If you have difficulty starting your chain saw or it stalls during operation, then check its ignition coil to ensure it functions properly. Electrical currents run through the ignition coil and transmit electricity to the spark plug. The electricity creates sparks within the spark plug, and the sparks ignite the fuel in the engine, enabling the chain saw to run. Testing the ignition coil at home is simple to do and requires minimal tools. In order to ensure safety, it is important to check that the ignition switch is off first to prevent accidental start-up of the chain saw while disassembling it.
Put on protective eye-wear and leather or cloth work gloves. Remove the cover located on the top of the chain saw by unscrewing each of the screws that holds it in place. The removal of the cover will unveil the spark plug. Remove the rubber boot that covers the spark plug by pulling it away from the spark plug.
Find an appropriately sized socket to fit the spark plug, and attach it to a socket wrench. Some chain saws come with a special spark plug wrench that also can be used. Use the socket wrench or spark plug wrench to unscrew the spark plug, turning the wrench counterclockwise until the spark plug detaches completely from the threads.
Reattach the spark plug boot to the loose spark plug, grabbing only the spark plug boot and being careful not to touch the spark plug. The exposed tip of the spark plug contains electrodes that generate electricity. Find a metal surface on the chain saw, such as the cylinder, and press the electrode tip of the spark plug firmly against the metal surface.
Turn the chain saw's ignition switch to the "On" position. Pull the chain saw's starter cord with quick, hard pulls. Sparks should form at the location where the spark plug presses against the metal surface. The sparks indicate that the ignition coil functions properly. If the spark plug doesn't create sparks, then the ignition coil is defective and needs to be replaced.
Things You Will Need
- Protective eye-wear
- Leather or cloth work gloves
- Socket wrench or spark plug wrench
- Insulated pliers (optional)
- Before disassembling the chain saw, ensure the ignition switch is off. Once the spark plug has been removed, turning the ignition switch back on is necessary to test the ignition coil.
- When the spark plug is attached to the boot, it also attaches to a wire that connects to the ignition. Never touch the spark plug when it is connected with the boot because it could shock you. Instead, hold the rubber boot with your fingers. If at any point you need to touch the spark plug directly, do so using a pair of insulated pliers.
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