guy48065, I think I understand what you are asking. So here is a little primer on kill switches. Yes some call them dead man switch or kill switch. And most all of them are designed to work even if you don't have the lanyard to make them operate properly. But not as you seem to think. Mercury have a toggle type switch setup that you inserted the clip on and flipped the toggle switch up into the run position. Then if you fell out or got out of your seat, the clip (attached to the lanyard that was attached to the operator) would pull out flipping that toggle switch back down and the engine would stop. And if for some reason that lanyard was lost and you needed to go, you could simply flip the toggle switch up and the engine wold now run again. But you don't have any kill switch operation that way. It looked something like these.
Other marine engine manufactures did something quite similar. But their operation was basically the same. hey use a "C" type clip and install it around a push button setup like these.
So as you can see that even if you lost the lanyard you still can manipulate the kill switch to run the engine in and emergency situation.
Does that mean you don't need the kill switch. Yes and no. Some people never you theirs even with it installed. They simply disable its function and boat on. So the kill switch can all the engine to run either way. Would I run my boats with teh kill switch disabled that way? Absolutely not. It is there for a very good reason. I hope that clarifies things a lot better. JMHO
