2001 Edition Yamaha F225A and LF225A Outboards Service Manual, Page 28Get this manual
GEN INFO
General information
Trim ram retraction function When the outboard motor is tilted up and held in place with the tilt stop lever and the PTT switch is pressed to "DN," the trim ram will be retractedAlthough the gear pump attempts to draw oil from the tilt cylinder and trim cylinder lower chambers, after the PTT switch has been pressed, fluid cannot be drawn from the tilt cylinder lower chamber because the tilt ram is secured in place by the tilt stop leverOnly the PTT fluid from the trim cylinder lower chamber can be drawn, and as the fluid pressure decreases, the trim ram retracts into the trim cylinderSince the tilt ram is secured in place, the PTT fluid pumped by the gear pump flows into the tilt cylinder upper chamber to increase fluid pressureAs result, the down-relief valve opens, and the PTT fluid is released into the reservoir