1966 R69S Advance-Retard

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maddrobh
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Joined: Thu Oct 22, 2020 5:33 am

1966 R69S Advance-Retard

Post by maddrobh »

Some interesting work by a PO. Having a somewhat weak spark, I thought that I'd replace the points & condensor. On removing the A/R unit (allen bolt had been overtightened), I thought I'd compare with the piccies in the Barrington bible to determine which generation A/R unit. Have a look at the photo... I'm surprised how well the bike seemed to run!
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Daves79x
Posts: 489
Joined: Sun Aug 09, 2015 8:13 pm
Location: Knox, PA. USA

Re: 1966 R69S Advance-Retard

Post by Daves79x »

The pre-load plates look to be pretty far inward. Might take a while to return to proper idle? What else am I missing?

Dave
Dave

maddrobh
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Joined: Thu Oct 22, 2020 5:33 am

Re: 1966 R69S Advance-Retard

Post by maddrobh »

The plates are ‘reversed’, the left hand should be in the place of the right hand and vice-versa (as I understand it from the Barrington manual photos). This causes the springs to rub and bend against the plate. Also, the max advance is not controlled by the steel spring stop but by one of the pillars on which one spring is mounted.

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schrader7032
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Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Re: 1966 R69S Advance-Retard

Post by schrader7032 »

From the image on Duane Ausherman's site, those adjustable plates look to be properly positioned.

http://w6rec.com/duane/bmw/advance/advance1.JPG
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Jim D 5112
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Re: 1966 R69S Advance-Retard

Post by Jim D 5112 »

Looks to me like the two pictures have the plates reversed.

Daves79x
Posts: 489
Joined: Sun Aug 09, 2015 8:13 pm
Location: Knox, PA. USA

Re: 1966 R69S Advance-Retard

Post by Daves79x »

From the Barrington book, it looks like the advancer pictured is an early A advancer with two different anchor plates and two different springs. and if the Barrington picture is correct, the one shown here is indeed wrong. Later versions had identical anchor plates and springs.

Dave
Dave

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schrader7032
Posts: 7682
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Re: 1966 R69S Advance-Retard

Post by schrader7032 »

Didn't we have a recent discussion about advance units? I seem to remember there were three versions...early on the springs were different sizes and in the end the springs were the same.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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