[PeteKz]

Let me add to John's recommendations:
For those of you looking for a replacement coil in a pinch, the MSD 8222 is designed for a CDI system, as is the Pertonix Blaster 2, and several others. The important point to note is that CDI ignitions work differently than points-and-breaker or transistor switched ignitions. They work best with coils with a low primary resistance, on the order of 0.5 to 0.7 ohms. Any coil with a low primary resistance will work in a pinch, and probably "forever."

There is another set of threads in this forum with Systems Consulting about what is the "best" coil to use with the Bosch CDI, and they argue persuasively that the OE Bosch black coil is the "best." It probably is, but if you get say, "only" 35,000 volts instead of 40,000 volts at the spark gap, a substitute coil will light the fire with plenty of energy to spare. Don't believe me? Hand someone your beer and hold the ignition cable while cranking it.

Heck, almost any coil will work in a pinch, but get one with the primary coil resistance above if you have a choice.

For the curious, the OE Bosch coil measures 0.5 to 0.6 ohms across the primary windings, and about 700 ohms across the secondary windings.