The Kohler 10 horsepower engine has a single ignition coil that creates the electricity or "spark" that allows the fuel mixture in the engine cylinder to ignite. As the engine ages, the coil can start to malfunction, leaving you with an engine that will either run poorly or not start at all. Checking the coil is easy and can be done in a few short steps. The procedure will take about 10 minutes.
Place the engine on a workbench or flat surface; clean any debris from around the engine cylinder. Locate the spark plug wire coming out of the front of the engine, leading down onto the spark plug going into the engine cylinder.
Pull the spark plug wire off the spark plug. Attach the alligator clip coming from the lead connected to the spark tester to the end of the spark plug. Connect the spark plug wire to the spark tester. Adjust the gap setting knob located at the top of the spark tester to 4.2mm.
Start the engine while looking at the window in the spark tester; if the spark is consistent and a blue colour, the ignition coil is fine. If the spark is weak or non-existent, the ignition coil needs to be replaced.