Yamaha F400A User manual

Read this manual carefully before operating this
outboard motor.
OWNER’S MANUAL
F400A
FL400A
F450A
FL450A
6KN-28199-K0-E0
U6KNK0E0.book Page 1 Monday, November 7, 2022 10:23 AM

Read this manual carefully before operating this outboard motor. Keep this
manual onboard in a waterproof bag when boating. This manual should stay
with the outboard motor if it is sold.
U6KNK0E0.book Page 1 Monday, November 7, 2022 10:23 AM

Important manual information
EMU25108
To the owner
Thank you for selecting a Yamaha outboard
motor. This Owner’s Manual contains infor-
mation needed for proper operation, mainte-
nance and care. A thorough understanding of
these simple instructions will help you obtain
maximum enjoyment from your new Yamaha.
If you have any question about the operation
or maintenance of your outboard motor,
please consult a Yamaha dealer.
In this Owner’s Manual particularly important
information is distinguished in the following
ways.
: This is the safety alert symbol. It is used
to alert you to potential personal injury haz-
ards. Obey all safety messages that follow
this symbol to avoid possible injury or death.
EWM00782
A WARNING indicates a hazardous situa-
tion which, if not avoided, could result in
death or serious injury.
ECM00702
A NOTICE indicates special precautions
that must be taken to avoid damage to the
outboard motor or other property.
TIP:
A TIP provides key information to make pro-
cedures easier or clearer.
Yamaha continually seeks advancements in
product design and quality. Therefore, while
this manual contains the most current prod-
uct information available at the time of print-
ing, there may be minor discrepancies
between your machine and this manual. If
there is any question concerning this manual,
please consult your Yamaha dealer.
To ensure long product life, Yamaha recom-
mends that you use the product and perform
the specified periodic inspections and main-
tenance by correctly following the instruc-
tions in the owner’s manual. Any damage
resulting from neglect of these instructions is
not covered by warranty.
Some countries have laws or regulations re-
stricting users from taking the product out of
the country where it was purchased, and it
may be impossible to register the product in
the destination country. Additionally, the war-
ranty may not apply in certain regions. When
planning to take the product to another coun-
try, consult the dealer where the product was
purchased for further information.
If the product was purchased used, please
consult your closest dealer for customer re-
registration, and to be eligible for the speci-
fied services.
TIP:
The F400AST, FL400AST, F450AVT,
FL450AVT and the standard accessories are
used as a base for the explanations and illus-
trations in this manual. Therefore some items
may not apply to every model.
EMU25123
F400A, FL400A, F450A, FL450A
OWNER’S MANUAL
©2022 by Yamaha Motor Co., Ltd.
1st Edition, January 2022
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.
Printed in Japan
U6KNK0E0.book Page 1 Monday, November 7, 2022 10:23 AM

