Ok, I have a 2001 4 stroke 115 with too many hours and a hole in the block where #3 connecting rod used to be.
I also have a 2002 140 HP 4 stroke with the same length shaft, but no lower unit (removed by crash). Most of the electronics are stripped off it - it was in a boat yard and they used it for parts. But the mechanics are unmolested, and it has less then 100 hours on it. The boat yard guarantees it, and even tossed in a gasket set.

MY QUESTIONS: 1, on a 1-10 scale, how hard is it to swap this power head? (note, the transom mount is missing from the 140 and will have to come off the 115 if I do it that way) 2: Will the 115 electronics work on the 140 HP motor, or will I need a different ECM or???. (I know the injectors are the same so that's not an issue)

RELEVANT : I've swapped out a few 2 stroke power heads for friends, am an old hot rodder with tools and a service manual so I'm not a total green horn - just slightly....

It is very stressful to be the only knowledgeable person aboard a yacht, because you sometimes, like entering harbour and tying up, you need to be everywhere at once. Moreover, you are never off duty, so you never get a rest.

The bigger the boat, the worse this effect gets. On a 145 ft yacht, I would want to have at least four experienced and watch leader qualified people aboard.

Any good quality premium or high performance marine gear oil. Marine gear oils contain corrosion inhibitors and anti-foaming agents that standard 80/90 wt gear oils do not.