6 Reasons Why Your Motorcycle Accelerates By Itself


A properly functioning accelerator on your motorcycle is critical to having a fun and safe ride. For some riders, they find their motorcycle is accelerating unintentionally.  Essentially, their motorcycle is accelerating by itself.

Why does my motorcycle accelerate by itself? A motorcycle may accelerate by itself because of a sticky throttle cable, an out-of-adjustment throttle cable, a throttle body that is stuck open, or a sticky twist throttle. If you have an electronic actuated throttle, self acceleration may be caused by a bad throttle position sensor or corrosion in the wiring.

As you can see, there are quite a few reasons why your motorcycle might be accelerating on its own. This is not a normal operation and should be taken care of as quickly as possible. We will go over some of the most common reasons why your motorcycle is accelerating by itself and what you can do about it.

Why A Motorcycle Accelerates By Itself

You may be reading this article because you have noticed that your motorcycle is accelerating by itself. This means that it is getting more or all throttle when you are not using it. This puts you in a really unsafe situation when out on the road, so I’m glad you found this article so you can learn how to keep yourself safe. 

To understand why your motorcycle is accelerating by itself, it is important to understand how your motorcycle accelerates. Your motorcycle may be cable driven or electronic. Cable-driven throttles on motorcycles are more common, but electric-actuated throttles are becoming more prevalent. It is important to know which type of throttle your bike has to know exactly what could be causing it to accelerate by itself. 

A cable-actuated throttle is when a physical cable is used from the throttle handle and goes to the throttle body on your motorcycle. Your throttle body needs to be opened more as you accelerate to allow more air into your engine. 

Your throttle cable does need servicing from time to time. Over time it can get contaminated with dust and debris causing the throttle cable to get sticky. This will keep the throttle body open and cause your motorcycle to accelerate even when you let off the throttle. 

Your throttle cable may also need to be adjusted. This can normally be adjusted fairly easily and this is something you can do yourself. You can check the owner’s manual on your bike for the proper adjustment procedures. 

If you have an electronic actuated throttle, this means there are wires that send a signal to the throttle body and tell it how far to open according to the twist of the throttle on your handlebar. This kind of design may require electronic testing from a professional, but we will go over a few of the common reasons why it may be causing your motorcycle to accelerate by itself. 

Electronic actuated throttles may stick due to a bad throttle position sensor. This is what tells the throttle body to open and close with the signals it receives from the twist throttle. If this has gone bad, it can cause the motorcycle to accelerate by itself.

You might also find that you may have corrosion in the wiring for your throttle. This can happen because the motorcycle has been parked outside or has been exposed to a lot of moisture over its life so far. Corrosion in the wiring may be difficult to find on your own, but a professional technician would be able to help so you aren’t throwing parts trying to fix something that doesn’t need to be fixed. 

While it is important to understand which type of throttle you have, there are also issues that can plague both cable and electronic actuated throttles. 

Your throttle body can get dirty over time while riding. The throttle body on a motorcycle is located between the air cleaner and the intake manifold of the engine. If it does get dirty, the flap that is opened in the throttle body can get stuck open if dirt and debris are in the way. This causes the motorcycle to accelerate by itself. 

Another reason may be that the twist throttle itself could be sticking. This is probably most common as the twist throttle is exposed directly to sunlight and weather more than a sensor or cable. 

How To Fix A Motorcycle Accelerating By Itself

The good thing is that most of those items are something you can fix in your garage at home. Let’s start with one of the most common reasons, a sticky twist throttle. 

To find out if the twist throttle is causing your motorcycle to accelerate by itself, you can do so by, well,  starting your motorcycle and twisting the throttle. When you let off the twist throttle watch it and see if it returns to its resting position. If you notice it is returning to the resting position but slowly, this is a good sign it’s your twist throttle sticking. 

You may be able to find a procedure on how to properly inspect your twist throttle in your owner’s manual. Online videos help as well if you are a visual learner and chances are someone else has already had this issue before. 

If your throttle cable needs to be lubricated, you remove your throttle cable and clean it. Then you will apply the correct lubricant. Make sure not to over-lubricate your cables as an excess lubricant can attract dirt and debris. 

If you suspect it’s the throttle body that’s sticking, cleaning it should do the trick.  You don’t always have to remove the throttle body to clean it, but on some motorcycles it may be easier to take it off in order to get a thorough cleaning.  It is important to remember to use the proper cleaner, especially if it is electronically controlled. Keep in mind that motorcycles may have more than one throttle body that opens when you use the throttle. 

If your motorcycle has a carburetor, it’s good to keep the throttle plates cleaned as these act in place of a throttle body. Be sure to check your carburetor linkages as well since these can cause a throttle to accelerate. 

How To Prevent A Motorcycle From Accelerating By Itself

While these tips and tricks help in a pinch, the best way to keep your motorcycle from accelerating by itself is preventative maintenance. 

First, always have your motorcycle inspected before each riding season or at least twice a year. Whether you perform the inspection yourself or it is done by a professional technician, it is important to make sure it is done properly. 

In these inspections, you might find a few of the items listed above before you start riding. It is best to find out about potential issues before they become a real problem on the road. 

Some things you can do include routinely cleaning your throttle bodies or carburetor. Make sure that your throttle is responsive but doesn’t stick. Lubricate your throttle cable as directed in your service manual. Sometimes relearning an electronic throttle body is necessary so it will properly accelerate as well. 

How To Handle A Self Accelerating Motorcycle

If you’re reading this article, you may have found yourself riding your motorcycle and had the intention to slow down but your motorcycle didn’t. This is a situation that you don’t want to happen but it can happen to any motorcycle at any time. It is important to know how to react given this circumstance. 

First, take a deep breath and ensure the throttle is not being applied. Next, check your lanes as you may want to get over into an emergency lane as soon as possible to stop your motorcycle. Then pull in the clutch to begin slowing down. If your throttle is stuck, your bike may rev high but this is ok, especially in an emergency situation. 

The most important thing to remember is we are trying to stop your motorcycle in a safe place so you can inspect what may be happening. You will want to hit the kill switch on your bike. Make sure you are in a safe spot to do this. Once you have hit the kill switch come to a complete stop. Next inspect your twist throttle, throttle cables, or linkages and see if anything is visually out of place. 

If you cannot find anything out of place, it would be recommended to call a tow truck and have it taken to a shop. If you have to limp your motorcycle home or to the shop, just remember that the kill switch will be your friend while coming to a stop. 

It is important to note that if you are going to drive it with the throttle sticking, make sure your engine rpms are not too high when accelerating from a stop as you may injure yourself by losing control of your bike. It is not recommended to drive your motorcycle if the throttle is sticking. 

Riding a motorcycle should be fun, but also safe. Make sure your bike is inspected and your preventative maintenance is done properly. We all want to enjoy the ride, but we want to make sure you make it back safe as well. Ride on! 

Kyle Cannon

Kyle currently works as a mechanical engineer and graduated with a minor in automotive engineering. He loves restoring motorcycles, has a vast knowledge of how they work, and has sold his restoration projects to customers from all over the United States.

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