Table of contents
Safety information ............................. 1
Outboard motor safety.................... 1
Propeller ............................................. 1
Rotating parts..................................... 1
Hot parts ............................................ 1
Electric shock..................................... 1
Power trim and tilt .............................. 1
Engine shut-off cord (lanyard)............ 1
Gasoline ............................................. 2
Gasoline exposure and spills ............. 2
Carbon monoxide .............................. 2
Modifications...................................... 2
Boating safety ................................. 2
Alcohol and drugs .............................. 2
Personal flotation devices (PFDs) ...... 2
People in the water ............................ 2
Passengers......................................... 2
Overloading........................................ 3
Avoid collisions .................................. 3
Collisions with floating or submerged
objects ............................................ 3
Weather.............................................. 4
Passenger training ............................. 4
Boating safety publications................ 4
Laws and regulations ......................... 4
General information .......................... 5
Identification numbers record ......... 5
Outboard motor serial number........... 5
Key number........................................ 5
EC Declaration of Conformity
(DoC) ............................................ 5
CE Marking / UKCA Marking .......... 5
Compliance mark label ................... 6
Read manuals and labels................ 7
Warning labels ................................... 7
Engine data recording..................... 9
Specifications and requirements... 11
Specifications................................ 11
Installation requirements............... 12
Boat horsepower rating.................... 12
Mounting outboard motor ................ 12
Digital electronic control
requirements.............................. 12
Battery requirements .................... 13
Battery specifications....................... 13
Propeller selection ........................ 14
Counter rotation models .................. 14
Start-in-gear protection ................ 14
Engine oil requirements ................ 15
Fuel requirements ......................... 15
Gasoline ........................................... 15
Anti-fouling paint .......................... 16
Outboard motor disposal
requirements.............................. 16
Emergency equipment.................. 16
Emission control information ....... 16
U.S. insular areas ............................. 16
Components.................................... 17
Components diagram ................... 17
Optional items .................................. 19
Helm Master™ EX (upgradable) ... 22
Digital electronic control ............... 22
Control lever ..................................... 23
Power trim and tilt switches ............. 23
DEC alert indicator ........................... 24
Speed control switch ....................... 24
Neutral hold switch .......................... 25
Station selector switch ..................... 25
Center engine switch........................ 26
Single lever switch ........................... 26
6X6 switch .................................... 27
Main switch ...................................... 27
Start/Stop switch panel.................... 27
All Start/Stop switch panel
(optional) ....................................... 27
Engine shut-off cord (lanyard) and
clip ................................................ 28
Outboard motor equipment .......... 28
Power trim and tilt switch on
bottom cowling ............................. 28
Tilt limiter .......................................... 29
Tilt support lever for power trim and
tilt model ....................................... 29
U6KNK0E0.book Page 1 Monday, November 7, 2022 10:23 AM

Table of contents
Cowling lock lever ............................ 29
Flushing device ................................ 30
Fuel filter........................................... 30
Instruments and indicators ............ 31
CL5 Display ................................... 31
Engine control system .................... 34
Alert system .................................. 34
Helm Master control system alert .... 34
Digital electronic control alert .......... 34
Overheat alert................................... 34
Low oil pressure alert....................... 35
Water separator alert........................ 36
Installation ....................................... 38
Installation ..................................... 38
Mounting the outboard motor.......... 38
Operation ......................................... 40
First-time operation....................... 40
Filling engine oil................................ 40
Breaking in engine............................ 40
Getting to know your boat ............... 40
Checks before starting engine ...... 41
Fuel level .......................................... 41
Removing top cowling ..................... 41
Fuel system ...................................... 42
Controls............................................ 42
Engine shut-off cord (lanyard).......... 43
Engine oil.......................................... 43
Outboard motor ............................... 43
Flushing device ................................ 44
Installing top cowling ....................... 44
Checking power trim and tilt
system .......................................... 45
Battery.............................................. 46
Filling fuel ..................................... 46
Operating engine........................... 47
Sending fuel ..................................... 47
Starting engine ................................. 47
Checks after starting engine ......... 52
Cooling water ................................... 52
Warming up engine....................... 52
Procedure for warming up engine.... 52
Checks after engine warm up....... 53
Shifting ............................................. 53
Stop switches................................... 53
Shifting.......................................... 53
Neutral hold switch operation....... 54
Center engine switch operation.... 54
Single lever switch operation........ 55
Stopping boat ............................... 56
Boat direction ............................... 57
Stopping engine............................ 59
Procedure for stopping engine
(6X6 switch)................................... 59
Trimming outboard motor............. 59
Adjusting trim angle (Power trim
and tilt) .......................................... 60
Adjusting boat trim ........................... 61
Tilting up and down ...................... 61
Procedure for tilting up (power trim
and tilt models) ............................. 62
Procedure for tilting down................ 64
PTT TotalTilt™.................................. 65
Shallow water .............................. 66
Cruising in shallow water ................. 66
Operating in other conditions ....... 67
Maintenance.................................... 69
Transporting and storing outboard
motor ......................................... 69
Storing outboard motor.................... 69
Lubrication ....................................... 69
Flushing cooling water passage....... 70
Cleaning the outboard motor ........... 71
Checking painted surface of
outboard motor............................. 71
Periodic maintenance ................... 71
Replacement parts ........................... 71
Severe operating conditions ............ 72
Maintenance chart 1......................... 73
Maintenance chart 2......................... 75
Greasing ........................................... 77
Inspecting spark plug....................... 79
U6KNK0E0.book Page 2 Monday, November 7, 2022 10:23 AM

