SP,

Forgive me if I get into fundamentals you know in your sleep, but I will start from the beginning. Your kill switch on a magneto-ignited engine is a grounding switch. When the switch is "on", the ignition is grounded. No engine operation. If you want a manual switch and a servo operated limit switch, they need to be wired in parallel so that either can independently ground the magneto. Wire them both up, but do not plug into the magneto. Test start the engine (assuming you can kill the engine through the throttle). The engine should start. If it doesn't you have other issues. Plug in in one of the switches and leave it in the 'open' or off position. Engine should still start and should be killed by closing the switch ('on' position). Plug in the second and repeat.

I have a Quadra 42 and US41 I have operated for years and I only remember one blade into which I could plug the kill switch. You should be able to test start and kill the engine to identify what is going to work for you.

Good luck,

Bedford