Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 213Get this manual
Priming Power Trim System ,Fill system with Quicksilver Power Trim and Steering
Trim Indicator Gauge Needle Adjustment1234Turn ignition key to "RUN" positionTi lt outboard to fu ll "IN" position Needle of trim ind icator gauge should be in fu ll "IN" position If not, tilt outboard to full "our position to gain to trim sender and engage tilt lock leverLoosen trim sender screws and reposition trim sender Tighten trim sender screws
Fluid or Automatic Transmission Fl uid (ATF) Type or
FARefer toFill, Check, and Purge" on page 5B-5
IMPORTANT: Run Trim System in shortjogs" until pump motor primes and trim system movesIf trim motor is run without priming pump, drive shaft failure could result