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Barry Robin
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VBMWMO #52
San Francisco, Ca.
Joined: 10/27/2006
Posts: 192

I'm looking for that spring-loaded metal sealing ring spacer that goes on the front of a bosh magneto, in the space between the mag and the hole in the engine timing chest-I don't quite know what to call it-but it's the part that stops the oil from splashing all over the engine.

Looks like it went missing when it got it back from being rebuilt.

I can find the R12 version for sale but not the earlier version.

I'm looking for the earlier version that fits on most R52/62/11/16.

Any chance anyone's got one just sitting around that you might want to part with? Or anyone who might? Or someone who sells them.

Darryl.Richman
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VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2185
Looking in my Parts Books

Looking in my R52/R62, R11 and R12 parts books, it appears that there are three different forms for this "Verschlußdeckel" (seal cover). The part numbers are:

for R52/R62 (and surely, R57/R63) and R11 Series 1: M 56 G 9
R11 Series 2-4: M 56 G 9 a
R11 Series 5 and R12: M 56 G 9 c

While I don't have an answer for your problem, I am surprised and fascinated that BMW had updated this part twice.

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Barry Robin
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VBMWMO #52
San Francisco, Ca.
Joined: 10/27/2006
Posts: 192
Why am I not surprised? I can

Why am I not surprised? I can find the earlier R52/62 version for sale from Dreher and I find the R12 version everywhere. Unfortunately, I need the Series 2-4 kind.

See, Darryl-this is why I always refer to the R11s as the unloved bastard love-child of BMW.

Barry Robin
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VBMWMO #52
San Francisco, Ca.
Joined: 10/27/2006
Posts: 192
I just slid the generator

I just slid the generator back, and it looks like the piece is actually there. It looks like the seals blew out, allowing lots of oil to spew over the engine case.
Oh well; one problem solved, another takes it's place. I guess that I'm looking for the various seals that go on it.

Darryl.Richman
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VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2185
So, there should be a felt

So, there should be a felt seal between the cover and the magneto shaft. It fits in a groove in the cover and should be fairly tight on the shaft. If you can't find the part somewhere, you can just buy or obtain some felt scrap and cut one out. When you get a new felt in place, use some heavy bearing grease and rub it into the inner surface where it seals against the magneto shaft. This will help seal the joint and also prevent any dirt from wearing against the shaft.

The cover seals against the crankcase with a round cork gasket. The light spring between the magneto and the cover is supposed to hold the cover and gasket tight against the case. On my R52, this has never worked, probably the case in this area isn't really very close to flat. So, I goop up the cork gasket with Yamabond or Ultra Grey non-hardening gasket sealer on both sides before installing the magneto on the motor. Because you have to install the magneto with the points set to just breaking and not move it or the cam gear in the motor as you install it, and you will want to make the least mess possible with the gasket sealer, it's worth practicing what you are trying to do a couple times before you actually do it with the sealer on the gasket.

Good luck!

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Bruce Frey
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VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
Any chance the breather was

Any chance the breather was not reinstalled correctly? This could create more pressure in the crankcase.

Bruce

Barry Robin
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VBMWMO #52
San Francisco, Ca.
Joined: 10/27/2006
Posts: 192
Darryl- I remember how much

Darryl-
I remember how much of a pain in the neck it was the first time. Gooping it up in place without removing it (and potentially screwing up the timing) is what I'll try first.

Bruce-Good idea! 'll check it out but I assume that it's fine; I've been using the bike all these years without a problem.

Bruce Frey
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VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
When you said it was just

When you said it was just rebuilt that was the first thing that came to mind.

Good luck!

Bruce

salmeland
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VBMWMO #8264
Joined: 04/04/2012
Posts: 6
Sealcover

Hi,
I made some new then I restore my R-12 engine
This is modify with oilseal instead of feld ring.
I can offer it for 20 euro+ shipping

  • Seal cover Bosch magneto
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Barry Robin
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VBMWMO #52
San Francisco, Ca.
Joined: 10/27/2006
Posts: 192
Wow-Rather nice seals you've

Wow-Rather nice seals you've made up there. I assume that the gold colour is bronze or brass.

If you've two to spare, I'll take 'em. Let me PM you.

-B

salmeland
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VBMWMO #8264
Joined: 04/04/2012
Posts: 6
Seals
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Knallert

spider rust
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VBMWMO #8708
Joined: 04/07/2014
Posts: 92
Magneto seals

RRC Tuning sells the lot.

spider rust
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VBMWMO #8708
Joined: 04/07/2014
Posts: 92
Nitrile oil/grease seal for magneto chain gear shaft.

You can buy a modern seal that replaces the felt seal. I used felt and had no trouble cutting out a felt o ring.
This is what was originally used and worked! Cork can be cut and a thicker cork used to compensate any irregularities in the seal ring face.

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