How to Test a Chainsaw Coil

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Things You'll Need

  • Pliers

  • Spark plug wrench

  • Replacement spark plug

Chainsaws, as well as other small, two-cycle engines that use recoil starters, use ignition coils that are instrumental in the starting process. If the ignition coil on your chainsaw fails, it will prevent the saw from starting because it does not allow the spark plug to operate. The ignition coil can be tested by examining the base of the spark plug. It will take approximately 15 minutes to test the coil on the chainsaw.


Step 1

Remove the spark plug wire from the chainsaw and then use a spark plug wrench to remove the spark plug. Set the old plug aside and have a new spark plug ready.

Step 2

Use the screwdriver to remove the recoil starter assembly from the side of the chainsaw.

Step 3

Locate the kill switch at the bottom of the starter winding, which is silver in color and round. Disconnect the kill switch from its plastic wiring harness and then replace the starter assembly.


Step 4

Use the end of a flathead screwdriver to spread the spark plug gap slightly and then place the spark plug boot on top of it.

Step 5

Pull the start rope on the chainsaw and watch the end of the plug as you do. If you observe a spark jumping between the tips of the spark plug gap, it means the chainsaw coil is good. If there is no spark, it means the chainsaw coil will need to be replaced.



Andrea Walk

Andrea Walk began writing in 2001, authoring user guides for technical software. She holds a Bachelor of Arts in political science from Loyola University, where she was a member of the Dean's Grade Review Committee for English. Walk is a member of the Automotive X-Prize team Global-E.