Installing a kill switch is somewhat similar to taking out insurance…You might never use it… but the fact that you have it for when it’s needed gives you the peace of mind to sleep easy at night.
This post is a guide on how to test, install and bypass a motorcycle kill switch, safety switch and fuel cut-off valve.
And I’ll be sure to sprinkle in a few of the top products that I’d recommend for each installation too!
>> If you’re planning on bypassing the circuit, then click here to learn about the symptoms of a faulty kill switch before deciding that a bypass is the best course of action for you to take.
Ok, Had your Weetabix? Great! Because it’s time to dive into the first section.
What Are The Best Type Of Kill Switches To Install On A Motorcycle?
In most cases, the make and model of a bike will determine the most suitable type of kill switch to install. For example, some bikes use 9-pin plugs while others use just 6, some are fitted with starter relays while others have a simple red button.
So, really the best type of kill switch to use is the one that you’re prepared to install, as the more features it has, the more complex the installation becomes.
This is why it’s important to take a look at the bike beforehand to get an idea of the method, tools and components (such as relays) that you’ll need for carrying out the installation.
That being said, the majority of kill switches I’ve found being sold online are somewhat mediocre at best. So I’d highly reccomend to check if your motorcycle’s manufacturer offer a high quality product before attempting to buy one online.
One generic kill switch that will likely do the job and is currently being sold on Amazon is the Gebildet 2pcs 22mm Handlebar Mounting Switch.
what Tools Do you need to Install A kill switch?
Ever heard the saying “a mechanic is useless without his tools”…? Well, if you haven’t, then now you have. And there’s a lot of truth in this statement as without the right tools, you’re essentially shooting in the dark.
The following section will cover a list of recommended tools for installing a kill switch. However, if there are tools you don’t have or simply cannot get hold of then do not worry as not every tool on this list is essential.
Check out the list of tools below:
- Multimeter (optional but recommended for testing circuit)
- Test Light (optional)
- Ring terminals
- Wire crimping tool
- Electrical connectors
- Cable Ties
- Low Voltage Wire Connectors – 3 terminals (for two-stroke motorized bikes only)
- Cable wrap sleeves (totally optional but recommended)
- Diagonal cutting pliers (to cut wires)
Testing Your Kill Switches Circuit For ‘Continuity’
First things first, your new kill switch must be tested for ‘continuity’, but what the heck is ‘continuity’ and why should you be testing for it?
The word “Continuity” derives from the word ‘continuité’ in the language of ‘Middle French‘, which is essentially a word used (by electricians) to describe (or prove) a continuous path of which electrical current flows (i.e., a closed circuit)’. This type of test is carried out using a multimeter when set to ‘Ohms/resistance’ (Ω) or set to, you guessed it… “continuity”.
The image below illustrates ‘continuity’, or otherwise provides an image of a closed circuit to show proof of a continuous flow and the current passing through.
Carrying out A Continuity test
To begin the test, take each probe (from the multimeter) and attach each of them to the ends of wires from the kill switch (either way is fine).
When the kill switch is in the normal position (i.e., de-activated/off) there is no continuity. Conversely, when the switch is ‘on’ (i.e., activated) then continuity should be present.
Note: When continuity is not present the multimeter will display ‘O, L’ (open loop), however, if continuity is present then the multimeter will give you a reading above ‘0’ (typically between 0 and 1 Ohms for non-load components such as switches, thermostats and fuses).
But, if you’re still unsure, then watch the video tutorial below to learn how to properly carry out a continuity test.
What should be the Goal When Installing A Kill Switch?
Regardless of whatever bike you have, the principle of installing and operating a kill switch will always remain the same… The goal is to ground or kill power going to the ignition coil.
This is because if we ground the power, then we prevent the spark plugs ignition. And if we prevent the spark plugs ignition, then we prevent the engine from being able to ignite fuel and air.
Simple enough…but not always easy!
And it’s likely you may still encounter differences in ignition systems for varying engine types. So use the list below to jump straight into the most relevant section:
- Four-stroke engine ignition setup
- Two-stroke engine ignition setup
- Motorized Bike (with Magneto coil assembly)
Installing A Kill switch to the Ignition System
Remember, We are trying to ground out or short power supply to the ignition coil.
But with varying manufacturers comes varying colours associated with the ground and power wires within a circuit. So I’ve divided the most common types of wiring looms into sections to help you figure out the best route to go down.
