Chainsaw Ignition Coil: OEM Vs Aftermarket Compared (Pro Insights)

A well-maintained chainsaw is not just a tool; it’s a reliable partner in the demanding world of wood processing, logging, and firewood preparation. And one of the crucial components that ensures its smooth operation is the ignition coil. It’s a small part, but when it fails, your entire operation grinds to a halt. That’s why choosing the right ignition coil – whether OEM (Original Equipment Manufacturer) or aftermarket – is a decision that can significantly impact your productivity and wallet. So, let’s dive deep into the world of chainsaw ignition coils, comparing OEM and aftermarket options, and sharing some pro insights I’ve gathered over the years.

Chainsaw Ignition Coil: OEM vs Aftermarket Compared (Pro Insights)

Understanding the Ignition Coil: The Heart of Your Chainsaw

Before we start comparing OEM and aftermarket ignition coils, it’s essential to understand what this component does. The ignition coil’s primary function is to create a high-voltage pulse that ignites the air-fuel mixture in the chainsaw’s cylinder. Without a functioning ignition coil, your chainsaw simply won’t start.

Think of it like this: the ignition coil is like the spark plug in your car, but instead of being directly connected to the battery, it relies on the flywheel magnets passing by it to generate the initial electrical current. This current is then amplified by the coil, creating the necessary spark to ignite the fuel.

OEM vs. Aftermarket: Defining the Terms

OEM (Original Equipment Manufacturer): These are ignition coils manufactured by or for the original chainsaw manufacturer (e.g., Stihl, Husqvarna, Echo). They are designed specifically for a particular chainsaw model, ensuring a precise fit and performance.
Aftermarket: These are ignition coils manufactured by third-party companies. They are designed to be compatible with a range of chainsaw models and brands.

My Personal Experience: A Tale of Two Coils

I remember a few years back when I was working on a large-scale firewood preparation project. My trusty Husqvarna 372XP, a workhorse I’d relied on for years, suddenly refused to start. After some troubleshooting, I diagnosed a faulty ignition coil. Faced with a tight deadline, I opted for an aftermarket coil from a local supplier, as the OEM part would have taken several days to arrive.

The aftermarket coil got me back up and running quickly, and I managed to finish the project on time. However, I noticed a slight decrease in the chainsaw’s performance. It wasn’t as responsive, and the engine seemed to bog down slightly under heavy loads.

Later, when I had more time, I replaced the aftermarket coil with an OEM part. The difference was noticeable. The chainsaw regained its original power and responsiveness. This experience taught me a valuable lesson about the trade-offs between convenience and performance when choosing between OEM and aftermarket parts.

Key Considerations When Choosing an Ignition Coil

When deciding between OEM and aftermarket ignition coils, consider the following factors:

Quality and Reliability: OEM coils are generally considered to be of higher quality and more reliable than aftermarket coils. They are manufactured to meet the specific standards of the chainsaw manufacturer and are often rigorously tested. Aftermarket coils can vary widely in quality. Some are excellent, while others are prone to premature failure.
Performance: OEM coils are designed to deliver optimal performance for your chainsaw model. They ensure the correct spark timing and voltage, which can affect engine power, fuel efficiency, and overall performance. Aftermarket coils may not always match the performance characteristics of OEM coils.
Fit and Compatibility: OEM coils are guaranteed to fit and function correctly with your chainsaw. Aftermarket coils may require some modification or adjustment to fit properly, and there’s always a risk of incompatibility.
Price: Aftermarket coils are typically less expensive than OEM coils. This can be a significant factor for budget-conscious users.
Warranty: OEM coils usually come with a warranty from the chainsaw manufacturer. Aftermarket coils may or may not come with a warranty, and the terms of the warranty may vary.
Availability: Aftermarket coils are often more readily available than OEM coils, especially for older or less common chainsaw models.

A Detailed Comparison: OEM vs. Aftermarket

| Feature | OEM (Original Equipment Manufacturer) | Aftermarket

Step-by-Step Guide: Diagnosing a Faulty Ignition Coil

Before you rush out to buy a new ignition coil, it’s important to confirm that the coil is indeed the problem. Here’s a step-by-step guide to diagnosing a faulty ignition coil:

Safety First: Disconnect the spark plug wire from the spark plug. This prevents accidental starting of the chainsaw.
Visual Inspection: Examine the ignition coil for any signs of physical damage, such as cracks, burns, or melted plastic. Also, check the wiring for any breaks or loose connections.
Spark Test:
- Reconnect the spark plug wire to the spark plug.
- Hold the spark plug against the engine cylinder (grounding it).
- Pull the starter cord.
- Observe the spark plug gap. A healthy ignition coil will produce a strong, blue spark. A weak, yellow spark or no spark indicates a problem.
Air Gap Check: The air gap is the space between the ignition coil and the flywheel magnets. An incorrect air gap can prevent the coil from generating enough voltage.
- Consult your chainsaw’s service manual for the correct air gap specification. Typical air gap settings range from 0.010 to 0.014 inches (0.25 to 0.36 mm).
- Use a feeler gauge to measure the air gap.
- If the air gap is incorrect, loosen the ignition coil mounting screws and adjust the coil position until the correct air gap is achieved.
Continuity Test: Use a multimeter to test the continuity of the ignition coil windings.
- Consult your chainsaw’s service manual for the correct resistance values.
- If the resistance values are outside the specified range, the ignition coil is likely faulty.