Table of contents
Inspecting engine idle speed ........... 79
Changing engine oil.......................... 79
Why Yamalube ................................. 79
Inspecting wiring and connectors .... 79
Inspecting propeller ......................... 80
Removing propeller .......................... 80
Installing propeller............................ 81
Changing gear oil ............................. 81
Inspecting and replacing anode(s) ... 83
Checking battery (for electric start
models) ......................................... 84
Connecting the battery..................... 84
Disconnecting the battery ................ 86
Trouble Recovery ............................ 88
Troubleshooting ............................ 88
Temporary action in emergency ... 91
Impact damage ................................ 91
Running in an emergency
(twin engines or triple engines) ..... 91
Replacing fuse ................................. 92
Power trim and tilt will not
operate.......................................... 93
Steer-by-wire system will not
operate.......................................... 93
Water separator-alert is activated
after leaving port........................... 94
Treatment of submerged motor .... 95
INDEX ............................................... 97
U6KNK0E0.book Page 3 Monday, November 7, 2022 10:23 AM

1
Safety information
EMU33623
Outboard motor safety
Observe these precautions at all times.
EMU36502
Propeller
People can be injured or killed if they come in
contact with the propeller. The propeller can
keep moving even when the motor is in neu-
tral, and sharp edges of the propeller can cut
even when stationary.
Stop the engine when a person is in the
water near you.
Keep people out of reach of the propeller,
even when the engine is off.
EMU40272
Rotating parts
Hands, feet, hair, jewelry, clothing, personal
flotation device (PFD) straps, etc., can be-
come entangled with internal rotating parts of
the engine, resulting in serious injury or
death.
Keep the top cowling in place whenever pos-
sible. Do not remove or replace the top cowl-
ing with the engine running.
Only operate the engine with the top cowling
removed according to the specific instruc-
tions in the manual. Keep hands, feet, hair,
jewelry, clothing, PFD straps, etc., away from
any exposed moving parts.
EMU33641
Hot parts
During and after operation, engine parts are
hot enough to cause burns. Avoid touching
any parts under the top cowling until the en-
gine has cooled.
EMU33651
Electric shock
Do not touch any electrical parts while start-
ing or operating the engine. They can cause
shock or electrocution.
EMU33662
Power trim and tilt
Body parts can be crushed between the mo-
tor and the clamp bracket when the motor is
trimmed or tilted. Keep body parts out of this
area at all times. Be sure no one is in this area
before operating the power trim and tilt
mechanism.
The power trim and tilt switches operate even
when the main switch is off. Keep people
away from the switches whenever working
around the motor.
Never get under the lower unit while it is tilted,
even when the tilt support lever is locked. Se-
vere injury could occur if the outboard motor
accidentally falls.
EMU33672
Engine shut-off cord (lanyard)
Attach the engine shut-off cord so that the
engine stops if the operator falls overboard or
leaves the helm. This prevents the boat from
running away under power and leaving peo-
ple stranded, or running over people or ob-
jects.
Always attach the engine shut-off cord to a
secure place on your clothing or your arm or
leg while operating. Do not remove it to leave
the helm while the boat is moving. Do not at-
tach the cord to clothing that could tear
loose, or route the cord where it could be-
come entangled, preventing it from function-
ing.
Do not route the cord where it is likely to be
accidentally pulled out. If the cord is pulled
during operation, the engine will shut off and
you will lose most steering control. The boat
could slow rapidly, throwing people and ob-
jects forward.
U6KNK0E0.book Page 1 Monday, November 7, 2022 10:23 AM

