YAMAHA F225A, FL225A PARTS CATALOGUE
F225A
FL225A
SERVICE MANUAL
290435
69J-28197-3D-11
NOTICE
This manual has been prepared by Yamaha primarily for use by Yamaha dealers and their trained
mechanics when performing maintenance procedures and repairs to Yamaha equipment. It has
been written to suit the needs of persons who have a basic understanding of the mechanical and
electrical concepts and procedures inherent in the work, for without such knowledge attempted
repairs or service to the equipment could render it unsafe or unfit for use.
Because Yamaha has a policy of continuously improving its products, models may differ in detail
from the descriptions and illustrations given in this publication. Use only the latest edition of this
manual. Authorized Yamaha dealers are notified periodically of modifications and significant
changes in specifications and procedures, and these are incorporated in successive editions of this
manual.
Microsoft and Windows are registered trademarks of Microsoft Corporation.
Important information
Particularly important information is distinguished in this manual by the following notations:
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS
INVOLVED!
WARNING
Failure to follow WARNING instructions could result in severe injury or death to the machine
operator, a bystander, or a person inspecting or repairing the outboard motor.
CAUTION:
A CAUTION indicates special precautions that must be taken to avoid damage to the outboard motor.
NOTE:
A NOTE provides key information to make procedures easier or clearer.
1
F225A, FL225A
SERVICE MANUAL
©2001 by Yamaha Motor Co., Ltd.
1st Edition, June 2001
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.
Printed in the Netherlands
Contents
General information
Specifications
Periodic checks and adjustments
Fuel system
Power unit
GEN
INFO
SPEC
CHK
ADJ
FUEL
POWR
1
2
3
4
5
Lower unit
Bracket unit
Electrical systems
Troubleshooting
Index
LOWR
BRKT
–+
ELEC
TRBL
SHTG
6
7
8
9
GEN
INFO
General information
How to use this manual.................................................................................1-1
Manual format............................................................................................1-1
Symbols.....................................................................................................1-2
Safety while working......................................................................................1-3
Fire prevention...........................................................................................1-3
Ventilation..................................................................................................1-3
Self-protection ...........................................................................................1-3
Parts, lubricants, and sealants ..................................................................1-3
Good working practices .............................................................................1-4
Disassembly and assembly .......................................................................1-4
Identification...................................................................................................1-5
Applicable models .....................................................................................1-5
Serial number ............................................................................................1-5
Features and benefits....................................................................................1-6
Newly developed V6 4-stroke engine........................................................1-6
Valve train system .....................................................................................1-9
Intake system ..........................................................................................1-11
Exhaust system .......................................................................................1-11
Fuel system .............................................................................................1-13
PTT (Power trim and tilt) unit...................................................................1-17
Technical tips ...............................................................................................1-18
Fuel injection control................................................................................1-18
Fail-safe function table ............................................................................1-20
PTT (Power trim and tilt) unit...................................................................1-21
Cooling system ........................................................................................1-26
Lubrication system...................................................................................1-26
Propeller selection.......................................................................................1-27
Propeller size...........................................................................................1-27
Selection..................................................................................................1-27
69J3D11
Predelivery checks ......................................................................................1-28
Checking the fuel system ........................................................................1-28
Checking the gear oil...............................................................................1-28
Checking the engine oil ...........................................................................1-28
Checking the battery................................................................................1-28
Checking the outboard motor mounting height........................................1-29
Checking the remote control cables ........................................................1-29
Checking the steering wheel ...................................................................1-30
Checking the gearshift and throttle operation..........................................1-30
Checking the tilt system...........................................................................1-30
Checking the engine start switch and engine stop switch/
engine shut-off switch ............................................................................1-30
Checking the cooling water pilot hole ......................................................1-31
Test run ...................................................................................................1-31
Break-in ...................................................................................................1-31
After test run ............................................................................................1-31
1
2
3
4
5
6
7
8
9
69J3D11
GEN
INFO
General information
How to use this manual
Manual format
The format of this manual has been designed to make service procedures clear and easy to understand. Use the information below as a guide for effective and quality service.
1
Parts are shown and detailed in an exploded diagram and are listed in the components list.
2
Tightening torque specifications are provided in the exploded diagrams and after a numbered
step with tightening instructions.
3
Symbols are used to indicate important aspects of a procedure, such as the grade of lubricant
and lubrication point.