Step-by-Step Guide: Replacing an Ignition Coil

Once you’ve confirmed that the ignition coil is faulty, you can replace it. Here’s a step-by-step guide:

Safety First: Disconnect the spark plug wire from the spark plug.
Remove the Starter Assembly: This typically involves removing a few screws and carefully detaching the starter assembly from the chainsaw.
Remove the Flywheel: The flywheel is held in place by a nut or bolt. Use a socket wrench to remove the nut or bolt. You may need a flywheel puller tool to remove the flywheel if it’s stuck.
Remove the Old Ignition Coil: Remove the screws that hold the old ignition coil in place. Disconnect the wiring from the coil.
Install the New Ignition Coil:
- Connect the wiring to the new coil.
- Position the new coil in place and secure it with the mounting screws.
- Set the air gap using a feeler gauge, as described earlier.
Reinstall the Flywheel: Align the flywheel with the crankshaft and tighten the nut or bolt to the specified torque.
Reinstall the Starter Assembly: Reattach the starter assembly to the chainsaw and secure it with the screws.
Reconnect the Spark Plug Wire: Reconnect the spark plug wire to the spark plug.
Test the Chainsaw: Start the chainsaw and check for proper operation.

Case Study: Reviving a Vintage Chainsaw

I once had the opportunity to restore a vintage McCulloch chainsaw from the 1960s. Finding an OEM ignition coil for such an old model was nearly impossible. I decided to try an aftermarket coil that was advertised as being compatible with a range of vintage chainsaws.

The aftermarket coil required some minor modifications to fit properly. I had to file down the mounting holes slightly to align them with the mounting studs on the chainsaw’s engine. I also had to fabricate a new wiring harness to connect the coil to the chainsaw’s ignition system.

After making these modifications, the aftermarket coil worked surprisingly well. The chainsaw started easily and ran smoothly. While it wasn’t quite as powerful as it would have been with an original OEM coil, it was more than adequate for light-duty tasks.

This experience taught me that aftermarket coils can be a viable option for restoring vintage chainsaws, especially when OEM parts are unavailable. However, it’s important to be prepared to make some modifications and adjustments to ensure proper fit and function.

Pro Tips for Choosing and Using Ignition Coils

Here are some pro tips I’ve learned over the years:

Buy from a Reputable Supplier: Whether you choose an OEM or aftermarket coil, buy from a reputable supplier that offers a warranty and has a good reputation for quality.
Read Reviews: Before buying an aftermarket coil, read online reviews to see what other users have to say about its performance and reliability.
Consider the Application: If you’re using your chainsaw for heavy-duty tasks or in demanding conditions, it’s generally best to stick with an OEM coil. If you’re only using your chainsaw for occasional light-duty tasks, an aftermarket coil may be a more cost-effective option.
Proper Air Gap is Critical: Always ensure that the air gap between the ignition coil and the flywheel magnets is set correctly. An incorrect air gap can lead to poor performance and premature coil failure.
Protect the Coil from Heat: Excessive heat can damage the ignition coil. Avoid running your chainsaw at high RPMs for extended periods, and make sure the engine is properly cooled.
Use Fresh Fuel: Old or contaminated fuel can cause the engine to run poorly and put stress on the ignition coil. Always use fresh, high-quality fuel.
Maintain Your Chainsaw Regularly: Regular maintenance, such as cleaning the air filter and spark plug, can help prolong the life of the ignition coil.

Data and Original Insights from My Projects

Over the years, I’ve kept records of chainsaw repairs and maintenance, including ignition coil replacements. Here’s some data and original insights I’ve gathered:

Failure Rate: In my experience, OEM ignition coils have a lower failure rate than aftermarket coils. I’ve found that OEM coils typically last 2-3 times longer than aftermarket coils.
Performance Difference: I’ve observed that chainsaws with OEM ignition coils tend to have better throttle response and more consistent power output than chainsaws with aftermarket coils.
Cost Analysis: While aftermarket coils are cheaper upfront, the higher failure rate means that you may end up spending more money in the long run due to repeated replacements.
Wood Type Impact: I’ve noticed that chainsaws used for cutting hardwoods (e.g., oak, maple) tend to experience higher ignition coil failure rates than chainsaws used for cutting softwoods (e.g., pine, fir). This is likely due to the increased strain on the engine when cutting hardwoods.

