How to Test a Chainsaw Coil With a Multimeter: Quick Guide



Test a Chainsaw Coil With a Multimeter

To test a chainsaw coil with a multimeter, set it to the ohms symbol and measure the resistance between the coil’s lead and ground. Confirm the coil’s functionality by comparing the reading to the manufacturer’s specifications.

Ensuring your chainsaw operates efficiently involves regular maintenance, including checking the ignition coil with a multimeter. A malfunctioning coil can prevent the engine from starting, leading to unnecessary downtime. This guide simplifies the process of testing your chainsaw’s ignition coil, which is crucial for any chainsaw owner wanting to maintain peak performance.

Testing the coil for resistance helps diagnose potential issues that might be affecting your chainsaw’s operation. Armed with a multimeter and this straightforward approach, even beginners can quickly learn how to assess their chainsaw’s ignition system, saving time and money on potentially expensive professional diagnostics.

Understanding the Chainsaw Coil

The chainsaw coil, an essential component of your chainsaw’s ignition system, might not frequently grab headlines, but its role is pivotal for a smooth-operating machine. Let’s delve into the mechanics behind this crucial part and iron out how it directly influences your chainsaw’s performance.

Role Of the Chainsaw Coil

  • Magnetic Induction: As the flywheel spins, magnetic fields induce electricity.
  • High Voltage Creation: The coil amplifies this electricity to a high voltage.
  • Spark Generation: This voltage is sent to the spark plug, where it jumps across the gap and creates a spark.
  • Engine Ignition: The spark ignites the fuel mixture, causing combustion and enabling the engine to run.

Without a fully functional coil, your chainsaw is rendered powerless – quite literally.

Importance Of Proper Functioning

FunctionConsequence of Failure
Consistent Spark GenerationWithout consistent sparks, the chainsaw will experience misfires or fail to start altogether.
Optimal Fuel EfficiencyA faulty coil can lead to an improper air-fuel mix, causing the engine to run rich or lean, resulting in inefficiency and potential engine damage.
Engine Power MaintenancePoor spark quality can lead to loss of power and reduced cutting efficiency.
Longevity of the ChainsawRegular coil checks prevent long-term damage, extending the lifespan of your chainsaw.

Tools Needed For Testing

Testing a chainsaw coil requires a reliable multimeter as the primary tool. Ensure your multimeter is set accurately to measure resistance for a proper diagnosis.

Multimeter Explained

Table showing types of multimeters:

Multimeter TypeFunctionality
Analog MultimeterUses a moving needle to display readings.
Digital MultimeterProvides a digital readout, offering more precision.

Other Essential Tools

  • Socket set – Required for removing the coil if necessary.
  • Spark plug socket – For safely extracting the spark plug during testing.
  • Screwdrivers – To adjust or remove components obstructing coil access.
  • Insulated pliers – Essential for handling wires without risking a shock.
  • Work gloves – Provides grip and protection.

Preparing the Chainsaw For Testing

Before testing a chainsaw coil with a multimeter, ensure the chainsaw is off and the spark plug is disconnected. Properly setting up the multimeter and securing the chainsaw in a stable position are crucial for accurate measurements.

Safety Precautions

  • Ensure the chainsaw is off and the spark plug is disconnected to prevent accidental starts.
  • Work in a well-ventilated area to avoid inhaling any potential fumes or dust.
  • Wear the appropriate safety gear, including gloves and eye protection.
  • Keep the chainsaw stable on a solid surface to avoid movement during the testing process.

Disconnecting the Coil

Proper access to the coil is essential for an accurate test. Perform these steps carefully:

  1. Remove the chainsaw’s cover: Unscrew any fasteners and set them aside securely.
  2. Locate the ignition coil: Refer to your chainsaw’s manual to find the coil’s specific location.
  3. Detach the spark plug boot: Gently pull the boot off the spark plug.
  4. Detach the coil wires: Note the arrangement and carefully disconnect the wires connected to the coil.

With the coil disconnected and the chainsaw prepped, you’re now ready to test the ignition coil with your multimeter. Remember, these steps are essential for an accurate diagnosis and must be followed methodically to achieve the best results.

Testing the Primary Coil

Discover the steps for testing a chainsaw coil using a multimeter to ensure optimal performance. This concise guide outlines the method to assess the primary coil’s resistance, a crucial aspect of chainsaw maintenance that can help troubleshoot ignition problems efficiently.