Safety information
2
EMU33811
Gasoline
Gasoline and its vapors are highly flamma-
ble and explosive. Always, refuel according
to the procedure on page 47 to reduce the
risk of fire and explosion.
EMU33821
Gasoline exposure and spills
Take care not to spill gasoline. If gasoline
spills, wipe it up immediately with dry rags.
Dispose of rags properly.
If any gasoline spills onto your skin, immedi-
ately wash with soap and water. Change
clothing if gasoline spills on it.
If you swallow gasoline, inhale a lot of gaso-
line vapor, or get gasoline in your eyes, get
immediate medical attention. Never siphon
fuel by mouth.
EMU33901
Carbon monoxide
This product emits exhaust gases which con-
tain carbon monoxide, a colorless, odorless
gas which may cause brain damage or death
when inhaled. Symptoms include nausea,
dizziness, and drowsiness. Keep cockpit and
cabin areas well ventilated. Avoid blocking
exhaust outlets.
EMU33781
Modifications
Do not attempt to modify this outboard mo-
tor. Modifications to your outboard motor
may reduce safety and reliability, and render
the outboard unsafe or illegal to use.
EMU33742
Boating safety
This section includes a few of the many im-
portant safety precautions that you should
follow when boating.
EMU33711
Alcohol and drugs
Never operate after drinking alcohol or taking
drugs. Intoxication is one of the most com-
mon factors contributing to boating fatalities.
EMU40281
Personal flotation devices (PFDs)
Have an approved PFD on board for every
occupant. Yamaha recommends that you
must wear a PFD whenever boating. At a mi-
nimum, children and non-swimmers should
always wear PFDs, and everyone should
wear PFDs when there are potentially hazard-
ous boating conditions.
EMU33732
People in the water
Always watch carefully for people in the wa-
ter, such as swimmers, skiers, or divers,
whenever the engine is running. When some-
one is in the water near the boat, shift into
neutral and stop the engine.
Stay away from swimming areas. Swimmers
can be hard to see.
The propeller can keep moving even when
the motor is in neutral. Stop the engine when
a person is in the water near you.
EMU33752
Passengers
Consult your boat manufacturer’s instruc-
tions for details about appropriate passenger
locations in your boat and be sure all passen-
gers are positioned properly before acceler-
ating and when operating above an idle
speed. Standing or sitting in non-designated
locations may result in being thrown either
overboard or within the boat due to waves,
wakes, or sudden changes in speed or direc-
tion. Even when people are positioned prop-
U6KNK0E0.book Page 2 Monday, November 7, 2022 10:23 AM

Safety information
3
erly, alert your passengers if you must make
any unusual maneuver. Always avoid jump-
ing waves or wakes.
EMU33763
Overloading
Do not overload the boat. Consult the boat
capacity plate or boat manufacturer for maxi-
mum weight and number of passengers. Be
sure that weight is properly distributed ac-
cording to the boat manufacturer’s instruc-
tions. Overloading or incorrect weight
distribution can compromise the boat’s han-
dling and lead to an accident, capsizing or
swamping.
EMU33773
Avoid collisions
Scan constantly for people, objects, and oth-
er boats. Be alert for conditions that limit your
visibility or block your vision of others.
Operate defensively at safe speeds and keep
a safe distance away from people, objects,
and other boats.
Do not follow directly behind other boats or
waterskiers.
Avoid sharp turns or other maneuvers that
make it hard for others to avoid you or un-
derstand where you are going.
Avoid areas with submerged objects or
shallow water.
Ride within your limits and avoid aggres-
sive maneuvers to reduce the risk of loss of
control, ejection, and collision.
Take early action to avoid collisions. Re-
member, boats do not have brakes, and
stopping the engine or reducing throttle
can reduce the ability to steer. If you are not
sure that you can stop in time before hitting
an obstacle, apply throttle and turn in an-
other direction.
EMU48100
Collisions with floating or submerged
objects
If the outboard motor hits a floating object or
an obstacle in the water while cruising, the
following could occur:
The passengers and any loose equipment
or luggage could be thrown forward due to
the sudden deceleration.
Parts of the outboard motor could come
loose as a result of the impact and could be
thrown into the boat.
The boat or outboard motor could be dam-
aged as a result of the impact.
When you operate the boat in an area where
there might be floating objects or obstacles in
the water, be sure to adjust the trim angle of
the outboard motor, slow down, and operate
carefully. For further information, see page
66.
If the outboard motor hits a floating object or
an obstacle in the water, make sure that there
are no abnormalities with the boat and the
outboard motor. If anything abnormal is
found, return to the nearest harbor at low
speed and have a Yamaha dealer inspect the
outboard motor.
ZMU06025
U6KNK0E0.book Page 3 Monday, November 7, 2022 10:23 AM

