1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 163Get this manual
Powerhead to Driveshaft Housing S Temporarily install flywheel with nut, as shown
Clean holes (threads) and bolts thoroughly, with Locquic Primer (92-59327-1)Dry, apply Loctite 271 to bolts, and installThere are bolts (3 each side, backside)Torque in Steps to 45 lbft(61.0 Nm)
S Install lifting eye (91-90455) onto flywheelThread on at least full turnsS After checking mating surfaces between powerhead and driveshaft housing for condition and cleanliness, use hoist to lift powerhead, being careful not to damage powerhead to driveshaft housing gasket surfaceS Place new gasket over locating pins on driveshaft housing-to-powerhead mating surfaceS Apply small amount of Quicksilver 2-4-C wTeflon to driveshaft splinesS Recheck for correct installation of tip-seal in crankshaft seal carrierS Use hoist to lower powerhead into driveshaft housing, turning flywheel, if necessary, to align crankshaft splines with driveshaft splinesLower so that powerhead is fully installed and aligned on locating pins