My 1979 GS 1000 has a Dyna S and Accel coils and 8.8 mm suppression wires installed by the PO. I lost spark on 1 and 4. That coil primary reads open. I do not get a reading from the iron core where the mounting holes are drilled to either output as I would think I would, but see 14K ohms from one output to the other. I have a set of Dyna Green dual-output 3 ohm coils, read about 4.5 ohms across the primary, and nothing across the core to output, one coil reads 14K between the outputs, the other does not. I'm figuring that the Accel coil (the 1 and 4 coil) with the open primary is bad. The Dyna Green that shows 14K ohm between ouputs seems good, but what does anyone think about the one that seems open between the two outputs? Bad? I was going to replace both Accels with the Dyna Greens, but now I don't know. Any opinions? BTW, today is a beautiful fall day; I REALLY wish I was riding instead of troubleshooting!