4
The components list consist of parts and part quantities, as well as bolt, screw, O-ring, and hose
dimensions.
5
Service points regarding removal, checking, and installation are shown in individual illustrations
to explain the relevant procedure.
NOTE:
For troubleshooting procedures, see Chapter 9, “Troubleshooting.”
1
1-1
69J3D11
T
R
.
.
How to use this manual
Symbols
The symbols below are designed to indicate the content of a chapter.
General information
GEN
INFO
Specifications
SPEC
Periodic checks and adjustments
CHK
ADJ
Symbols 1 to 6 indicate specific data.
123456
Fuel system
FUEL
Power unit
POWR
Lower unit
LOWR
Bracket unit
BRKT
Electrical systems
ELEC
Troubleshooting
– +
TRBL
SHTG
1
2
3
4
Special tool
1
Specified oil or fluid
2
Specified engine speed
3
Specified tightening torque
4
Symbols 7 to A in an exploded diagram indicate the grade of lubricant and the lubrication point.
7890A
A M
E
Apply Yamaha 4-stroke motor oil
7
Apply water resistant grease (Yamaha grease A)
8
Apply molybdenum disulfide grease
9
Symbols B to G in an exploded diagram indicate the type of sealant or locking agent and the application point.
BCDEFG
GM
4
LT
271
Specified measurement
5
Specified electrical value
6
(resistance, voltage, electric current)
D C
Apply corrosion resistant grease
0
(Yamaha grease D)
Apply low temperature resistant grease
A
(Yamaha grease C)
LT
242
LT
572
SS
5
6
7
8
9
®
Apply Gasket Maker
B
Apply Yamabond No. 4
C
Apply LOCTITE
D
69J3D11
®
No. 271 (Red)
Apply LOCTITE
E
Apply LOCTITE
F
Apply silicon sealant
G
®
No. 242 (Blue)
®
No. 572
1-2
GEN
INFO
General information
Safety while working
To prevent an accident or injury and to
ensure quality service, follow the safety procedures provided below.
Fire prevention
Gasoline is highly flammable.
Keep gasoline and all flammable products
away from heat, sparks, and open flames.
Ventilation
Gasoline vapor and exhaust gas are heavier
than air and extremely poisonous. If inhaled
in large quantities they may cause loss of
consciousness and death within a short time.
When test running an engine indoors (e.g., in
a water tank) be sure to do so where adequate ventilation can be maintained.
1
Parts, lubricants, and sealants
Use only genuine Yamaha
and sealants or those recommended by
Yamaha, when servicing or repairing the
outboard motor.
Under normal conditions, the lubricants mentioned in this manual should not harm or be
hazardous to your skin. However, you should
follow these precautions to minimize any risk
when working with lubricants.
parts, lubricants,
Self-protection
Protect your eyes by wearing safety glasses
or safety goggles during all operations involving drilling and grinding, or when using an air
compressor.
Protect your hands and feet by wearing protective gloves and safety shoes when necessary.
1-3
1. Maintain good standards of personal and
industrial hygiene.
2. Change and wash clothing as soon as
possible if soiled with lubricants.
3. Avoid contact with skin. Do not, for
example, place a soiled rag in your
pocket.
4. Wash hands and any other part of the
body thoroughly with soap and hot water
after contact with a lubricant or lubricant
soiled clothing has been made.
5. To protect your skin, apply a protective
cream to your hands before working on
the outboard motor.
69J3D11
Safety while working
6. Keep a supply of clean, lint-free cloths for
wiping up spills, etc.
Good working practices
Special tools
Use the recommended special tools to protect parts from damage. Use the right tool in
the right manner—do not improvise.
Tightening torques
Follow the tightening torque specifications
provided throughout the manual. When tightening nuts, bolts, and screws, tighten the
large sizes first, and tighten fasteners starting
in the center and moving outward.
Non-reusable parts
Always use new gaskets, seals, O-rings, cotter pins, circlips, etc., when installing or
assembling parts.
Disassembly and assembly
1. Use compressed air to remove dust and
dirt during disassembly.
2. Apply engine oil to the contact surfaces
of moving parts before assembly.
3. Install bearings with the manufacture
identification mark in the direction indicated in the installation procedure. In
addition, be sure to lubricate the bearings
liberally.
4. Apply a thin coat of water-resistant
grease to the lip and periphery of an oil
seal before installation.
