How To Test A Chainsaw Coil With A Multimeter

Is Your Chainsaw Acting Like It's Seen a Ghost? Maybe It's the Coil!

So, your trusty chainsaw has decided to take an unscheduled vacation? It's sputtering, refusing to start, or generally acting like a toddler who's been told it's nap time.

Before you declare it possessed and call a chainsaw exorcist (yes, those exist in my imagination!), let's check the coil.

Think of the coil as the tiny, but mighty heart of your chainsaw's ignition system. It's responsible for giving the spark plug the jolt it needs to bring that engine to life!

Gear Up: Your Chainsaw Coil Detective Kit

You'll need a few things. First, you need your chainsaw, obviously! Then a trusty multimeter and the user manual is always a plus.

Finally, a dash of courage and a sprinkle of "I can totally do this!" attitude.

The Resistance Rumble: Primary Winding Check

First, set your multimeter to the Ohms setting, usually marked with the Omega symbol (Ω).

Next, find the two low-voltage terminals on your coil. These are often the smaller wires or terminals.

Touch one probe of your multimeter to one terminal and the other probe to the other terminal. Now, read the resistance!

The reading should be something small, usually between 0.5 and 5 Ohms. If it reads zero, that is bad.

An infinite reading (like the multimeter is showing "OL" or something similar) also means your primary winding is toast.

Secondary Showdown: High-Voltage Havoc Hunt

Now for the high-voltage side! Find the spark plug wire terminal on the coil. This is where the wire that connects to the spark plug goes.

Put one probe of your multimeter on the spark plug wire terminal. Touch the other probe to the metal core of the coil. Usually you can find an exposed metal piece somewhere on the coil to touch it to.

This time, the resistance reading should be much higher. Expect something in the range of 2,000 to 15,000 Ohms.

If you get a zero or an infinite reading, Houston, we have a problem! (Your secondary winding is likely kaput.)

The Ground Truth: Insulation Inspection

For this test, you will check if the coil winding is properly insulated from the coil core. If the insulation fails, then electricity is able to flow from the winding into the core and this wastes energy from the spark plug.

Set your multimeter to the highest resistance setting, usually 2M Ohm.

Touch one probe to either of the primary winding terminals and touch the other probe to the metal core of the coil. The multimeter should display infinite resistance. Anything smaller than 1M Ohm would indicate that the coil insulation is damaged.

Repeat the process with the secondary terminal.

Decoding the Data: What Does It All Mean?

If your readings are within the expected ranges, congratulations! Your coil is likely innocent, and the chainsaw gremlins are hiding elsewhere.

But if your readings are way off, or you're getting zero or infinite readings where you shouldn't be, chances are your coil has gone to the great chainsaw parts bin in the sky.

Time for a replacement! Don't worry, swapping out a coil is usually a pretty straightforward job.

Disclaimer Time! (Because Lawyers)

I'm just a friendly internet helper, not a certified chainsaw whisperer. If you're not comfortable working with tools or electricity, please consult a qualified technician.

Also, always disconnect the spark plug wire before working on your chainsaw to avoid any unexpected jolts. Safety first, friends!