Introduction: How to Prevent Thefts Steal Your Motorcycle for Less Than US$ 2

Picture of How to Prevent Thefts Steal Your Motorcycle for Less Than US$ 2

This is my first Instructable. It will teach you to how to install a secret interrupter in your motorcycle and prevent the engine to start without your knowledge.

It can be useful to prevent theft to steal your motorcycle. It works as an additional lock system.

Here in Brazil, it's very useful.

The principle is simple: The Engine need the Ignition coil work to make the Spark Plug to Work and make possible the engine to run... All we will do is to create a way to disable the Ignition coil and, by consequence, disable all the Engine.

NOTE: This instructable is available in Brazilian Portuguese in my Blog.

Step 1: Materials and Tools

Picture of Materials and Tools

You will need:
- Some Tools (The tools that come with the motorcycle can do the service well)
- 1~2 meters of double wire
- An Small Interrupter (black or other Dark color if possible)
- A Cutting Tool
- Electric Tape

Most motorcycles come with basic tools, that can be very helpful in an emergency situation. These tools can handle this job, but if you have better tools to work, use them.

The wires will be connected to the interrupter and to the Ignition coil of the Motorcycle.

The Cutting tool is necessary to cut the wires and the Electric tape to isolate them.

Step 2: Locate the Ignition Coil

Picture of Locate the Ignition Coil

The ignition coil is a part of the engine that generate electric pulses to the spark plugs. The Spark Plugs are the parts located on the engine cylinder head. They receives the electric pulse and make a little spark, and this spark makes the ignition of the engine (the explosion of the combustion into the cylinder head).

In most cases, the ignition coil is located under the fuel tank. If don't, just follow the spark plug's wire, it starts on the ignition coil. If you have doubts about the location of the ignition coil, please head the Service Manual of your motorcycle.

So, we need to remove the fuel tank and all parts that depends it. Normally you just need to remove the seat and if your motorcycle have a body kit, the body kit too.

Now you have a full view of the motorcycle engine. If it is 1 cylinder, you have only one Spark Plug... 2 Cylinder, 2 Spark Plugs, and so on... If you still have doubts about the Ignition Coil location, just follow the wire from the Spark Plug... it will end on the Ignition Coil.

Step 3: The Ignition Coil

Picture of The Ignition Coil

The ignition coil is the part responsible to receive the energy from the battery and/or the engine movement, and convert it into a high voltage electric pulse, and send this pulse to the Spark Plug. This pulse is controlled by an another device, normally the CDI, but in some cases, the ECU. This control is done by a low-voltage wire, that transfer a very small pulse to the Ignition coil.

If you cut this little wire, the ignition coil will not generate the pulses to the spark plug... And it is what we want. We will put the interrupter in the wire, to close and open this circuit.

Step 4: Place the Interrupter

Picture of Place the Interrupter

Now the most important step of this instructable: The Secret.

You need to find some place on your motorcycle to hide the interrupter. This place can be any place you imagine... Under the fuel tank, under the air box filter, in back of the headlight, hide in the bodykit... Any place. You must decide it carefully, because it is all the security of this system: the secret. If anyone can find this interrupter, anyone is able to start the engine, and it is very bad.

Once you decided the place, use double-faced glue tape to fix temporarily the interrupter in the place you want, and try to use the wires to reach from this place to the Ignition coil's place.

It's possible? Ok! Fine! Let's go to the next step.
It's not possible? Fine... try to think in another place to put the interrupter.

Step 5: Soldering the Wire

Picture of Soldering the Wire

Now you need to soldering the wire on the interrupter and on the ignition coil.

The wire (double wire), must be soldered to the interrupter.

Now, cut the little wire of the ignition coil (make sure you have space to do a soldering in each piece of wire of the ignition coil), and solder one wire to the one wire from the ignition coil, and do the same to the other wire. You'll get some like this:


Step 6: Testing

Picture of Testing

Now the electrical installation is completed.
Turn the interrupter to the ON position and try to start the motorcycle (do now worry about the fuel tank... the motorcycle have fuel enough to run for a minute in the carburetor).