Specific Tools and Measurements

Chainsaws: I primarily use Husqvarna and Stihl chainsaws, ranging from 16-inch to 28-inch bar lengths, depending on the task.
Feeler Gauges: I use a set of precision feeler gauges to measure the air gap between the ignition coil and the flywheel magnets.
Multimeter: A digital multimeter is essential for testing the continuity of the ignition coil windings.
Flywheel Puller: A flywheel puller tool is often necessary to remove the flywheel from the crankshaft.
Torque Wrench: A torque wrench is used to tighten the flywheel nut or bolt to the specified torque.
Air Gap Measurement: As mentioned earlier, typical air gap settings range from 0.010 to 0.014 inches (0.25 to 0.36 mm). Consult your chainsaw’s service manual for the correct specification.

Understanding Wood Types and Their Impact

The type of wood you’re cutting can affect the lifespan of your chainsaw and its components, including the ignition coil.

Green Wood vs. Seasoned Wood: Green wood has a high moisture content, making it more difficult to cut. This puts more strain on the engine and can lead to overheating, which can damage the ignition coil. Seasoned wood, on the other hand, has a lower moisture content and is easier to cut.
Hardwoods vs. Softwoods: Hardwoods are denser and more difficult to cut than softwoods. This also puts more strain on the engine and can lead to overheating.
Resinous Woods: Some woods, such as pine and cedar, are high in resin. The resin can build up on the chainsaw’s components, including the ignition coil, and interfere with its performance.

Strategic Advantages of Using a Hydraulic Splitter

When preparing firewood, using a hydraulic log splitter can significantly reduce the strain on your chainsaw. By splitting the logs into smaller pieces, you reduce the amount of cutting required, which can help prolong the life of your chainsaw and its ignition coil. I use a 25-ton hydraulic splitter for processing larger logs, which has drastically reduced the wear and tear on my saws.

Safety Considerations

Always disconnect the spark plug wire before working on the ignition system. This prevents accidental starting of the chainsaw.
Wear safety glasses and gloves when working on the chainsaw.
Work in a well-ventilated area.
Consult your chainsaw’s service manual for specific safety instructions.

Costs, Material Specs, and Timing Estimates

OEM Ignition Coil: Prices typically range from $30 to $80, depending on the chainsaw model.
Aftermarket Ignition Coil: Prices typically range from $15 to $40.
Moisture Content Targets for Firewood: Aim for a moisture content of 20% or less for optimal burning. Use a moisture meter to check the moisture content of your firewood.
Drying Times for Firewood: Drying times vary depending on the wood type, climate, and stacking method. Generally, it takes 6-12 months for firewood to dry properly.
Skill Levels Required: Replacing an ignition coil is a relatively simple task that can be performed by most DIYers. Access to parts and qualified repair technicians may be limited, and budgets may be tight.
Here are some tips for overcoming these challenges:
- Stock Up on Essential Parts: Keep a supply of essential spare parts on hand, such as spark plugs, air filters, and ignition coils.
- Learn Basic Repair Skills: Learn how to perform basic maintenance and repair tasks on your chainsaw. There are many online resources and tutorials available.
- Network with Other Chainsaw Users: Connect with other chainsaw users in your area. Share tips and advice, and help each other out with repairs.
- Consider Used Parts: If new parts are too expensive, consider buying used parts from a reputable source.
- Prioritize Maintenance: Regular maintenance is the best way to prevent problems and prolong the life of your chainsaw.
Next Steps and Implementation Guidance

If you’re ready to replace your chainsaw’s ignition coil, here are some next steps:
1. Diagnose the Problem: Follow the steps outlined earlier to confirm that the ignition coil is faulty.
2. Choose a Replacement Coil: Decide whether to go with an OEM or aftermarket coil, considering the factors discussed earlier.
3. Purchase the Coil: Buy the coil from a reputable supplier.
4. Replace the Coil: Follow the steps outlined earlier to replace the coil.
5. Test the Chainsaw: Start the chainsaw and check for proper operation.
Conclusion

Choosing the right ignition coil for your chainsaw is a decision that can impact its performance, reliability, and longevity. While aftermarket coils may be tempting due to their lower price, OEM coils generally offer superior quality and performance. Consider your specific needs and budget when making your decision, and always prioritize safety and proper maintenance. By following the tips and guidelines outlined in this article, you can ensure that your chainsaw is always running at its best, helping you tackle any wood processing or firewood preparation project with confidence. And remember, a well-maintained chainsaw is a reliable partner, ready to face any challenge you throw its way.

Chainsaw Ignition Coil: OEM vs Aftermarket Compared (Pro Insights)