6 Reasons Motorcycles Can Shut Off While Riding (Explained)

You’re riding down the highway, enjoying the fresh, open air. You’re holding the throttle open and can only hear the steady rumble of your bike beneath you.

Suddenly the engine noise disappears. Your hand is still on the throttle so you look down at your control panel only to realize your bike has no power. Your bike is off and you can coast to a stop.

This is a frightening scenario that can happen to the best of us. If this should happen to you, it’s good to know what to look for and how to prepare yourself if your bike shuts off while riding.

Here is the short answer to why motorcycle shuts off while riding:

There are a few reasons a bike can shut off while riding. Low fuel or a faulty battery are the main reasons a bike will shut off while riding. But it could be a few other reasons as well, all of which are linked to either fuel or electrical issues.

Reasons Motorcycle Shut Off While Riding

Here are common reasons motorcycles shut off while riding:

Fuel Source Issues

Fuel is an obvious reason for a bike not to start. However, there are a few variations of fuel problems that might cause your bike to stall while riding.

1. Out of Fuel

If you’ve ever been unfortunate enough to be caught on a bike that shut off while riding, I’d be willing to bet the first thing you checked was the fuel tank.
Running out of fuel happens to the best of us!

Some bikes may not have a fuel gauge, or they may have a faulty fuel gauge. Whatever the reason, just remember- it happens!

If you are riding a carbureted bike, you’ll have a reserve switch on the fuel valve, for just these occasions.

2. Fuel Pump

If the fuel tank is full but the bike still won’t start, it could be fuel pump failure.

3. Contaminated Gas

Your fuel system is sensitive. If debris contaminated your fuel, the bike won’t be able to function correctly. The same is true if any liquid other than gasoline gets caught in your tank.

Water and diesel fuel are the most common culprit to gas contamination. This is why you should put nothing besides gasoline in your tank.

If you think your fuel has become contaminated, its best to dump the fuel and clean the tank. There are products you can purchase to clean the tank or you can take your bike to your local dealer/independent shop.

While you are cleaning the tank, it might also be a good idea to check for holes or leaks in the tank where the contaminate may have gotten in.

Electrical System Issues

Your bike’s charging system has three principal parts. The battery, stator, and regulator rectifier. Each of these components serves multiple functions and work in tandem with each other while the bike is running.

If one of these components is not working, you may experience several problems with your bike, including the bike shutting off while riding.

4. Bad Battery

The battery gives your bike the initial power it needs to start. It also picks up the slack when your stator isn’t able to keep up with the electrical demand of your bike. This should only happen when you’re going at slow speeds with low RPMS.

While the bike is running, the battery is being recharged by the stator. The regulator rectifier is also acting as a safeguard against the alternator to make sure it doesn’t send out too much power. Since all three components work in tandem, if they are not getting all the voltage they need, they will fail and potentially kill the bike.

When you’re checking your bike for the shut down culprit, be sure you check the battery terminals. You would be shocked at how many times a battery problem is actually just a simple hardware problem.

However, you won’t always be this lucky. Sometimes, it truly is a bad battery that has lost its charge, for whatever reason. The best way to test a battery is by doing a load test. Specs vary on pass or fail, depending on style of battery.

For example, a sitting battery could have a surface voltage (no load) of 12.4 Volts, which is satisfactory. But as soon as you put a load on it, the voltage drops to 3. This would be a bad battery. Using a battery tender could save the battery if it still has voltage during load test.

Please also read our article about motorcycle gear problems and solutions.

5. Bad Spark Plugs

The spark plug is a key player in creating power for your bike to go. When it sparks, it ignites the air fuel mixture in the combustion chamber when the piston is at its highest position (a.k.a top dead center). If something is wrong with your spark plug, it won’t ignite properly, which is why misfire, backfires, or a feeling of weak power happens.

There are a few reasons a spark plug can go bad. One is if your bike is running lean. This can create premature wear on your spark plugs. If your bike is running lean, this means the air-to-fuel ratio is more in favor of air.

Since the spark plug relies on the air fuel mixture to ignite, if there is more air than fuel, this will cause the fuel to burn hotter and risk the spark plug melting. Spark plugs can also foul out because of excessive fuel or oil.

Sometimes, it doesn’t matter how well you take care of your bike or the spark plugs. Eventually, they will give it out simply from wear.

6. Faulty Stator

Your stator gives voltage to several components on your bike and helps produce a voltage that eventually gets to the spark plug. The stator also charges your battery while the bike is on.

The ECU controls spark and will primarily get its voltage from the battery. If the stator does not feed the battery, then it can not produce a spark.

When your stator is failing, you’ll experience a few problems. Your bike will be hard to start, and the engine may misfire or backfire.

If the stator fails, you get no spark, which means the bike won’t start at all. It would also be likely that your battery constantly dies after riding because the stator is not recharging it.

Make sure to also read our article about whether motorcycle engine braking is good or bad.

What Should You Do If Your Bike Shuts Off While Riding?

Speaking from personal experience, riding a bike at 80 mph on a freeway that suddenly loses power is a very frightening experience. It takes some nerves and trust in physics to get me to the shoulder and come to a safe stop.

You should also be reading our article which talks about 6 Reasons Motorcycles Backfire When Starting

But if I can do it, you can too (but hopefully you don’t have to). Just keep these things in mind:

1. Stay Calm

I know, easier said than done, but I really have been caught in some hairy situations while riding and the number one reason I could get through them was because I could stay calm.

When we freak out and do things out of panic or fear is when we put ourselves in the most danger.

2. Don’t Slam on Your Brakes

When something goes wrong while riding, your first instinct may be to bring the bike to a screeching halt, but when it comes to motorcycles, this is rarely the best solution. In fact, the opposite is true.

When something goes wrong while riding, it’s often best to lean in and give the bike more gas, or swerve. Rarely is it a good idea to bring your bike to an immediate stop.

3. Use Whatever Momentum You Have Left to Pull Over

If you’re on the freeway or highway when your bike loses power (like me), use the momentum you have to switch lanes into the shoulder. Another reason to not slam on the brakes.

You’ll feel a bit like you’re playing frogger, but it can be done (trust me). It may also be a good idea to ride in the outside lanes and only use insides for passing, for this very reason.

4. Get to a Safe Spot Before Inspecting Your Bike

It might be tempting to immediately hop off your bike and begin crawling under it to see why it shut off, but this is ill advised, especially if you’re on the highway. Do your best to push the bike to a parking lot or area with low traffic before you inspect it.

Besides, unless you’re carrying an expansive tool kit, there wouldn’t be much you could do on the side of the road, anyway.

Also read our article about things to check if your motorcycle smells like gas.

Final Thoughts

The best way to avoid having your bike stall out is to keep your tank full and battery charged. It’s also important to inspect your bike between services, especially if something doesn’t feel right.

As we just learned, even a small part, like a spark plug, can cause havoc on your system.

Sources

Motorcycle Stator, Alternator, And Battery Fundamentals | motorcyclecruiser.com

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