2009-2010 Suzuki DF70A DF80A DF90A Outboard Service Manual, Page 270Get this manual
2B-4 Power Trim and Tilt: TrimTilt Down Circuit When the PTT switch is operated in the "DOWN" position, the electric motor will rotate in counterclockwise direction and turn the gear pump Check valve (1) will open; oil will flow from the reservoir to the spool valve (2)This makes spool valve (3) move to downward, and causes the "UP" pressure main check valve (4) to open Oil in the lower chamber will return to pump, and then oil pressure increase will open the "DOWN" pressure main check valve (5), allowing oil flow to the upper chamber of cylinderThis makes the piston rod push down and the engine will tilt down Oil flows from the reservoir to the pump through check valve (1)Surplus oil in the pump flows through the "DOWN" relief valve (6) and returns to the reservoir When the trim motor stops, both the "DOWN" pressure main check valve (5) and the "UP" pressure main check valve (4) will close to retain tilttrim position In the trim area, the trim piston and floating tube are moving with the piston rod When full trimtilt down position is attained, sustained operation of the "DOWN" relay will cause oil to be returned to the reservoir through the "DOWN" relief valve (6) 3 2