Four-Stroke Engine Ignition System Setup
Most four-stroke engines use a universal ignition system comprising an ignition coil, CDI and battery. Within this type of system, the ignition coil will contain two sides. One side will have two terminals (for the earth and power supply), and the other side will have a single terminal (that attaches to the spark plug via the HT lead/cable).
The following sections will provide you with instructions for installing a universal motorcycle kill switch to a four-stroke engine:
Locate the spark plug (i.e., the spark plug cap) and work your way back from there.
Chase the lead from the spark plug cap back to the ignition coil (a barrel or cylinder-shaped component) that will look something like this:
Identify the wire supplying power to the coil (usually a red/blue/green wire) and follow the wire back to its connecting points (i.e., back to where it joins the wires from the engine or CDI unit).
It should look something like this:
Most motorcycle ignition systems will use a power supply coloured red/orange/blue (with a blade-shaped connector), and a ground that can be identified by a black wire with a ring terminal (attached to the rectangular metal block in the centre of the ignition coil).
However, you can still find this differs from bike to bike.
Read Me: If you’re still unsure then follow the steps in this quick test to identify the power supply wires within your bikes ignition system:
Identifying the Wire Providing power to the ignition coil This test is simple. Step 1 Start the bike up and leave it running. Step 2 Ground out the power supply to the ignition coil! To identify the providing power source, you must bridge a piece of metal (preferably an insulated screwdriver) to the ignition coil terminal and the motorycles frame (or any other part of the motorcycle witha alrge surface area such as the exhaust, suspension, engine cover or fender) Reading the results The terminal that causes the engine to shut off (when bridging the ground) will be the power supply.
Fit the kill switch housing (i.e., the part containing the switch) to the motorcycle’s handlebars.
Note: I tend to mount kill switches on the right-hand side of the handlebars (i.e., the side with the throttle) but the left-hand side is fine too if that’s where you prefer to install it.
Feed the wiring from the kill switch across the handlebars to run down the neck stem, then along the top or downtube (depending on your bike’s setup) to meet the location of where the ignition coil is situated.
Note, that you may also need to remove the petrol tank, seat, fairings and number plate to provide access for wiring.
Here’s an image explaining the names of the various parts of a motorcycle frame.
Splice into the middle of the wire you identified as a power supply (i.e., the wire being fed from the stator/engine/CDI).
Join the green/blue/red wire from the kill switch to the power wire, then join those two wires up with the wire that feeds the ignition coil its power.
Here’s my attempt at drawing this out below.
As you can see (in the image above), the black ground wire runs from the kill switch to the CDI. But if there is no available ground wire coming from the CDI, then you can simply ground the wire anywhere on the external engine or frame.
Check out the image below to see how this is done:
If your bike is fitted with or has previously had a factory-fitted kill switch, then it’s likely you’ll discover a black wire with a white stripe and a solid green wire situated somewhere near the ignition coil.
If the wires already have male or female bullet connectors, then fit your kill switch wires with the opposite connectors and attach them. However, if no bullet connectors are present then a naked wire-to-wire connection (with a solder if you choose) will work just fine.
How to Replace or Upgrade A Factory fitted Kill Switch
The example video below will explain how to replace or upgrade a factory-fitted kill switch even if your new kit comes with limited or additional functionality and different months of the manufacturer-fitted product.
Note that the CX500 in the example video uses a red 9-pin plug for the kill switch while the aftermarket comes with a 6-pin.
Some kill switches and housing are manufactured to provide additional features such as switching off headlights while cranking (i.e., starting up), horn or beep operations and start/stop functions that require additional wiring and additional pins (to house those wires) in connectors.
But if you find that your part is not like for like, then using a relay may substitute features or you can simply remove unwanted features by leaving particular wires unattached. Just be sure to tape them up and prevent them from grounding out on the bike.
Installing a Kill Switch On A Two-Stroke Motorized Bike (with Magneto coil assembly)
It’s common to find a two-stroke motorised bike fitted with a magneto assembly ignition system which is a lot less familiar to the majority of riders today. In fact, a magneto system doesn’t even use an external ignition coil but instead uses a component called a ‘magneto coil (or a U-shaped part in layman’s terms)’ situated beneath the engine’s outer casing (inside the “magneto assembly”).
