Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 106Get this manual
Exhaust Manifold and Cylinder Head
1Bracket
2Bolt (1-316 in(30mml]
345678910 11 12 13 14 16 17 18 19 20 21 22 23 24 25 Stud (4 Each) Washer (Large) (8 Each) Washer (Small) (8 Each) Wing Nut (4 Each) Exhaust Manifold Cover Gask.et Bolt (17 Each) [6-34 In(25mm)] Pipe Plug Mount (4 Each) Washer (8 Each) Nul (8 Each) Cylinder Head (2 Each) O-ring (6 Each) Bolt (48 Eac h) (1-964 in(80mmll Clamp (2 Each) Thermostat (1 43) (2 Each) Gasket (2 Each) Cover (2 Each) Bolt (4 Each) in(3 1.8mm)) Elbow Fitting (2 Each) Hose (2 Each) [21-12 in(546mm)J Tee