I don't know about the big ones, but I have a 15 hp Evinrude that my Grandfather bought new in 1965. Still cranks on first pull. Replaced gears in foot once about 30 years ago due to a duck hunting mishap. Other than that, impellor and plugs every few years just because...........I bet the little thing has 2000 hours on it! It has been a Stone Pony!