There's the safety factor, too. Glow engines can't start unless the glow lighter is attached. Gas engines can start any time the coil is hot. All it has to do is fire once to do damage. Picture a kid walking up and flipping a 22" prop - the gas engine pops - the kid goes to the hospital with bruised and/or cut fingers. Hopefully that's all he has.

Yea, maybe it's farfetched, but I don't take that chance. All my gassers have had electric grounding switches.

Dr.1