How to Test a Generator Stator

Checking the stator -- the stationary part of your outboard motor's generator -- requires a digital multimeter. Nearly all problems that are ascribed to the stator are the result of a simple loose connection in the boat's wiring harness or some missing insulation. If the trouble isn't with the wiring harness, it may be a short that grounds a lead on the stator. Once that's proven untrue, the diagnostic path leads away from the stator, perhaps to a short between the stator and the secondary coil-- the output side -- of the ignition coil, or a short between the coil and the ground. Once you learn to test the stator, though, your worries about its condition will be settled.

Things You'll Need

  • Wrench set
  • Digital multimeter
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Instructions

    • 1

      Remove the engine cover. Remove the flywheel cover, using the appropriate wrench for the bolts that hold the cover in place -- each engine may have different sizes, and some may require metric wrenches.

    • 2

      Check your individual generator set's operator manual or engine operator's manual for the resistance range across any pair of terminals on the stator.

    • 3

      Place the multimeter's black terminal on one of the paired leads on the stator and the red lead on the other. If the resistance between any pair is out of specification, test the pair again.

    • 4

      Visually inspect the wiring harness for breaks, damage or physical problems such as broken wires, broken solder joints and damaged insulation. If the wiring harness is in order, shift the black probe to the secondary side of the ignition coil and touch the red probe to each stator lead again

    • 5

      Take note of the results, to determine whether or not there is a short to ground, or an "open" circuit -- a disconnect -- between the coil and the stator. If no obvious breaks are found, replace the coil and repeat the test. If the shorts or open circuits are still present, replace the stator..