If the motorcycle starts, the installation is correct. Now turn the interrupter OFF. The motorcycle engine must stop and you will can't start if again until turn ON the interrupter again. This is the behavior we want.
If the motorcycle doesn't starts, try to change the position of the interrupter (maybe ON is OFF and OFF is ON). If it still doesn't starts, double-check the installation and all soldering points... And finally if you can't determine the problem... simply remove everything and solder the wire you just cutted. And look for someone more technically capable. :o)


JaretG (author)2016-07-25

I haven't tried this yet but IT WILL BE one of my winter PROJECTS. THANKS!

RanaA25 (author)2015-12-29

what if my bike kick start not self starter ?

CarlosC147 (author)RanaA252016-01-11

Yes, it will work.
No matter which method you use to start the bike. Kicking, pushing or going downhill, the engine needs to generate the sparks to ignite the fuel in the cylinders.

Madrias357 (author)2009-06-03

Worked great for dad's car. As if being stickshift wasn't bad enough (clutch down to start it) you had to flip the switch hidden in the ash tray. Otherwise, it won't start.

Ma77h3w (author)Madrias3572011-03-27

A "stickshift" isn't normally started with the clutch down..

JJrulz (author)Ma77h3w2011-04-18

Uhm. Do you drive? Because I think youll find you cannot start a stickshift/manual car unless the clutch is in. Not only is it not abnormal, its the only way possible

bpfh (author)JJrulz2011-07-21

Never heard of this feature on a manual. Ever. You either put it into neutral, or get a big jerk when you turn the key on every manual I've been in.

What make/model has this feature?

ericgfx01 (author)bpfh2015-01-16

Hehe. I remember as a kid wanting to listen to the radio, mom had just loaded us into the car, so I reached over and turned the key. Not quite getting the just one-click... car lurched forward, nearly hitting the parked car infront of us. Whoops. I think that was a mid 80's nissan sentra. Good memories.

jsgraham (author)bpfh2011-08-12

All vehicles manufactured for use in the United States after 1990 were required to have a switch to lock out ignition of the vehicle, unless the clutch was fully depressed. I had a 1984 Honda Prelude with a 5-speed manual transmission. It had lock out switch on the clutch. But then again, Honda is known to implement safety features that most manufacturers don't do until forced to by the Federal DOT.

Now, that's not to say that the switch hasn't been bypassed. People do that, and there are videos on YouTube that show how to do it.

bpfh (author)jsgraham2011-09-27

I did not know about this. Ok, on an auto, yes, you cannot do anything to the car unless you are in "N", but here in Europe, where most cars are manual, you have no sort of cut out like this...


lalunette (author)JJrulz2011-12-22

Modern manual cars have a sensor that forces you to completely depress the clutch pedal or the starter won't get power to crank the engine.

The 2011 Chevrolet Spark I drove in France this past summer and my '91 Honda Civic wagon had this feature... my '91 Lada wagon doesn't.

Cheers !!

ttibbenham (author)JJrulz2011-05-28

Some 'stick shift' cars have a 'brake applied or clutch down' "safety feature" which prevents the engine starting while a gear is engaged: I own one at the moment.
I have also driven lots of 'stick shift' cars without this feature so whether you need 'clutch down' to start just depends on which car you have.

Hammerhead46 (author)ttibbenham2011-12-22

A lot of automatics are now making you put the brake on to move the shift lever to a forward or reverse gear.
LONG overdue.

Ma77h3w (author)JJrulz2011-07-21

You can start the car with the clutch down, but normally you put it in neutral is what I meant

GtrPngn (author)JJrulz2011-05-25

anyone who has driven and understands how a manual transmission car works would know that it can be started both clutch in or just in neutral.

graydog111 (author)Ma77h3w2012-02-17

I must have the clutch depressed to start my GMC stickshift PU.

lperkins (author)Ma77h3w2012-02-16

It's not necessary unless the vehicle has some kind of safety interlock. However, disengaging the clutch before starting does slightly decrease the wear on your starter motor since it doesn't have to turn any of the transmission beyond the clutch. Whether or not this is significant depends on the vehicle.

criggie (author)Ma77h3w2012-02-16

Like everything, it depends. Modern cars have all sorts of electronic jiggery pokery to force the driver to do things in a certain way.

