Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 160Get this manual
5Install crankshaft cover6Apply oil to threads of bolts and torque bolts in sequence and two steps2 4 aCenter Bolts (4) 1.74 in(45 mm) LongOuter Bolts (6) .98 in(25 mm) Long
Thermostat Housing
1Install ThermostatAlways use new gasketd
Crankcase Cover Bolt Torque Center Bolts Qty4 (Larger Diameter M8) 1st: 11 lbft(15 Nm) 2nd: 22 lbft(30 Nm) Outer Bolts Qty6 (Smaller Diameter M6)) 1st: 53 lbin(6 Nm) 2nd: 106 lbin(12 Nm)
Exhaust Cover
1Install exhaust covers as shown with new gaskets as shown2Torque bolts in sequence and in two steps7 1
Thermostat Gasket (Always Use New Gasket) Thermostat Cover Bolt (2) By-Pass Hose