Looking for a guide on how to test your chainsaw coil? Well, you’re just at the right place!
There could be many reasons for your chainsaw just stopped working. There could be a defect in the spark plug, a problem in the carburetor, a clogged air filter, etc. Among all these reasons could also be a defective ignition coil which needs to be fixed in order to get your chainsaw back into its proper working.
Now if you think there’s a problem with the chainsaw coil, you’ll of course need to check it first. By checking it, we mean testing the coil to confirm if this is what’s causing the issue. For the testing of a chainsaw coil, people either perform two tests without a multimeter or use a multimeter to measure the resistance of the coil. Both methods are to be described below.
Our article contains a detailed step-by-step guide on how to test a chainsaw coil with a multimeter and without a multimeter. So, continue reading and by the end of this article, you’ll be able to test your chainsaw ignition coil without a problem!
Firstly, What is the Function of an Ignition Coil in a Chainsaw?
The ignition coil is basically the part of the chainsaw that allows electricity to transmit from the ignition coil to the spark plug. Spark plugs receive electricity from the ignition and the electrical currents that run through them. When the spark plug is ignited by electricity, sparks are created inside, igniting the engine fuel, which enables the chain saw to run.
Signs that You Have a Weak or Defective Ignition Coil
There are certain hints that point toward having a weak or defective ignition coil. If you see these signs, that means you need to fix the coil.
- The engine will not start.
- As soon as the engine reaches operating temperature, it stalls.
- Starting is difficult. It has to be done repeatedly.
- If it gets too hot, it stops working.
- Sounds of spluttering.
- Vibrations or jerks that are unusual.
- 0 or close to 0 reading on the multimeter.
Tools You’ll Need for Testing a Chainsaw Coil
Here are a few tools that you need when inspecting your chainsaw coil.
- A wrench and screwdriver
- A multimeter
- A brush and a piece of cloth for the cleaning (if needed).
- New sparks plug because the old one might need to be replaced.
Testing Your Chainsaw Coil – With and Without Multimeter
So, in case your chainsaw isn’t working, and you need to check the ignition coil, here’s what you can do. You can either test it manually that is, without a multimeter or you can use a multimeter to get the resistance readings.
Let’s read in detail about both of these.
TESTING WITHOUT MULTIMETER
Here are the steps to carry out without a multimeter.
Find the Spart Plug and Remove It
For different chainsaw models, spark plugs would be located at different places. So, to look for the spark plug of your particular chainsaw, you must read the manual.
Most probably, here’s how you can find the spark plug.
- You need to turn off the ignition button first.
- Then pull the cover gently off the lock which would be located either behind the air filter or above it. You’ll pull the cover by twisting it.
- Now you can reveal the spark plug by removing the spark plug wire or rubber boot. Again, you’ll have to gently twist and pull the rubber boot.
- Now to remove the spark plug, using the wrench, rotate the plug anticlockwise to unscrew and unplug it.
Test the Ignition Coil Now
Now that the spark plug has been removed, here are the two tests you’ll need to carry out to test your ignition coil.
- First of all, clean up the spark plug so that any dirt or debris could be cleared.
- Then reattach the rubber boot carefully. Push/press the tip on some metal surface and turn on the ignition.
- Start the engine by pulling the starter cord strongly. You’ll see a spark. A proper spark would be visible when the light is dimmed, so, try this under a dimmed light.
- In the event of a spark forming on the surface, the ignition coil is functioning properly. Otherwise, either the coil or the spark plug may need to be replaced.
- Use a new spark plug to perform this test on it. If a spark appears on the spark plug, it confirms that it was defective.
- However, in the case that the new spark plug does not spark, then the coil is the problem.
In some cases, a damaged coil may cause a spark when the chainsaw has cooled down. In order to ensure that it is the coil that is malfunctioning, here’s what you need to try.
- Firstly, you need to access the coil by using a screwdriver to remove the recoil or cover on the engine, which could be located on either side of the chainsaw.
- Then, you’ll see the ignition coil attached to a kill wire. You need to disconnect that kill wire. As a result, the coil will be isolated from all of the wirings.
- Here, you need to perform test 1 again after reattaching the recoil.
- After doing so, if there is no spark, then the coil is damaged. Otherwise, the kill switch or wiring may be the problem.
TESTING WITH MULTIMETER
Here’s a complete guide to testing the coil using a multimeter.
- The Spark Plug Needs to be Disconnected and Tested
- Take Out the Spark Plug
- Check the Coil’s Primary Ignition Circuit
- Make Sure the Secondary Circuit of the Coil is Working
- Disable the Chainsaw’s Fuel Pump
- Get the Chainsaw Going by Cranking its Engine.
