# Adding a relay to stop motorcycle engine

I have a Honda CG125 - kickstart CDI motor cycle and I am adding a security system in it which has a relay to cut off the engine remotely.

The ignition coil has two cables coming to it, one green and other black/light green. one of the cable is coming from CDI and the other is ground.

I am planning to install relay to one of these wires. I connected the Voltmeter to find out the voltage, when I kick the starter the voltage seems to go very high like 10,000 V etc.

Is this OK to install relay to one of these cable to stop engine - the relay 12 V / 40 A ?

• In a word, "no". Among other options, you could use a high voltage relay but, more importantly, how do you plan to turn it on and off? – EM Fields Dec 25 '14 at 19:39
• The security device has a GSM module, when I send an SMS to power off, it will activate the relay.. – Ahmed Dec 25 '14 at 19:49
• OK, now that you can turn the relay ON and OFF remotely, can you use its contacts - on the low voltage side of the CDI - to keep the spark from being generated in the first place? If you can do that, or something like that, it'll save you the  for the high voltage relay. – EM Fields Dec 25 '14 at 20:02