Mercury Mariner 25HP 4-Stroke Outboard Service Manual 1997, Page 199Get this manual
Power Trim Flow Diagrams
Reservoir and Feed Oil Oil Under Pressure
Return Oil
Up Pressure 2530 psi (min)
aElectric MotorTrim RamImpact Relief Valve
nOil Pump
o Up Circuil Feed ValveShuttle Valve
dShock Piston