1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 135Get this manual
Cylinder Block Cover 18 lbft(24.4 Nm)
Electrical Component Plate 13.5 lbft(18.3 Nm) Loctite 271 Required
Exhaust Cover (and Divider Plate) 18 lbft(24.4 Nm)
We recommend that you read the sub-section on reassembly BEFORE proceedingThere are specifics relating to this engine which are NOT applicable to prior engines