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Onan JC Stumper


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  #21  
Old 11-27-2016, 10:09:32 AM
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Default Re: JC Stumper

Captain, I have a MDJB 1966 vintage. The magnaciter toasted when the unit ran out of fuel under a load. I searched for a replacement back I 1998 the only one I could find was from ONAN I had limited internet and searches turned up nothing else. I bought the ONAN replacement It has been perfect .
Today I would try a imported sx 40 avr cheep replacement
good luck
Bob
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  #22  
Old 11-27-2016, 11:03:32 AM
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Default Re: JC Stumper

The SX460 isn't rated to deliver the current needed by a magniciter set's field.

This one claims to be good for 15A, but as I recall, the mangeciter fields needs even more than that. Still, it might be a good starting point for some experiments.
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  #23  
Old 11-27-2016, 01:26:59 PM
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Default Re: JC Stumper

Jim I have looked into a number of the generic chinese regulators and no matter what the model number implies it usually turns out that the unit is only rated for 5 A or so. Sometimes it will say a few more amps for 10 secs or so peak but inevitably it is less than what is required for a magneciter. I was surprised to see that the direct from Onan replacement for the magneciter existed. I have never seen it come up in the years I have been watching the Stak. Cheers Dan
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  #24  
Old 11-27-2016, 05:55:43 PM
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Default Re: JC Stumper

Thanks for all the information everyone.

So my plan is to disconnect the magniciter/regulator and then troubleshoot the generator starting. Replace the regulator with the one recomended. Once it starts and runs perfect at 1800 rpm, I'll test the current magniciter/regulator and see if it is actually toast, replace components or replace the whole thing.

It'll be a few days, but I'll update the status.
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  #25  
Old 09-11-2017, 01:08:59 PM
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Default Re: JC Stumper

Sorry, for the long delay. Yesterday, I added the Garretson regulator behind the fisher 622 regulator. The Generator starts perfectly and stabilizes at 1800 rpm. Problem 1 is Fixed.

The second problem is that in about 2-3 minutes the Magnacitor/voltage regulator starts smoking. I believe we all agreed it is toast because of Problem 1.

So now I have a decision to make.

The Onan direct replacement is now $1,427.

The Powertronics listed below is cheaper 700ish, but I'm concerned about rewiring it.

Has anyone used the Powertronics regulator with success? I'd rather spend the $1,427 and be sure I did it correctly, than inadvertently screw something up trying to convert the Powertronics just to save $700.

With that being said I'm willing to save $700 if it is a fairly strait forward conversion.

V/R,
captainjdog


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Originally Posted by EricWood View Post
Thats an Onan static exciter/regulator assembly that replaced the old Magneciter guts.

Hold on to your seat.... The static unit alone listed in 2015 for $1063. The "kit" listed for $1345.

Powertronics, has a universal regulator (XR8) and a static exciter module (SEM250A) for a combined total of $733.

http://www.power-tronics.com/technic...intechpage.htm

Sending the attachment along as a little help and reference for what you have. Apologies for splitting it in half--was a little to large for allowed upload as a single document.
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  #26  
Old 09-11-2017, 02:13:26 PM
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Default Re: JC Stumper

The powertronics has a good reputation and they do make even higher power addon static exciters for their VR. I would have reasonable confidence in their products. There is an other approach that you may wish to consider. A complete YD genend from a newer JC would bolt on to your engine. There are a few kicking around out there and I suspect that that would be a lot cheaper than the Onan replacement and possibly even the Powertronics unit. The last one I bought ran me $400 plus shipping. You would need a VR on top of that but the SX460 works fine on a YD gen end and there is even room in the control box for it. For that matter a complete JC can sometimes be found quite reasonable. Something to consider. Cheers Dan
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  #27  
Old 09-11-2017, 03:10:51 PM
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Default Re: JC Stumper

Dan

Thanks for offering option C. I get annoyed when blind myself between to 2 options, and then someone informs me of an obvious alternative that I didn't even consider.

V/R,
Justin
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  #28  
Old 09-11-2017, 06:51:53 PM
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Default Re: JC Stumper

I have a SX1N3B magneciter complete that I will never use. I believe this is correct for your set. I can look it up in the parts manual if you are interested to be sure.

It can be yours for the cost of postage.

In checking the master parts book to be sure of which exciter your set was built with, I am not finding an exact model match. I am using the model # in post 3 of this thread. Can you double check the model number?

Last edited by Max Thompson; 09-12-2017 at 07:08:45 AM.
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  #29  
Old 09-12-2017, 11:45:03 AM
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Default Re: JC Stumper

Max,

Wow! I'm blown away by your kindness. I'm definitely interested. PM Sent.

V/R,
Justin
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  #30  
Old 09-12-2017, 04:07:24 PM
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Default Re: Onan JC Stumper

Max's offer is really good, but I have a model 808 in my magniciter 7.5jb

https://www.flightsystems.com/standb...regulator.html

just another option
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