Bad Stator Symptoms – Signs of a bad Stator

A motorcycle stator is one of the most critical components of your motorcycle, and it belongs to the “electrical system” of your bike. But most of the experienced riders cannot describe the functioning of a stator as nobody wants to touch the electric components.

However, the stator is a significant part that provides current to all the electronic items on the motorcycle. Once it goes bad, your bike is going to face a lot of problems.

If you want to know about the symptoms of a bad stator and how you can prevent such issues, this article is for you. Let’s get started with the most common symptoms of a bad stator.

If you want to identify the common symptoms of a bad stator, it is essential to learn the process of how a stator works and what its roles are in the motorcycle.

What is a stator?

A stator is the stationary part of the alternator system of the motorcycle that powers all the electronic components, including the spark plugs. It has electromagnets with coils of copper wounded on soft iron bars. When the magnetic shaft within rotates, these coils generate an electric current. This current later travels to other equipment such as spark plugs, headlamps, lights, etc.

The main symptom of a bad stator is related to this function. If a stator is in bad condition, it won’t provide enough power to the spark plugs resulting in a weak spark or no part at all. As an outcome, your bike would start with difficulty and eventually stop moving at all. That’s why it is vital to have a good stator to continue using your motorcycle.

When it comes to recognizing the signs of a bad stator, things are not that easy as most of the symptoms can also point towards other components’ failures. For example, if a bike is difficult to start or doesn’t start at all, it can be due to a faulty spark plug, bad plug wires, a bad engine, or anything else.

However, certain signs point precisely towards a bad stator, and we will discuss them in detail.

Most Common Bad Stator Symptoms

The motorcycle is hard to start/doesn’t start at all

The first common symptom is when it becomes difficult to start the bike or when it does not get started at all. As we already know, the primary function of a stator is to supply current to the spark plug. Therefore, if the stator starts working poorly, your spark plug won’t receive enough power. As a result, the bike won’t start or become painful to start.

This symptom might be the aftereffect of damaged spark plugs, but now you know about motorcycle stators, you can check your stator when you witness such signs.


Misfiring is one of the most typical consequences of a faulty stator. When your motorcycle misfires, it loses its steady rhythm for a few seconds and automatically catches it back after a while. You might not understand the reason for such unexpected shocks as they can be temporary and very short. But in the long run, if you have a weak stator, your bike will eventually stop running as it won’t be getting enough power supply.


Backfiring is a phenomenon that usually takes place alongside misfiring.

If misfiring is the desynchronization during the fuel burning, backfiring is the ignition of unburnt fuel in the exhaust pipe. In simple words, when the stator doesn’t generate power for the ignition system at the right moment, it leads to a delayed spark into the exhaust system. This backfiring can critically damage the exhaust system or other crucial parts of a bike.

Plus, backfiring can be scary if you don’t have much experience with motorcycle issues.

Low and high RPMs discrepancies

The above-given issues might result from other faults, but this problem directly points towards a bad stator coil. Your motorcycle might operate perfectly at a slower speed or lower RPMs (revolutions per minute). But when it starts to misfire and backfire at higher RPMs (higher speed), it is evident that your bike has a bad high-speed coil.

Plus, you can experience an exactly opposite phenomenon if your low-speed coil goes bad. In such conditions, your bike will show ignition problems at low speeds and run perfectly at high speed.

Low and high-temperature discrepancies

Like RPM issues, low and high-temperature discrepancies can also be an obvious sign of a bad stator coil. During these issues, your bike will operate flawlessly at a particular temperature such as low or high temperature but will misfire and backfire at the opposite temperature levels.

Once you recognize that your bike is behaving in a particular way in low or high temperatures, you should check for your stator’s condition and the ignition coils.

Preventing/Avoiding Stator Issues

The total cost of replacing a stator can cost you $300 to even $1500, and it is highly reasonable to take care of your stators and increase their life tenure. But before we move on to the steps to prevent stator issues, it is equally important to understand what causes a stator to fail in the first place.

