How to Test the Ignition Coils for a Husqvarna Chainsaw

Lift the rubber boot, or HT lead wire, from the end of the spark plug. Unscrew the spark plug and remove it from the cylinder. Fit the new spark plug into the boot of the HT lead wire.

Switch the chainsaw's ignition switch to the "On" position. Set the Husqvarna chainsaw onto the ground. Place your right foot in the rear handle. Hold the HT lead wire so the tip of the spark plug is about 3 to 5cm from a metal point on the engine block, grounding the circuit. Wear work gloves.

Pull quickly on the recoil starter rope and look for a blue spark across the plug's tip and the metal spot on the engine block. If the spark is a weak yellow color, replace the ignition module.

Check the function of the ignition switch if there's no spark at all. Unscrew the Husqvarna's ignition switch; follow the manufacturer's instructions, as the process is different for most models. Disconnect the short circuit wire from the ignition switch. Repeat the spark plug test, same as before. If the chainsaw sparks, replace the starter switch.

Check the length of the HT lead wire and the rubber boot for any damage or loose connections. Make sure the short-circuit wire isn't grounded against a metal spot on the engine and isn't pinched. Replace any damaged wires and repeat the spark test. If a spark still doesn't occur, replace the entire ignition module.