Re: identity needed picture
Based on the shape of the lower unit and the hood, it is probably late 1970s--say 78-79. Parts are still available. It should be electronic ignition with electric eye inside the distributor instead of points. There may be a plate on the distributor saying "electronic distributor". If it has points, it is early '70s. Three Tillotsen carbs with 1 3/16 venturi, probably somewhere around .066 jets. The ID plate should be inside the front lower pan on the starboard side just below the cables and fuel line.
The 75 was the low horsepower engine of the 75,85,90 three cylinder line with all having the same bore and stroke. Additional HP was gained with port timing and larger carbs. 90 had different lower unit gearing.
Very simple to work on, a good starter engine even if it has some minor problems. Before buying, have him remove the plugs and put his thumb over the hole while turning the flywheel. It will either have compression or none. If it has compression, any other problems will be minor. If it has no compression on one cylinder, that calls for a rebuild. Not a difficult job, but not for a beginner--who needs or wants to buy a problem? (other than me)
Later if he wants, it can be retrofit with any tilt/trim from any Chrysler/Force till at least 1990. Tilt and trim was never changed. How much is the seller asking?