The confusion obvious on this thread is all to do with the peculiarities of using a rotary key switch to control the mags instead of a sensible toggle switch for each mag. All part of Cessna and Piper's attempts to make spam cans seem like motor cars rather than aeroplanes.
Aeroplanes which are proud to be such and don't feel the need to masquerade as road vehicles (Cubs, Chippys, Lancasters etc) use toggle switches. All aeroplanes should.
I know of a certain Tiger Moth where the passenger caught those "sensible" toggle switches with his sleeve so they got switched off, putting the aircraft down in a field.
BTW, there was no key on the piston engined RAF aircraft I flew. Just a rotary switch.