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wolds
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VBMWMO #8011
Joined: 11/08/2010
Posts: 92

Thought I'd share some info on a clock repair I've been working on. So the bike I purchased has the original clock in it which appears to be losing about a minute per day. I peeled the bezel off its face and removed the movement at which time I discovered that the clock has an adjustment screw. You can access this screw without taking the clock apart (wish I had figured that out before dismantling it). There is a hole in the upper LH area on the back of the housing with a plus and minus symbol on it. If the clock hasn't been tampered with and if you look inside the hole you're looking at the back of the movement and when the movements are adjusted they place a small label over the hole. You should be able to push your precision screwdriver tip through the paper to get to the adjustment. This screw put a variable amount of tension on the oscillator spring which sets the rate that the clock runs at. Also found out that if you have one of the quartz clocks the face off of the original clock will fit the quartz clock. If anyone is interested in me posting some pictures let me know. I also am looking into using VDO bezels as replacements. The VDO PN is A2C53186024-S and is 52mm in diameter. I'm going to order a few of these from Jegs who is a VDO dealer.

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2007 BMW R1200RT
1979 Yamaha XS650 "cafe"
1976 BMW R90S
1976 BMW R60/6

RickR90s
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Farmington Hills, MI
Joined: 11/28/2016
Posts: 63
clock repair

good info.

I've worked on a number of these over the years. The stock R90s clocks use a magnet loaded flywheel that oscillates between a set of field coils. Beside the adjustment for fast/slow, if you have the clock apart, pay close attention to the gap between the magnets on the flywheel and the small coils. There's an adjustment for centering the flywheel.

Older, high mileage clocks often develop a scraping noise due to the magnets hitting the coils. In short order, the wires in the coils break and your clock dies.

AFAIK, the coils, and assorted parts are NLA.

Rick

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wolds
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Joined: 11/08/2010
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Thanks for the info. Clock

Thanks for the info. Clock isn't making any abnormal sounds and the bike only has 38K on it. So if I wanted to separate the circuit assembly from the mechanical portion of the clock it simply lifts off? I have put about two turns CW on the adjustment screw and I think I'm close. Been checking the sweep hand against the stop watch of my iphone over a 24 hr period looking for deviation.

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2007 BMW R1200RT
1979 Yamaha XS650 "cafe"
1976 BMW R90S
1976 BMW R60/6

RickR90s
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Farmington Hills, MI
Joined: 11/28/2016
Posts: 63
clock

Yes, the PCB just lifts off.

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RickR90s

wolds
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Joined: 11/08/2010
Posts: 92
thanks

thanks

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2007 BMW R1200RT
1979 Yamaha XS650 "cafe"
1976 BMW R90S
1976 BMW R60/6

wolds
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VBMWMO #8011
Joined: 11/08/2010
Posts: 92
thanks

thanks

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2007 BMW R1200RT
1979 Yamaha XS650 "cafe"
1976 BMW R90S
1976 BMW R60/6

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