Mine's a late 60's holden (GM to americans) and it starts better in neutral with the clutch out (connected), because the weight of the flywheel helps keep the gubbons turning over.
You can still start it perfectly well with the clutch in (separated) but its easier on the motor the other way.

"Stick" is a silly word... here we refer to them as manual or automatic.
An automatic transmission generally still has a gearstick... I've never seen a pushbutton automatic outside of a Bus, but google says Chrysler made them for cars.

Project Upcycle (author)2011-08-15

around here that wont stop someone from stealing your bike. Here they drive up in a van, four guys pick your bike up and throw it in, close the door and they are gone.

tamasic1 (author)Project Upcycle2014-04-06

Exactly! I had a 83 Honda that had a braided steel security cable you could loop around an object and it plugged into a box at the very bottom of the frame. There was a fiberoptic cable that ran through the center of this. If cut it would start honking the horn which I upgraded to a screaming Mac truck db'd air horn. Their hearing would have been totally destroyed before they could rip off the side cover and cut the battery cable.

Yep that's how they did me. I live in a quiet dead end neighborhood too. My wife of the time was at home and they stole her from right in front of the house. While I was at work. Now my bike is gone and the wife has been Ex'd ; <

Yard Sale Dale (author)2012-11-16

I knew someone who installed something similar in a car (I think it was wired into the key switch system). A small hidden knob would disable the car.

nin99 (author)2011-05-30

First off, Great tutorial!

I was thinking of this same concept for a car. Interrupt the battery-to-starter wire. Same concept.

dreamberry (author)nin992012-06-11

Yes, I think you want a "battery cutoff switch". They put 'em in race cars for some reason.

It might be useful for dealing with a wrecked vehicle to prevent shorts (fire hazard). Also for repairs on the car, a quick battery shutoff would be useful.

ac-dc (author)nin992012-01-02

It's not the same concept, practically speaking even if technically possible. The battery to starter wire is very heavy gauge to carry hundreds of amps current. It would require a relatively huge switch and wire to do it.

There is going to be a wire between the ECM and ICM or ICM and ignition coil pack that you could put the switch on instead. That's the equivalent of what this instructable did to the motorcycle.

VadimS (author)ac-dc2012-08-10

Well a switch from the ignition to starter (solenoid) would be easy, and it only caries a small current.

xfirexstarzx (author)2009-04-22

I did something like this a few years ago to my moped, because it didn't have a keyed switch. I used a reed switch and soldered it in parallel with my ignition switch. I stuck it in the headlight, so it wasn't noticable, and had a chrome rare earth magnet to make the switch open because my kill switch needs to be open in order for the bike to run. The chrome magnet blended in with the chrome headlight. When you get off the bike, just pull the magnet and the bike won't start.

ToolboxGuy (author)xfirexstarzx2012-02-16


Even if you drop or lose your magnet, you can leave yourself a spare just about anywhere on the bike (or car) for that matter - even use an EMPTY spare key box's magnet as the spare!

Now all we need is a micro cell phone+GPS to get powered up and autodial you should someone attempt to start the vehicle without said switch in place!

Since I drive a minivan and a Subaru Forester, my cars are not nearly as big of a target as the BMWs and Mercedes Benz making up 40% of the vehicles in the parking lot at work.

7070x (author)2012-02-01

I ve seen this 'hidden safety switch" trick. But frankly, for less than $2 I guess I would :

* get a medium duty lock.
* put the lock leg in between chain-eyes. Bike can not and will not roll.
* dont lose the key

I live in a region where bikes are stolen at least 5 units every single day. Most of them are already booked/logged, meaning the preps have a laundry list of "would-be-stolen-bikes" based on model, year, and MSRP. Ironically, many of these stolen bikes are being sold in the black market for parts down to nuts and bolts. Common methods are using fake/duplicated keys, T-shape smart tool, re-wiring etc all done within minutes. I had once ran on two blokes pulling a stolen bike by hand. So, when you're bike can roll without could not even start, it stil is steal-able. (is this is even a word?!)

pro5200 (author)7070x2012-02-15

you are right, I agree with you, but it just slow down a thief.
in my place at least there is two popular ways is quite effective in preventing theft:

1. using the padlock, sometimes also coupled with the large chain LOL :D

2. If your have motorcycle with conventional ignition key, replacing the original ignition key, with the key form of nazi or E form, or replace the ignition key with smart key shutter

abadon (author)2012-02-09

I use heavy high carbon steel chain and a high grade padlock i keep in my backpack whenever I park my machine. The padlock's shackle and the chain is too large for most ordinary bolt cutters and the high carbon steel in the padlock shackle and chain links really slows down grinders and saws.

