1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 227Get this manual
Striker Plate Replacement Visually inspect striker plates and replace if worn excessively
Trim Indicator Gauge
A Quicksilver Trim Indicator Gauge accessory kit is available for the power trim sender (if not previously installed)
Fill, Check, and PurgePower Trim System
TO FILL: IMPORTANT: This trim system is pressurizedRemove "Fill" plug only when outboard is tilted to the full "Up" position or the trimtilt rams are fully extendedRetighten "Fill" plug before tilting outboard down or retracting tilttrim ramsRemove "Fill" plug and O-ringSystem is full when oil level is present at fill holeTighten "Fill" plug securely
aStriker Plate (2)LockwasherLocknutTorque to 80 lbin(9.0 Nm)
Trim engine to full "up" positionEngage tilt lock leverTrim system fluid can only be checked when engine is in this positionSlowly remove fill screw and check fluid levelFluid level should be visible in fill tubeIf necessary, add Quicksilver Power Trim and Steering Fluid or Automatic Transmission Fluid (ATF) Type F, FA or Dexron II to power trim systemReinstall fill screw; tighten screw securely