I installed a new key switch for my '68 Johnson 40 hp electric start. there is a terminal on the switch labeled magneto that has continuity with ground only when the switch is in the off position. I assume i can use this as a kill switch. Where do I attach it at the motor? The previous owner had no kill switch that I could find so I'm assuming that they were just choking the motor out to kill it. The solenoid also has two posts and I figured out what one starts the motor but I have no idea what the other post is for. Please help.