K100..BMW Motometer instruments .....the German motorcycle industry goes electronic for its instruments....

With the introduction of the K series 4 cylinder 1000cc BMW motorcycle in 1983 came the first total use of electronic instruments for BMW motorcycles and it wasn't without its problems.
Motometer continued as the instrument supplier for the motorcycle side of BMW and a new large binnacle with speedometer on the left, tachometer on the right and a liquid crystal display quartz clock in the middle.
Left click on the illustrations to enlarge them....

BMW K series....

The instrument binnacle and the accessory instrument.

Exploded parts list drawing...

Speedometer details....

Tachometer detail....

Gearchange indicator and trip odometer and reset detail....

Pages from DQs somewhat scribbly and cryptic workbooks with information on connecting test  and calibrating equipment to the K100 instruments and the figures to calibrate it...
so calibration figures for the speedometer are....
49.7cycles/second (hertz) = 60kph
66 cps(hertz)                           =80kph
82.1 cps(hertz)                       =100kph
97.9cps(hertz)                       =120kph
113.4cps(hertz)                     =140kph
128.7cps(hertz)                     =160kph
The rear wheel had a metal disc with "teeth" on it that a hall effect pickup in the final drive was set near and detected the passing of the sheet metal "teeth"...the speedometer then displayed this as kph or mph and drove an odometer by a form of servo motor.
The instrument binnacle suffered from mild corrosion on internal terminals such that the signal would be lost and the speedometer stop working. 
A frustrating instrument at best....
The LCD display on the clock and the gearchange indicator would, with time and vibration, segment to a black blob appearing visually and masking any reading.
Once Motometer stopped the supply of parts in the early 1990's it became almost impossible to repair....