The industry standard for plug gap for many years was .035". It takes approximately 8-10 KV to fire a clean spark plug with that gap. A .050" gap will require at least double that voltage, which might not work well, especially with a 6V ignition system.
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!