How to Change the Spark Plugs on a Kohler Twin Cam

A Kohler V-Twin twin-cam engine that drives a boat's generator requires resistor-type spark plugs. Kohler's maintenance program for twin-cam engines requires that these plugs be changed after every 500 hours of operation. The spark plugs can be found in a recess at the center of the side of each head. A good practice for a plug change while under way is to remove and replace one plug at a time, beginning with the plug on the port side of the engine.

Things You'll Need

  • Dry shop rag
  • Universal spark plug wrench
  • Feeler gauge
  • Foot-pound torque wrench
  • Phillips screwdriver
  • Dielectric grease
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Instructions

  1. Removal

    • 1

      Allow the engine to cool completely. Clean any dirt, grease or oil from the spark plug recess on the port side -- the left side, as you face toward the front of the boat -- of the engine, using low-pressure air from the boat's compressor to remove loose dirt. Use a dry shop rag to remove greasy or oily deposits from the recess.

    • 2

      Grasp the boot of the spark plug wire and pull the boot from the plug. Remove the plug from the engine using a universal spark plug wrench.

    • 3

      Inspect the spark plug that you are removing from the engine and determine the color of the deposit on the plug. Sniff the electrode to check for the odor of fuel or oil.

    Installation

    • 4

      Check the gap of the new plug using a feeler gauge. Adjust the spark plug gap to 0.03 inch, if needed.

    • 5

      Thread the plug into the head using only your hand; should you feel any resistance after the first two full turns, remove the plug and reinstall it. Tighten the plug to 20 foot-pounds using a foot-pound torque wrench.

    • 6

      Push the tip of a Phillips screwdriver into the mouth of a tube of dielectric grease to collect a bit of the grease on the tip of the screwdriver. Insert the tip of the screwdriver into the spark plug wire boot and onto the contact inside the boot.

    • 7

      Push the boot onto the spark plug. Repeat the process of removal and installation for the spark plug on the starboard side of the engine.