How to Test a Marine Outboard Motor Power Pack

When your outboard motor has a rough idle, hesitates when you accelerate or stumbles when you're running at a steady speed, you may begin to suspect the power pack has gone bad. Marine power packs control the ignition, the idle and most of the other functions of your outboard motor, so it is possible that you're right. Being sure about your guess, though, is more than a matter of trusting your gut. The test requires a special load adapter, but in the end you'll know what's up with your motor.

Things You'll Need

  • Digital multimeter
  • Stevens PL-88 load adapter
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Instructions

    • 1

      Turn a digital multimeter to the 500 VAC scale.

    • 2

      Pull the ignition coil lead that comes from the power pack. Connect the red end of a Stevens PL-88 load adapter to the ignition coil lead and the black end of the adapter to the engine ground.

    • 3

      Connect the black multimeter lead to the engine ground. Connect the red multimeter lead to the red end of the load adapter.

    • 4

      Crank the engine and record the multimeter's reading, which should be 190 VAC or more. Remove the load adapter and repeat the test for all other power pack leads.

    • 5

      If the multimeter reads more than 190 VAC but the ignition is not performing properly, have the power pack replaced.