To my great shame, I have always been very blasé when holding spark plugs against an earth point, but today I got my comeuppance.
Having already checked the kill-switch, the magenteo spacing, the point gap and the plug-gap on a Briggs and Stratton lawnwomer engine, I did as I always do; held the plug by the HT lead boot and pressed the body upon the engine block. Then, my trusty assistant yanked upon the recoil starter.
No spark.
I leant closer, putting my left hand against the chassis of the mower for balance. "AGAIN" I shouted!
Fuck me! I felt every single ignition pulse in the top right of my chest. DUH DUH DUH DUH DUH DUH! It was like being shot by a machine gun. I emitted words - some of which are swears, some of which are not even words, swears or otherwise - and then fell onto the floor in a heap. My assistant (in this instance, my long suffering girlfriend) upon seeing I was not dead, also fell to the floor in howls of laughter.
The worst of it all: I had been off the booze for nearly three days, yet then NEEDED a bottle of lager to calm the heart. (Fortunately there was a nice bottle of Dutch stuff in the fridge)
The lesson I have learnt is; always get someone else to hold the plug....