1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 133Get this manual
Rocker Arm Shaft Assembly 12Apply engine oil to the the rocker shaft and armsLocate the end of the rocker shaft that gets installed towards driven gear (oil holes will line-up with the mating oil holes in the cylinder head)Slide the rocker arms onto rocker shaft as shown
Rocker Arm Shaft Installation
1Install the rocker arm shaft assembly as shownTighten bolts to the specified torque