However, some old engines DID have magnetos that did not ground properly, which is why we were taught to consider EVERY airplane as having a "hot ignition" system. The old Cubs and Champs at the small field I learned to fly at did not always have the switches off, or proper maintenance, so you had to have a LOT of respect for the engines when you went out to help the owner get his engine propped. Several of the planes I learned to fly in had no starters...T-Craft BC-12D, PA-11, 7AC...several of us learning to fly there got a LOT of lessons and practice on hand-propping those airplanes.

With models, it's a different story. The methanol in our fuels will cause the glow plug element to get hot. Combine this with enough compression or an already-warm/hot engine, and you can get one to fire without the glowplug battery attached. I know, I've done it!