Safety information
4
EMU33791
Weather
Stay informed about the weather. Check
weather forecasts before boating. Avoid
boating in hazardous weather.
EMU33881
Passenger training
Make sure at least one other passenger is
trained to operate the boat in the event of an
emergency.
EMU33891
Boating safety publications
Be informed about boating safety. Additional
publications and information can be obtained
from many boating organizations.
EMU33602
Laws and regulations
Know the marine laws and regulations where
you will be boating—and obey them. Several
sets of rules prevail according to geographic
location, but all are basically the same as the
International Rules of the Road.
U6KNK0E0.book Page 4 Monday, November 7, 2022 10:23 AM

General information
5
EMU25172
Identification numbers record
EMU25186
Outboard motor serial number
The outboard motor serial number is
stamped on the label attached to the port
side of the clamp bracket.
Record your outboard motor serial number in
the spaces provided to assist you in ordering
spare parts from your Yamaha dealer or for
reference in case your outboard motor is sto-
len.
EMU41572
Key number
The key identification number is stamped on
the spare key as shown in the illustration.
Keep the spare key in a safe place and record
this number in the space provided for refer-
ence in case that you need a new key.
EMU38984
EC Declaration of Conformity
(DoC)
This declaration is included with outboard
motors that conform to European regula-
tions.
This outboard motor conforms to certain por-
tions of the European Parliament directive re-
lating to machinery.
Each conformed outboard motor accompa-
nied with EC DoC. EC DoC contains the fol-
lowing information;
Manufacturer
Model name
Engine code
Applied directives
EMU48442
CE Marking / UKCA Marking
This label is affixed to outboard motors that
conform to European regulations.
1. Outboard motor serial number location
1. Serial number
2. Model name
3. Motor transom height
4. Engine code
1
3412
ZMU01692
1. Key number
1
U6KNK0E0.book Page 5 Monday, November 7, 2022 10:23 AM

General information
6
CE marking
Outboard motors affixed with this “CE” mark-
ing conform with the directives of;
2006/42/EC, 2014/30/EU, and 2013/53/EU.
UKCA marking
This product is in compliance with the Recre-
ational Craft Regulations 2017, Electromag-
netic Compatibility Regulations 2016 and
Supply of Machinery (Safety) Regulations
2008.
EMU46133
Compliance mark label
Engines affixed with this label conform to the
regulations for each country.
This label is affixed to the clamp bracket or
swivel bracket.
Regulatory Compliance Mark (RCM)
Engines affixed with this mark conform to
certain portion(s) of the Australian Radio
Communications Act.
ICES-002 Compliance Label
Engines affixed with this mark meet all re-
quirements of the Canadian Interference
Causing Equipment Regulations.
1. CE marking location
1
6EE-43394-90
15210026
1. Compliance mark label location
1. Regulatory Compliance Mark (RCM)
1. ICES-002 Compliance Label
1
ZMU08190
1
ZMU08191
1
U6KNK0E0.book Page 6 Monday, November 7, 2022 10:23 AM

General information
7
EMU33524
Read manuals and labels
Before operating or working on this outboard motor:
Read this manual.
Read any manuals supplied with the boat.
Read all labels on the outboard motor and the boat.
If you need any additional information, contact your Yamaha dealer.
EMU33836
Warning labels
If these labels are damaged or missing, contact your Yamaha dealer for replacements.
3
2
4
1
U6KNK0E0.book Page 7 Monday, November 7, 2022 10:23 AM

