Masterclass: How to Test Motorcycle Ignition Coil with Multimeter Like a Pro

Are you experiencing trouble starting your motorcycle? Does it sputter and cough, refusing to fire up? The culprit might be a faulty ignition coil. Knowing how to test motorcycle ignition coil with a multimeter is a valuable skill for any motorcycle owner, as it can help you diagnose the problem and potentially save you a trip to the mechanic.

Understanding the Ignition Coil’s Role

The ignition coil is a crucial component in your motorcycle’s electrical system. Its primary function is to transform the low-voltage electricity from the battery into a high-voltage current, which is then sent to the spark plugs. This high-voltage spark ignites the air-fuel mixture in the combustion chamber, allowing your engine to run.

Identifying Symptoms of a Faulty Ignition Coil

Before you start testing, it’s essential to recognize the common signs of a failing ignition coil:

• Difficulty starting: The engine may crank but not fire up.
• Misfiring: The engine runs rough, with a noticeable sputtering or hesitation.
• Backfiring: The engine may backfire through the exhaust or intake.
• Reduced power: The motorcycle may experience a loss of power or acceleration.

Tools You’ll Need

To test your motorcycle ignition coil, you’ll need a few basic tools:

• Multimeter: A digital multimeter with both AC and DC voltage measurement capabilities is essential.
• Screwdriver: You’ll need a screwdriver to remove the ignition coil cover.
• Wire connectors: These can be useful for connecting the multimeter probes to the ignition coil terminals.
• Safety glasses: Always wear safety glasses when working with electrical components.

Testing the Ignition Coil: A Step-by-Step Guide

Now, let’s delve into the process of testing your ignition coil using a multimeter:

1. Disconnect the Ignition Coil

• Locate the ignition coil on your motorcycle. It’s usually positioned near the spark plugs and has a distinctive cylindrical shape.
• Disconnect the electrical connectors leading to the ignition coil. Be careful not to damage the connectors.

2. Set Your Multimeter to Resistance Mode

• Turn on your multimeter and set the dial to the resistance (OHM) setting.
• Select an appropriate resistance range for your multimeter. Most ignition coils have a resistance between 0.5 and 10 ohms.

3. Test the Primary Winding

• Connect the multimeter’s positive (red) probe to the positive terminal of the ignition coil.
• Connect the negative (black) probe to the negative terminal of the ignition coil.
• Note the resistance reading on the multimeter. This represents the resistance of the primary winding of the ignition coil.

4. Test the Secondary Winding

• Disconnect the multimeter probes from the primary winding terminals.
• Connect the positive (red) probe to the high-voltage terminal (usually marked with a “HT” or “HV”).
• Connect the negative (black) probe to the ground terminal (usually the metal body of the ignition coil).
• Note the resistance reading on the multimeter. This represents the resistance of the secondary winding of the ignition coil.

5. Compare Readings to Specifications

• Consult your motorcycle’s service manual or online resources to find the specified resistance values for your ignition coil.
• Compare your measured resistance values to the specifications. If the readings are significantly different, it’s likely that the ignition coil is faulty.

6. Testing for Continuity

• Set your multimeter to the continuity setting.
• Connect the probes to the primary winding terminals.
• If the multimeter beeps, it indicates that there is continuity in the primary winding.
• Repeat the process for the secondary winding.
• If you don’t hear a beep, it suggests a broken circuit.

Interpreting the Results

Here’s what the test results might indicate:

• High resistance: A high resistance reading in the primary or secondary winding suggests that the coil is damaged and needs to be replaced.
• Low resistance: A very low resistance reading might indicate a short circuit in the coil.
• No continuity: If the multimeter doesn’t beep when testing for continuity, it signifies a broken circuit within the coil.

Troubleshooting and Repairing a Faulty Ignition Coil

If your ignition coil test reveals a problem, you’ll need to replace it. Here’s a basic guide for replacing an ignition coil:

• Disconnect the battery to prevent accidental electrical shocks.
• Remove the old ignition coil by disconnecting the electrical connectors and loosening the mounting bolts.
• Install the new ignition coil by reversing the removal process. Ensure the connectors are properly secured.
• Reconnect the battery and start your motorcycle.

Beyond the Basics: Advanced Testing Techniques

While the basic multimeter test provides a good starting point, advanced techniques can provide a more comprehensive assessment of your ignition coil. These include:

• Testing for voltage at the ignition coil: This can help determine if the coil is receiving the correct voltage from the ignition system.
• Testing for spark at the spark plug: This confirms that the coil is generating a sufficiently strong spark to ignite the fuel.
• Using an oscilloscope: This tool can help visually examine the shape and timing of the spark generated by the coil.

Final Thoughts: Riding Smoothly Again

By understanding how to test motorcycle ignition coil with a multimeter, you can diagnose and troubleshoot a common electrical problem. A faulty ignition coil can leave you stranded, but with the right knowledge and tools, you can quickly identify and address the issue, getting you back on the road.

Frequently Asked Questions

1. What is the typical resistance of an ignition coil?

The resistance of an ignition coil varies depending on the make and model of the motorcycle. However, most ignition coils have a primary winding resistance of 0.5 to 10 ohms and a secondary winding resistance of 5,000 to 20,000 ohms.

2. Can I test an ignition coil while it’s still installed on the motorcycle?

It’s possible to test an ignition coil while it’s still installed, but it’s generally recommended to disconnect it for more accurate results.

3. How often should I test my ignition coil?

There’s no fixed schedule for testing your ignition coil. However, it’s a good idea to test it if you experience any of the symptoms mentioned earlier.

4. Can I replace an ignition coil myself?

Replacing an ignition coil is a relatively straightforward task that most motorcycle owners can handle themselves. However, if you’re unsure about the process, it’s always best to consult a qualified mechanic.