Home › Forum › Ask A Member › 1957 Johnson 35 hp Mercury switch › Re: 1957 Johnson 35 hp Mercury switch
1955 HAS a cutout switch, not connected to the mercury switch. The base of the cutout switch was grounded to complete the circuit, and worked any time the vacuum was too high.
35hp also had a cutout switch, but the base was mounted on a plastic plate. The base was grounded through the mercury switch, so it only worked when the vacuum was too high AND the throttle was at a slow setting.
Reason: The 35hp had the fuel-saver "Cruise Throttle". There was a possibility of the vacuum switch causing a high speed miss when the throttle was in cruise throttle position. To prevent that from happening, the cut-out switch base was not grounded (was disabled) in cruise throttle position, but was grounded and enabled at slow position.