Why Do Motorcycles Have A Kill Switch?


As you may have noticed, motorcycles have a number of buttons and switches around the handlebars and on the instrument cluster. Some motorcycles will have more than others depending on how new it is.

One particular switch, the kill switch, sometimes poses a mystery to motorcyclists. A lot of them wonder why a motorcycle has one in the first place and may question how it works.

Why do motorcycles have a kill switch? A motorcycle has a kill switch because it lets a motorcyclist turn off the motorcycle without needing to take a hand off the handlebars since the button is within reach of the thumb. This lets the motorcyclist have total control of the motorcycle up until it’s turned off.

I have owned over a dozen motorcycles in the last few years and have seen every type of kill switch the motorcycle industry has to offer. This article will explain further the purpose of a kill switch and how to properly use one.

Purpose Of A Kill Switch

You’ve probably noticed that big red button or switch on the right hand side of your handlebars on your motorcycle and it can seem a little intimidating. Any button that’s red will likely have an impact on the machine’s functionality. But there’s a logical reason why a motorcycle has a button/switch like this.

This button, known as the kill switch, is a mechanism that almost all motorcycles have. The name of it explains exactly what it does: kills, or immediately turns off, the motorcycle. It takes both hands to operate a motorcycle properly and the kill switch helps with keeping the rider safe. The kill switch is in reach of the right thumb (almost always) which makes it easy to turn off the motorcycle instead of having to take one of your hands off the bike to turn the key off.

Though this is a nice button to have during emergencies, it generally wasn’t initially created for them. It’s a way for a motorcyclist to turn off their bike when they’re ready to park it and leave. In other words, it’s for every day use.

Engineers designed motorcycles this way because if you have to take one hand off the handlebars to turn the key off, it’s possible to slip the clutch while doing so and risk jolting forward unexpectedly. A kill switch helps you stay in total control of your motorcycle.

There are times when a kill switch comes in handy in certain emergency situations. Such situations many include tipping the motorcycle over on to yourself while it’s still on; it’s useful to have a switch that will immediately shut the bike off to prevent further burns and injuries. If you have electrical problems on your motorcycle and you’re seeing sparks, a kill switch comes in handy to immediately turn off the bike, stop the spark, and prevent further damage and/or injury.

How Does A Kill Switch Work?

A good part of understanding why a motorcycle has a kill switch is understanding how it works. It’s there for a reason, but it’s possible for it to be abused and ruin some parts of the motorcycle when it isn’t used right.

A kill switch is wired to the ignition coil (the part of the motorcycle that sends a spark through a spark plug wire to the spark plug and sparks the engine). The switch breaks the ground circuit in the ignition coil so that the coil no longer has a positive and a ground. This will make it so the ignition coil is no longer firing and delivering a spark to the spark plug. When an engine doesn’t have a spark, it can no longer run which ultimately makes the engine turn off.

Kill switches come in different forms, usually either a button or a flip switch that can look similar to a light switch. The button form (which is more common among newer motorcycles) requires the rider to hold it down for a few seconds because engineers realize it’s possible to accidentally push the button while out for a ride.

The switch kind is made to be accident-proof, meaning you need to put in some effort to flip it. That way a motorcyclist doesn’t accidentally flip it while out for a ride.

To properly turn off your motorcycle, you’ll need to pull in the clutch, hit the kill switch and wait for the motorcycle to turn off, then turn the key to the “off” position.

Is It Bad For The Motorcycle To Use The Kill Switch?

From an outsider’s perspective, it may seem like it isn’t good for the motorcycle to use the kill switch very often. Suddenly cutting off power to the engine sounds like a bad practice.

In actuality, using the kill switch on the motorcycle isn’t bad for the bike at all. It’s like unplugging an electronic from the wall outlet. There aren’t any repercussions the engine suffers by suddenly withdrawing the spark it needs to continue to run. In addition, there isn’t a point where you can use the kill switch too much on a motorcycle.

However, there are situations where you can cause damage to the motorcycle from the kill switch if you’re not using it properly. Such situations may include pushing the button over and over again even when the motorcycle is already off, like pushing it 10+ times within a few seconds. This won’t cause immediate damage, but if done habitually over time it could ruin the ignition coil.

Situations Where You Should Not Use the Kill Switch

A motorcycle kill switch has a specific purpose which is to let a motorcyclist safely turn the motorcycle off when they’re done riding. There are times where it’s inappropriate to use which could make a situation dangerous for the rider.

You should never use a kill switch while the motorcycle is moving. Some motorcycles have a safety feature accompanied with the switch which means the wheels or the steering could lock up. Locked up wheels and steering is incredibly dangerous while moving on a motorcycle.

It still isn’t a good idea to use the kill switch even if your motorcycle doesn’t have these locking-up mechanisms. Some motorcycles simply coast after hitting the switch which means a possible traffic hazard for those around you since you don’t have power to accelerate and get out of people’s way.

It’s possible for the kill switch to stall the starter for a few seconds, so if you use the kill switch while riding it’s not guaranteed you’ll immediately be able to start the motorcycle back up at a time where you need it to.

A Few Things To Remember

If your motorcycle has a kill switch, there are a few things to remember for the future to prevent a lot of frustration. If you have a switch that goes from on to off (instead of a spring switch or button), make sure it’s turned back to “on” before you go to start your motorcycle again. Otherwise, you’ll push your starter and nothing will happen. A lot of people forget to check this and wonder why their motorcycle isn’t starting, usually resorting to thinking it’s a battery issue.

Also note that the terminology of a kill switch varies between manufacturers and motorcycle riders. A kill switch may also be known as a “stop switch” or an “emergency stop.” Don’t let the term “emergency stop” alarm you because it still serves the same function on most motorcycles.

Remember to only place your thumb over the kill switch if you intend to immediately use it. Though they’re placed and designed to make it hard to accidentally hit, it’s always a good practice to simply wrap your thumb around the handle bar until you’re ready to use the switch. Some riders have a habit of riding with their thumb out and end up accidentally hitting the button while riding.

Recent Content