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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Madmike on May 10, 2010, 05:35:12 AM

Title: LP Question
Post by: Madmike on May 10, 2010, 05:35:12 AM
On my 4106 I am doing a test of the propane system. I have soaped all the connections i could find. I have noticed that the tank has a LP gas Valve and a Liquid Valve. I think the generator runs on the liquid one, but not sure. Either way I can smell propane pretty bad when it is running and I used up 20lbs in about an 1-1/2.
Title: Re: LP Question
Post by: robertglines1 on May 10, 2010, 05:43:25 AM
My lp Generator         works on vapor side..ck lp regulator and valve inside generator box..I have a 7.5 and uses about 1.2gal per hr at full load book says about 2 gal per hr..ck pressure reg setting..maybe to high
Title: Re: LP Question
Post by: desi arnaz on May 10, 2010, 05:51:25 AM
what kind of generator? do you have a red hat?
Title: Re: LP Question
Post by: Madmike on May 10, 2010, 06:09:04 AM
It is an Onan 6.5kw. Is there anything that would run on liquid? Maybe it is just marked Liquid but it just runs the generator. Not sure I am still trying to figure it all out. I did get the stove and oven to work but the heaters and the fridge would not work.
Title: Re: LP Question
Post by: robertglines1 on May 10, 2010, 06:19:14 AM
are hoses hooked to both discharge valves??liquid and vapor??was it hooked up when you got it???does it have a pressure regulator simular to your grill before the carb on generator??could be at tank end but between the two.....
Title: Re: LP Question
Post by: Madmike on May 10, 2010, 06:24:42 AM
I will have to look. I know one of them goes to the requlator. The other hose goes to the generator, I think. But i don't remember seeing a regulator on that one. If the pressure is too high can you have blow by in the generator?
Title: Re: LP Question
Post by: desi arnaz on May 10, 2010, 06:48:50 AM
the generator should have a red hat which only allows propane to pass when the generator is on,also even with the red hat powered up you should get nothing coming out until there is a vacuum created by the generator.
Title: Re: LP Question
Post by: boogiethecat on May 10, 2010, 07:07:19 AM
It's most likely that your gene should be hooked up to the vapor port, not the liquid port, especially if it's an air cooled engine.

Alt all engines that run on liquid propane will have water hoses hooked to the regulator (forklifts mostly) because the liquid propane needs to be heated and vaporized before it can go to the carb ot it will freeze quickly.
While non-water heated regulators might work for a while on liquid LPG, they will eventually freeze and as you may have seen, use absurdly high amounts of fuel because they really don't know what to do with liquid lpg.
If your gene is water cooled, take a look at your regulator and see if there are water cooling hoses going to it... if so, it uses liquid.   If not it probably doesn't.

Check the model number of the regulator and you can also find out what it's supposed to run on.

My guess is that someone in the past who didn't understand the system hooked the gene to the liquid port in error.
Title: Re: LP Question
Post by: Madmike on May 10, 2010, 07:32:01 AM
I know it is not water cooled. It has been in the bus since 1995. I will read the manual when I get home and see what the deal it with it. I have traced the pipes as far as i could but Will look again.
Title: Re: LP Question
Post by: jeffacc on May 10, 2010, 10:12:54 AM
My generator is a 6.5 k Onan it is air cooled and it uses liquid  not vapor I am a HVAC tech and worked for a propane company for 10 years no mistake about it. Check your model # the tag will will tell you what it is or see your manual good luck.