Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 117Get this manual
43Remove screws from speed limiter 46Remove bolts from each thermostat cover and remove thermostat (120 degrees)
aBolts (2 Each)Thermostat Cover
47Remove 24 bolts from each cylinder head and remove both cyli nder headsaScrews (2 Each)Speed Limiter