Cracked Ignition Coil - 1990 BMW R100 GS
BMW 12-13-1-243-910 / Bosch 0 221 500 200
These "grey" ignition coils are known to crack. In my case, it took 25 years as this ignition coil is the original that came with my R100 GS that I bought new.
Primary resistance: 1.21 ohms.
Secondary resistance: varied between 8.95 K ohms and open circuit.
Left ignition lead: 4747 ohms.
right ignition lead: 4799 ohms.