RotaryRacer had just posted a 1985 Four Winns Catalog:
http://fourwinns.com/content/assets/doc ... atalog.pdfThe first concern on a boat that old is Wood Rot. They said that the transom, stringers and floor have already been re-done, so the question is: did they do a good job? Any records of the job, or pictures. Did they use marine plywood, cheap plywood, pine, or non-wood options? I would look under the boat at the running surfaces, looking for any surface that is concave or convex where it should be straight. That could mess with the boats handling (less than 1/8" is probably OK). If the rebuild was done properly, you could have a boat which will last many years.
Also, about 97% of boat buyers will not buy this old, so you are in a buyers market. Price should be quite negotiable. It wouldn't surprise me if you could get that boat for closer to $1000.
Size: Many people on this forum describe the Horizon 170 as being comfortable for 4 adults, and crowded with 6, so don't expect it to be practical with "8-9 passengers". 2 adults and 4 kids is probably good though.
There are many other maintenance items to be concerned about, but I am going to let others chime in. If you do your own mechanical work, it could be a good fit for you.
Good luck, and welcome to the forum.
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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings