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Onan 7.5 JB's Recovery Towards A New Life


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  #11  
Old 01-14-2017, 11:06:11 PM
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Jim McIntyre Jim McIntyre is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

The main 'con' with the potted AVR is it can't be repaired...
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Old 01-14-2017, 11:06:53 PM
yellowlister yellowlister is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

It looks like Cummins was already at it when they started to take over.. only painting the outside sheet metal tins.. all of the older onans have the tins painted inside and out.. maybe you should work your magic on it and repaint it to be better than when it left the factory
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Old 01-14-2017, 11:22:55 PM
JohnnyC JohnnyC is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

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Originally Posted by yellowlister View Post
It looks like Cummins was already at it when they started to take over.. only painting the outside sheet metal tins.. all of the older onans have the tins painted inside and out.. maybe you should work your magic on it and repaint it to be better than when it left the factory
I noticed that too, although my ex-15.0JC was not painted inside too and it was (I think) a 1982 or 1983 model. Anyway, what you and I noticed answers one earlier question in my other thread. The question: Was this JB repainted since there was some minor overspray on the meters? The answer is no. I don't know how the meters got some overspray on them, but the overspray is an exact match to the Onan green and in my documentation it lists the meter package as an accessory that was purchased.

JohnnyC
New Jersey
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  #14  
Old 01-14-2017, 11:30:43 PM
JohnnyC JohnnyC is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

Just a few additional pictures of my adventure traveling to pick up the JB at the beginning of a snow storm. The storm was not anything major, but did make the roadways slippery and there were a few accidents on the highway.

The first picture shows Route 78 in Pa east of Allentown. The snow was accumulating on the surface of the highway. For those out here from the warm south, this amount of snow would have shut down your state. Up here it is considered a very minor inconvenience especially when getting stuck behind a driver from the warm south doing 25 mph on a 65 mph highway.

The second picture shows the snow as it just started after I bolted down the JB to the wooden bed of my trailer. The JB was also strapped and wrapped in plastic too. It did not budge a hair during the entire 130 mile trip back to north Jersey.

JohnnyC
New Jersey
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Old 01-14-2017, 11:38:48 PM
JohnnyC JohnnyC is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

Lastly for tonight, here are several more pictures.

Picture #1) This shows one of the spark plugs. I assume it must be original. It is a Champion and notice circled in red - Made In USA. The threads look good compared to the substandard crap made today. I think they make the spark plugs in Mexico now.

Picture #2) This picture shows the compression tester readings on both cylinders. 140 psi and 130 psi. The difference between the 2 cylinders is 7.7% which easily falls within the 10% tolerance. The tester tool is made by Snap-On and I use it frequently. I believe the reading are correct. Why high compression in a factory tri-fuel set?


JohnnyC
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Old 01-14-2017, 11:56:32 PM
JohnnyC JohnnyC is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

Last pictures for tonight - I am tired and want to start reading the tons of documentation that came with the purchase.

The pictures below are of the LT II Transfer Switch. I have no experience and no interest in switches, but I thought I'd post a few pictures. There seem to be some really cool things inside the switch such as a charger and a digital clock that does something. I got several manuals and supplement paper work on the switch and I will spend a few minutes to read up on it.

My plans for tomorrow

In the morning I want to:
1) Remove the wiring in the control box that is used for connecting the transfer switch. That will reduce the rats nest of wires already inside the control box. If I ever want to hookup the transfer switch, the wiring looks straight forward to reconnect and I got schematics, wring diagrams, manuals and all kinds of documentation on the switch.
2) secure the a/c voltage wires. they are hanging out of the metal cable uncapped and can easily short out or electrocute someone when the set is running. The set is wired for 120/208 3 phase.
3) Hook up a demand regulator and my propane tanks to run the JB correctly.
4) Put away all the tools and crap in my Jeep Grand Cherokee that I hauled along the journey.

I only have the morning to play since the "boss" wants to go to IKEA to look are cabinets for her kitchen and other crap.

JohnnyC
New Jersey
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  #17  
Old 01-15-2017, 12:07:53 AM
nothingbutdarts nothingbutdarts is online now
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Default Re: My 7.5 JB's Recovery Towards A New Life

Use your borescope down the plug hole and see if it's got flat top or high compression pistons!
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  #18  
Old 01-15-2017, 12:29:51 AM
JohnnyC JohnnyC is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

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Originally Posted by nothingbutdarts View Post
Use your borescope down the plug hole and see if it's got flat top or high compression pistons!
I was thinking about it earlier. It may be hard to see a dome, but are high compression pistons identified by a notch of some sort for JB and JC sets?

-------------------------
I found out where this JB was installed. It was installed in a school in Pa. Look at the attached picture below. It shows a "bill of materials and submittal data". Weird thing is the Onan set specified is a 7.5 JB-4R which is a 3 phase only set, right? If that is true, I wonder how they ended up with an extended stack 1 and 3 phase set. All the other specs listed are what I have except for the "critical muffler". I thought the switch was only a 30 amp switch. Looks to be a 60 amp switch by the specs listed in the sheet below. Interesting..

**** Correction: The statements on the 60 amp switch and the 7.5 JB-R4 appear to be what was installed prior to the JB I just purchased. The document in the attachment below was not dated but following the paper trail of other related documents, it may be a document from 1984.
JohnnyC
New Jersey
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  #19  
Old 01-15-2017, 01:00:13 AM
yellowlister yellowlister is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

Did you get the muffler too? It's 12 wire right?
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Old 01-15-2017, 01:03:20 AM
MBB MBB is offline
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Default Re: My 7.5 JB's Recovery Towards A New Life

Johnny do us a favor and check the twinslan site and see if all the documentation you received is listed. If not could you scan it and post it or send it to one of us to do it for you. We will send it back.

Regarding the units from Toledo Jim mentioned the units at least mine still had points so I can use either one. The electronic ignition was an add on. I posted a picture when I first got my units we had never seen them prior. These units were from airports all over the country at least that's what I was told. I'm not implying yours was from there just filling you in. Look on the gen side and see if you see the Electronic ignition on the back outside.
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