1968 Evinrude Triump 55HP 3 Cylinder Switch Unknown

[mfarish]

I am making a new wiring harness for this motor but I have one "object" I do not know what it is.Can anyone identify it for me? It is a round diaphram type electrical switch (has two wires going to it) and approx. 2 inches in diameter thatis connected or bolted to the crankcase close to the carburators and near the throttle arm linkages. The rubber diaphram is dry rotted on mine but I do not know what it's function is. Can anyone HELP??Thanks..........

[Droll]

This item are probably the vacuum switch (( one DK Green wire + 1 Red & Green stripe ).From manual is installed to allow current flow to continue to the lower unit after the ignitions switch has been turned to the off positionPreventing the engine to jump in to forward gear when ingnition is tured off ( jump forward )

[seahorse5]

The round vacuum switch also is to prevent "Model T" starts when you turn the key on. That takes fingertips off if you are near the flywheel. If a cylinder is near top dead center with enough fuel vapor in it, the ignition may spark the moment the key is turned on, since it is a battery powered electronic ignition. The vacuum switch prevents power to the ignition module until the engine is cranking over and crankcase vacuum pulls the diaphragm in to complete the circuit.

[mfarish]

Hmmmmm.....2 different ideas...I really thank you guys for helping me very much. Turns out, after much un-wrapping of the tape from the rotten wiring harness I have figured it out. One side of the switch is fed 12V with ignition in the "ON" position, the other wire goes through the harness connectors to the shift control switch PURPLE/GREEN wire.......so it does have to do with the shifting....