Harley Davidson Ignition Coil Problems: What You Need To Know

An ignition coil is a component of the spark plug circuit of a Harley Davidson motorcycle that provides electricity to the spark plug. It is responsible for converting the low voltage of a battery into the high voltage needed to spark the gasoline engine.

The spark plug sends high voltage to the combustion cylinder chamber, which ignites the fuel mixture and causes the engine to start. An ignition coil is part of the electronic circuit in an engine with an electronic ignition system. It transforms the battery’s voltage to the high voltage required for the spark plug to spark.

Here, we will cover Harley Davidson Ignition Coil Problems and solutions. We will also provide tips on avoiding these issues and keeping your motorcycle running smoothly.

Harley Davidson Ignition Coil Problems

Harley Davidson Ignition Coil Problems Sings And Solutions

Harley Davidson Ignition Coil Problems Sings And Solutions

Harley Davidson ignition coil problems can be a frustrating issue for motorcycle owners. The ignition coil is an essential component of the motorcycle’s ignition system, responsible for generating the high voltage needed to ignite the fuel and air mixture in the engine. When the ignition coil malfunctions, it can lead to a variety of issues, including misfires, hard starting, and even engine stalling. Below we discuss symptoms reasons and solutions:

Symptoms Of A Bad Ignition Coil

If you are experiencing issues with your Harley Davidson kickstand, it may be a sign of a bad ignition coil. If you are experiencing any of these symptoms, it is important to have your bike inspected by a qualified mechanic who can diagnose and repair any issues with the ignition coil. Some common symptoms of a faulty ignition coil include:

  • Engine Misfires Or Stalls: If your engine is misfiring or stalling frequently, it could be due to a malfunctioning ignition coil.
  • Difficulty Starting The Bike: A bad ignition coil can make it difficult to start your Harley Davidson, requiring multiple attempts or causing the engine to crank but not start.
  • Decreased Fuel Efficiency: A faulty ignition coil can cause the engine to run inefficiently, leading to decreased fuel efficiency and potentially higher fuel consumption.
  • Rough Idling: If you notice that your bike is idling roughly or has an uneven idle speed, it could result from a failing ignition coil.
  • Loss Of Power: A bad ignition coil can cause a loss of power or performance in your Harley Davidson.

Solutions Of Harley-Davidson Ignition Coil Problems

Solutions Of Harley-Davidson Ignition Coil Problems

Gasoline-powered vehicles, such as Harley Davidson motorcycles, require an ignition coil to start the engine cycle. The ignition coil is a component that helps create a spark that ignites the fuel in the cylinders and causes the engine to turn over.

Several problems with Harley Davidson ignition coils can occur, including shorting, cracking, and misfiring. If you notice an issue with your ignition coil. It’s important to take it to a mechanic for inspection and repairs. Here are some common issues and how to fix them:

  1. Check For Loose Or Damaged Wiring Connections: One of the most common causes of ignition coil problems is loose or damaged wiring connections. Make sure all connections are secure and free from any corrosion.
  2. Test The Ignition Coil With A Multimeter: Use a multimeter to test the resistance of the ignition coil. A reading that is significantly higher or lower than the specified range could indicate a faulty coil.
  3. Replace The Ignition Coil: If testing confirms that the ignition coil is faulty, it will need to be replaced. Make sure to choose a high-quality replacement that is compatible with your specific Harley Davidson model.
  4. Inspect Other Components: Ignition coil problems can sometimes be caused by issues with other components, such as spark plugs or the ignition control module. Inspect these components and replace them if necessary.
  5. Seek Professional Help If Needed: If you are unsure about how to diagnose or fix an ignition coil problem, it is recommended to seek assistance from a professional mechanic who specializes in Harley Davidson motorcycles. They will have the expertise and tools necessary to accurately diagnose and repair any issues.

How To Avoid Harley-Davidson Ignition Coil Problems

How To Avoid Harley-Davidson Ignition Coil Problems

Avoid driving with Harley Davidson bad coil symptoms to prevent engine failure or backfire. It is important to check the Harley-Davidson coils regularly for signs of weakness, such as burnt spark plug wires or an arcing coil. Replace the ignition coil if you detect a weak spark. Monitor the engine idle and start-up to ensure the coils are working properly. This will ensure that they don’t become damaged or burned out.

Keep The Spark Plugs In Good Condition

An ignition coil provides the primary current required for fuel combustion. It creates a spark between two electrodes, which in turn creates high-voltage pulses to ignite the fuel mixture in an engine. If the ignition coil is weak or unable to create a spark, it will be unable to start the engine.

In addition, if the ignition coil is not working properly, it might not generate the high-voltage spark signals necessary for combustion. As a result, the engine would not be able to start. You should do regular maintenance to keep the spark plug in good condition and ensure proper performance of the Harley-Davidson ignition coil. This includes replacing the spark plug after each use and keeping them clean and dry.

Keep A Check On The Tires

It is important to inspect the tires of your Harley Davidson at regular intervals to ensure they are in good condition. If either of the tires is worn out, it can affect the functioning of the ignition coil and lead to bad ignition.

It’s also important to replace the tires when they need replacing. Using a multimeter, you must also properly connect the spark plug and gap in the wire. You should measure the voltage supplied when looking for signs of damage in ignition coils.

