Suzuki DF9,9 Service Manual page 278

TILT UP
(1) When the PT switch is operated in the "UP" position, the motor and gear pump will rotate in a clockwise
direction.
(2) Pressurized oil will open the check valve A and oil flow from the gear pump enters the spool valve B,
moving it to the lower. Following operation of the spool valve B, it open the down check valve C and
returns oil from the upper chamber D of the tilt cylinder to the gear pump.
(3) Pressure built up by the gear pump will then open the up check valve E, oil will enter the lower chamber
F of the tilt cylinder and thereby pushing the tilt piston upward.
(4) Oil in the upper chamber D of the tilt cylinder is returned to the gear pump through the down check valve
C.
(5) Throughout the tilt-up action operation range, there is a difference in oil volume between the upper and
lower chambers of the tilt cylinder, and in order to settle the oil shortage, oil is returned from the reservoir
to the gear pump through the check valve A.
(6) When the motor stops, both the down check valve C and up check valve E will close to retain tilt
position.
(7) When the engine is fully tilted up, oil pressure will correspondingly increase in the lower chamber F of
the tilt cylinder. But, to protect the PT unit from excessively high pump pressure, the up relief valve G
begins to open.
Tilt piston
DF9.9T/TH "K8" ('08) MODEL 12-29
Tilt rod
Gear pump
Reservoir
PT motor