Motor
I have the same boat (1986 c-25, fixed keel, tall rig) and just went through the same thing. The boat came with a Yamaha 9.9 2 stroke that worked well. I wanted a second motor for peace of mind and really wanted a four stroke. I researched, called a catalina dealer, and asked alot of questions. In the end, I felt the 8-9.9 hp four strokes were just too heavy so I went with a Mercury (Tohatsu) 6 hp longshaft. The motor runs great, will push the boat at hull speed (6.2 mph) which is all any motor can do, and sips gas. The nice thing is I can take it off by myself if need be. I bought mine on craigslist for $500. It was like new and only had 10 hours on it. Paid less than 1/3 of the current price for that motor at WM. I haven't regretted mu decision one bit even though some said it wasn't enough motor. So far that hasn't been my experience!