Re: Does a 1988 60 hp Mariner have a thermostat?
First of all you have to have a place to put it. Since it is 3/8 in in dia (give or take) and and inch and a half long, and has to be in the water, there aren't many places it can go if you have one.........still puzzling that you wouldn't; but if the rest of Mercs didn't have them back then (my '89 115 tower didn't) maybe Merc decided to not use them on any? Dunno!
Anyway where to put it? About the only place that gives you that kind of room is to slide it down along side a cylinder and since the top of the engine is the hardest to keep cool, slid down adjacent to the top cylinder is where it would probably be.
Additionally, a separate cover for it would be prudent rather than having to remove the whole water jacket cover to change it out, so they mount it on top of the water jacket cover, near cylinider #1 under a separate cover. If it ain't there you must not have one......that's where mine is on my '02, 90 hp.
Sorry for any disinformation; just trying to be helpful.
Mark