SELVA MARINE Kingfish 25, Service Manual

Page: 61 / 398

2-15
TECH
FEA
Technical features and description
PTT unit
Outline
The PTT unit consists of the motor unit, the gear pump unit, the valve unit, and the cylinder unit. The
main valve
1
, which is a component of the valve unit, consists of the up valve
a
, the down valve
b
, and the shuttle piston
c
. The motor-driven gear pump 2 changes its rotating direction to move
the main valve
1
and control the PTT fluid flow direction. The relief valves
3
and
4
and the protec-
tion valves
5
and
6
are installed in both the upstream and downstream fluid passages to control
the fluid pressure. The manual valve 7 opens and closes both passages to enable manual opera-
tion of the tilt function.
The piston absorbers
8
and
9
are installed in the cylinder unit piston to absorb crash impacts and
prevent damage to the PTT unit if the outboard motor collides with objects while operating.
d
Upstream passage
e
Downstream passage
f
Reservoir
È
F25
É
FT25
1
7
b
f
2
4
5
6
a c
8
9
b
d
e
a
c
1
2
3 4
5 6
7
8
9
a b c
e d
f
3