Mrs Blade and I had occasion to visit the local tyre fitting establishment today.
One of the fitters motor bike was parked at the side of the building and I noticed that he'd fitted quite a novel accessory into the end of his handlebars. Screwed into the end of the rubber grip on the off-side was a spark plug with the ceramic part and terminal protruding by a couple of inches.
Has anybody any suggestions as to what function the plug might perform?