Re: 1973 Evinrude wont shut off
Sounds like one of the wires to short the motor (shut it off) on the key switch has come loose, or popped off, or frayed or something.
If you ask for a wiring diagram for that motor right here on iboats there is a good chance someone will be able to help you. So, start a new thread so that "Wiring Diagram" is part of the title/headline of your thread.
But, before you do all that just look at the prongs on the key switch,and check for disconnected or broken wires.