General information
8
EMU47880
Contents of labels
The above warning labels mean as follows.
1
EWM01682
Keep hands, hair, and clothing away
from rotating parts while the engine is
running.
Do not touch or remove electrical parts
when starting or during operation.
2
EWM01672
Read Owner’s Manuals and labels.
Wear an approved personal flotation de-
vice (PFD).
Attach engine shut-off cord (lanyard) to
your PFD, arm, or leg so the engine
stops if you accidentally leave the helm,
which could prevent a runaway boat.
3
EWM04450
Vapor separator tank (VST) contains pres-
surized fuel.
To reduce the risk of spraying fuel during
VST service:
1. Wrap fuel hose connector in a cloth then
disconnect hose slowly to release pres-
sure.
2. Remove band from fuel nipple.
3. Open drain cap to drain the fuel from
VST.
6EE-G2794-40
6EE-H1994-40
1
3
2
6EE-G2794-50
6EE-H1994-50
1
2
3
WARNING
Vapor separator tank (VST) contains pressurized fuel.
To reduce the risk of spraying fuel during VST service:
1. Wrap fuel hose connector in a cloth then disconnect hose slowly to release pressure.
2. Remove band from fuel nipple.
3. Open drain cap to drain the fuel from VST.
AVERTISSEMENT
Le réservoir du séparateur de vapeur (VST) contient du carburant sous pression.
Pour réduire le risque de pulvérisation du carburant pendant l’entretien du VST:
1. Envelopper le connecteur de durite d’alimentation dans un chiffon, puis détacher
lentement la durite pour libérer la pression.
2. Enlever la sangle du raccord de carburant.
3. Ouvrir le capuchon de vidange pour vidanger le carburant du VST. 6GR-2415H-00
U6KNK0E0.book Page 8 Monday, November 7, 2022 10:23 AM

General information
9
EMU33851
Other labels
EMU35133
Symbols
The following symbols mean as follows.
Notice/Warning
Read Owner’s Manual
Hazard caused by continuous rotation
Electrical hazard
EMU48010
Engine data recording
This model’s ECM stores certain engine data
to assist in the diagnosis of malfunctions and
for research, statistical analysis and develop-
ment purposes.
Although the sensors and recorded data will
vary by model, the main data points are:
Engine status and engine performance
data
This data will be uploaded only when a spe-
cial Yamaha diagnostic tool is attached to the
engine, such as when maintenance checks or
service procedures are performed.
Yamaha will not disclose this data to a third
party except in the following cases. In addi-
tion, Yamaha may provide engine data to a
contractor in order to outsource services re-
lated to the handling of the engine data. Even
4
ZMU05696
ZMU05664
ZMU05665
ZMU05666
U6KNK0E0.book Page 9 Monday, November 7, 2022 10:23 AM

General information
10
in this case, Yamaha will require the contrac-
tor to properly handle the engine data we
provided and Yamaha will appropriately
manage the data.
With the consent of the boat owner
Where obligated by law
For use by Yamaha in litigation
For general Yamaha-conducted research
purposes when the data is not related to an
individual engine or owner
U6KNK0E0.book Page 10 Monday, November 7, 2022 10:23 AM