- Check the Chainsaw for Sparks
- Install the Ignition Coil on the Chainsaw
- Coil Resistance Check
- Calculate the Coil’s Resistance
- Using a Multimeter, Measure the Resistance
- View The Measurements
The Spark Plug Needs to be Disconnected and Tested
When testing the ignition coil using a multimeter, it’s important to disconnect and test the spark plug first. The spark plug is the component that ignites the fuel mixture in the engine’s combustion chamber, and it’s crucial to ensure that it’s in good working condition.
Disconnecting the spark plug is essential in isolating the ignition coil from the engine and other sources of electrical interference, which could affect the accuracy of the readings. To test the spark plug, inspect it for signs of wear or damage, such as fouling or cracks. A fouled spark plug can prevent the engine from starting or cause it to run poorly.
Take Out the Spark Plug
Taking out the spark plug is an important step when testing the ignition coil of a chainsaw. The spark plug provides access to the ignition coil, allowing you to test its primary and secondary circuits. To remove the spark plug, you should use the appropriate tool to avoid damaging it.
Before removing the spark plug, ensure that the area around it is clean and free of debris. Dirt and debris can cause problems when reinstalling the spark plug and may even damage the threads of the cylinder head.
Check the Coil’s Primary Ignition Circuit
After disconnecting and removing the spark plug, the next step in testing the ignition coil using a multimeter is to check the coil’s primary ignition circuit. The primary circuit is responsible for creating a magnetic field around the coil when current flows through it.
To test the primary circuit, you should connect the multimeter to the coil’s positive and negative terminals. Set the multimeter to the resistance or ohms setting and check the readings. If the readings are within the range specified in the chainsaw’s manual, the primary circuit is functioning correctly. If the readings are out of the specified range, the ignition coil is faulty and needs to be replaced.
Make Sure the Secondary Circuit of the Coil is Working
After checking the primary circuit, the next step in testing the ignition coil using a multimeter is to make sure the secondary circuit of the coil is working. The secondary circuit is responsible for creating the high voltage that ignites the fuel mixture in the engine’s combustion chamber.
To test the secondary circuit, you should use a spark tester or spark plug tester to check for a spark. Place the tester between the spark plug and the ignition lead, and then start the engine. If the tester produces a spark, the secondary circuit is working correctly. If the tester does not produce a spark, the ignition coil is faulty and needs to be replaced.
Disable the Chainsaw’s Fuel Pump
Before testing the ignition coil using a multimeter, it’s important to disable the chainsaw’s fuel pump to prevent fuel from entering the engine. Fuel in the engine can be dangerous when testing electrical components, and it’s crucial to take precautions to avoid a potentially hazardous situation.
To disable the fuel pump, you should locate the fuel pump switch and turn it off. Alternatively, you can remove the fuel pump fuse or disconnect the fuel lines to the carburetor. Once the fuel pump is disabled, you should also turn off the chainsaw’s ignition switch to prevent accidental starting during testing.
Get the Chainsaw Going by Cranking its Engine
After disabling the fuel pump and ignition switch, the next step in testing the ignition coil using a multimeter is to get the chainsaw going by cranking its engine. This step is necessary to test the ignition coil’s ability to produce a spark and to ensure that the chainsaw’s engine is in good working condition.
To crank the engine, you should pull the chainsaw’s starter cord or use an electric starter, depending on the chainsaw’s model. It’s important to follow the chainsaw’s starting instructions carefully to prevent damage to the engine or injury to yourself.
Check the Chainsaw for Sparks
Once the engine is running, the next step in testing the ignition coil using a multimeter is to check the chainsaw for sparks. A spark indicates that the ignition coil is producing the high voltage required to ignite the fuel mixture in the engine’s combustion chamber.
To check for sparks, you should remove the spark plug from the engine and reattach it to the ignition lead. Then, ground the spark plug against the engine block and crank the engine. If a spark is visible at the end of the spark plug, it indicates that the ignition coil is producing the required voltage.
Install the Ignition Coil on the Chainsaw
Before proceeding with further tests, the ignition coil needs to be reinstalled on the chainsaw to ensure proper functioning. Installation steps may vary depending on the chainsaw’s make and model, but the ignition coil typically sits on top of the engine, held in place by mounting screws or bolts.
To install the ignition coil, first, clean the mounting surface and check for any damage to the coil or engine. Then, align the mounting holes of the ignition coil with those of the engine and secure the coil in place using the screws or bolts provided. Make sure that the ignition coil is installed securely and that all electrical connections are reattached.
Coil Resistance Check
Measuring the resistance of the coil can help identify any issues that may be affecting its performance, such as a short circuit or an open circuit. To perform a coil resistance check, first, disconnect the coil’s electrical connector from the wiring harness.
