As a follow up... the starter went back in this AM and now it sounds like a diesel
car or truck... PERFECT. Started up normally for the first time since I've owned this boat.
On a side note: When I took the old starter gear
(Bendix) out of the starter, like 50 little pieces and a spring all fell out. They were all broken and loose. Apparently, the people who did the starter install cheaped out on the Bendix and put in a car-type one. Also, they cheaped out on everything, since I found the hardware
from the old starter in the engine
room strewn about where the new starter is.
Yet another instance for me of: "Never let a yard touch your boat." I've literally never seen one do a good job in all my years.