the making of a kill switch

angus67

angus67

Welder's penetrate deeper!!
Messages
5,288
Reaction score
417
Points
133
Location
Shelton, Wa
So, I'm down to the kill switch. But am unsure what to do. I dont want to use the stock kill switch...I plan on getting a 7/8 throttle with no switch box later.
Was wondering if I can just put a switch on one coil(not the plug wire, the other wire) wire so that when I flip the switch it grounds to frame? sound ok?If so, use the red or the orange, or does it mattter?
Or...do I put a switch that just opens the circiut?


So, ground out, or open circuit, wich one?
http://www.xs650.com/forum/showthread.php?t=183
 
Last edited:
I prefer open circuit, I guess either would work. Just make sure it works...the kill switch saved my ass when the throttle stuck last year. Now I know why hondas run dual throttle cables.
 
pyrocentric said:
I prefer open circuit, I guess either would work. Just make sure it works...the kill switch saved my ass when the throttle stuck last year. Now I know why hondas run dual throttle cables.
Click to expand...

open the ground circuit, grounding the hot wire would be putting 12v straight to ground with blown fuses, melted wires ect.:yikes:
 
I think that angus67 means to ground out the negative terminal on the coil, which would be OK for a capacitor PM system because once the engine stops, there is no more power and it requires a heroic effort to restart the engine.

But, for a conventional battery powered system, flipping a switch to ground the negative terminal of the coil would leave it powered up when the engine stops and unless you also had an ignition switch, the coil would soon burn up.

Also, if you were working on the electrical system and needed the power on, then you would also have power to the coil, even if the engine was not running. So, a kill switch should open the circuit to the coil in a conventional battery powered system.
 
yes. I run a battery. I asked many times wich wire is the power/ground. many said it didnt matterand that the orange was the same as the red/white. help me out here. I'm aiming to start it saturday.
 
angus,

After you have decided which terminal you are going to use for the battery to the coil, the other terminal is considered to be the ground terminal because it gets a ground from whatever is driving the coil.

So, if you are going to have a kill switch that will ground the coil to shut off the ignition to kill the engine, then it will not be the terminal that you chose to be the battery terminal. It will be the other terminal.

However, it is not recommended that you ground the negative terminal to stop the engine if you are running a battery because the coil would still be on after the engine stopped.

If you are running a battery setup, then the kill switch should be in series with the wire that is feeding +12 to the coil and the ignition system.
 
Put a normally closed momentary push button switch or a toggle switch inline with the red/white wire. This is the wire that supplies the coil with 12v. By flipping the switch, you will baically be removing power from the coil, and the coil will stop sparking. This is essentially the same way the stock switch/wiring is configured.

Posted via Mobile
 
but the original kill isnt a momentary switch.
But that would work i guesse.
Just another quicky that I'm sure I wont understand the question to when answered: Does it matter which terminal on the coil the red/white and orange goto? Ive understood it dosent.
 
angus67 said:
but the original kill isnt a momentary switch.
But that would work i guesse.
Just another quicky that I'm sure I wont understand the question to when answered: Does it matter which terminal on the coil the red/white and orange goto? Ive understood it dosent.
Click to expand...

No, the factory is more like a toggle. If you use a momentary switch, you will have to hold the button down until the engine completely dies.

If you have a single coil, the wires can go to either terminal.

Posted via Mobile
 
OK guys....if you use a momentary switch to open the power to the coil MOMENTARILY that will certainly kill the ignition and stop the engine, but when you release the momentary switch, push button, whatever, the power will return to the coil(s), so you will have to follow suit and turn off the ignition switch else the coil will overheat due to the current still flowing through it with the engine not running to interrupt the power, so the power will be on 100% of the time as long as the ignition switch is on.

Also, when you release the momentary kill switch and reach over to turn off the ignition switch, there is a good chance that the coil will produce a spark into both cylinders. This could blow a carb off the engine if one of the pistons just happens to be in its intake stroke when the spark occurs.

If you are working on the electrical system, say checking the headlight, then the coil will have current going through it because the kill switch is making contact and this will overheat the coil as well.

So, as I mentioned above...I would not recommend using a momentary kill switch for a battery powered system

In a PM alternator system that uses a capacitor instead of a battery, there is no power available after the engine stops, so you could use a momentary kill switch in that application. In fact, you do not even need an ignition switch in a PM / capacitor setup because the electrical system is dead if the engine is not running. And, because it requires a heroic effort to start a kick only engine, I don't even thing you need the ignition switch for anti theft purposes.

So, in review:

1. Momentary kill switch for a battery powered ignition? Not recommended.
2. Momentary kill switch for a PM / capacitor setup? OK.
 

Similar threads

eazyrider
HHB CDI Wiring Help
Replies
2
Views
537
eazyrider
eazyrider
Dxs650
Hugh hand built PMA relay confusion
2
Replies
20
Views
1K
Dxs650
Dxs650
rem61
Relay Question
Replies
4
Views
356
rem61
rem61
toglhot
Handlebar switch gear.
Replies
0
Views
274
toglhot
toglhot
XS1204
Original Starter Button Question..
2
Replies
35
Views
2K
XS1204
XS1204
Back
Top