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Topic: Bad Onan Generator Starter? (Read 378 times) previous topic - next topic

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Bad Onan Generator Starter?
My Onan Emerald 6500 LP Gas conversion worked like a champ and started right up until this fall. At that point it became hard to start and I had to crank the starter for longer periods to get it going. Now I think the starter has gone bad. It...

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Re: Bad Onan Generator Starter?
Reply #1
Before condemning the starter, verify voltage at the large lug on the generator to generator clean metal housing. If it drops below 12.0 VDC with batteries in good condition, yes it could be a bad starter (excessive draw), but could also be a bad...

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Re: Bad Onan Generator Starter?
Reply #2
Thanks Brett. I'll do some checking.

  • nitehawk
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Re: Bad Onan Generator Starter?
Reply #3
I am sitting here thinking about my Onan starter. It "crapped" out because the little plastic cage that is supposed to push the gear back out of engagement broke and the spring worked its way up to the end of the starter so the gear only backed...

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Re: Bad Onan Generator Starter?
Reply #4
Thanks Nitehawk. I hope Brett's suggestions prevent me from having to do this but your step-by-step instruction will be a great help if/when I need to do it.

Re: Bad Onan Generator Starter?
Reply #5
I've been plugging away at this job as time and weather allows and am getting close to pulling the generator. It may take a day or longer for me to complete once the generator is pulled out. I can't run the refrigerator on gas if it's shut off at...

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Re: Bad Onan Generator Starter?
Reply #6
Is your generator LIQUID or vapor LP?  Many of that vintage had the generator on a separate (liquid) tap-- not related to the vapor tap for house LP appliances.  If this is what you have, merely close the liquid valve on the tank, start the...

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Re: Bad Onan Generator Starter?
Reply #7
You can turn off the gas remove the line at the generator and install a plug in the line and then turn the gas back on.

Re: Bad Onan Generator Starter?
Reply #8
Thanks guys. Brett, here are a couple photos of the tank....

Re: Bad Onan Generator Starter?
Reply #9
Can't really tell from the photo. 

Is the regulator in the lower left of the picture for the generator? If so, is it fed by the liquid or vapor port.

Re: Bad Onan Generator Starter?
Reply #10
Can't really tell from the photo. 

Is the regulator in the lower left of the picture for the generator? If so, is it fed by the liquid or vapor port.
It looks like the liquid valve has nothing...

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Re: Bad Onan Generator Starter?
Reply #11
Ya, blowing up the picture on my computer instead of a smaller device-- I think you are correct.

So where does  the vapor line "T" off to the generator regulator?

Re: Bad Onan Generator Starter?
Reply #12
I was told that the 2 valves on the right side were for liquid and for vapor, the lower being the liquid but I really know nothing about what goes where.

Re: Bad Onan Generator Starter?
Reply #13
I think this photo will help...

Re: Bad Onan Generator Starter?
Reply #14
The two valves on the tank WILL be labeled.  You can clearly see "Vapor" on the top one and guarantee the bottom one says Liquid.

The question is where does the generator feed tie in to the vapor port-- assume before the house regulator, but not...

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Re: Bad Onan Generator Starter?
Reply #15
The two valves on the tank WILL be labeled.  You can clearly see "Vapor" on the top one and guarantee the bottom one says Liquid.

The question is where does the generator feed tie in to the...


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Re: Bad Onan Generator Starter?
Reply #16
Should be able to find a cap at any propane store.

Turn off the vapor port.  Since the generator is not operating, light the stove to remove all pressure.

Remove that line and cap it off while doing the repair.  If it is cool outside and your...

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Re: Bad Onan Generator Starter?
Reply #17
OK. It all makes sense to me now. I just need to get a plug for the line (as Ron the red tractor said) where it plugs into the generator.
Is this plug available say, at the local Ace Hardware?

Re: Bad Onan Generator Starter?
Reply #18
More likely at a propane store.

And, suggest bleeding off pressure before doing this.

Re: Bad Onan Generator Starter?
Reply #19
Thanks Brett and everyone. While I have the generator out I'm also going address and attempt to correct any problems I have with regulators and gas flow -- and I'm also going to replace the rear spark plug that is impossible to get at.

Re: Bad Onan Generator Starter?
Reply #20
If (actually big IF) you have the in-generator Impco J regulator, be sure you get the HIGH TEMP gasket set:
Century Fuel Products | Generator Conversion Kits | Forklift Parts

With the regulator in the propane tank compartment, don't really know...

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Re: Bad Onan Generator Starter?
Reply #21
Brett, this is what I have...

Re: Bad Onan Generator Starter?
Reply #22
SOOOO, two regulators for the generator, one in propane locker, one at the generator. 

Looks like either would be easy to work on without removing the generator.

Much easier than the ones that are inside the generator.

  • nitehawk
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Re: Bad Onan Generator Starter?
Reply #23
I found the regulator in the propane tank compartment to be the one that failed on me. This was also the one that supplied the propane to the generator regulator.

Re: Bad Onan Generator Starter?
Reply #24
More likely at a propane store.

And, suggest bleeding off pressure before doing this.
These are standard flare or pipe plugs and are less expensive at the big box store, plumbing supply store or...

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