New Arco starter.
Thanks for the quick response J. Thought I had it right.
Oddly, starter has always worked with no problems, although lately has developed the slow crank when hot issue. I removed it while I had the manifolds, risers, and mufflers out to get to and fix a leak at the transom exhaust flange. Cleaned the starter up and just for kicks took it to Autozone for a bench check. It didn't fire the bendix out, just spun it at full speed. I then jumped it with 12v at the house, it was only turning over very slowly. It's 25 years old so I guess it was time. In case anyone else reads the thread, Arco starter was purchased from Marine Parts Source for $121.46. New wiring was included to the starter relay. Straight forward rewiring requried (diagram included).
1988 Tristar 190 Sport, 351W w/GT-40's, 1:1 Velvetdrive