Here’s what it looks like:
This type of ignition setup will usually have three wires coming from the coil which include:
- White wire: used for any 6v LED light (you can cut this wire and remove it to prevent it from grounding out on the engine).
- Black wire: A (negative) ground wire that connects to CDI (from the magneto coil)
- Blue/Red/Green: (Positive) Power wire that connects to the CDI (from the magneto coil)
Wiring Up The Kill Switch to A Magneto Assembly
Magneto assemblies usually use red and black or blue and blue wiring that you can locate around the magneto assembly (i.e., the engine’s outer casing).
Usually, the wires will have bullet connectors that are used to connect the magneto to the CDI unit, but if it doesn’t, then splice into the wires about midway between the engine and CDI.
It should look something like this:
Attach “one” low-voltage wire connector to the red wire coming from the CDI unit, then attach another connector to the black wire coming from the CDI unit (same as in the image above).
Re-attach the black wire coming from the engine to the black wire inserted into the low-voltage connector. Then do the same for the other wire, so red to red for this example.
Take the black wire from the kill switch and insert it into the connector with the black-to-black wires. After that, insert the red/blue wire coming from the kill switch into the connector with the red-to-red wires.
Choose a suitable place on the bike’s handlebars to mount the kill switch housing (preferably next to the right-hand throttle grip) then unscrew and fit the housing to your chosen area.
How to Install a Hidden Electrical Ignition Kill Switch
Pro Tip: Because there is no limit to the number of kill switches you can install on a motorcycle, then why not install a second kill switch in addition to the factory-fitted or aftermarket handlebar-fitted kill switch to reduce the chances of a thief finding both?
Doing so may well buy you enough time to catch them in the act or at the very least recover the bike back in one piece.
OK, so how do you install a hidden kill switch?
Simple! The same way you install a normal kill switch.
Locate the power supply to the ignition coil and splice the power cable, only this time you’ll fit a smaller switch housing that can be hidden anywhere on the bike.
A simple toggle switch or slide switch will be perfect for this type of setup.
These kinds of switches can be easily hidden in varying places such as under the petrol tank, under the seat, behind the headlight or anywhere you believe to be inconspicuous.
Use a Junction Box To Hide Your Kill switch
There are no rules as to where a kill switch can be installed but if you have a really expensive bike then I’d recommend hiding the kill switch in a junction box (link to Amazon) for added security.
Installing a Fuel System Cut-off Valve
Shutting off or preventing an engine from running doesn’t always have to be by prevention of the engine’s ignition, as starving an engine of fuel will also result in the same outcome. In fact, fuel system cut-off valves are great for increasing an engine’s performance… and in our case, preventing theft.
So, What Exactly Is a fuel cut-off valve And How Does it Operate?
A fuel system cut-off valve is a simple component that is spliced to the fuel hose (i.e., the hose coming from the fuel tank) and is used to control the amount of fuel being fed to the engine.
This type of valve will generally have two functions, they can either be switched on… or conversely switched off.
And while the operation of the fuel cut-off can be easily figured out by thieves, they can heavily increase your level of security when combined with the kill switch ignition. Equally, a fuel cut-off valve may also be useful in preventing the supply of fuel to an engine in the circumstances of an emergency.
Sidenote: It's important to note that installing additional kill switches will come as a trade-off. Because, while they do increase your level of protection, they will also increase the amount of time it takes to reinstate each of the functions when heading out for a ride.
How to Install A Cut Off Valve to the Fuel System
This installation is a simple job that requires just one cutting tool, which can be a Stanley knife, pocket knife, diagonal cutting pliers (link to Amazon) or a simple pair of scissors. Whatever comes to hand first will do.
Sidenote: Before you start, ensure the valve is set to off to avoid unwanted fuel leaking through it during this installation
Locate the fuel hose coming from the fuel tank and cut it about halfway down.
Note: If you have a fuel filter then make sure to cut nearer to the top of the hose (i.e., the part close to the fuel tank) so you can control the fuel flow before it reaches the filter.
Insert the nipple from the valve into the fuel hose that you have cut and then mount the fuel valve to a mounting point on the frame of the motorcycle.
It should look something like this:
Note: If you do not have a mounting point, then you can always use a cable tie instead.
Push the remaining hose (that leads down to the engine) over the other nipple of the cut-off valve and secure all the attachment areas with cable ties.