5. Check that moving parts operate normally after assembly.
1
2
3
4
5
6
7
8
9
69J3D11
1-4
GEN
INFO
General information
Identification
Applicable models
This manual covers the following models.
Applicable models
F225AET, FL225AET
Serial number
The outboard motor serial number is
stamped on a label attached to the port
clamp bracket.
1
Model name
1
Approved model code
2
Transom height
3
Serial number
4
Model name
Approved
model code
F225AET 69J
FL225AET 69K
1-5
Starting
serial No.
X: 000101–
U: 150101–
X: 000101–
U: 100101–
69J3D11
Identification / Features and benefits
Features and benefits
Newly developed V6 4-stroke engine
The F225 is a newly developed 60-degree V6 4-stroke engine with a very compact and lightweight
design. Its size and weight are almost the same as the V6 2-stroke engines that are in current use.
This F225 offers numerous advantages of a 4-stroke engine. Compared to conventional 2-stroke
models, it emits much cleaner exhaust gases, offers a better fuel economy, and realizes lower noise
levels at idle and full throttle.
Through the newly developed “In-bank exhaust system,” which discharges exhaust gases from the
center of both banks, the engine block and the surrounding equipment have been made compact. In
addition, the six independent intake passages help to achieve a high level of driveability and power
output.
60˚
1
1
2
3
4
Electronic Fuel Injection
1
In-bank exhaust system
2
Pulse tuned long intake tracks
3
Individual inside track fuel injectors
4
5
6
S69J1250
7
8
9
69J3D11
1-6
GEN
INFO
Crankcase
The crankcase is made of cast aluminum, however steel has been cast into the areas for the crankshaft bearings. By distinguishing the area that requires strength from the area that allows the use of
a lighter material, both weight reduction and a stronger construction have been achieved.
The caps for the crankshaft bearings are secured with four bolts to ensure a high level of assembled
rigidity.
General information
S69J1260
Casted aluminum
1
Steel
2
Crankcase
3
Cylinder block
4
Crankshaft
The crankshaft has been forged to realize a high-strength and high-rigidity construction. In the 60degree V6 cylinder configuration, the crankshaft pins are staggered 60 degrees from each other.
60˚
60˚
60˚
60˚
60˚
60˚
Crankpin #1
1
Crankpin #2
2
Crankpin #3
3
1-7
Crankpin #4
4
Crankpin #5
5
Crankpin #6
6
S69J1270
69J3D11
Features and benefits
Piston
The piston has been carved out of a forged stock. To prevent the valves from coming in contact with
the piston, the piston is provided with a valve recess. If the engine goes out of timing and a valve
opens when the piston is at top-dead-center, this recess prevents the valve from coming in contact
with the piston, thus preventing engine damage.
1
2
3
S69J1280
4
5
6
7
8
Valve spring
1
Valve seal
2
Piston
3
Valve stem
4
69J3D11
Intake valve
5
Intake camshaft
6
Valve lifter
7
Valve recess
8
9
1-8
GEN
INFO
Valve train system
The valve train consists of a total of four camshafts, with two in each bank.
The camshafts are driven with the combination of a belt and chains. The crankshaft turns the belt to
drive the exhaust camshafts in both banks. Chains connect the exhaust camshafts to the intake
camshafts in the cylinder heads to drive the intake camshafts.
In addition, the timing belt offers quieter operation, and the cam chains help to achieve a compact
configuration through the use of individual driven sprockets.
Timing belt
The timing belt, which is driven by the drive sprocket that is attached to the crankshaft, rotates the
driven sprockets that are attached to the exhaust camshafts of both banks. The drive sprocket for
the timing belt is secured to the crankshaft by four bolts, and it can be removed easily for servicing.
In addition, the material of the driven sprockets has been changed from the previous metal to plastic
for weight reduction.
General information
Driven sprocket
1
Timing chain
2
Intake camshaft
3
Crankshaft
4
Drive sprocket
5
1-9
Timing belt
6
Exhaust camshaft
7
Hydraulic timing belt tensioner
8
S69J1290
69J3D11
Features and benefits
Tensioner
A timing chain tensioner is provided at the mid-span of the timing chain, between both camshafts.
The timing chain tensioner uses the force of a spring to maintain its tension. After the engine is
started, oil is pumped into the tensioner, and the resulting pressure causes the tension to increase.
