I had a Keikhaefer Merc, 30 hp I think
, in the late '70s. I don't remember what model year it was but it ran great. I also inherited a 90 hp "tower of power" inline six around '77 or '78. I think it was a mid 60s model. Total POS. Sucked gas worse than a JohnnyRude looper and was hard to start hot or cold. Me and another brother in law ran a fuel consumption test. If I remember correctly at WOT we burned a six gallon tank in something like 20 minutes. No power tilt on that pig and if you left it tilted all the gas would leak out of the carbs into the water or on the ground. It would burn up a set of those high dollar surface gap spark plugs in no time. You did not dare jump start those motors or jump off someone else unless you disconnected the battery. It would fry the power pack or whatever they called it. I did not keep it long and it was a long time before I would even consider owning another Merc.
Brother in law tried to start that thing with a pull cord one day and it jerked his 200# azz right over the transom. I was laughing so hard I could not help him get back in the boat.