Causes of a Failed Stator

There are multiple reasons behind a failing stator, but the most common one is time. Stators have a very long life cycle, and if you take good care of them, they can even last for 200,000 miles. But the more you run your bike, the more it gets exposed to vibrations, heat, cold, wind, water, etc., the sooner your stator will die out.

Another most common cause of stator falling apart is power overload. Stators produce power for all the electronic accessories of your bike. But if you use extra accessories along with lights, such as heated grips, GPS, stereo, and other accessories, it will require your stator to provide more power to these accessories. The stator will also have to provide the constant current to the spark plugs. As a result, your stator will get exhausted soon and may even get burned.

Here are some things that you should notice and implement to protect your stator and your motorcycle’s other components.

Mileage and Cleaning

Mileage is the first thing that points toward your bike’s maintenance. You expose your stator to wind, dirt, heat, and other external objects when you ride your bike.

If you want to keep all your motorcycle components, including the stator, in a healthy state, you must clean your bike after traveling a certain distance. Regular cleaning your bike will result in better longevity of your stator, and you will be able to use the same stator of thousands of miles.


As already discussed, a stator’s function is to initiate the ignition and provide power to all the electronics present on your motorcycle. However, the stator has a limit up to which it can provide power to all the electronics.

That’s why it is logical that we don’t put extra pressure on your bike’s stator by not overcrowding it with electronics. This reduces the overall amperage, relieves the stator of doing additional work, and gives extra life to it.


The simple rule of vibration for your motorcycle is – Avoid vibrations as much as you can. While riding, unwanted shocks or blows can take a heavy toll on your bike and its components, including the stator. Such vibrations begin to rub the varnish from the windings that serve as an insulator on your stator. It can eventually kill your stator.

Hence, we recommend that you stay away from potholes, avoid exposing your bike to unwanted jolts, and use a good pair of shock absorbers. All these measures will reduce the toll on your bike and extend the life of your stator.


What Is The Stator And How Does It Work?

A stator is a component of the motorcycle that generates power for all its electrical components. In technical terms, it is a combination of soft iron poles that have copper wire wounded around them. These coils are connected in series to form a stator and, as a result, generate the DC power to operate the motorcycle.

When the magnet on the shaft spins, the stator creates an alternating current (AC). Later, this AC travels through a rectifier/regulator that converts it to DC power and offers a consistent output.

How do I know if my stator is bad?

Several signs show that your stator is in bad condition, such as no spark, weak spark, or intermittent spark (also known as misfiring). It will lead to difficulty in starting the motorcycle, or it won’t start at all.

What causes a stator to go bad?

Several factors damage a motorcycle stator, such as overcrowding of electronics on the bike or exposure to high heat for a long time. Overcrowding electronics would demand even more electrical power than the stator can generate.

Can you bypass a stator?

When stators are completely damaged, it is better to replace them with a new one. However, if you have sound knowledge of electronics and motorcycles, you can bypass a stator by using an ignition coil, batteries, capacities, resistors, etc.

All you have to do is take out the stator, find the issue, and re-wound the copper wiring using the new AWG wire. Then, after some time, you have to cure it in the oven and connect the cables to phases, and the task will be complete.

Remember that it requires attention to detail, and if you don’t have enough experience, it is wise to contact an experienced mechanic to fix your stator.

How much does it cost to have a stator replaced?

Usually, the overall cost of replacing your stators can cost you between $250 and $1,500.

How much voltage should a motorcycle stator put out?

Typically, a motorcycle stator puts out a voltage of 20 to 50 volts, depending on your motorcycle.

What are the signs of a bad voltage regulator?

There are numerous signs of a bad voltage regulator such as high or low or even no voltage output, dim lights, faulty high beam headlamp, more corrosion around battery terminals, and dead battery. Other signs include the need to frequently add more water to the battery, improper engine functioning, etc.

How do I know if my voltage regulator is working?

The easiest way to know if your voltage regulator is working or not is by using a multimeter. You can purchase one from any hardware store, online, or at an automotive store.

A multimeter will immediately tell you the voltage running through your battery and indicate to you about your regulator.

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