A total of three tensioners are used, one for the timing belt, and one for each timing chain of both
banks, to maintain proper tension and to ensure the reliability of the valve train.
1
2
3
S69J1300
4
5
6
7
8
Intake camshaft
1
Exhaust camshaft
2
Timing chain
3
Timing chain tensioner
4
Hydraulic timing belt tensioner
5
69J3D11
9
1-10
GEN
INFO
Intake system
Throttle valve
A total of six intake throttle valves are provided, one for each cylinder. Together with the intake
silencer that offers enhanced intake efficiency and the injectors that are provided at each throttle
body, the throttle valves help to improve the intake efficiency of the engine. As a result, this engine
produces a higher power output and realizes better driveability.
General information
S69J1310
Throttle valve
1
Exhaust system
In-bank exhaust system
The exhaust passage of the F225 is located in the V bank, a layout that is the opposite of conventional V6 engines. By providing the exhaust passage in the V bank, the engine has been made considerably more compact.
Exhaust gas
1
1-11
S69J1320
69J3D11
Features and benefits
Exhaust passage during idle
To reduce noise when the engine is idling, the exhaust gas passage of the F225 has adopted a labyrinth construction. During idling, the exhaust gas passes through the passage on the side of the
exhaust guide, and enters the upper case through a hole in the upper case gasket. When it fills the
upper case, the exhaust gas enters another passage on the side of the exhaust guide through
another hole in the upper case gasket. Then, it is discharged through the idle port that is provided in
the upper case.
The exhaust manifold and muffler in the upper case are surrounded by the water jackets to reduce
exhaust noise. The water jackets also help prevent corrosion by preventing the exterior of the
exhaust manifold and muffler from coming in direct contact with the exhaust gas.
1
2
3
S69J1330
4
5
6
7
8
Idle port
1
Oil pan
2
Exhaust manifold
3
Muffler
4
Exhaust gas
È
Water
É
69J3D11
9
1-12
GEN
INFO
Fuel system
The fuel flows in the following order: fuel filter, low-pressure fuel pump, vapor separator, high-pressure fuel pump, and injectors. The excess fuel at the injectors passes through the pressure regulator and fuel cooler, and returns to the vapor separator.
When the engine start switch is turned on, the injectors of all cylinders operate before the pump
relay is actuated to prevent the injectors from sticking.
General information
Fuel filter
1
Low-pressure fuel pump
2
Vapor separator
3
High-pressure fuel pump
4
1-13
Fuel injector
5
Pressure regulator
6
Fuel cooler
7
S69J1340
69J3D11
Features and benefits
Low-pressure fuel pump
The F225 has adopted a newly developed, low-pressure electrical fuel pump, in place of the lowpressure mechanical fuel pump used in the previous electronic fuel injection system. With the adoption of the electric pump, the routing of the fuel system has been made more compact. To prevent
the over-pumping of fuel, this pump operates for 10 seconds, and stops for 20 seconds when the
engine is operating at low speeds.
The pump operates constantly if the engine speed is 1,200 r/min or higher, or for several seconds
(which vary by ambient temperature) after the engine is started. At other times, it operates for 10
seconds, and stops for 20 seconds to prevent over-pumping.
1
2
3
Vapor separator
1
Low-pressure fuel pump
2
Fuel filter
3
On
4
Off
5
10 seconds
6
20 seconds
7
S69J1350
4
5
6
7
8
69J3D11
9
1-14
GEN
INFO
Electronic control system
The ECM of the F225 controls the ignition timing, the fuel injection timing, the fuel injection volume,
and the ISC and it maintains a stoichiometric air-fuel ratio in all operating conditions, including starting and idling. Also, the ECM converts the signals from the input sensors and sends instructions to
each part.
