Anatomy of a boat ignition switch?

I have a sea nymph with a dt65 suzuki outboard. Last time In took it out, everything worked fine, except my ignition switch was locked. ended up buying one on ebay and installed it. I tested it all before install with a continuity tester, and all worked fine...I hooked it up after making sure I got all the wiring right, and it all worked...the choke, the on power, the start. Only prob is, now it wont turn off. I wish I knew what I may have done wrong. My only quess is that the switch has a black wire and a black/yellow stripe wire that I wasnt sure about. The old switch had two black wires one of which was capped off (not connected). Now the black in the control box tees off to I quess the main ground plus off to the emergency kill switch. I wired it both ways, (with black and black w yellow and it still wodnt turn off. if I knew the anatomy of it, I might be able to figure it out? I disconnected the battery and it was still running. What actually kills the engine?