'85 Mercury 75Hp Starting Problem

I am hoping that someone can help me. I lost spark to my motor, replaced that switch box to no avail. Continued with diagnostics by disconnecting a black/yellow wire and now spark is back. This tells me that there is a short somewhere is the stop circuitry. I replaced the key switch and starter solenoid. The kill switch seems to be working. Manual says to look at a stop switch. I cannot find it anywhere in my manual. Is this the same as the kill switch?

Any help is much appreciated.