Many years ago, about 40 in fact we lived in an area not far from the in-laws. I picked up my obsession for lawnmowers from my father-in-law (God rest his soul). Anyway, one day he rocked up on out doorstep with a Victa Corvette, the old style with the metal grass catcher and impulse starter, telling me he could not get it started and as he thought that 2 heads were better than one he brought it round to me to see if I had any ideas that he hadn't thought about. A few cranks later and plenty of fuel on board, the old girl still wouldn't start. "We should check the spark" he suggested. Great idea, out comes the spark plug and we attached the ignition lead to it and like a couple of novices held on the frame for contact just behind the spark plug hole (which was horizontal). Wound up the starter and let it rip. Unbeknowns to us at the time the reason it would not start was because the brass float in the carburettor had a pin hole in it and was full of fuel therefore preventing it from floating and shutting off the fuel flow. So where did the excess fuel go, into the cylinder of course, so when we cranked it over the fuel shot out the spark plug hole, hit the sparking ignition lead and whoosh, you can imagine the rest, I ended up with 2nd degree burns from the wrist to the armpit and still bear the signs of it today, off work for 2 weeks. Not funny but an experience all the same. Guess who is very careful checking the spark now?