I have had an old Mercruiser 165hp for 28 years now. It has been interesting to maintain it over the years. I'm a practical guy who doesn't mind being busy. There is a ton of stuff you can diagnose yourself and fix. Cast iron block and cast iron manifold are heavy though. Nowadays, you would want an aluminum block, with metal sleeves in there for the 2nd set of pistons, when rebuilding.
My brother did boat surveying in Victoria/Sidney and around the island. He found from talking to people who live on the west coast that they like to pull the outboard off the back of the boat and take it to cambell River for maintenance, or replacement. I guess with lifts, hoists, cranes being at a premium they can pull this off easier/cheaper and get back on the water sooner.