more with plugs out. Be sure that you have them gapped at .020 both the same as it is waste spark system. Next confirm oil level. Then confirrm better than 1/2 tank fuel. You would be surprised about coincidences.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan Hydrolocked? [message #313831 is a reply to message #313821] |
Sun, 26 February 2017 15:52 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Also you may have to hold choke open by hand to create a "clear flood" situation while cranking locally. The throttle will already be wide open by the governor.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan Hydrolocked? [message #313833 is a reply to message #313821] |
Sun, 26 February 2017 16:20 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Palmerdad wrote on Sun, 26 February 2017 13:38So I was giving the Onan a Sea Foam treatment through the carb and gave it a bit too much of a spurt and it bogged down and stalled and now won't restart. I pulled the plugs and engaged the starter several times. It coughed out some liquid from one of the plug ports but once the plugs were reinstalled it still won't start. Anyone have thoughts on what I should try next? I didn't want to try anything else until I got some different opinions as I don't want to make it worse and I've never dealt with this before.
James,
You did it wrong, but unless you upended the gallon jug into the intake, I very much doubt that you did any damage. The clearance volume of these engines is HUGE.
If you really think that the combustion chambers need cleaning, take the covers off, then take the heads off and clean them. If the gaskets don't get damaged (and there is no reason that they should) screw the heads back on. If you don't even own a torque wrench, just put the heads back on with a 3/8 standard length ratchet by hand. Get the screws tight, but not over tight.
Yes, as you have been told, put it back together and try cranking with the choke held open for three trys of 20~30 seconds. If it hasn't fired, let the choke close and try again.
These old L-heads are pretty forgiving.
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: Onan Hydrolocked? [message #313835 is a reply to message #313821] |
Sun, 26 February 2017 17:30 |
Palmerdad
Messages: 60
Registered: August 2016
Location: Traverse City
Karma: 0
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Thanks guys. I had heard a lot of good things about Sea Foam and used it in my Wheel Horse tractor with good results so I figured it would be good for the Onan. I will try some of the things you've suggested tomorrow. One of the plugs was quite dirty when I took it out so I'm thinking of replacing that one anyways.
-James Palmer, Traverse City, MI
1976 Eleganza
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| Re: Onan Hydrolocked? [message #313842 is a reply to message #313821] |
Sun, 26 February 2017 18:56 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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After you have done everything Jim, Matt, and Larry suggested and get it running again, I suggest that you change oil very soon. That engine is a horizontally opposed AIR COOLED engine. It is built with a large gaps in the pistons and rings to allow thermal expansion and to stay at running at widely varying temperatures. When it is cold things (rings, pistons, etc.) contract and allow anything liquid in the cylinders to flow right past them and into the crank case.
One other thought is while you have the plugs out, run a quick compression check. If one or both cylinders read low, squirt or two of oil into the cylinders, crank the engine over a few tines, and recheck the compression again.
Oh, BTW, I found a good use for that Sea Foam. It, like antifreeze, makes a good weed killer.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Onan Hydrolocked? [message #313889 is a reply to message #313821] |
Mon, 27 February 2017 19:27 |
Palmerdad
Messages: 60
Registered: August 2016
Location: Traverse City
Karma: 0
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Sea Foam can be used as a fuel treatment, it can also be injected straight into the throttle body. I spritzed a little starter into the Onan and it fired right up. I guess a false alarm. Changed the oil after and she is purring along very nicely. I do think I can hear an improvement over what she sounded like before the treatment. Like I said, it worked well on my older Wheel Horse tractor so I think Sea Foam is a good product to help burn off deposits. See this video of a guy who tested it with a borescope to see before and after. He mentions trying other products and not seeing the difference that he saw with the Sea Foam.
https://www.youtube.com/watch?v=WdT4DPFXIkM
-James Palmer, Traverse City, MI
1976 Eleganza
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| Re: Onan Hydrolocked? [message #313900 is a reply to message #313821] |
Tue, 28 February 2017 09:10 |
jknezek
Messages: 1057
Registered: December 2007
Karma: 5
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I use SeaFoam in my gas when the coach is going to sit for more than a couple weeks. Seems to work better than Stabil for me. I don't see a problem with it and it comes highly recommended for this purpose from several mechanics I know that work on older vehicles. I've never used it direct into the carb though. The guy at Pinellas Power recommends something else for injecting direct into Honda generator carbs and I used that to great effect. Some kind of Mercury (marine engine) injector cleaner I believe. I think some of these "mechanic in a can" products do simple things pretty well. But success seems to vary greatly among people that use them, not just across various products but across various users of the same product. Probably depends on what you expect to get out of them.
Thanks,
Jeremy Knezek
1976 Glenbrook
Birmingham, AL
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| Re: Onan Hydrolocked? [message #313902 is a reply to message #313821] |
Tue, 28 February 2017 09:51 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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I never had auto shop class, but my friend always quotes his community college advanced engines class instructor--- if you have to add stuff to your gas and oil , you are using the wrong gas and oil.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan Hydrolocked? [message #313903 is a reply to message #313902] |
Tue, 28 February 2017 10:53 |
jknezek
Messages: 1057
Registered: December 2007
Karma: 5
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JohnL455 wrote on Tue, 28 February 2017 10:51I never had auto shop class, but my friend always quotes his community college advanced engines class instructor--- if you have to add stuff to your gas and oil , you are using the wrong gas and oil.
Well, yes. But depending on how old you are, your instructor probably didn't have to deal with the problems of ethanol in gasoline in intermittent use 40+ year old engines. I agree that finding pure gas would be the correct gas to use, making your instructor absolutely correct, but it isn't so easy to find, and what I do find tends to come from gas stations that might not have very clean tanks. Plus they charge an arm and a leg. So some fuel stabilizer to fix the gas is a modern solution to a modern problem for not so modern engines.
Thanks,
Jeremy Knezek
1976 Glenbrook
Birmingham, AL
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| Re: Onan Hydrolocked? [message #313904 is a reply to message #313821] |
Tue, 28 February 2017 11:36 |
Palmerdad
Messages: 60
Registered: August 2016
Location: Traverse City
Karma: 0
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I've gone to great lengths (and expense) to use Ethanol free fuel (which up here always means premium) since I bought the GMC. Not sure what po have used though. I'm hoping to replace fuel lines, clean up the engine/carbs and then feel some freedom to mix fuels depending on how long it will sit between use.
-James Palmer, Traverse City, MI
1976 Eleganza
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| Re: Onan Hydrolocked? [message #313906 is a reply to message #313904] |
Tue, 28 February 2017 12:22 |
Justin Brady
Messages: 769
Registered: April 2015
Location: Bell Buckle, TN
Karma: 11
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I have used seafoam to clean out countless old motorcycle engines. It works a treat if you use it correctly. It won't fix mechanical problems, but it certainly cleans things out.
There's nothing wrong with using it in the Onan.
As for it getting into the oil, that's actually a good use for it as well, you can put some in the oil, run it for a while and then drain it to clean out the oil galleys. You'd be surprised how much crud comes out of a 40yr old engine.
Justin Brady
http://www.thegmcrv.com/
1976 Palm Beach 455
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| Re: Onan Hydrolocked? [message #313917 is a reply to message #313821] |
Tue, 28 February 2017 21:39 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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With the exception of the outdated rubber fuel lines that simply are not e10 compatible and must be replaced with barrier type, I have had zero issues from e10 in any cars, GMC or the Onan. Small engines especially 2 strokes that don't get used regularly are another story. I quit using Stabil as well but try to not exceed 9 months without adding fresh fuel.
John Lebetski
Woodstock, IL
77 Eleganza II
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