As long as the tach terminal is grounded by the normally-closed contacts on the relay, the engine won't have any spark. When the button is pushed, the first relay self-holds, and the second one opens the ground circuit, and keeps it open until the ignition switch is turned off again. The starting procedure is simple- - - -turn the ignition to the "on" position, hold the push button in, and engage the starter. Stomp switch or solenoid, the procdeure is the same. as soon as the engine starts, release the push button and drive on. If you forget to push the button, it's very obvious- - - -the engine cranks, but it won't start.
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!