Yamaha 40V, 50H User Manual

OWNER’S MANUAL

Read this manual carefully before operating this

outboard motor.

40V
50H

63B-28199-7F-E0

EMU25052

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.

Important manual information

WARNING

NOTICE

TIP:

TIP:

EMU25107

To the owner

Thank you for selecting a Yamaha outboard
motor. This Owner’s Manual contains infor­mation needed for proper operation, mainte­nance 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
hazards. Obey all safety messages that fol­low this symbol to avoid possible injury or
death.

EWM00781

A WARNING indicates a hazardous situa­tion which, if not avoided, could result in
death or serious injury.

ECM00701

A NOTICE indicates special precautions
that must be taken to avoid damage to the
outboard motor or other property.

there is any question concerning this manu­al, please consult your Yamaha dealer.
To ensure long product life, Yamaha recom­mends that you use the product and perform
the specified periodic inspections and main­tenance by correctly following the instruc­tions in the owner’s manual. Any damage
resulting from neglect of these instructions is
not covered by warranty.
Some countries have laws or regulations re­stricting 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 war­ranty may not apply in certain regions. When
planning to take the product to another coun­try, consult the dealer where the product was
purchased for further information.
If the product was purchased used, please
consult your closest dealer for customer re­registration, and to be eligible for the speci­fied services.

The 40VEO, 40VMHO, 50HETO, 50HMHO
and the standard accessories are used as a
base for the explanations and illustrations in
this manual. Therefore some items may not
apply to every model.

EMU25121

A TIP provides key information to make pro­cedures easier or clearer.

Yamaha continually seeks advancements in
product design and quality. Therefore, while
this manual contains the most current prod­uct information available at the time of print­ing, there may be minor discrepancies
between your machine and this manual. If

40V, 50H

OWNER’S MANUAL

©2010 by Yamaha Motor Co., Ltd.

1st Edition, April 2010

All rights reserved.

Any reprinting or unauthorized use

without the written permission of

Yamaha Motor Co., Ltd.
is expressly prohibited.

Printed in Japan

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............................................ 1

Gasoline exposure and spills ............ 2

Carbon monoxide.............................. 2

Modifications ..................................... 2

Boating safety ..................................2

Alcohol and drugs ............................. 2

Personal flotation devices ................. 2

People in the water ........................... 2

Passengers ....................................... 2

Overloading....................................... 2

Avoid collisions ................................. 3

Weather ............................................ 3

Passenger training ............................ 3

Boating safety publications ............... 3

Laws and regulations ........................ 3

General information .......................... 4

Identification numbers record...........4

Outboard motor serial number .......... 4

Key number....................................... 4

EC Declaration of Conformity

(DoC).............................................. 4

CE Marking ......................................4

Read manuals and labels................. 6

Warning labels ................................. 6

Specifications and requirements..... 9

Specifications ................................... 9

Installation requirements ................ 10

Boat horsepower rating................... 10

Mounting motor ............................... 11

Remote control requirements.........11

Battery requirements......................11

Battery specifications ...................... 11

Mounting battery ............................. 11

Multiple batteries............................. 11

Propeller selection.......................... 11

Start-in-gear protection ..................12

Engine oil requirements .................12

Fuel requirements.......................... 12

Gasoline .......................................... 12

Muddy or acidic water.................... 13

Anti-fouling paint ............................ 13

Motor disposal requirements.......... 13

Emergency equipment................... 13

Components .................................... 14

Components diagram..................... 14

Fuel tank ......................................... 16

Fuel joint.......................................... 17

Fuel gauge ...................................... 17

Fuel tank cap................................... 17

Air vent screw.................................. 17

Remote control box ......................... 17

Remote control lever ....................... 17

Neutral interlock trigger ................... 18

Neutral throttle lever........................18

Tiller handle..................................... 18

Gear shift lever................................18

Throttle grip ..................................... 19

Throttle indicator ............................. 19

Throttle friction adjuster................... 19

Engine shut-off cord (lanyard)

