According to the manual, closed cooling was an option.
Just for the record, the 1987-91 TriStar manual lists the following options:
- Power Slot Package
- Fresh Water Cooling System
- Boat Cover
- Trick Release
- Tonneau Cover
- Sun Top
"Fresh Water Cooling System" is a confusing term isn't it? At first it sounds as though it would be the same as "raw water." The manual describes it:
-The fresh water cooling system is self-contained and consists of a water to water heat exchanger, reservoir and interconnecting hoses. Water supplied by the raw water system removes heat from engine coolant in the heat exchanger. The engine water pump circulates coolant throughout the system."
I have a whole file of TriStar pics but only one or two have FWC as I recall.
2005 X2, Viper Red, MCX, OJ TZ-X5 prop, PPass, rear 750 sacs, KGB, IBS, Bennett Wake Plate, custom wake shaper
(previous) 2001 X5, 1991 TriStar 190