2009 Yamaha F40 Outboard Service Manual, Page 52Get this manual
TECH FEA PTT unit
Outline
Technical features and description
The PTT unit consists of the motor unit, the gear pump unit, the valve unit, and the cylinder unitThe main valve a, which is component of the valve unit, consists of the up valve a, the down valve and the shuttle piston cThe motor-driven gear pump changes its rotating directions to move the main valve and control the PTT fluid flow directionsThe relief valves c, and the protection valves and are installed at both the upstream and downstream fluid passages to control the fluid pressureThe manual valve opens and closes both passages to enable manual operation of the tilt functionThe piston absorbers and are incorporated into the cylinder unit piston to absorb crash impacts and prevent damage to the PTT unit in case the outboard motor collides with objects while operating