That's a stomp switch for a 12V starter, which is a good thing. The small terminal should have a wire connected to the coil + terminal which bypasses the ballast resistor during starting to provide full battery voltage to the coil. After the engine starts the resistor will drop the voltage at the coil to around 9V to keep from burning the points.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!