Mercury Mariner 4 and 5HP 4-Stroke Outboards Service Shop Manual 1999, Page 156Get this manual
CYLINDER BLOCK AND CRANKCASE
7Assemble connecting rod to piston, secure with piston pin and new piston pin clips
NOTE: Make sure the connecting rod is orientated correctly for reassembling (3H6 mark must face the oil pan)NOTE: Reassemble the piston so that the arrow faces the camshaft
4-Stroke Outboard Oil (92-828000A 12)
aConnecting Rod (3 H6 must Face the Oil Pan)PistonPiston PinPiston Pin Clip (2)
eDirection Arrow (M ust Face The Camshaft)Piston Pin Clips Sho uld Bridge the Notch in the Piston