Mystery part - probably in hub

[azcaveman]

I made the mistake of not carefully documenting my tear down  (1961 A7, Frame GA7.16443) and I have a mystery part. It is most likely related to the bearing/dust cover in the front or rear hub.
There were no felt washers in the hubs as described in my docs I could not find this stamped part in any drawings.
It appears to be zinc-plated steel and fits nicely within the dust cover as seen in the attached photos. Can anyone help with a drawing or description? 
Thanks!

[WozzA]

If you flip it over could your mystery part be the plate that goes under the split washer from a K2F maggy ATD ?   
Part # 498,339  https://www.draganfly.co.uk/bsa/bsa/a710--b3133--c101112--m202133/category/1009-k2f

[muskrat]

I wonder how you know that Woz LOL.
az might want to sell it
Cheers

[WozzA]

Yes Musky after a lot of investigative detective work I discovered mine was missing 
Darned if I know how it made it over to the USA coz we're still in lock down..   

[azcaveman]

Wozz, you replied while I was typing my reply.

Wozz, that was some amazing sleuthing! The problem is I can't figure out where it goes from viewing the drawing. The parts list calls out a split copper washer 185,015 that appears to sitting out in space somewhere but I can't see a washer with 2 holes.  I had reassembled the magneto a few days ago and did not realize I had left out a part. Gotta pay more attention to what goes in the cleaning solution...

[WozzA]

The bolt that holds the ATD on the Maggy has 2 threads, 1 normal Right hand thread to attach to the end of the mag,  then a left hand thread to remove the bolt from the ATD... the 2 holes in the plate line up with the 2 pins...  & the split washer sits on top of it then replace the bolt.. 
The split washer fits in the recess to stop it falling out.   

[RichardL]

This attached picture might help and here is the link:

http://www.davelindsley.co.uk/magneto-advance-retard-options.html

I went looking when Wozza came up with the idea. I'm not saying Wozza is not correct. He may well be, but some stuff is confusing me. The ATD washer is quite thin (about 0.023"). You could easily bend it by hand. AZ's looks thicker to me. Also, I think it may be much smaller in diameter than a rear wheel-bearing dust cover. Finally, the holes in the ATD piece are virtually in the edge of the shoulder, almost distorting the shoulder.

Now, the thing is, my respect for Wozza makes me wonder if I am completely misinterpreting the part in your pictures.

Ready to be enlightened.

Richard L.

EDIT: OK, thickness may be exaggerated by the shadow in AZ's photo. One down.

[azcaveman]

The thickness of the metal in the mystery part is 24 thou. (0.61mm) and the pictures were perfect. I did not understand that the split washer was directly under the nut that holds the drive gear. I'll confirm tomorrow when I pull it apart.

Thanks again!

[Swarfcut]

 Looks very much like the magneto washer, but the hole in the middle looks a bit bigger than usual. One to hand has a diameter of 44mm, central hole is 15mm, small locating holes at 35mm centres. Not saying this is a genuine original part, but that's the size of one that fits.

 Swarfy.

[RichardL]

C'mon AZ, put me out of my misery and tell us the O.D. I'll tell you this, I don't think there's anything else on a '61 A7 it could be. Have you been working on your lawnmower lately?

Richard L.

[azcaveman]

OK guys. Here's my crappy drawing.
Richard, funny you should ask about lawnmowers. I rebuilt my dad's 40 year old push mower and rebuilt the transaxle in his 40 year old John Deere rider last month. Does anyone need a bit of Bentonite grease?

[RichardL]

BINGO! We have a winner!

...and a loser (me  ) for ever doubting Wozza.    (It was, really, just the tiniest pinch of doubt.)

Richard L

[azcaveman]

Yes indeed, Wozz is the winner!
I thought I must have a picture of the part somewhere in my hundred or so photos and I dug up the one in the black tote. I also included a photo of it sitting in its newly-found home(back where it was for 60 years before some bozo removed it. <grin>

Thanks guys.

[Swarfcut]

 AZ...Looks like you struck lucky with that washer, the hole in the middle will pass over the hex head, unlike the standard washer which must be fed on from the plain end of the retaining bolt. I have never got that self extracting p*ss poor bolt arrangement to work, so if the standard centre hole washer gets screwed there's no chance of easy replacement.

Happy ending!!!!

 Swarfy

[WozzA]

Woooo  Hoooo...      so what do I win???   
The only reason I suggested the washer is because for the last couple of weeks I've been chasing a in tune / out of tune problem & decided to do a Maggy swap over from my other bike ... when something didn't look right...   YEP the very same washer on the plunger is missing... and I've re timed that maggy 3 or 4 times without noticing it missing..   DOH...   
BTW...  if anyone has a spare for sale I'm interested..