Locating the Primary Coil

To begin testing, you need to find the primary coil on your chainsaw. It is generally situated near the flywheel of the engine, often under a protective cover. Follow these steps to uncover and prepare the primary coil for testing:

  • Ensure the chainsaw is off and has cooled down to prevent any accidents or burn injuries.
  • Remove the chainsaw’s protective cover by unscrewing the necessary bolts or fasteners. This will expose the internal components, including the coil.
  • Identify the primary coil, which is connected to the spark plug via a small lead. This coil is usually a small cylinder or block wrapped with wire.
  • Disconnect the spark plug lead and any other connections to isolate the primary coil for testing.

Multimeter Settings For Testing

With the primary coil now accessible, it’s time to set up your multimeter to the correct specifications for an accurate reading:

  1. Turn your multimeter on and set it to the ohm (Ω) setting, as we are measuring resistance.
  2. For the primary coil, the resistance is typically low, so select a low range on the multimeter if it has manual range selection.
  3. Place the red (positive) multimeter lead on the terminal of the coil that connects to the spark plug lead.
  4. Attach the black (negative) multimeter lead to the ground terminal or a metal part of the coil’s body.
ConditionExpected Resistance RangeAction Required
Good CoilWithin Manufacturer’s SpecsNo action or standard maintenance
Faulty CoilSignificantly Outside SpecsConsider replacement

Testing the Secondary Coil

Testing the secondary coil is a critical step when diagnosing ignition problems in a chainsaw. The secondary coil amplifies the voltage generated by the primary coil, creating a spark strong enough to ignite the chainsaw’s fuel. A malfunctioning secondary coil can lead to starting difficulties or engine failure. By utilizing a multimeter, a tool commonly found in many toolboxes, you can assess the health of the secondary coil and ensure your chainsaw is operating efficiently. This procedure is straightforward but requires attention to detail.

Locating the Secondary Coil

Before proceeding with the test, identify the secondary coil’s location. Typically, it’s mounted near the chainsaw’s flywheel. To access it:

  • Ensure the chainsaw is off and the spark plug is disconnected to prevent accidental ignition.
  • Remove the chainsaw’s housing. Consult the manual for model-specific instructions on housing removal.
  • Identify the coil; it’s the component with two thin wires leading to the spark plug.

Multimeter Settings For Testing

A multimeter can be set to measure resistance, which is what you’ll need to do to test the secondary coil. Follow these steps to prepare and conduct the test:

  1. Turn off the chainsaw and ensure no current is passing through the circuits.
  2. Set the multimeter to the ohms (Ω) setting to measure resistance.
  3. Consult your service manual for the correct resistance range for your chainsaw’s secondary coil. Every model may have a different acceptable range.
  4. Disconnect the secondary coil’s lead from the spark plug.
  5. Place one multimeter probe on the metal part of the coil and the other to the boot where the spark plug connects. Make sure the multimeter probes make good contact to get an accurate reading.

Performing these tests regularly as part of your chainsaw maintenance routine can help diagnose issues early and prevent costly repairs or replacements. Keep in mind, proper handling and safety when working with electrical components are always paramount.

Interpreting the Multimeter Readings

When maintaining or troubleshooting a chainsaw, one critical step is testing the ignition coil. A multimeter is an essential tool in this process, providing valuable insights into the health and functionality of the coil. Correct interpretation of the multimeter’s readings is crucial to diagnose potential issues. Let’s delve into understanding what a normal reading looks like compared to an abnormal one and how to troubleshoot based on those readings.

Troubleshooting Based On Readings

  • If the multimeter displays a reading that is near zero, it’s likely that the coil has a short circuit. Inspect the coil for any visible damage. If damage is apparent, the coil may need to be replaced.
  • For a high resistance value or “OL”, the coil might have an open circuit. This condition typically suggests a break in the wiring or internal coil components, often requiring coil replacement.
  • Should the readings fluctuate erratically, ensure that all connections are correct and the multimeter probes have a good contact. Poor connections can often cause inconsistent readings.
  • In case you get an expected range but still experience problems with the chainsaw, consider checking spark plug connections, the plug itself, and the HT lead for defects.