Specifications and requirements
11
EMU40501
Specifications
TIP:
“(SUS)” indicates that the specification is for
the outboard motor when it is equipped with
a stainless steel propeller.
EMU48360
Dimension and weight:
Overall length:
1217 mm (47.9 in)
Overall width:
652 mm (25.7 in)
Overall height X:
2059 mm (81.1 in)
Overall height U:
2186 mm (86.1 in)
Motor transom height X:
640 mm (25.2 in)
Motor transom height U:
767 mm (30.2 in)
Dry weight (SUS) X:
447 kg (985 lb)
Dry weight (SUS) U:
458 kg (1010 lb)
Performance:
Full throttle operating range:
5000–6000 r/min
Rated power:
294.2 kW (400 HP) (F400ASTU,
F400ASTX, FL400ASTU, FL400ASTX)
331.0 kW (450 HP) (F450AVTU,
F450AVTX, FL450AVTU, FL450AVTX)
Idle speed (in neutral):
650–750 r/min
Power unit:
Type:
4-stroke DOHC V8 32 valves
Total displacement:
5559 cm³ (339.2 c.i.)
Bore ×stroke:
96.0 ×96.0 mm (3.78 ×3.78 in)
Ignition system:
TCI
Spark plug (NGK):
ILMAR7H-9
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Steering system:
Remote steering
Starting system:
Electric starter
Starting carburetion system:
Fuel injection
Valve clearance IN (cold engine):
0.17–0.24 mm (0.0067–0.0094 in)
Valve clearance EX (cold engine):
0.37–0.44 mm (0.0146–0.0173 in)
Battery rating (CCA/SAE):
700 A
Battery rating (MCA/ABYC):
900 A
Battery rating (RC/SAE):
170 minutes
Battery rating (CCA/EN):
670 A
Battery rating (20HR/IEC):
110 Ah
Maximum generator output:
102 A (F450AVTU, F450AVTX,
FL450AVTU, FL450AVTX)
104 A (F400ASTU, F400ASTX,
FL400ASTU, FL400ASTX)
Lower unit:
Gear shift positions:
Forward-neutral-reverse
Gear ratio:
1.79 (25/14)
Trim and tilt system:
Power trim and tilt
U6KNK0E0.book Page 11 Monday, November 7, 2022 10:23 AM

Specifications and requirements
12
Propeller mark:
Y (F400ASTU, F400ASTX, F450AVTU,
F450AVTX)
YL (FL400ASTU, FL400ASTX,
FL450AVTU, FL450AVTX)
Fuel and oil:
Recommended fuel:
Premium unleaded gasoline
Min. pump octane number (PON):
89
Min. research octane number (RON):
94
Recommended engine oil:
YAMALUBE 4 or 4-stroke outboard
motor oil
Recommended engine oil grade 1:
SAE 10W-30/10W-40/5W-30
API SG/SH/SJ/SL
Engine oil quantity (without oil filter
replacement):
7.5 L (7.93 US qt, 6.60 Imp.qt)
Engine oil quantity (with oil filter
replacement):
7.8 L (8.24 US qt, 6.86 Imp.qt)
Lubrication system:
Wet sump
Recommended gear oil:
YAMALUBE outboard gear oil or Hypoid
gear oil
Recommended gear oil grade:
SAE 80W API GL-5 / SAE 90 API GL-5
Gear oil quantity:
1.830 L (1.934 US qt, 1.610 Imp.qt)
(FL400ASTU, FL400ASTX, FL450AVTU,
FL450AVTX)
1.950 L (2.061 US qt, 1.716 Imp.qt)
(F400ASTU, F400ASTX, F450AVTU,
F450AVTX)
Noise and vibration level:
Operator sound pressure level (ICOMIA
39/94):
83.1 dB(A)
EMU33556
Installation requirements
EMU33566
Boat horsepower rating
EWM01561
Overpowering a boat can cause severe in-
stability.
Before installing the outboard motor(s), con-
firm that the total horsepower of your out-
board motor(s) does not exceed the boat’s
maximum horsepower rating. See the boat’s
capacity plate or contact the manufacturer.
EMU40491
Mounting outboard motor
EWM02501
Improper mounting of the outboard mo-
tor could result in hazardous conditions
such as poor handling, loss of control,
or fire hazards.
Because the outboard motor is very
heavy, special equipment and training is
required to mount it safely.
Your dealer or other person experienced in
proper rigging should mount the outboard
motor using correct equipment and complete
rigging instructions. For further information,
see page 38.
EMU34954
Digital electronic control re-
quirements
The digital electronic control is equipped with
a start-in-gear protection device(s). This de-
vice prevents the engine from starting unless
it is in neutral.
U6KNK0E0.book Page 12 Monday, November 7, 2022 10:23 AM

