I just had a heavy duty mower engine overhauled. When the guy opened it, he called me to ask how old the mower / engine was: the answer is I don’t know (same thing as seeing the odometer on a car and having no complete records). I’ve had the mower for 12 years, bought it used from another guy who himself had bought it from the city’s roads and parks maintenance department. From what I gathered on the manufacturer’s web site and the identification plate, the thing could be between 35 and 20 years old (ISEKI mower with all aluminum Kawasaki engine manufactured in the US). In fact they still sell a version of it. The mechanic told me he was surprised the engine looked like new, it just needed new piston rings (the oil scrubbing ring -rough translation of the French term- was worn, and new valves (the admission one eaten by dust in the air intake), the rest was still like factory fresh. I’m just leaving to pick it up this morning, going to put the mower back together over the weekend and see...
I guess that a well-designed, well manufactured and reasonably well looked after piece of machinery is not quite eternal, but almost...