Reply To: 1962 Gale 40 hp Wiring

[frankr]

Yes, safety switch is closed at “Start” and slower

Yes, an evolution from the old mercury switdhes

Yes vacuum cutout is normally open, closes at high vacuum

Yes, center is one side of the switch, case (lower left) is other side of switch

At high RPM under no-load condition such as neutral or lost prop, etc, a high intake manifold vacuum is created. That is applied to the switch which closes and shorts one cylinder to the case. But since the switch is mounted on plastic it is not grounded. Enter the safety switch. It provides a ground return for the cut-out switch. BUT only at slower throttle settings. Reason: at certain speeds and loads such as cruise throttle, the vacuum switch might close when not required, providing a hard to diagnose high speed miss. The safety switch disables the cut-out switch at high throttle settings.

Yes your understanding of the fuel saver / cruise throttle is correct