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Onan JB Thermomagnetic Choke


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  #101  
Old 09-08-2017, 09:36:27 AM
JoeE. JoeE. is offline
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Default points.... here is what I was thinking.

This set I see on ebay has a notch.

I guess I can cut a notch with a hacksaw in the existing set and put them back on the machine and see if adjusting works that way.
The way they are now, there is no easy way to move them incrementally to get fine adjustment of the gap.
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  #102  
Old 09-08-2017, 09:28:03 PM
dracer dracer is offline
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Default Re: points.... here is what I was thinking.

may be I am seeing things but the points in the pic have a notch for adjusting and it appears there is a place for a eccentric screw for adjustment
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  #103  
Old 09-09-2017, 04:28:42 PM
JoeE. JoeE. is offline
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Default

I ended up making a little notch in the side of the bass and reinstalled them... got it pretty close to .020. Hard to get it exact.
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  #104  
Old 09-09-2017, 05:07:45 PM
Leon N. Leon N. is offline
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Default Re: Onan JB Thermomagnetic Choke

Make sure the points are not pitted when and if you use a feeler gage to set the gap.
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  #105  
Old 09-09-2017, 05:59:27 PM
JoeE. JoeE. is offline
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Default Points

I forgot to look when I had them off, so I shined a bright light and used a real intense magnifier and looked in there and they look okay to me... Flat and smooth.
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  #106  
Old 09-12-2017, 10:23:37 PM
JoeE. JoeE. is offline
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Default reinstalling shrouds....

Put the starter back on today.

Then, I started to put the sheet metal shrouds back around the cylinders.

Didn't get far doing that. I see I should have put the shrouds on THEN put the starter back on.
It's difficult bolting the starter back in place, but it's impossible to get the initial 3 pieces around the cylinders with the starter in place. Main reason is that the large multi-sided shroud that goes around the back of the cylinder and drops down between the starter and the block makes it hard to get the two small end pieces of shroud put on.. what with the little springs that hold them in place.
I forgot how hard it was to get those off in the first place.
That rear shroud thing makes it difficult to do the starter bolts.


Wondering out loud here... there is no way to leave all this vacuflow shroud stuff off the machine and have it cool itself correctly, is there?

I'd have to come up with a whole different set up.... like off one of the other type of forced cooled generators... right?
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  #107  
Old 10-23-2017, 02:43:39 PM
nothingbutdarts nothingbutdarts is offline
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Default Re: Onan JB Thermomagnetic Choke

I have been using the incorrect timing mark I believe!

In the picture in post #68 here, it is showing a circled in red pointer, that is the pointer I have been using for setting timing, after reading a few service manuals, this is the INCORRECT pointer to use for adjusting points and timing, you are supposed to use the cast in timing mark on the gear cover/front cover. I guess I have to fix a few units I have!
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  #108  
Old 10-23-2017, 06:17:40 PM
Max Thompson Max Thompson is online now
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Default Re: Onan JB Thermomagnetic Choke

Some sets do not have the pointer, then use mark on front gear cover.

Quick way to check: Pull #1 plug, rotate flywheel until #1 comes to TDC then see where timing marker lines up.
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  #109  
Old 10-29-2017, 11:48:07 PM
nothingbutdarts nothingbutdarts is offline
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Default Re: reinstalling shrouds....

Quote:
Originally Posted by JoeE. View Post
[FONT="Times New Roman"] Wondering out loud here... there is no way to leave all this vacuflow shroud stuff off the machine and have it cool itself correctly, is there?

I'd have to come up with a whole different set up.... like off one of the other type of forced cooled generators... right?
It has to be either Vac-U-Flo or pressure cooled, the only cooling they have!
They can be switched but, you have to have ALL of each different cooling syst. components to switch which includes the flywheel.

Quote:
Originally Posted by Max Thompson View Post
Some sets do not have the pointer, then use mark on front gear cover.

Quick way to check: Pull #1 plug, rotate flywheel until #1 comes to TDC then see where timing marker lines up.
So Max,
What have you found on sets with two pointers??

I pulled the plugs on a JC, got to #1 TDC plus or minus a few degrees because of not having the front cooling tin off I can not get true TDC, it appeared as the side mounted pointer is really close to being accurate at TDC. Maybe a flywheel tooth off.

And your experience?
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  #110  
Old 10-30-2017, 07:08:40 AM
Max Thompson Max Thompson is online now
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Default Re: Onan JB Thermomagnetic Choke

The flywheel is keyed to the crank, no way to get it on wrong. The distributor is another story, first time I reinstalled a distributor it took several tries to get it right.

The timing marks should line up with one of the pointers.
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