"Ron" writes:
I own a 34' sailboat that has a 1985 Yanmar 3GM30F that needs repaired.
Can't get the rpms out of it that I had in the past plus I am blowing some
black smoke and while in the slip if I give it hard throttle I can see
black
floating on the water. This all occurred after the injector pump was
replaced and adjusted by a yard mechanic.

Sounds like a timing problem.

Some else has already suggested the solution.

Mack Boring awaits your money.

Lew