Then, use a multimeter set to the ohm (Ω) setting to measure the resistance across the ignition coil’s primary and secondary windings. Typically, a working ignition coil will have a resistance reading of between 0.4 and 2 ohms for the primary winding and between 6,000 and 15,000 ohms for the secondary winding, depending on the make and model of the chainsaw.
Calculate the Coil’s Resistance
To calculate the expected resistance for the ignition coil, you’ll need to consult the manufacturer’s specifications or technical data for the make and model of the chainsaw. The specifications should provide information on the expected resistance range for the ignition coil’s primary and secondary windings.
Once you have this information, you can calculate the expected resistance values for the ignition coil by applying Ohm’s law. This law states that the resistance (R) of a conductor is equal to the voltage (V) across the conductor divided by the current (I) flowing through the conductor (R = V/I).
Using a Multimeter, Measure the Resistance
To measure the resistance of the ignition coil, first, set the multimeter to the ohm (Ω) setting. Then, connect the multimeter’s test leads to the ignition coil’s primary and secondary terminals. With the ignition coil disconnected from the chainsaw’s electrical system, touch one lead of the multimeter to the primary terminal of the ignition coil and the other lead to the secondary terminal of the ignition coil.
The multimeter should display the resistance value of the ignition coil, which can be compared to the expected resistance values calculated earlier. By measuring the resistance of the ignition coil, you can determine whether the coil is within the expected resistance range, which can help diagnose any issues affecting its performance.
View The Measurements
If the measured resistance falls within the expected resistance range for the ignition coil’s primary and secondary windings, it’s a good indication that the ignition coil is functioning correctly. However, if the measured resistance values fall outside the expected range, it’s an indication that there may be an issue affecting the ignition coil’s performance.
Viewing the measurements also enables you to identify the specific problem affecting the ignition coil. For example, if the measured resistance is too high or too low, it may indicate a problem with the ignition coil’s windings, such as a short or open circuit.
Testing the Chainsaws for Ignition Coil from Top-Most Brands
Because Husqvarna and Stihl are the two best chainsaw brands ever, it’s often asked how to test their ignition coil. Well, here’s how you do it in the case of each of the two brands.
Testing Husqvarna Chainsaw
When your Husqvarna chainsaw fails to start, it’s likely that the ignition coil is the issue. To test if the ignition coil is indeed faulty, follow these steps:
- Disconnect the spark plug wire from the chainsaw’s plug by pulling the boot from the spark plug.
- Clip the clamp of an ignition tester with the spark plug and insert the probe end of the tester into the plug boot. Start the saw.
- Check the window of the ignition tester for a spark. If you see a spark and the chainsaw starts, it means the plug and coil are working correctly.
- Remove the clamp from the plug and connect it to the ground spot on the saw. Try to start the saw while observing the ignition tester window. If you see a spark, the problem is with the spark plug; otherwise, it’s the ignition coil.
- Remove the screws holding the outer cover of the chainsaw and expose the ignition coil next to the carburetor.
- Disconnect the grounding wire from the coil and attempt to start the chainsaw. If you see a spark, the problem is with the chainsaw’s electrical system, and the ignition coil is working fine.
Testing Stihl Chainsaw
If your Stihl chainsaw isn’t starting, a possible issue could be a faulty ignition coil. Testing the ignition coil is important to determine whether or not it is causing the problem. Here are the steps to follow:
- Remove the spark plug from the chainsaw.
- Disconnect the kill wire from the ignition coil to isolate it.
- Attach the flip side of the spark checker to a grounded metal surface and the other end to the spark plug wire.
- Pull the cord to start the chainsaw and observe the spark checker for any sparks.
- If you see a spark, the ignition coil is working properly. If you do not see a spark, the ignition coil needs to be replaced.
- To replace the ignition coil, first, remove the screws holding the outer cover of the chainsaw and remove the cover.
- The ignition coil will be located near the spark plug.
- Disconnect the old ignition coil and install the new one.
- Reattach the outer cover and screws.
- Test the chainsaw to ensure it is starting properly with the new ignition coil.
You may want to check out the Best Stihl Chainsaws here.
How to Test a Chainsaw Coil – FAQs
In conclusion, testing a chainsaw coil is a straightforward process that can be done with minimal tools and experience. Regular maintenance and checks of the ignition system can save you time, money, and effort in the long run. By understanding the steps involved in testing a chainsaw coil, you can quickly identify the root cause of your chainsaw’s starting issues and resolve them.
It is essential to remember to disconnect the chainsaw’s spark plug and disable the fuel pump before testing the ignition coil. Additionally, it is crucial to use a reliable multimeter to measure the coil’s resistance accurately. Finally, while testing the coil, make sure to observe the ignition tester carefully to determine if the coil is working correctly.
With these tips and guidelines, you can test and maintain your chainsaw’s ignition coil to ensure that it continues to function correctly and provide efficient cutting performance for years to come.