General information
Pulser coil
Throttle position
sensor
Thermo switch
Intake air temperature
sensor
Intake air pressure
sensor
Stop switch
Engine temperature
sensor
Oil pressure sensor
Shift cutoff switch
ECM
(Electronic
control
module)
Low-pressure fuel pump
High-pressure fuel pump
Injectors
ISC (Idle speed control)
Ignition coils
Overheat monitor
Oil pressure monitor
Buzzer
Tachometer
Diagnostic system
Neutral switch
1-15
Personal computer
S69J1360
69J3D11
Ignition and fuel injection timing
Firing order : #1, #2, #3, #4, #5, #6
Injection order : #1 and #4 → #2 and #5 → #3 and #6 (group injection)
Features and benefits
Cylinder
Cylinder #1
Cylinder #2
Cylinder #3
Ignition
Injection
Ignition
Injection
Ignition
Injection
Crankshaft angle
180˚
120˚
Compression
Intake
Intake
TDC
Compression
720˚
Combustion Exhaust
Combustion Exhaust
TDC
Compression
TDC
: Ignition spark
: Wasted spark
Intake
Combustion Exhaust
1
2
3
4
5
Cylinder #4
Ignition
Injection
Cylinder #5
Ignition
Injection
Cylinder #6
Ignition
Injection
Exhaust
Combustion Exhaust
Combustion Exhaust
Intake
Intake
Compression
Intake
Combustion
TDC
Compression
6
TDC
7
Compression
8
S69J1370
9
69J3D11
1-16
GEN
INFO
PTT (Power trim and tilt) unit
The PTT unit has been newly developed for the F225. Based on the field-proven 61A type, its PTT
fluid passage and internal valve construction have been changed for this application. Although the
valves of the 61A type have been distributed to the various areas of the gear pump housing, the
valves of the new PTT unit have been concentrated in the vicinity of the gear pump to improve their
serviceability. In addition, the material of the gear pump housing has been changed to enhance its
corrosion resistance.
General information
Gear pump
1
Main valve
2
Relief valve
3
C
B
A
DD
A
B
C
(A)
(B)
Manual valve
4
61A type
È
F225 type
É
(C)
(D)
S69J1380
1-17
69J3D11
Features and benefits / Technical tips
Technical tips
Fuel injection control
The F225 injects fuel simultaneously to the following cylinder pairs: #1 and #4, #2 and #5, and #3
and #6. Optimal injection timing is provided in accordance with the operating conditions of the
engine.
Starting fuel injection volume and injection timing
The injectors are actuated in sync with the standard crankshaft position signals (BTDC 70°) for cylinder pairs #1 and #4, #2 and #5, and #3 and #6, respectively.
(Compression TDC)
CYLINDER #1
CYLINDER #2
CYLINDER #3
CYLINDER #4
CYLINDER #5
CYLINDER #6
SIGNAL #1/4
SIGNAL #2/5
SIGNAL #3/6
INJECTION #1/4
INJECTION #2/5
INJECTION #3/6
#6
Compression Combustion Exhaust Intake Compression Expansion
Intake
Exhaust
Combustion Exhaust
B70
#1 #2 #3 #4 #5 #6 #1 #2
Compression Combustion Exhaust Intake Compression
Intake
Combustion Exhaust
B10 B70 B10
Intake
B70 B10
Compression
Intake
B70 B10B10 B70 B10
Combustion Exhaust Intake Compression
Compression Combustion Exhaust
Compression Combustion Exhaust
Intake
Compression Combustion Exhaust
B70 B10
B70 B10
Intake
B70 B10
1
1
2
3
4
Starting injection start timing
(standard position BTDC 70
˚)
S69J1390
Normal fuel injection volume and injection timing
To control the actuation timing of the injectors, the injection ending timing is established by using the
top-dead-center of the intake stroke as the standard, for cylinder pairs #1 and #4, #2 and #5, and #3
and #6, respectively.
(Compression TDC)
CYLINDER #1
CYLINDER #2
CYLINDER #3
CYLINDER #4
CYLINDER #5
CYLINDER #6
SIGNAL #1/4
SIGNAL #2/5
SIGNAL #3/6
INJECTION #1/4
INJECTION #2/5
INJECTION #3/6
Synchronous injection completion timing
#6
Compression Combustion Exhaust Intake Compression Expansion
Intake
Exhaust
Combustion Exhaust
B70
B10 B70 B10
#1 #2 #3 #4
Compression Combustion Exhaust Intake Compression
Intake
Combustion Exhaust
B10 B70 B10
Intake
Compression
B70 B10
INJF
Combustion Exhaust Intake Compression
Compression Combustion Exhaust Intake
Intake
Compression Combustion Exhaust
Intake
#5 #6 #1 #2
Compression Combustion Exhaust
B70 B10
B70 B10B70 B10
B70 B10
5
6
7
8
69J3D11
#3/6 synchronous injection start/completion
timing setting range
9
S69J1400
1-18
GEN
INFO
Over-revolution control
If the engine speed exceeds 4,500 r/min, while the shift is in neutral, ignition is stopped. The various
stages of ignition cutoff are shown in the table below.
