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LP Gen Experts please advice

May 11, 2015, 05:09:10 pm

LP Gen still not working
Last week FT did some troubleshooting & replaced the Onan Marquis LP Generator PC/Circuit board ... where the on board start button is ... I don't think anything was wrong with the board, but the start button was sticking ... The start button  could have been simply fixed ... anyway no big deal so now it has a new board and a spare. ... I knew the board would not fix the issue, because when a start button from inside (remote) was pushed and i hold the accelerator slightly open Generator started and ran, just as soon as I let go of the Accelerator it shut of. So FT suggested next part to be replaced is the "Onan 305-0826 Voltage Regulator" 
( I could not stay in one more day in NAC for another part delivery, I came home)
The Regulator is $405 from Cummins / Onan or this one Onan 305-0826 Direct-Fit Replacement Voltage Regulator is $269.
My question is do i  purchase a Voltage Regulator myself (easy to replace) and hope for the best .... or Try to get an appointment from Cummins/Onan (2 hr min $ 288 labor) and have them deal with it?  So at Cummins/Onan Service it could cost me $700 ... or i could get lucky for $269 with none Cummins/Onan brand part.  Has anyone have any experience with Generator & RV Controls Repair and Replacements, Engine Monitoring, Idle...
Thank you,
AL

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Re: LP Gen Experts please advice

Reply #1 – May 11, 2015, 06:43:48 pm

Al,

May be a repeat, but what are the symptoms?

Assume you have a LIQUID LP generator (i.e. the regulator is inside the generator).

The regulators have been problematic-- and ARE overhaulable. You just need to make sure you get the high temp/silicone gasket kit.  Probably $50.  This assumes you are willing/able to pull the generator and do above-basic mechanical work (i.e. if you have ever worked on a carburetor you have the skill set).

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Reply #2 – May 11, 2015, 07:21:21 pm

Symptoms: It has started and operated without any issues for 2 years. It has less than 400hr on it. Engine Cranks but does not start. It does start and stay running if i pull and hold just a little bit the Throttle lever.
Model # 6.5NHMFA26115C It is a Onan Marquis 6500 LP. I believe it is Liquid (there are two feeds out of the LP tank one Liquid and one vapor, I assume liquid line is for the Onan Gen)

Last week FT replace the Control PCB assembly & as a next step they were going to replace the Voltage Regulator. I could not stay one more night for another part for $400 may or may not solve the problem. What does Voltage Regulator have anything to do with starting and staying running? I would think that the Voltage regulator is for after it starts generating voltage to "regulate" no?
I can take the whole thing a part if i have to, if I believe there is a light at the end of the tunnel ... but if this is something need to be left to experts then i will let it be ... I thought that is what i was doing at FT but after replacing the board ... they suggested i go to Onan.
Thank you,

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Re: LP Gen Experts please advice

Reply #3 – May 11, 2015, 09:46:05 pm

I'd bet with Brett, something in the fuel supply & if the regulator is problematic, I'd start by putting a gage in the line.

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Reply #4 – May 12, 2015, 12:53:28 am

Dave,
"regulator"  what regulator voltage regulator ?  Fuel Supply is fine. Gen runs as long as i manually move the Throttle lever open.
Thank you,
AL

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Re: LP Gen Experts please advice

Reply #5 – May 12, 2015, 10:10:07 am

Was talking about the propane regulator....but if you can hand throttle the beast, probably a wrong guess. I still can't imagine it being a problem with any of the circuit boards.

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Reply #6 – May 21, 2015, 12:50:21 am

Drum Roll please ... What was the problem, what was broke? $400 Voltage Regulator (did not buy, thank God!) no ... so what was it.
It was the THROTTLE ROD CLIP ... Cost of Part $11  Labor cost at Cummins Fort Worth, TX  .. don't ask, but they were efficient and got my Generator running in and out first think in the morning ... so all good :-)

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Re: LP Gen Experts please advice

Reply #7 – May 21, 2015, 01:01:19 am

yeah, voltage regulator will NOT cause running problems. The engine controls itsself to correct rpm/frequency and the voltage regulator just sets the proper output voltage. the two do not have anything to do with one another. Sounds like they were just throwing parts at it with no clue what to actually look for.

Throttle rod clip sounds like something that connects the speed governer to the carburetor butterfly... pretty simple. Glad someone competent finally looked at it.

and FYI, any voltage regulator or control board that is available new or one you send to Flight Systems for remanufacturing will be better than a new OEM onan board. Flight systems is one of the best companies I deal with. I fix major commercial generators and their parts are awesome.

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Reply #8 – May 21, 2015, 11:03:39 am

Thank you Car54.

Yes someone was trowing parts at it ... despite my extensive explanation of already done troubleshooting. Anyway no one is perfect, so this one goes down as lessons learned. And you are right it was the "Throttle rod clip sounds like something that connects the speed governer to the carburetor butterfly... pretty simple. Glad someone competent finally looked at it. " So over all it cost me $500 where it should have only cost $126(part & labor) ... If they took out 4 more bolts as i had asked ... Anyway .. I am letting this one go.

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Re: LP Gen Experts please advice

Reply #9 – May 21, 2015, 05:26:33 pm

Hi

Glad you got the problem fixed.  For the next time around, if you have starting issues, what Brett was referring to is the FUEL regulator- big round thing with a button in the middle on your Onan engine.  The button is a primer and when you push it, you can hear the LP going thru it.  I always start mine from the engine and not remote (personal preference) and prime the engine first.  Sometimes you need to hold the prime button for a few seconds till the engine gets going.  These regulators are, as Brett said, overhaulable by a good local shop that works on LP engines.  FT is probably used to diesels and just randomly throwing ideas.

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Re: LP Gen Experts please advice

Reply #10 – May 21, 2015, 06:34:14 pm

My LP Gen is liquid, so it has no FUEL regulator "no primer. There is a "heat" switch (inside) to get the liquid LP to vaporize (I believe)
Onan Gen Tech at Cummins (30+ years experience) knew what was going on right from the get go. He indicated to me that the Gen i have is one of the best ones that they made and it did not have a secondary regulator , since it was a Liquid only LP.
Problem was simple Throttle rod was disconnected due to clip (plastic) got old. This was inline with my own troubleshooting. My problem was not removing 4 more bolts (myself) to get the Gen out 6-8 more inches so i could remove the top cover, it is heavy and i did not have enough equipment with me (while in Galveston) I trusted that it will get done in FT the following week and did not mess with it. I also respected (to much) ... Got to tell folks what to do and how to do it sometimes, since I was paying for it    Lesson learned.

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