1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 211Get this manual
CYLINDER BLOCKCRANKCASE
Crankcase and Crankshaft Installation
1Install crankshaft main bearings
NOTE: Align the projection of the bearings with the notch in the cylinder body and crankcaseApply oil to bearings before installing110
4-stroke Outboard Oil (92-828000A12)
a-Main Bearings 2Install upper and lower oil seal