Sep 16, 2020 · CDI ignition systems soon earned a considerable reputation for their reliability-and-cost ratio, which made them sound alternatives to O.E. components. Whether it’s a CDI Electronics distributor, ignition coil, or something as simple as wiring harness, you can rely on its quality and durability in the marine environment. The power pack supplies voltage to the ignition system's power coils. A malfunctioning or dead power pack can cause your Johnson outboard to have problems at start up. You can use a multimeter to test the power pack. However, because the power pack has varying voltage levels, a peak voltage adapter will also have to be hooked up to the multimeter.