Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 231Get this manual
POWERHEAD
Cylinder Head
REFNOQTY1 10 11 12 13 14 15 16 24 TORQUE DESCRIPTION CYLINDER HEAD (PORT) CYLINDER HEAD (STARBOARD) GASKET BOLT (2 IN DOWEL PIN GASKET COVER THERMOSTAT (143 degrees) SCREW (M6 25) ELBOW (STARBOARD) ELBOW (PORT) HOSE (21-12 IN HOSE (11-12 IN STA-STRAP TEMPERATURE SENSOR (STARBOARD) RETAINER SCREW (M8 12) 30 lb-ft (40.7 Nm) then tighten additional 90 lb-in lb-ft Nm