1982 115 HP occasional miss new plugs, new wires, new coils, new power pack

[dubstewart]

My 1982 115 HP will drop a cylinder (5,400 down to 4,100 RPM) while running on the lake. It might run OK for 4-5 minutes then drop the cylinder for 10 sec up to 3-4 minutes then run OK for a spell before doing it again. I have replaced all plug wires, coils, power packs and now will replace the ignition switch. Does anyone have any suggestions?

[boats.net]

Have to test voltage output of source coil, trigger coils and CDI output with apeak reading voltmeter at time engine drops fire to find failed part.