Mercury Mariner 25HP 4-Stroke Outboard Service Manual 1997, Page 214Get this manual
Hydraulic System Troubleshooting Flow Chart OUTBOARD WILL NOT HOLD TILTED POSITION DURING REVERSE ANDIOR TRAILS OUT DURING HIGH SPEED DECELERATION
Manual release valve and -ring damaged
Inspect manual release valve
Manual release valve ana O-rings appear to be .K- Clean and reinstall manual release valve
Replace manual re-
lease valve and 0rings
Trim will not hold reverse thrust
Trim system holds
thrust: reverse Testina com olete
Trim system holds thrust: reverse Testine complete Debris andl or shock
Remove and inspect piston rod assembly for debris andlor shock ball hang up
Shock piston appears O.K- Clean and reinstall piston rod assembly