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Topic: Onan 6.5 generator-propane switching back to liquid side. (Read 1129 times) previous topic - next topic

Onan 6.5 generator-propane switching back to liquid side.

Guess my Onan 6.5 LP generator is different!!!  Finally got it switched to the high pressure vapor side of tank and it would not run properly.  Was running really rough and voltage was jumping.  Took it to a Onan Generator Dealer (Key Power Systems, Attica, NY) that does nothing but Commercial Mobile, Installation, Parts, Sales, Service, Full Service on nothing but Onan generators.  Was told that it will not run properly on liquid, with out changing all the LP lines (current lines not large enough for vapor),  orifices, and changing out to a vapor lp regulator, and they refuse to do that.  Says that it will ruin the engine (valves and pistons) running the way it is on vapor.  The guy who said this is their resident expert tech on the Onan LP generators.  So, if they can get a kit to rebuild the Onan obsolete liquid LP regulator, we are having them change it back to liquid.  If they can't get a kit or new regulator, I guess the generator becomes obsolute Onan junk which will be pulled out of the compartment and replaced with a Honda 2k gas generator.
1994 U225
build #4514

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #1 –
Pat,

That response is a real shocker for the many of us who have run our propane generators on HIGH PRESSURE (before regulator) vapor for over a decade.

Did they open the regulator to see if it was contaminated with a light viscosity grease-like contaminant?  That would be my first move.

Harking back over a decade, this was well-discussed with the chief engineer with Marshall Gas who makes most of the RV regulators-- sadly no longer in business as well as a guy at Onan Corp.

The only justification for his "won't run on vapor" would be if he though you were coming off the house side of the house regulator.  Indeed, that would not be enough pressure to run the generator.  Might ask again making sure he knows that you are talking about HIGH PRESSURE (pre house regulator) propane.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #2 –
Quote from: wolfe10 –
Pat,

That response is a real shocker for the many of us who have run our propane generators on HIGH PRESSURE (before regulator) vapor for over a decade.

Did they open the regulator to see if it was contaminated with a light viscosity grease-like contaminant?  That would be my first move.

Harking back over a decade, this was well-discussed with the chief engineer with Marshall Gas who makes most of the RV regulators-- sadly no longer in business as well as a guy at Onan Corp.

The only justification for his "won't run on vapor" would be if he though you were coming off the house side of the house regulator.  Indeed, that would not be enough pressure to run the generator.  Might ask again making sure he knows that you are talking about HIGH PRESSURE (pre house regulator) propane.

Brett
No, it is coming before the house regulator.  But I not in a position to argue with him, as their main argument is from the liability point of view, which I do understand.  Plus he is about the only knowledgeable game in the area that I can locate.    And he is calling the obsolute LP regulator on the back of the generator a vaporizer, and admits that it is likely  contaminated with a light viscosity grease-like contaminant.  What really fries me is that the current line of Onan LP generators are set up for vapor, and not liquid;  and the fact that Onan has left us hanging with a obsolete LP regulator and no approved replacement for it!!!
1994 U225
build #4514

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #3 –
Pat,

Not sure I understand the "liability" statement.  A line full of high pressure vapor is, if anything, less dangerous than a line full of high pressure liquid.  Both are at exactly the same pressure, based on temperature of propane tank. In either case, the line would have the same design specs.

But, particularly if he is the only game in town and can get you running, so be it.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #4 –
Pat, check with these people,www.nashfuel.com
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #5 –
Update!!!
The shop has it running on vapor!!!  Says it sounds and performs great!  He said he did some "checking" and it can run on vapor.  The replaced both "new, not properly gapped" spark plugs with new, properly gapped, ones, cleaned the lp regulator.  He is waiting for a new circuit board to come in to replace my very corroded one.  She should be home by the weekend. 

I have to give him my hats off for not standing, what he thought was his proper ground, and going the extra steps to research the genset running on vapor!
Key Power Systems, Inc. 953 Creek Rd, Rt 98. Attica, NY
(585) 591-0996
1994 U225
build #4514

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #6 –
Pat,

Good news-- there are too many of us with the same generator running just fine on high pressure vapor. 

Please verify that when he overhauled the regulator that he went back with the high temp silicone gasket set.

The regular gasket set is not meant for the high heat location of the regulator on the Onan.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #7 –
Quote from: PatC –
Update!!!
The shop has it running on vapor!!!  Says it sounds and performs great!  He said he did some "checking" and it can run on vapor. 

I have to give him my hats off for not standing, what he thought was his proper ground, and going the extra steps to research the genset running on vapor!

Great news, and how refreshing to hear of a shop that is willing to go the extra bit and look beyond their initial thoughts like that. 
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320
 

Re: Onan 6.5 generator-propane switching back to liquid side.

Reply #8 –
Quote from: Michelle –
Great news, and how refreshing to hear of a shop that is willing to go the extra bit and look beyond their initial thoughts like that. 
Refreshing???  it caught me completely off guard because the last I had talked to him, he had no intention of even considering the idea to the point that I felt that he considered it to be sacrilegious.  I don't know what made him change his mind, cause I had came away with the idea that there was no way he would even consider it possible.

Brett - will verify the high temp silicone gasket set.
1994 U225
build #4514