How to Test the Kohler Ignition Coil

Updated April 17, 2017

Kohler manufactures a wide variety of small engines. The ignition coil is bolted to the top of the engine beside the flywheel. As the flywheel spins around the two points of the coil, it creates electricity or spark; it travels through the coil wire to the spark plug. When the spark gets to the engine cylinder, it ignites the fuel causing the piston to turn. If the ignition coil malfunctions, the engine will not start. Testing the ignition coil can be done in a few minutes.

Move the unit so the engine sits on hard, level ground. Set the parking brake.

Remove the spark plug wire from the spark plug, located at the front of the engine. Remove the spark plug with the spark plug socket. Inspect the spark plug for damage and fouling. If the spark plug is fouled, the end of the plug will be black with some build-up of sludge. If damage is found, replace the spark plug.

Remove the plastic engine housing with the 3/8-inch wrench; there are five bolts around the side of the engine holding down the housing. The ignition coil is located on top of the engine with the spark plug wire connected to it. Remove the small black wire on the bottom right corner of the coil -- this will bypass the ignition switch.

Plug one end of the spark tester into the spark plug. Connect the accessory cord plug cap to the ground terminal on the side of the spark tester. The accessory cord plug cap comes with the spark tester when purchased. Connect the other end of the cord plug (alligator clip) to a ground point on the engine block a hex bolt head works.

Adjust the spark tester screw located on top of the tester to 2.0mm. Start the engine and move the throttle to the full throttle position. Watch the tester; if in the spark tester window there is a strong blue spark the coil is working. If there is no spark, or the spark is weak, the coil is damaged. If the spark is visible, shut down the engine.

Increase the gap on the spark tester to 8.0mm and start the engine. Advance the throttle to the full throttle position and watch the spark; the spark should still be visible and consistent.


When finding a ground for the spark tester never place it on a painted metal surface.


Keep your hands clear of the spark tester while the engine is running to avoid electrical shock.

Things You'll Need

  • Spark tester
  • Spark plug socket
  • 3/8 Wrench
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About the Author

Based out of Orlando, Fla., Yvonne Grant has since 1997 done everything from designing and outlining company handbooks to preparing reports for the IRS. She maintains a popular interior design blog where she gives advice and design tips. Grant has bachelor's degrees in both business and interior design from the University of Central Florida and the International Academy of Design and Technology.