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How To Test a Chainsaw Coil with a Multimeter? Guide 2023

Chainsaws, invaluable woodworking, and tree maintenance tools rely on a complex ignition system to function effectively. One critical component of this system is the chainsaw coil, which generates the electrical charge needed to power the engine. You should learn the answer to “how to test a chainsaw coil with a multimeter?”

Over time, these coils can wear out, leading to issues with the chainsaw's performance. However, diagnosing a faulty chainsaw coil isn't always straightforward. I’ll delve into the nitty-gritty of chainsaw coils, exploring what they are, the symptoms of a failing coil, and, most importantly, how to test them using a multimeter.

Short Guide

“The user manual for your chainsaw will provide the correct reading for your chainsaw's resistance. Find the coil on your chainsaw. You can measure the resistance by connecting the negative and positive cords of the multimeter to the negative and positive terminals of the coil in your chainsaw. “

What is a Chainsaw Coil?

A chainsaw coil, also known as an ignition coil, is an essential part of the chainsaw's ignition system. It functions as a transformer, converting low-voltage electricity from the battery or magneto into high-voltage energy to spark the spark plug. This spark ignites the air-fuel mixture in the engine, propelling the chainsaw into action.

What are the Symptoms of a Bad Chainsaw Coil?

Identifying a faulty chainsaw coil can be challenging, but certain symptoms can provide crucial clues. If you notice a weak or inconsistent spark, difficulty starting the chainsaw, or if it fails to start at all, a malfunctioning coil might be the culprit. Understanding these signs is pivotal for timely repairs.


How to Test a Chainsaw Coil with a Multimeter?

Before testing the chainsaw coil, ensure your safety by wearing appropriate protective gear, gloves, and goggles. Additionally, disconnect the chainsaw's spark plug wire to prevent accidental starts. So, how to test a chainsaw coil with a multimeter?

Step-By-Step Guide on How to Test a Chainsaw Coil with a Multimeter

So, you've got a chainsaw acting up, and you suspect the coil might be the culprit. Don't fret; I've got you covered with a step-by-step guide on how to test that chainsaw coil using a multimeter. Trust me, it's easier than it sounds!

Step 1: Safety First, Always!

How to Test a Chainsaw Coil with a Multimeter

It's crucial to disconnect the spark plug wire from the spark plug. This step ensures that your chainsaw won't unexpectedly roar to life while you're testing. Safety goggles and gloves won't hurt either – better safe than sorry, right?

Step 2: Multimeter Magic!

how to set multimeter on resistances mode

Now, grab your trusty multimeter and set it to the ohms setting. Think of this as the magic wand that will help you measure the resistance in the electrical circuits. Setting it right is key, so ensure you have the ohms setting dialed in. 

Step 3: Touch and Go!

How to connect multimeter probes to spark plug wire

Take one of the multimeter leads and gently touch it to the terminal on the chainsaw coil connected to the spark plug wire. At the same time, touch the other lead to the terminal connected to the engine block. It's like connecting the dots but with wires!

Step 4: The Big Reveal – Reading the Resistance!

what should aspect multimeter display for resistance

Voila! Your multimeter should display a resistance value. This number is your secret code to unravel the chainsaw's mysteries. Grab your chainsaw's manual or hit the internet to find the manufacturer's specifications for your specific model. Compare the resistance value you just got with these specifications. Multimeter should read between 5K to 30K ohms.

Step 5: Decoding the Results!

Now comes the fun part – interpreting the readings. If your resistance reading matches the manufacturer's specs, congratulations! Your chainsaw coil is in the clear and not the source of the problem. If your reading is lower than the specified range, it's bad news – your coil is shorted and needs a replacement. 

On the flip side, if the reading is higher than it should be, your coil is open, signaling that it's time for a new one. For Primary resistance, the acceptable resistance range is 0.4 – 2 ohms. And, for secondary resistance, the acceptable resistance range is 6 – 12 ohms.


Interpreting the Results

  • Within Specifications: Your chainsaw coil is in good condition if the resistance reading aligns with the manufacturer's specifications.
  • Lower Than Specifications: A resistance reading lower than the manufacturer's specifications indicates a shorted coil, necessitating replacement.
  • Higher Than Specifications: Conversely, a reading higher than the specified resistance points to an open coil, which also requires replacement.

Troubleshooting Tips

If your chainsaw coil tests fine but your chainsaw still refuses to start, consider inspecting other ignition system components. The issue could lie with the spark plug, ignition switch, or flywheel. It's crucial to methodically troubleshoot to identify the root cause accurately.

Troubleshooting Tips

Always opt for a genuine OEM coil when replacing a faulty chainsaw coil. Generic coils may not function correctly, potentially causing damage to your chainsaw. Now you know the answer - how to test a chainsaw coil with a multimeter?

Different Types of Chainsaw Coils

Chainsaw coils aren't a one-size-fits-all deal. There are different types, each tailored to specific chainsaw models and needs. Understanding these types can help you pick the right coil for your chainsaw.

1. Standard Ignition Coils: These are your run-of-the-mill coils in most everyday chainsaws. They work by taking low voltage from the battery or magneto and converting it into high voltage for the spark plug.