Ignition cutoff cylinder in neutral
Set speed (r/min) #1 #2 #3 #4 #5 #6
4,500
4,750
: Indicates a misfire at either cylinder (once, due to simultaneously firing).
: Indicates a misfire at both cylinders (twice continuous).
If the engine speed exceeds 6,200 r/min, while the shift is in forward or reverse, the ignition is
stopped. The various stages of ignition cutoff are shown in the table below.
Ignition cutoff cylinder in forward or reverse
Set speed (r/min) #1 #2 #3 #4 #5 #6
6,200
General information
6,250
6,300
6,350
6,400
6,450
: Indicates a misfire at either cylinder (once, due to simultaneously firing).
: Indicates a misfire at both cylinders (twice continuous).
Dual-engine control
When two outboard engines are used, if one of the engines enters any one of the control modes, the
other engine will also control its ignition. This control is activated with the same engine speeds as
with other control modes.
Shift cutoff control
If the shift cut switch is activated with the engine operating under 2,000 r/min, the system causes
one or two cylinders to misfire in order to facilitate shifting. The system causes cylinders #1 and #2,
or #4 and #5 to misfire when the engine speed is over 850 r/min, and cylinder #1 or #4 to misfire
when the engine speed is under 850 r/min.
1-19
69J3D11
Fail-safe function table
Technical tips
Symptom
Incorrect pulser
coil signal
Incorrect engine
temperature sensor signal
Incorrect throttle
position sensor
signal
Incorrect intake air
temperature sensor signal
Incorrect neutral
switch signal
Incorrect intake air
pressure sensor
signal
Incorrect oil pressure sensor signal
Incorrect shift cut
switch signal
Incorrect thermoswitch signal
FAIL-SAFE FUNCTION
Ignition Injection ISC
Engine starting:
Only the cylinders
outputting normal
signal ignite at
BTDC10°, and all
cylinders thereafter.
Normal control
Ignition timing is
fixed to BTDC10°.
Normal control
Normal control Normal control Normal control Normal control
Normal control
Normal control Normal control
Normal control Normal control
Normal control Normal control
All cylinders inject
simultaneously
based on the cylinder that is outputting a normal signal.
Engine temperature
sensor is fixed to
40 °C to activate
normal control.
Correction is made
to the basic injection map.
Intake air temperature sensor is fixed
to 40 °C in order to
activate normal
control.
Correction is made
to the basic injection map.
Only in neutral:
900 r/min
Only in neutral:
900 r/min
Opening angle
is fixed to 60%.
Only in neutral:
900 r/min
Only in neutral:
900 r/min
Only in neutral:
900 r/min
In neutral:
900 r/min
In gear:
850 r/min
Only in neutral:
900 r/min
Engine
condition
Idle speed
increases
Idle speed
increases
Idle speed
increases
Idle speed
increases
Idle speed
increases
Idle speed
increases
Idle speed
increases
Idle speed
increases
DIAGNOSIS
CODE
13
15
18
23
28
29
39
45
46
1
2
3
4
5
6
69J3D11
7
8
9
1-20
GEN
INFO
PTT (Power trim and tilt) unit
In the newly designed PTT unit, the up-main valve, down-main valve, up-relief valve, and downrelief valve have been concentrated in the gear pump housing in order to improve the serviceability
of the engine and ensure reliable operation.
General information
Tilt cylinder
1
Trim cylinder
2
Manual valve
3
Up-main valve
4
Down-main valve
5
Up-relief valve
6
Down-relief valve
7
Gear pump
8
Reservoir
9
Tilt ram
0
Tilt piston
A
Tilt piston absorber
B
Free piston
C
Shock return valve
D
Trim ram
E
Trim piston
F
Power trim and tilt motor
G
Up-shuttle piston
H
Down-shuttle piston
I
S69J1410
1-21
69J3D11
Technical tips
Trim-up and tilt-up function
When the PTT switch is pressed to “UP,” the power trim and tilt motor operates the gear pump and
fluid pressure is generated. As a result, the fluid pressure pushes the up-shuttle piston upward,
enters the trim cylinder and tilt cylinder lower chambers through the up-main valve, and then pushes
the tilt ram and trim ram upward.
