I'm pretty sure the 12V foot start trucks had a second ignition switch terminal (IGN 2) that was included in the bypass circuit to keep voltage from being applied to the coil during cranking by the bypass terminal on the foot switch if the ignition switch was turned off. The "I" terminal on the key start solenoid serves the same purpose as the small bypass terminal on the foot start switches- - - -supplying battery voltage to the coil during cranking.
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!