Specifications and requirements
13
EWM01581
If the engine starts in gear, the boat can
move suddenly and unexpectedly, pos-
sibly causing a collision or throwing
passengers overboard.
If the engine ever starts in gear, the
start-in-gear protection device is not
working correctly and you should dis-
continue using the outboard. Contact
your Yamaha dealer.
This digital electronic control unit is only
available for the outboard motor which you
have purchased.
Prior to use of the digital electronic control
unit, set it in order to operate your outboard
motor only. Otherwise, it will not be possible
to operate the outboard motor.
Perform setting of the outboard motor and
the digital electronic control unit in the follow-
ing cases.
If a used outboard motor is installed
If the digital electronic control unit is re-
placed
If the ECM (Electronic control module) of
the used outboard motor is replaced
If the ECM (Electronic control module) of
the digital electronic control unit is re-
placed
Consult your Yamaha dealer for setting.
EMU25695
Battery requirements
EMU44881
Battery specifications
For U.S. insular areas
It is necessary to meet only two of the three
specifications (CCA, MCA, and RC) in one of
the following combinations:
CCA/SAE and RC
MCA/ABYC and RC
For Others
The engine cannot be started if battery volt-
age is too low.
EMU36293
Mounting battery
Mount the battery holder securely in a dry,
well-ventilated, vibration-free location in the
boat. WARNING! Do not put flammable
items, or loose heavy or metal objects in
the same compartment as the battery.
Fire, explosion or sparks could result.
[EWM01821]
Battery cable
The battery cable size and length are critical.
Consult your Yamaha dealer about the bat-
tery cable size and length.
EMU36303
Multiple batteries
To connect multiple batteries, such as for
multiple engine configurations or for an ac-
cessory battery, consult your Yamaha dealer
about battery selection and correct wiring.
Battery isolator
Your outboard motor is capable of charging
an accessory battery separate from the start-
ing battery using an optional isolator lead.
Battery rating (CCA/SAE):
700 A
Battery rating (MCA/ABYC):
900 A
Battery rating (RC/SAE):
170 minutes
Battery rating (CCA/EN):
670 A
Battery rating (20HR/IEC):
110 Ah
U6KNK0E0.book Page 13 Monday, November 7, 2022 10:23 AM

Specifications and requirements
14
Contact your Yamaha dealer for installation
of an optional isolator lead with over-current
protection.
EMU41604
Propeller selection
Next to selecting an outboard motor, select-
ing the right propeller is one of the most im-
portant purchasing decisions a boater can
make. The type, size, and design of your pro-
peller have a direct impact on acceleration,
top speed, fuel economy, and even engine
life. Yamaha designs and manufactures pro-
pellers for every Yamaha outboard motor and
every application.
Your Yamaha dealer can help you select the
right propeller for your boating needs. Select
a propeller that will allow the engine to reach
the middle or upper half of the operating
range at full throttle with the maximum boat-
load. Generally, select a larger pitch propeller
for a smaller operating load and a smaller
pitch propeller for a heavier load. If you carry
loads that vary widely, select the propeller
that lets the engine run in the proper range for
your maximum load but remember that you
may need to reduce your throttle setting to
stay within the recommended engine speed
range when carrying lighter loads.
Yamaha recommends to use a propeller suit-
able for the “Shift Dampener System (SDS)”.
For further information, consult your Yamaha
dealer.
To check the propeller, see page 80.
Propeller example
EMU36313
Counter rotation models
Standard outboard motors rotate clockwise.
Counter rotation models rotate counterclock-
wise and are typically used in multiple motor
setups.
On counter rotation models, be sure to use a
propeller intended for counterclockwise rota-
tion. These propellers are identified with the
letter “L” after the size indication on the pro-
peller. WARNING! Never use a standard
propeller with a counter rotation motor, or
a counter rotation propeller with a stan-
dard motor. Otherwise the boat could go
in the direction opposite of that expected
(for example, reverse instead of forward),
which could lead to an accident. [EWM01811]
For instructions on propeller removal and ins-
tallation, see page 80.
EMU35141
Start-in-gear protection
Yamaha outboard motors or Yamaha-ap-
proved digital electronic control units are
equipped with start-in-gear protection de-
vice(s). This feature permits the engine to be
started only when it is in neutral. Always se-
lect neutral before starting the engine.
1. Propeller diameter in inches
2. Propeller pitch in inches
3. Type of propeller (propeller mark)
31
2
U6KNK0E0.book Page 14 Monday, November 7, 2022 10:23 AM