In addition, the fluid pushes the down-shuttle piston downward, opens the down-main valve, and
returns the PTT fluid from the tilt cylinder upper chamber to the gear pump.
The fluid from the trim cylinder upper chamber then returns to the reservoir.
The tilt ram and the trim ram extend simultaneously, and after the trim ram has extended completely, the tilt ram operates to tilt up.
1
2
3
Tilt ram
1
Tilt cylinder
2
Trim ram
3
Trim cylinder
4
Power trim and tilt motor
5
Reservoir
6
Gear pump
7
Up-shuttle piston
8
Up-main valve
9
Down-shuttle piston
0
Down-main valve
A
Return
È
Send
É
4
5
6
:
:
S69J1420
7
8
69J3D11
9
1-22
GEN
INFO
Trim ram retraction function
When the outboard motor is tilted up and held in place with the tilt stop lever and the PTT switch is
pressed to “DN,” the trim ram will be retracted.
Although the gear pump attempts to draw oil from the tilt cylinder and trim cylinder lower chambers,
after the PTT switch has been pressed, fluid cannot be drawn from the tilt cylinder lower chamber
because the tilt ram is secured in place by the tilt stop lever. Only the PTT fluid from the trim cylinder
lower chamber can be drawn, and as the fluid pressure decreases, the trim ram retracts into the trim
cylinder. Since the tilt ram is secured in place, the PTT fluid pumped by the gear pump flows into the
tilt cylinder upper chamber to increase fluid pressure. As a result, the down-relief valve opens, and
the PTT fluid is released into the reservoir.
General information
Tilt ram
1
Tilt cylinder
2
Trim ram
3
Trim cylinder
4
Gear pump
5
1-23
Reservoir
6
Down-relief valve
7
Return
È
Send
É
:
:
S69J1430
69J3D11
Technical tips
Trim-down and tilt-down function
When the PTT switch is pressed to “DN,” the power trim and tilt motor operates the gear pump and
fluid pressure is generated. As a result, the fluid pressure pushes the down-shuttle piston upward,
enters the tilt cylinder upper chamber through the down-main valve, and then pushes the tilt ram
downward.
In addition, the fluid pushes the up-shuttle piston downward to open the up-main valve.
The gear pump draws the PTT fluid from the tilt cylinder and trim cylinder lower chambers, and then
retracts the tilt ram and the trim ram.
Since the fluid pressure from the gear pump is applied to the tilt cylinder upper chamber, the tilt ram
moves downward first.
The hydraulic oil flows into the trim cylinder upper chamber from the reservoir.
When the outboard motor comes in contact with the trim ram, the trim ram moves downward simultaneously with the tilt ram, due to its own weight and the suction of the PTT fluid by the trim cylinder
lower chamber.
1
2
3
Tilt ram
1
Tilt cylinder
2
Trim ram
3
Trim cylinder
4
Power trim and tilt motor
5
Reservoir
6
Gear pump
7
Up-shuttle piston
8
Up-main valve
9
Down-shuttle piston
0
Down-main valve
A
Return
È
Send
É
4
5
6
7
:
:
S69J1440
8
9
69J3D11
1-24
GEN
INFO
Stationary condition
When the PTT switch is not pressed, the gear pump will not pump the fluid, the up-main valve and
the down-main valve will remain closed, and the PTT unit in the system remains constant. This will
allow the tilt ram and the trim ram to maintain their positions until the PTT fluid flows through the
system again.
When the outboard hits something in the water
If the lower casing comes in contact with an obstacle while the boat is in operation, a sudden extension force becomes applied to the tilt ram. This force causes the fluid pressure in the tilt cylinder
upper chamber to increase, and the tilt piston absorber to open and release the fluid pressure into
the space between the tilt piston and the free piston. As a result, the dampening effect of the tilt piston absorber and the oil lock mechanism prevent the PTT unit from damage, before the tilt piston
comes in contact with the top of the tilt cylinder.
After the collision, a force to return the outboard motor to its original position is generated due to the
weight of the outboard and the thrust of the propeller.
The PTT fluid passes through the shock return valve of the tilt piston, via the free piston, and into
the tilt cylinder upper chamber.
When the tilt piston comes in contact with the free piston, the tilt piston stops.
General information
Tilt ram
1
Tilt cylinder
2
Tilt piston absorber
3
1-25
Tilt piston
4
Shock return valve
5
Free piston
6
S69J1450
69J3D11
Loading...