2001-2002 Yamaha 50HP F50Z/T50Z Ouboard 4-stroke engines service manual, Page 28Get this manual
IIGeneral information Trim-down function When the power trim and tilt switch is pressed to "Down", the motor turns the gear pump counterclockwise and the power trim and tilt fluid flows in the opposite direction to that of the trim-up functionTilt-up function When the trim cylinder tops out, the check valve is pushed down by the end screw wallThis causes the ball in the check valve to move down, opening the fluid passage and allowing the power trim and tilt fluid to flow from the upper part of the trim cylinder, through the down-shuttle piston and the down-main valve, and back to the gear pumpIn addition, fluid is also sucked in through the reservoir and the pressurized fluid continues to flow into the lower part of the trim cylinder, pushing up the tilt piston and free piston, and further extending the ramAs the tilt piston moves up and off of the trim cylinder base, the base moves up and pushes the balls outward to fit into holes of the power trim and tilt cylinderOnce the balls have been fitted into the holes the trim cylinder base cannot moveThe end of the tilt-up range is when the tilt piston tops out in the trim cylinder and the ram is fully extendedThe tilt-up function operates when the fluid pressure is under 10 MPa (100 kgfcm2, 1,423 psi)When the fluid pressure in the lower part of the trim cylinder increases to over 10 MPa (100 kgfcm2, 1,423 psi), the up-relief valve opens and allows the pressurized fluid to flow into the reservoirThus, the tilt piston and free piston are not pushed up and the ram cannot be extend further