Yamaha F50 Service Manual

62Y3A111-26
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Tilt-up function
1Power trim and tilt cylinder
2Ram
3End screw
4Check valve
5Trim cylinder
6Reservoir
7Down-main valve
8Gear pump
9Up-main valve0Up-shuttle piston
ADown-shuttle piston
BTrim cylinder base
CFree piston
DTilt piston
EBalls
ÈReturn
ÉSend
ÊMoving direction
:
:
:
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678
96
0 6 A
B C D
E
S62Y1400
Technical tips 

GEN 
INFO
General information
1-2762Y3A11
Circular flow
1Power trim and tilt cylinder
2Ram
3Trim cylinder
4Motor
5Reservoir
6Up-relief valve7Gear pump
8Free piston
9Tilt piston
ÈReturn
ÉSend
:
:12
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5 7 8 9
S62Y1410 

62Y3A111-28
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Tilt-down function
When the power trim and tilt switch is pressed to “Down”, the motor turns the gear pump counter-
clockwise, thus pumping the power trim and tilt fluid to the down-main valve. As a result, fluid pres-
sure opens the down-main valve and the down-shuttle piston, which causes fluid to flow into the
upper part of the trim cylinder and forces the tilt piston down.
When the tilt piston and the free piston reach the trim cylinder base, it pushes the base down,...

GEN 
INFO
General information
1-2962Y3A11
Tilt-down function
1Power trim and tilt cylinder
2Ram
3Trim cylinder
4Down-relief valve
5Down-main valve
6Gear pump
7Reservoir
8Up-relief valve
9Up-shuttle piston
0Up-main valveADown-shuttle piston
BBall
CTrim cylinder base
DFree piston
ETilt piston
FBalls
ÈReturn
ÉSend
ÊMoving direction
:
:
:12
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456
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0 A
B
F C B DE
S62Y1420 

62Y3A111-30
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Stopping condition
When the power trim and tilt switch is not pushed (released), the gear pump does not pump the
fluid, the up-main valve and the down-main valve are closed, and the power trim and tilt fluid pres-
sure in the system remains constant. This allows the ram to maintain its position until the power trim
and tilt fluid flows through the system again.
When the outboard motor hits something in the water
The check valve of the trim cylinder and the tilt piston...

GEN 
INFO
General information
1-3162Y3A11
Damper function
1Power trim and tilt cylinder
2Trim cylinder
3Ram
4Tilt piston absorber
5Tilt piston
6Free piston7Check valve
8Tilt piston absorber
9Tilt piston
ÈSend
ÉMoving direction
:
:
S62Y1430
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62Y3A111-32
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Propeller selection1
The performance of a boat and outboard
motor will be critically affected by the size
and type of propeller you choose. Propellers
greatly affect boat speed, acceleration,
engine life, fuel economy, and even boating
and steering capabilities. An incorrect choice
could adversely affect performance and
could also seriously damage the motor.
Use the following information as a guide for
selecting a propeller that meets the operating
conditions of the boat and...

GEN 
INFO
General information
1-3362Y3A11
Predelivery checks1
To make the delivery process smooth and
efficient, the predelivery checks should be
completed as explained below.
Checking the fuel system 
1. Check that the fuel hoses are securely
connected and that the fuel tank is full
with fuel.
CAUTION:
This is a 4-stroke engine. Never use pre-
mixed fuel.
Checking the gear oil
1. Check the gear oil level.
Checking the engine oil
1. Check the oil level.
NOTE:
If the engine oil is above the maximum...

62Y3A111-34
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Checking the outboard motor 
mounting position
1. Check the position of the anti-cavitation
plate.
2. Check that the clamp brackets are
secured with the clamp bolts.
Checking the remote control cables
1. Set the remote control lever to the neu-
tral position and fully close the throttle
lever/throttle grip.
2. Check that the set pin a
 is aligned with
the alignment mark b
. Adjust if neces-
sary.
3. Check that the alignment mark c
 is
aligned with the mark d
. Adjust if...

GEN 
INFO
General information
1-3562Y3A11
2. Check that the throttle control lever con-
tacts the respective stoppers when the
throttle control lever is closed or fully
open.
Checking the tilt system
1. Check that the outboard motor can be
smoothly tilted up and down by operating
the power trim and tilt unit. 
2. Check that there is no abnormal noise
produced when the outboard motor is
tilted up and down.
3. Check that there is no interference with
wires and hoses when the tilted-up motor
is steered.
4....