The ignition short is so quick that it won't cause a backfire. As the torque on the input shaft unloads, power is lost to the solenoid pin, and the spring retracts it. Once that happens, power goes back onto the ignition system, and the engine restarts. It all happens in a fraction of a second. There's lots of good engineering involved in the setup, and people who choose to replace it with a toggle switch obviously don't understand how it's supposed to work.
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!