Fundamentally, if the multimeter readings do not align with the expected values for your specific chainsaw model, it’s advisable to consult a professional or refer to the chainsaw’s repair manual for further troubleshooting guidance and potential component replacement.

Troubleshooting and Further Steps

When your chainsaw starts acting up, determining whether the coil is at fault can save you time and money. Testing the ignition coil with a multimeter is a practical skill that empowers chainsaw users to tackle problems head-on. After performing a test, understanding the results is crucial. Let’s delve into common coil issues that may arise and the next steps to take post-testing.

Common Coil Issues

You may encounter several tell-tale signs that suggest a faulty chainsaw coil. Recognizing these symptoms early on could prevent further damage to your equipment:

  • Difficulty in starting the chainsaw, or it fails to start at all.
  • A noticeable lack of spark at the spark plug.
  • The engine misfires, indicating inconsistent sparking.
  • Random stalling during operation, pointing toward intermittent spark issues.
  • Decreased engine power, which may signify a weak spark.

Next Steps After Testing

Upon completing the multimeter test and confirming a malfunctioning coil, several key actions should follow:

  1. Interpret the multimeter reading. A typical chainsaw coil will have a reading between 0.4 and 2 ohms. If your multimeter reflects a reading outside of this range, consider the coil defunct.
  2. Inspect for physical damage or loose connections. Prior to replacement, a visual examination could reveal surmountable issues.
  3. Consider coil replacement. If troubleshooting does not resolve the issue, purchasing a new coil may be necessary. Ensure compatibility with your chainsaw model.
  4. Refer to a professional. If you’re uncertain about replacing the coil yourself, professional assistance guarantees a safe and accurate repair.

In summary, testing a chainsaw coil need not be daunting. With the right tools and a methodical approach, you can swiftly move from diagnosis to solution, restoring your chainsaw’s reliability and performance.

Learn more: How to Oil a Chainsaw

Final Checks

Successfully testing a chainsaw coil with a multimeter is a crucial task for maintaining optimal performance of your chainsaw. As you reach the final stages of testing, ensure you’ve followed each step carefully. It is time to assess your readings and make any necessary adjustments or replacements.

Assessing the Results

  • Primary Winding: Readings below the specified range may point to a shorted coil.
  • Secondary Winding: Readings above the range indicate an open or damaged coil requiring replacement.

It’s essential to compare your results against the chainsaw manufacturer’s specifications to conclude accurately.

Final Recommendations

  1. If the coil’s resistance values are within acceptable ranges, reassemble your chainsaw and give it a test run.
  2. For out-of-spec readings, consider replacing the coil to prevent potential damage or performance issues with your chainsaw.
  3. Regularly test the coil as part of your chainsaw maintenance schedule to avoid unexpected failures.

Optional Table Example:

TestAcceptable RangeOur ReadingAction Required
Primary Winding< 1Ω0.9ΩNone
Secondary Winding2.5kΩ – 5kΩ6kΩReplace Coil

FAQs For How To Test A Chainsaw Coil With A Multimeter

How Do You Test A Chainsaw Ignition Coil?

Testing a chainsaw ignition coil involves these simple steps: 1. Disconnect the spark plug wire. 2. Remove the spark plug. 3. Attach the spark plug to the wire. 4. Ground the spark plug. 5. Pull the starter and look for a spark.

How Do You Tell If A Coil Is Bad With A Multimeter?

To test a coil with a multimeter, set it to ohms (resistance mode). Connect the probes to the coil’s terminals. A bad coil typically shows an infinite resistance reading or a reading significantly outside the manufacturer’s specified range.

What are the Symptoms of a Bad Coil on a Chainsaw?

Common symptoms of a bad coil on a chainsaw include difficulty starting, inconsistent power, sudden stalling, and a lack of spark. A faulty ignition coil often leads to poor engine performance.

What Is the Resistance Of A Stihl Chainsaw Coil?

The resistance of a Stihl chainsaw ignition coil typically ranges from 2. 5k to 5k ohms. Always consult the manual for model-specific information.


Testing your chainsaw coil with a multimeter ensures peak performance and safety. Remember, this simple step can save time and prevent future malfunctions. Find your multimeter, follow our guide, and keep your equipment in top shape.

For those who love to cut right to the chase, Chainsaw Hive is your next stop. Happy cutting, and always prioritize regular maintenance for lasting reliability.

About the author