I am trying to build my own mud motor and i see where it is almost vital to install a kill switch, So here i go. I have an 18hp kohler magnum motor that is currently sitting on a craftmans lawn tractor so there was no need for a kill switch there. it is an electric start job so i was wondering where you splice in to the harness to attach your kill switch, i was thinking in the key loop to the coil. and if so how would i determine the exact wires to splice into. i know one wire just goes to ground and the purpose it to stop the spark from reaching the plugs by grounding the coil to the engine. the concept i have the direction i do not have. any help would be great.

looks like i am gonna wing it. lol