Note: While the remaining hose should have enough length to cover the distance to the engine, you may in some cases need to install a new hose that is able to cover a larger distance for the replacement.
Turn the valve to ‘ON’ and you’re ready to rock!
How to Bypass A Faulty Motorcycle Ignition Kill Switch
Scenario: You suspect you have a faulty kill switch and decided that a bypass is the best course of action to keep the engine running.
Ok! No probs, simple enough!
All you need to do is locate the kill switch’s associated wiring and test for continuity (with a multimeter).
If you’re unsure of how to test your kill switch for continuity, then jump back to the section where we talk about here: >> Testing Your Kill Switches Circuit For ‘Continuity’
Once you have confirmed the circuit or its associated equipment is faulty, then it’s time to bypass the circuit.
Remember, a kill switch operates by breaking a circuit when the kill switch is ON, and closing the circuit when the kill switch is OFF.
So to bypass the circuit, all we need to do is join the two wires in the circuit that the kill switch is breaking which will emulate the kill switch being OFF… or in our case deleted.
For example, say you could see a red wire supplying the feed to the kill switch and then another red wire going from the kill switch to the ignition coil. Then all you need to do is join those two red wires.
This will bypass the feed to the kill switch and instead run directly from the engine/CDI/stator directly to the ignition coil.
Here’s an example:
What You can do if the kill switch housing Must be kept for other functions
And if you prefer to keep the kill switches housing mounted to your handlebars, then you can easily identify the wires providing power by opening up the housing and seeing the wires that attach to the on/off button.
Note that you can join the wires together and leave them in the housing then close it back up and still have other functions without having to operate the kill switch. But this would only make sense if the button itself was faulty within the housing.
Bypassing a Kickstand Safety switch
Depending on the manufacturer the engine will run while the kickstand safety switches circuit remains open or closed. But regardless of whether the circuit is open or closed, in all scenarios, the kickstand MUST be up for the engine to run.
If you’re bypassing the circuit because of choice then move straight to the section on testing the circuit for the kickstand. However, if you are bypassing because you suspect it’s faulty, then test it first with the steps listed below.
testing To Find Out If the Kickstand Switch Circuit Is faulty
It’s probably wise to test the kickstand before bypassing the circuit to confirm that it’s actually faulty in the first place.
To do this, you’ll need to unplug the kickstand wire connectors.
Attach the red probe from your multimeter to one terminal and the black probe to the other terminal in the plug (or via the wiring if it’s a naked connection).
Switch the multimeter to continuity or resistance then put the kickstand up and note the reading. Then put the kickstand down, and make note of that reading too.
If the switch is faulty: You will have the same reading when the kickstand is both up and down.
If the switch is good, then you will have gotten different readings for each test.
Before you can bypass the kickstand safety switch circuit, you’ll need to verify whether the engine runs with the circuit open or with the circuit closed.
Testing To See If the Engine Runs When the Kill Switch Safety Circuit Open Or Closed
Step 1: Simulating an Open kickstand Safety switch circuit
To simulate an open circuit simply unplug the wire connector for the kickstand, and try to start the engine.
The engine runs When the Circuit is Open
Solution: Unplug the kickstand switch connector which will simulate an open loop.
Step 2 (only if the engine did not run in step 1)
if you had no success in the first step, then move on to testing to see if the engine runs when the circuit is closed.
To simulate a closed circuit, cut the wires coming from the engine before the connector (or after the connector on the side with wires leading to the kickstand) and join them together then start the engine.
Here are some images showing where to cut before and after the connectors.
The first image is showing before the connector:
This is where you would cut after the connector (either method is fine depending on preference)
The engine runs When the Circuit is Closed
Solution: Leave the wires joined together and happy days
Frequently Asked Questions
The following section will answer a few questions that have either developed during research or been asked by other readers researching this topic. So, anything I’ve missed during writing this post will likely be covered in the following sections.
This post has taken me weeks to write up and to say the least, I’m tired after writing it. But the goal is to help you get an idea of how to install any type of kill switch to your motorbike for whatever purpose you intend.
We covered ignition system setups, fuel system cut-offs and safety systems too, so there is no shortage of the ways and methods you can shut off an engine in an emergency or prevent theft from reading this post.
And for the most part, installing the kill switch is simply to cut out or prevent power which should put you on the right track regardless of whatever bike you have.