Stihl Ignition Coil Problems

At the heart of your Stihl chainsaw or leaf blower sits a vital component, silently and efficiently performing its duty – the ignition coil. This piece of hardware might seem insignificant in comparison to the roaring power of your Stihl engine, but when it begins to fail, you’ll quickly realize just how crucial it is.

This can be more evident if you look at how users express their frustration regarding Stihl ignition coil problems. If you’ve ever found yourself in the throes of frustration as your faithful tool refuses to roar into life or suffers from intermittent power loss, then this guide is about to become your new best friend.

From discovering common ignition coil problems to resolving them, we’ll guide you step by step with expert advice. Let’s jump. 

Stihl Ignition Coil Problems

Stihl Ignition Coil Problems

Stihl ignition coil problems can impact the effectiveness of your chainsaw. These issues often manifest as failure to start, subpar performance, or intermittent running, issues which can disrupt your work rhythm and make tree cutting a herculean task. 

This reveals the importance of the ignition coil’s inefficient energy transfer within the chainsaw’s engine. Here are some of the common ignition coil issues experienced by users. 

Weak Spark

For any ignition engine to function properly, it necessitates a strong spark. Nevertheless, numerous owners of Stihl small engines have noted that while their spark exists, it doesn’t seem sufficiently strong. This issue persists even after replacing the spark plug with a fresh one. 

Such a problem could be attributed to a faulty coil in the spark plug. A typical symptom is the engine operating adequately until it heats up. Once heated, they cease functioning as if they’ve run out of fuel.

In case you’ve encountered such an issue, ensure that the plug wire is tightly and securely twisted into the coil and there are no frail or broken sections along the wire. Also, confirm that it’s well connected to the spark plug connector.

Invest in an adjustable spark tester for clarity on this issue; it should be able to clear 6mm and display a bright blue or white color. If instead, it shows yellow or orange and fails to clear this gap, your coil might be at fault here. It would also help if you examine the resistance of both primary and secondary windings within your coil.

Engine Dies Suddenly

Several owners of Stihl small engines have reported an odd problem where their engines abruptly stop in the middle of cutting tasks and refuse to restart until they’ve cooled down. 

Despite having nearly new ignition coils, they still encounter this issue which gradually worsens over time. Often, the cause can be traced back to the plugs ‘opening up’ under heat stress when they start to fail. This is typically the most common reason and also the easiest one to rectify. 

However, if a new plug doesn’t resolve the problem, it’s advisable to check for a short or an open circuit on a coil. Ensure you have a clean air filter and try using fresh gas with Sta-Bil. 

If the engine starts but then exhibits the same symptoms, inspect your coil when it’s hot and look for any possible air leaks or loose bolts. An aftermarket coil is a cost-effective replacement option.

Burned or Fried Ignition Coil

Many Stihl chainsaw users have reported issues with the machine’s ignition coil, specifically instances of it burning out. These individuals noted that the chain tends to rotate at an unusually high rpm when the device is idle. Despite efforts to rectify this by cleaning out the sprocket housing and adjusting the low idle setting, they observed no improvement – the chain continued to spin at a rate higher than average idle rpm. 

Interestingly, applying and then releasing the brake handle seemed to restore normal idle speed, but this also resulted in the chain becoming immobile. A preliminary visual examination revealed that the ignition coil was burned or fried.

Upon further investigation, it was revealed that the ignition coil overheats due to a malfunction of the cooling system. This damages not only the ignition coil but also affects other parts of the chainsaw mechanism. 

On contacting Stihl customer service, most owners were advised to replace their burned ignition coils and check if there is any improvement. However, even after replacing it with a new one, few reported that they experienced similar issues again.

How to Diagnose and Replace A Bad Ignition Coil Stihl Small Engine

Diving into the guts of your Stihl engine may seem like a daunting task, but when it comes to diagnosing and replacing a bad ignition coil, it’s simpler than it appears. See the sections discussed below. 

Diagnosing Bad Ignition Coil

Diagnosing a faulty ignition coil in a Stihl small engine can be done through several steps. For an expert, it might come as second nature, but for the beginner or novice, here’s how you carry it out.

Firstly, start by observing any abnormalities during the motor operation. Misfiring and inconsistency in power delivery hint at ignition coil faults. If the starter pull feels heavier than usual on your Stihl chainsaw or motorized equipment, this could also indicate a potential issue.

The next step involves inspecting the spark plug – an essential element of the ignition system. A damaged spark plug can often lead to a perceived coil issue. Thus, reviewing it eliminates one more potential culprit from your list.

Lastly, perform a resistance test on the suspected coil using a multimeter. It may sound technical, but don’t worry; it’s quite straightforward with guidance. Compare your readings to the reference points mentioned in your user manual.

These are the comprehensive steps when diagnosing a faulty ignition coil in any Stihl small engine. Remember that presenting symptoms may vary slightly depending on each specific model of machinery. Don’t hesitate to consult professionals if needed!

Replacement Process

Once you have detected a bad ignition coil, the most effective solution is to replace the faulty ignition coil. For this, begin by ensuring you have your replacement parts and the necessary tools at hand. You must disconnect the spark plug lead from the spark plug before starting to prevent any accidental starts during repairs.

The next step is to remove the blower housing, providing access to the ignition coil. Once accessible, loosen it, but do not remove the two screws holding it. This permits slight adjustments when positioning your new coil.

Before installing your new Stihl ignition coil, make sure that it’s clean and free of rust or dirt. An improperly cleaned coil can cause operational problems.

Lastly, slide the new coil onto the mounting studs and adjust as needed using the original screws. Reconnect all leads once complete and ensure everything is snugly tightened.

Final Words

Stihl ignition coil problems can significantly impede the performance of your power tools. It’s crucial to recognize the symptoms early and take appropriate action to prevent further damage. Regular maintenance and check-ups are paramount in keeping your equipment running optimally. 

Remember that resolving complex issues should be left to professionals to avoid causing more harm than good. Don’t hesitate to consult with a certified technician if you encounter persistent or severe Stihl ignition coil issues.

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