2009 Yamaha F40 Outboard Service Manual, Page 54Get this manual
TECH FEA
Technical features and description
Tilt down operation
When the PTT switch is pressed to "DN," fluid pressure created by the gear pump flows into the down side of the shuttle piston and pushes the down valve allowing it to openAt this point, the fluid pressure forces the shuttle piston to slide to the up valve aThe protrusion of the shuttle piston opens the up valve a, which opens the return circuitThen, the PTT fluid flows into the upper chamber of the cylinder to force the tilt ram assembly to move downwardThe relief valve of the fluid pressure circuit will open when the fluid pressure exceeds the limitThe down-relief valve opens at 2.0 MPa (20.0 kgfcm2, 290.0 psi)