TSC (author)2011-06-03

Just take the spark plug out then stick it in you pocket then when you come back just put it back in and start it up!

pro5200 (author)TSC2012-02-08

i think a simple & better way, you can deceive theft with unplug your main fuse & replace with a dead fuse as a camouflage...

TSC (author)pro52002012-02-09


SecondTime (author)TSC2012-01-30

The Yamaha YZF series (and the Suzuki GSXR series and most other thing I've owned) has the spark plugs under the tank. I would expect to spend 2 hours or so changing the spark plugs on a supersports. You can't just whip them out when you park up.

TSC (author)SecondTime2012-02-01

Yeah well I know alot more about engines and stuff now and I'm starting to think that was not such a smart Idea!

darkstar$ (author)TSC2011-11-01

you might get water in the motor

TSC (author)darkstar$2011-11-01

True but you could put a rag or something in it then when you come back just take it out then put the spark pulg back in.

GingerMonkey (author)TSC2011-09-18

Although that would work, opening up the cylinder to crud getting in is probably not a good idea for the engine. Plus, my scoot's spark plug is miserable to get at.

cdonnally (author)2011-10-27

you could always just remove your spark plug cable. I used to travel a lot and I would put a padlock through the disc brake.

Project Upcycle (author)2011-08-15

the easiest way to prevent it is to put a Lo-Jack gps locator "24 hour recovery, guaranteed" sticker on the gas tank. It's not worth the risk to steal a motorcycle with a gps tracker on it.

abadfart (author)2011-08-06

if you put it on the battery then you could use it to disconnect the batter when your bike going in to storage

rreinert (author)2011-06-27

This doesn't really prevent someone from stealing your bike, unless their plan to steal it was to ride it away. This prevents unauthorized persons from STARTING your bike... But someone could still roll up in a truck or a van, and throw your bike in and be gone....

The best way to prevent theft is still the good 'old fashioned lock and chain!

OmegaRacer (author)2011-05-25

I followed your instructions on my Yamaha SR400, but I started having problems starting the bike afterwards. It eventually starts after 5mins of kicking...

After asking for help on another forum I got this response:

"You have probably partially destroyed the capacitor in the CDi box.

If you dis-connect the feed to the coil while the engine is running the capacitor has no where to discharge to - but is still being charged. Basically the voltage builds until the capacitor's insulation starts to break down. Once that happens its good bye CDi unit.

The only way to shut off the ignition is to kill the voltage that charges the capacitor - this is what the kill switch does when the black/white wire is shorted to the frame."

I'm no expert regarding electrics, but something's definitely not right here.
Be careful

mrcurlywhirly (author)2011-05-08

Did you think of putting a quick release bolt on the gearshift spline? just stick the gear lever in your pocket!
Pretty hard to go anywhere in neutral.

Seriously, i think the cutout is a good, cheap solution, but doesnt stop the bike from being rolled up a ramp into a ute. Maybe you could combine the cutout with a mercury tilt switch that earths the horn, that way if its moved off its sidestand (or centrestand if you have one) it will alarm. 

GsE-Lance (author)2011-03-21

Nice job, now you have to find out a way to stop them terrorising them :S

bynternet (author)2010-10-04

keep 'em coming!

cromas (author)2010-07-18

What would happen if the switch were to be toggled while the bike was running/in-motion? Would it seize up dangerously, or just slow down quickly, similar to running out of gas?

jay_kris_85 (author)cromas2010-07-18

similar to switching off your ignition while your bike is running.

About This Instructable




Bio: A motorbike rider who loves all about motorcycles and technology.
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