1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 238Get this manual
6 Apply Loctite 271 to retaining bolts and torque bolts to 60 lbin(6.8 Nm)Rotate drive shaft, prop shaft and move shift rod while housing is pressurized to check for leaks
aCoverBolts [Torque to 60 lbin (6.8 Nm)]
If pressure drop is noted immerse housing in water Re-pressurize to 10-12 p.s.iand check for air bubblesReplace leaking seals as necessaryRetest housingRemove tester from housing and install vent plug