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Do Motorcycles Have Alternators? Newer Models Do

You probably picture two wheels with a motor at the center and a chain drive in the back when you think about motorcycles. But there’s more to the story.

Whether a car, truck or motorcycle, requires a power generator that will output enough power to start a vehicle or various gadgets that need electricity.

Do motorcycles have an alternator? The answer is “yes.”

What is an alternator? 

An alternator is a source of electricity for a vehicle with enough power to make a spark strong enough to start the ignition system and other parts that need electricity to work (radio, heated grips, auxiliary lights, the GPS navigation system, etc.).

The term “alternator” comes from “alternating current.” It is a device within your vehicle that turns mechanical energy into electrical energy.

Three things are needed for an alternator to work: a coil of wire, magnet, and motion. The motion comes from the rotating engine, while the magnet and wire coil was added to complete the process of generating electricity. 

Why do vehicles have an alternator?

The alternator charges the battery while the regulator checks its voltage and makes sure it doesn’t drop below the optimum level.

  • Alternator – the mechanical energy is converted into AC current, running the motorcycle and charging the battery.
  • Regulator – the power coming from the Alternator is Alternating Current. The regulator’s job is to convert AC power to DC and keep the voltage output from the Alternator at a steady level.
  • Battery – is your bike’s power source and the engine’s heart. It gives power to the ignition system and provides power to the bike’s accessories when they need it.

Going back to the question: do motorcycles have alternators?

If your motorcycle is modern, the answer is YES.

If you are riding an old model, it may have a DC power generator or magneto instead of an alternator. Unlike modern motorcycles with many gadgets and features that require electricity, old motorcycles just needed the power to fire up the spark plug and start the bike.

Very few motorcycles have a car-style alternator. Car alternators are big, require housing, and heat up quickly. Therefore, besides the components of the alternator, it also involves cooling, making them too bulky for a motorcycle. The most common alternator found in motorcycles is a stator and rectifier/regulator that handles the power generation, conversion, and regulation.  

What is a stator?

A stator is the motorcycle’s version of an alternator. Its function is to generate the power needed by the bike and all its components that require electricity.

The difference between the two:

  • A car alternator is a fully self-contained, externally mounted unit that creates DC power; it uses an electromagnet.  
  • A motorcycle stator is an electrical system component that works with a rotating magnet to power AC. Stators are inside the engine case and use a permanent magnet. 

A MOTORCYCLE ALTERNATOR is a collection of components that converts AC to DC and maintains a continuous and steady power output; this includes the stator, magnets, and a rectifier/regulator

In short, a stator cannot work alone and needs the help of a magnet and rectifier/regulator to complete the function of an alternator in a motorcycle.

Where do you find the stator?

It’s usually mounted on either your motorcycle engine crankshaft’s left or right side. It’s considered as a part of the engine assembly. 

How Does A Motorcycle Alternator Work?

A stator works together with a rectifier regulator to accomplish the same goal as an alternator – to generate the DC power required to run the motorcycle, ATV, side-by-side, etc. The stator is the coil of wire housed inside the engine case.

Magnets spin within the stator to create an alternating current. The alternating current travels along a fairly heavy gauge wire through the case and into the rectifier/regulator, converting it to direct current (DC) power. The DC is then sent to the inverter, which turns it into AC.

Naturally, the stator can only produce so much current before it overheats. This is where the regulator comes in.

A regulator is a device designed to keep the battery constant. If the battery voltage drops too low, the regulator will raise the voltage to ensure the battery is at the proper level. If the battery voltage is too high, the regulator will lower the voltage to ensure it doesn’t exceed the optimal range.

Symptoms of a Stator Problem

  • Weak, intermittent, or no spark.
  • The headlight didn’t turn on when you switched the engine on.
  • No light on the dashboard. 
  • No power on other installed electricals (e.g., auxiliary light).
  • The battery goes dead when you turn the lights on.

Can you fix a defective stator on your own? 

Do remember that the stator is inside the engine. If you have experience as a professional mechanic, yes. If the answer is no, it is best to bring your motorcycle to the dealership and let a professional fix it. What you can do here is to help find the part replacement online and let the mechanic do his job. 


The stator (alternator) is one of the most essential components in your motorcycle. It can be challenging to diagnose and fix when it malfunctions. Still, a regularly scheduled tune-up can prevent problems from cropping up.

In fact, it is recommended that you get your motorcycle inspected at least once a year by a professional mechanic. This will help ensure that the stator is operating correctly.

Thanks for reading and ride safe.