Symptoms of a Bad Stator in a Dirt Bike – Easy to Locate?

Do you consider yourself a daredevil, easily tempted by a little rush? Do you like how it feels when adrenaline flows in your veins? 

Well, no wonder you got a dirt bike. Not only does it scratch that itch for a little adventure, but it is also perfectly legal to drive. In the proper terrain, of course. Everything was perfect until your bike began misbehaving. Maybe your stator is to blame - read on to find out.

In this article you will learn:

• Why does your bike need a stator?
• What are the common symptoms of a bad stator?
• What are the reasons your stator might fail?
• How to test a stator for issues?
• How to replace a stator?

Why does a dirt bike need a stator?

In short, a stator is the generator of electricity in almost every motorbike. Though dirt bikes are generally not equipped with too many accessories, they still need power for the ignition system. 

The stator looks like a round wheel with many coils planted on its circumference. It turns mechanical energy into electricity and charges the battery. The exact details of this mechanism are not important. Suffice to say the stator generates alternating current as you ride your bike. Since the battery can only function on direct current, there is a device called a rectifier that changes it to this current type. 

• Where do I find it?

Stators are generally found inside the engine case.

• How much does a new stator cost?

The price depends on the model of your bike. However, dirt bikes generally use simpler stators than regular motorbikes. You should be able to grab a new one for under $100 (an aftermarket one).

Symptoms of a bad stator

• Starting issues

Electricity is necessary for your bike to start. Therefore, your stator's health reflects on the ignition performance. In fact, it is a common symptom associated with a busted stator. 

The symptom itself includes issues with starting your bike. This means it might be delayed or take several attempts to perform. In case of severe damage, it won't start at all. 

• Misfiring

Your engine is composed of multiple cylinders, each of which produces the energy necessary to keep you on the move. Misfiring occurs when one of these cylinders' lags behind. 

With insufficient power, your wheels will lose momentum. These bouts are often random and do not last very long. Do not ignore this symptom, however. As the stator wears down, your dirt bike will break down entirely. 

• Backfiring

Perhaps one day as you were scaling the hills with the wind blowing in your back. You felt the excitement rush in your veins, but then an ungodly sound woke you from your reverie. You looked behind you, but everything was perfectly still. 

What you experienced was likely a backfire. This occurs when fuel residue gets into the exhaust pipe. Once there, it ignites due to the natural heat of the pipe itself. Not only can this damage your hearing, but it might also start a fire in your exhaust pipes. Left unchecked, it can cause severe harm to your dirt bike. 

Although backfiring might arise from various issues, it points to a bad stator if it happens simultaneously with misfiring. 

• Issues at one certain speed

Your stator sports different coils assigned to different speeds. If either misfiring or backfiring occurs solely at one certain velocity, one of the stator coils might be broken. 

• Issues at one certain temperature

The misfiring and backfiring might be tied to a certain temperature. If your bike acts up at one temperature but functions seamlessly at another, the stator coils might be to blame as well. 

• Battery drains

Your battery stores electric power, but it is the stator that charges it. As you drive your bike, you should always see the battery charging. In case it is draining as you drive, your stator is not generating sufficient power. 

While you might be able to drive for a while longer, a charged battery is vital to keep the bike in motion. Once it dies, so does your hope of starting the bike. To avoid walking a long way home, do not ride your bike until you remedy the issue. 

Why did my stator fail?

• Old age

Much like everything in the world, even your stator is not immune to the passage of time. Though stators generally have a long lifespan (50,000+ miles), they will atrophy with age. Since they are subject to greatly fluctuating temperatures, their metallic components expand and shrink a lot. This might loosen the coils and, in some cases, even break them. 

It goes without saying that the more you ride your dirt bike, the more strain you put on it. Thus, it will not last as long. Of course, you bought the bike to ride it in the first place, so there is little you can do about this natural wear and tear. 

• Dirt and dust

True to their name, the dirt bikes were made to be ridden in dusty environments. All the more reason you have to clean it regularly. Neglecting this need for maintenance will cause dust to accumulate inside the machine. Given enough time, it might damage the stator as well as other vital components.

• Overloading the circuit

Although the stator is the literal powerhouse of your bike, there is only so much current it can generate at one time. Turning on multiple electronics might lead to power fluctuation. While you are unlikely to need a GPS for motocross, gadgets such as the headlamp or radio might also lead to a malfunction. 

Turn off every non-vital gadget that requires electricity to operate. Sometimes, this simple fix does the trick.

• Vibrations and impacts

Though much more resilient than a common motorcycle, even dirt bikes are not completely invincible to vibration. If this happens too often, vital components in your stator will come loose. This will inevitably lead to an unsteady power supply. 

Obviously, you should avoid any crashes to prolong your stator's life. But riding in adverse terrains might mean you bump into too many rocks stuck in the ground. It might seem harmless, but the damage accumulates over time. Thus, make sure you perform your stunts in a smooth terrain. 

How to test stator performance

If you experience any of the problems mentioned above, there is a way to check the stator itself. All you need is a multimeter which is not that expensive. 

• Make sure your bike is off and the engine is sufficiently cool.
• Set your multimeter to measure resistance. The display should read O.L.
• Access the stator. Three phase wires are coming out.
• Measure the resistance between each pair (3 measurements in total). Since resistance does not have polarity, it doesn't matter which multimeter lead you connect to the wires.
• The resistance should always be above 0. Additionally, you can check the manufacturer's manual if you have one. It will specify what the resistance should be. If it lies outside of this interval, consider replacing your stator.

You can also perform a ground test. The procedure is similar. Instead of measuring the wires against each other, measure each one against a grounded metallic surface nearby. The multimeter should keep showing O.L. if you have a good stator.  

How to replace a stator on your dirt bike

Once the stator bites the dust, you'll have to replace it. To make the job in front of you easier, we've prepared this simple guide.

• Allow the engine to cool down to avoid burn injuries.
• Open the fairing to access the engine.
• Find the gasket cover and disconnect the electrical wire.
• Make sure you have a piece of cardboard under the bike as oil will leak out during this procedure.
• Remove the gasket cover bolts
• Remove the gasket cover itself.
• Loosen the stator bolts and then take them out. You can achieve this with a socket wrench.
• Take out the stator itself.
• Clean the cover that houses the stator.
• Place in the new stator. It has to be compatible with your bike model.
• Apply gasket sealant near the end of the electrical wire.
• Fasten the wire with the bolt.
• Apply some gasket sealant near the edges of the cover.
• Put the cover back and secure it with bolts. Be careful with the amount of pressure you exert or you might break them.
• Reconnect the wire and allow the interior to dry.
• Once dry, remove any excess sealant.
• Replenish the oil if you lost some due to spillage.
• Try to start the engine. If it works, check for oil leaks.
• Congratulations, you're done!

Conclusion

In conclusion, your dirt bike relies on the stator for power supply. A damaged stator will not produce enough electricity, making your bike act jumpy. Eventually, it won't start at all. Various telltale signs point to a stator issue, particularly if they happen together. Prolonging your stator's life span is possible by cleaning it regularly and avoiding rocky terrains. Reasonable use of electrical components is also advised if your bike has them. 

When your stator breaks down, you don't need to buy a new bike. All you have to do is buy a new stator and replace it. Stators are generally cheap and timely replacement can prevent bigger expenses later on. 

You can do this on your own if you are handy with the tool. Of course, going to a mechanic is always an option, but expect to pay more.