I'm pretty sure they made an air cooled and a water cooled version. Mike would know for sure.
I have an'84 75HP/4cyl lower unit on my '69 Merc800/80HP4cyl
For what it's worth I have two fuel tanks without cross connects. Port engine runs off a completely separate tank. generator also runs of stbd tank along
hey mcd, on youtube theres and excellent video of a guy doing a mercury motor water impeller replcement- its a 40 0r 50 hp I think- hope it helps! Gettin
Without the model year/serial or carb model can't be certain, but that .044 jet is most likely your idle air jet.
In a mid 90's motor the