Fill The Fuel Tank In Due Time

Fill The Fuel Tank In Due Time

If the motorcycle’s engine fails to start or runs rough, it could indicate a bad ignition coil. This can lead to a misfiring spark plug and poor engine performance. Before attempting to repair the problem, it’s important to diagnose it thoroughly.

First, check the fuel level in the tank regularly to ensure that it doesn’t run out before you can start riding the motorcycle. If your engine consistently fails to start or runs rough, there might be a problem with one of its ignition coils. In this case, replace them with new ones as soon as possible.

Keep Your Motorcycle Clean

Regularly cleaning Harley Davidson is essential to maintain its overall system and function properly. Dirt and grime can accumulate on the motorcycle, leading to issues with the ignition coil. You must, therefore, regularly clean your motorcycle to ensure it operates at its best. You can use a vacuum to remove dust and dirt from engine compartments, wheels, and other areas.

How Do You Test A Harley Davidson Coil?

How Do You Test A Harley Davidson Coil

Testing a Harley Davidson ignition coil is important in diagnosing any potential problems. By following these steps, you can effectively test your Harley Davidson ignition coil and determine if it is functioning properly or needs replacing. Here is the step-by-step guide on how to test a Harley Davidson coil:

  • Disconnect the spark plug wires from the coil.
  • Use a multimeter to set the resistance mode.
  • Connect the multimeter’s positive lead to the coil’s positive terminal and the negative lead to the negative terminal.
  • Check the resistance reading on the multimeter. The value should fall within a specific range, as specified by Harley Davidson.
  • If the resistance reading is outside the specified range, it indicates a faulty coil and should be replaced.
  • Repeat this combustion process for each coil on your Harley Davidson motorcycle.

Ignition Coil & Their Types

An ignition coil is a component of a spark ignition system of an internal combustion engine. It is a coil of wire with a primary coil, which acts as a transformer, and a secondary coil. The primary coil generates a voltage transferred to the secondary coil via an ignition spark gap.

The voltage in the primary coil creates an electric field around the spark gap. This electric field induces eddy currents in the secondary coil, producing voltage amplification that powers the spark plug.

Conventional Ignition Coil

Conventional Ignition Coil

Conventional ignition coils take energy from the battery and convert it to a voltage of 50,000 or more to create a spark that ignites the fuel. Older vehicles with a distributor have a single coil that provides voltage to the distributor.

The original big Twin coil was later replaced by a slimline coil that is more durable and compact, helping to keep the power lead separate from the electrical wire. The ignition coil comprises an iron core and primary and secondary windings connected to the electrical components. It plays a critical role in starting combustion in vehicles and is an essential component of most Single-coil engines.

Distributor-Less Or Dis Ignition Coil

DIS or Distributor-less ignition coils feature three or more coils grouped and rely on a device for magnetic triggering to control the speed of the engine and spark timing. To test if a DIS ignition coil is dead, one can use an ignition spark tester or multimeter to test resistance.

DIS ignition coils are usually powered and controlled by an Ignition Module, which can also fail. COP ignition systems have coils that sit directly on top of the spark plug, and the ECM or PCM can regulate spark timing for each cylinder.

Electronic Ignition Coil

Electronic ignition coils are used in automobiles and motorcycles to provide reliable performance and enhanced engine efficiency. An ignition coil is a device that takes low-voltage power from a battery and transforms it into high-voltage power, creating a spark that ignites the car’s fuel mixture. It is an important part of an engine’s ignition system. The coil gets its power from a Harley-Davidson spark plug battery.

Coil-On-Plug Or Cop Ignition Coil

The COP ignition coil is an engine component that provides voltage to the spark plug to ignite the fuel in the cylinder. It is a magnetic device typically made up of several turns of wire or a coil of wire wound around a core, with the core acting as an electrical node.

The ignition coil takes energy from the battery and sends it to the spark plug to create the spark needed for combustion. The spark plug usually mounts it, eliminating wires between the coil and plug.


Dealing with Harley Davidson Ignition Coil Problems can be frustrating for Harley Davidson owners. These issues can lead to engine misfires, poor performance, and even complete breakdowns. It’s important to address ignition coil problems as soon as they arise to prevent further damage to your motorcycle.

Whether you choose to replace the faulty coil or seek professional help, taking action is crucial for keeping your Harley running smoothly. By addressing these issues promptly, you can ensure that your rides are enjoyable and worry-free. Don’t let ignition coil problems hold you back from hitting the open road – take the necessary steps to keep your Harley Davidson in top shape.

Frequently Asked Questions

Can Bad Ignition Coil Be Repaired?

No, a bad ignition coil cannot be repaired. It is a component prone to wear and tear, and once it starts malfunctioning, it will need to be replaced.

What Causes Ignition Coil Damage?

Ignition coil damage can be caused by several factors, including age, heat, excessive voltage, and exposure to moisture or contaminants. Over time, the coil’s internal components can degrade, leading to reduced performance or failure.

Do Ignition Coils Get Weak?

Yes, ignition coils can weaken over time. The ignition coil transforms the battery’s voltage into the higher voltage needed to ignite the spark plugs.

What Do Ignition Coils Improve?

Ignition coils improve the efficiency and performance of the ignition system in a vehicle. They are responsible for converting the battery’s low voltage into the high voltage needed to create a spark at the spark plugs.

Can A Coil Cause Weak Spark?

Yes, a coil can cause a weak spark if it is faulty or damaged. The coil is responsible for generating the high voltage necessary to create a spark in the spark plugs.


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