Have a 1961 Larson 18 foot cruiser. Came with a bad 100 hp Johnson. So I bought a Merc 900. Turned out it wasn't worth fixing. Monday morning I tow the boat 250 miles to look at a Merc Mark 75. Is 60 hp going to be enough for that boat? Weren't those all that funny drive that you had to stop and restart motor to reverse. Think they were called dockbusters for a reason. Should I turn and run? If not, is $400 too much if it is in good shape? Help!!