How to Test a Magneto Coil With a Multimeter?

How to Test a Magneto Coil With a Multimeter?

If you’re a vehicle enthusiast, then you know that magneto coils are an important part of the ignition system. If your bike isn’t starting up like it used to, it might be time to test the coil. In this article, we’ll show you how to do just that using a multimeter. We’ll also provide some tips on troubleshooting and fixing common problems with magneto coils. So whether you’re a beginner or an experienced mechanic, read on for all the information you need to test your coil!

The Working Principle of Magneto Coil

Magneto coils are commonly used in ignition systems to create the high-voltage spark needed to ignite the fuel/air mixture in an engine. They are also used in other applications such as arc

A magneto coil is a type of device that uses electricity to create a magnetic field. It is found in many electrical devices, including generators, motors, and solenoids. The coil consists of an insulated wire that is wrapped around a metal core. When current flows through the wire, it creates a magnetic field.

The Working Principle of Magneto Coil

The magneto coil is a key component in the ignition system of any engine. Its function is to produce the voltage high enough to create the spark that ignites the fuel-air mixture in the cylinders. If the coil is not working properly, the engine will not run.

In order to understand how to test a magneto coil with a multimeter, it is first necessary to understand the working principle of the magneto coil itself.

The magneto coil is a simple device consisting of two parts: the primary winding and the secondary winding. The primary winding is made up of many turns of wire wound around a central core. The secondary winding is made up of fewer turns of wire wound around the outside of the primary winding. The two windings are electrically insulated from each other.

Magneto coils are responsible for providing the spark that ignites the fuel in an engine. The coil is essentially a transformer that takes the low voltage from the battery and transforms it into a high voltage needed to create a spark.

Over time, magneto coils can fail due to wear and tear or simply because they were not made to last forever. If your engine is having trouble starting or if it’s running rough, one of the things you should check is the magneto coil. In this article, we’ll show you how to test a magneto coil with a multimeter. [1], [2], [3], [4]

Signs of a Malfunctioning Magneto Coil

Testing the magneto coil is important because it helps ensure that the device is working properly. If the coil is not working properly, it can cause a number of problems. It is important to test the magneto coil in your engine regularly because it helps ensure that the engine is operating correctly.

But before testing the magneto coil, it is important to be aware of the signs that indicate that it may be malfunctioning.

Engine warning lights

One of the most common signs that something is wrong with the magneto coil is that the engine warning light comes on. If this happens, it is important to take the car to a mechanic as soon as possible so that they can diagnose and fix the problem.

Engine warning lights

Low accelerating power

If the magneto coil is not providing enough power to the spark plugs, it can also result in a loss of power when accelerating. This can make it difficult to overtake other vehicles or climb hills.

Vibration

Another common symptom of a problem with the magneto coil is vibration. If the coil is not mounted properly, it can cause the engine to vibrate. This can be extremely dangerous, as it can lead to engine failure. In order to avoid this problem, it is important to make sure that the coil is mounted correctly. If the problem persists, it is advisable to take the car to a mechanic so that they can diagnose and fix the problem.

Faulty engine start-up

Another common symptom of a malfunctioning magneto coil is that the engine is difficult or impossible to start. If the magneto coil is not providing enough power to the spark plugs, they will be unable to create a spark strong enough to ignite the fuel mixture. This can make it extremely difficult, or even impossible, to start the engine.

Another symptom of a problem with the magneto coil is that the engine may start but then stall soon afterwards. This is usually due to a loss of power from the coil as it struggles to maintain the magnetic field. [2], [4]

Testing Magneto Coil With a Multimeter

One of the most common ways to test a magneto coil is with a multimeter. A multimeter is an electronic measuring instrument that combines multiple measurement functions into one unit. A typical multimeter can measure voltage, current, and resistance. Some multimeters can also measure continuity, capacitance, and inductance.

Testing Magneto Coil With a Multimeter

Multimeters are essential tools for diagnosing electrical problems in a wide variety of devices and systems. They are often used by electricians, engineers, and technicians to troubleshoot circuits, test components, and check the health of batteries and other electrical system components. They are also a relatively simple and straightforward tool that can be used to test the continuity of an electrical circuit.

Remove the flywheel shroud

The first step in testing the magneto coil is to remove the flywheel shroud. This will give you access to the coil so that you can test it with a multimeter.

To remove the flywheel shroud, start by disconnecting the negative battery terminal. This will prevent any electrical shocks while you are working on the engine. Next, remove the bolts that hold the shroud in place. Once the bolts are removed, carefully lift off the shroud and set it aside.

Locate the magneto coil

With the shroud removed, you should be able to see the magneto coil. The coil consists of two wires wrapped around an iron core. If you are having trouble finding the coil, consult your vehicle’s repair manual. Once you have found it, you can proceed to the next step.

Remove the rubber casing

The next step is to remove the rubber casing that surrounds the spark plug and the coil. This will give you access to the terminals so that you can test them with a multimeter. To remove the casing, start by prying off the top cap with a flathead screwdriver. Once the top cap is removed, you should be able to see the two terminals that are exposed. Using a pair of needle-nose pliers, carefully disconnect the wires from these terminals. Once the wires are disconnected, you can proceed to testing the coil with a multimeter.

Set multimeter dial to Ohms

The first thing you need to do when testing the coil is to set the multimeter dial to Ohms. This will allow you to measure the resistance of the coil. To do this, simply rotate the dial on the multimeter until the symbol for Ohms is aligned with the needle. Turn off the auto-ranging feature if your multimeter has one. This will ensure that you get an accurate reading. Instead, set the multimeter to 40k Ohms range.

Probe the magneto coil terminals

With the dial set to Ohms, you can now probe the magneto coil terminals with the multimeter leads. Start with the primary winding terminal. This is the terminal that is connected to the power source. To test this terminal, touch the red lead of the multimeter to the U-shaped terminal and the black lead to the metal surface.

Repeat this process for the secondary winding terminal. This is the terminal that is connected to the spark plug. But this time, use the black lead to touch the rubber boot that is surrounding the terminal, touching the metal clip.

Probe the magneto coil terminals

In both cases, you should see a continuity reading on the multimeter. If you don’t, this could indicate that the coil is defective and needs to be replaced. Depending on the type of multimeter you are using, the acceptable reading may be in the range between 3k and 15k Ohms.

If the reading you get is higher than this range, it could indicate that the coil is damaged and needs to be replaced. [2], [5]

FAQ

How can you tell if an ignition coil is bad?

There are a few ways to tell if an ignition coil is bad. One way is to check for physical signs of damage, like cracks or breaks in the coil. Another way is to measure the resistance of the coil with a multimeter and compare it to the manufacturer’s specifications. Finally, you can test the coil by itself or while it’s still installed on the engine.

How many ohms should a coil read?

A good coil will read between 3k and 15k ohms. If your multimeter reads anything outside of that range, the coil is most likely bad.

How do you check a magneto coil?

The most common way to check a magneto coil is with an ohmmeter, also called a multimeter. This device measures electrical resistance and can tell you if the coil is intact and functioning properly.

To test your magneto coil with a multimeter, first disconnect it from the engine. Then, set your multimeter to the ohms setting and touch the probes to the terminals on the coil. If the reading is infinite, that means there is no continuity and the coil is bad. If your multimeter shows continuity, that means the coil is good.

What is the resistance for a magneto?

The resistance for a magneto should be between 0.75 and 0.85 ohms. If the resistance is outside of this range, it is likely that the magneto coil is damaged and will need to be replaced.

#How do you check if a magneto is working?

The most common way to check if a magneto is working is to use a multimeter. You can check the resistance of the coil and see if it is within the range specified in the manual. If the coil is open or shorted, then it needs to be replaced. Another way to test a magneto is by using a voltmeter, you can test the output of the magneto by measuring the voltage at the points where the spark plug wires attach to the coil.

Useful Video: How To Test a Lawn Mower Magneto Coil

Conclusion

This concludes our blog post on how to test a magneto coil with a multimeter. Testing the coil is a relatively simple process that can be done with a multimeter. By following the steps outlined in this blog post, you should be able to test the coil and determine if it needs to be replaced. Make sure to set your multimeter to the correct setting and to touch the terminals with the leads in the right order to get an accurate reading. If you get an “infinity” reading on the multimeter, this could indicate that there is a break in one of the wires. This is a definite indicator that the coil will need to be replaced. We hope you found it informative and useful. If you have any questions or comments, please feel free to leave them in the section below. Thanks for reading!

References:

  1. http://www.ankn.uaf.edu/publications/vs/magneto.html
  2. https://electrouniversity.com/how-to-test-a-magneto-coil-with-a-multimeter/
  3. https://www.aopa.org/news-and-media/all-news/2019/december/flight-training-magazine/how-it-works-magneto
  4. https://www.mecholic.com/2019/03/magneto-ignition-system-construction.html
  5. https://goneoutdoors.com/test-magneto-ignition-coil-7948575.html