2. High-Performance Ignition Coils: Designed for heavy-duty chainsaws or professional-grade models, these coils kick it up a notch. They deliver a higher voltage, ensuring strong and consistent sparks. Perfect for those demanding tasks.

3. Solid-State Ignition Coils: Sometimes known as electronic ignition coils, these fancy coils use solid-state components to produce precise and reliable sparks. They're more efficient and have a longer lifespan compared to traditional coils.


How to replace chainsaw coil?

Picking the right replacement coil is crucial to keep your chainsaw running smoothly. Manufacturers often provide part numbers for each coil type, making life easier. But what if you can't find that part number?

1. Chainsaw Model and Brand: Different chainsaw models require different coils. Always double-check your chainsaw's make and model to get a compatible coil.

2. Engine Type: Chainsaws come in two-stroke and four-stroke varieties; coils must match your chainsaw's engine type.

3. OEM vs. Aftermarket Coils: While aftermarket coils might be cheaper, don't compromise on quality. Opt for genuine OEM coils to ensure compatibility and reliable operation.

Putting It In Installing a New Chainsaw Coil

Feeling brave enough to install a new coil yourself? I've got your back with a simple guide:

1. Get Your Tools: This operation requires a screwdriver, socket wrench, and pliers. Ensure you have the right sizes; you don't want to damage any parts.

2. Disconnect the Spark Plug and Remove the Old Coil: Safety first – unplug the spark plug wire. Carefully remove the old coil from its mounting bracket with your trusty tools.

3. Pop in the New Coil: Now, seat the new coil in the mounting bracket, ensuring it's snug and secure. Tighten the screws, but remember – no need to go Hulk mode; you could damage the coil.

4. Reconnect the Spark Plug and Test: Reconnect the spark plug wire once the new coil is in place. Give your chainsaw a test run to ensure the new coil performs its job. Listen for smooth engine operation and look for a strong, consistent spark.


Beyond the Coil: Testing Other Ignition Components

Sometimes, the coil isn't the sole troublemaker in your chainsaw's ignition system. Here's how to test other components:

1. Spark Plug: Take out the spark plug and give it a once-over. If it's damaged or excessively dirty, it's time for a replacement. Ground the threaded part of the spark plug against the engine block to test it, then pull the starter cord. You're looking for a visible spark at the spark plug gap.

2. Ignition Switch: With a multimeter, check the ignition switch for continuity. If there's no continuity when the switch is in the "ON" position, it might be time for a new one.

3. Flywheel: Have a look at the flywheel's magnets. Make sure they're in good shape and properly aligned. Misaligned or damaged magnets can disrupt the ignition system. If needed, replace the flywheel to get things back in order.

Troubleshooting

So, you've tested all the components, but your chainsaw is still acting up. It happens. Here are some common ignition problems and how to tackle them:

1. Weak Spark: If you're seeing a weak spark, it could be due to a worn-out spark plug, a cranky ignition coil, or a feeble ignition module. Swap out the spark plug and test the ignition coil and module to determine the issue's root.

2. No Spark: If there's zero spark, check the ignition switch, kill switch, and wiring for any damage. Also, examine the ignition coil and module for faults. Replacing damaged parts should bring that spark back.


Chainsaw Coil Issues and Solutions

Chainsaw coils aren't immune to problems. Knowing these issues and how to fix them can save you time and money on repairs:

1. Overheating: Coils can overheat from extended use or incorrect voltage supply. Avoid overheating by maintaining the correct voltage and giving your chainsaw a breather during heavy-duty tasks.

2. Moisture Mishaps: Moisture can wreak havoc on the coil's insulation, causing all sorts of malfunctions. Store your chainsaw in a dry place, and if it does get wet, let it dry out thoroughly before firing it up.

3. Wear and Tear: Like any part, chainsaw coils wear out over time. Look for signs of wear during regular maintenance, and replace the coil before it is thrown in the towel.

Boosting Your Chainsaw Coil's Lifespan

Here's the secret sauce to keeping your chainsaw coil happy and healthy:

1. Regular Cleaning: Keep your chainsaw clean and free of debris. A clean chainsaw puts less strain on the coil and other parts, making them last longer.

2. Proper Storage: Store your chainsaw in a cool, dry place when it's not in use. A cover can protect it from dust and moisture, keeping the coil in prime condition.

3. Regular Maintenance: Tend to your chainsaw like it's your prized possession. Clean or replace the air filter, adjust the carburetor, and check the fuel system. A well-maintained chainsaw is easier on the coil, ensuring a longer lifespan.

4. High-Quality Fuel: Always opt for high-quality, fresh fuel and use the right oil-to-fuel ratio. Poor-quality fuel can lead to carbon buildup, which affects the spark plug and, indirectly, the coil.

5. Professional Tune-ups: Consider having your chainsaw professionally tuned up now and then. A pro can run thorough checks, making sure all components, including the coil, are tip-top.


Conclusion

Understanding how to test a chainsaw coil with a multimeter is invaluable for any chainsaw owner. With this knowledge, you can diagnose ignition issues promptly, enabling you to keep your chainsaw in top-notch condition.