and clip.......................................... 20

Engine stop button .......................... 20

Choke knob for pull type ................. 21

Manual starter handle ..................... 21

Main switch ..................................... 21

Steering friction adjuster ................. 21

Steering friction adjuster ................. 22

Power trim and tilt switch on

remote control or tiller handle .......22

Power trim and tilt switch on

bottom cowling .............................. 22

Trim tab with anode......................... 23

Trim rod (tilt pin) .............................. 23

Tilt lock mechanism......................... 24

Tilt support lever for power trim

and tilt model................................. 24

Tilt support lever for manual tilt

model ............................................ 24

Cowling lock lever(s) (turn type)...... 25

Alert indicator .................................. 25

Instruments and indicators............ 26

Indicators ....................................... 26

Table of contents

Alert indicator for three indicators ... 26

Overheat-alert indicator .................. 26

Oil level-alert indicator .................... 26

Digital tachometer .......................... 26

Tachometer..................................... 27

Trim meter....................................... 27

Hour meter ...................................... 27

Oil level indicator (digital type) ........ 27

Overheat-alert indicator .................. 28

Analog tachometer ......................... 28

Oil level indicators

(three indicators)........................... 28

Overheat-alert indicator .................. 28

Analog trim meter...........................29

Engine control system.................... 30

Alert system ...................................30

Overheat alert ................................. 30

Oil level alert and oil filter clogging

alert............................................... 31

Installation .......................................33

Installation ...................................... 33

Mounting the outboard motor.......... 33

Clamping the outboard motor ......... 34

Operation .........................................36

First-time operation ........................ 36

Breaking in engine .......................... 36

Getting to know your boat ............... 36

Checks before starting engine .......36

Fuel level......................................... 37

Remove the top cowling.................. 37

Fuel system..................................... 37

Controls........................................... 37

Engine shut-off cord (lanyard)......... 38

Oil.................................................... 38

Engine............................................. 38

Operation after long period of

storage.......................................... 38

Install top cowling............................ 39

Power trim and tilt system............... 39

Battery............................................. 40

Filling fuel and engine oil................ 40

Filling fuel for portable tank............. 40

Filling oil for manual starter

model ............................................ 41

Filling oil for electric start models.... 41

Oil level indicator operation.............43

Operating engine ........................... 44

Sending fuel (portable tank) ............ 44

Starting engine ................................ 45

Checks after starting engine .......... 49

Cooling water .................................. 49

Warming up engine........................ 49

Choke start models ......................... 49

Electric start and prime start

models ..........................................49

Checks after engine warm up ........ 50

Shifting ............................................ 50

Stop switches .................................. 50

Shifting........................................... 50

Stopping boat................................. 51

Stopping engine............................. 52

Procedure........................................ 52

Trimming outboard motor............... 52

Adjusting trim angle for manual tilt

models ..........................................53

Adjusting trim angle (Power trim

and tilt) .......................................... 54

Adjusting boat trim .......................... 54

Tilting up and down........................ 55

Procedure for tilting up (manual tilt

models) ......................................... 56

Procedure for tilting up (power trim

and tilt models).............................. 56

Procedure for tilting down

(manual tilt models)....................... 58

Procedure for tilting down

(power trim and tilt models)........... 58

Shallow water................................. 59

Power trim and tilt models...............59

Cruising in other conditions............ 60

Maintenance .................................... 61

Transporting and storing outboard

motor............................................ 61

Clamp screw mounting models ....... 61

Storing outboard motor ................... 61

Procedure........................................ 62

Lubrication (oil injection models).....63

Cleaning the outboard motor........... 63

Checking painted surface of

outboard motor.............................. 63

Table of contents

Periodic maintenance..................... 63

Replacement parts.......................... 64

Severe operating conditions ........... 64

Maintenance chart 1 ....................... 65

Maintenance chart 2 ....................... 67

Greasing ......................................... 68

Cleaning and adjusting spark

plug ............................................... 69

Checking fuel filter .......................... 70

Inspecting idle speed ...................... 70

Checking water in engine oil tank ... 71

Inspecting wiring and connectors.... 71

Checking propeller .......................... 71

Removing propeller......................... 72

Installing propeller........................... 72

Changing gear oil............................ 73

Cleaning fuel tank ........................... 74

Inspecting and replacing

anode(s)........................................ 75

Checking battery (for electric start

models) ......................................... 75

Connecting the battery.................... 76

Disconnecting the battery ............... 76

Trouble Recovery............................ 77

Troubleshooting .............................77

Temporary action in emergency..... 80

Impact damage ............................... 80

Replacing fuse ................................ 80

Power trim and tilt will not

operate.......................................... 81

Starter will not operate .................... 81

Emergency starting engine ............. 82

Engine fails to operate ...................83

Cold engine fails to start ................. 83

Treatment of submerged motor...... 84

Safety information

EMU33622

Outboard motor safety

Observe these precautions at all times.

EMU36501

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
neutral, 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.

EMU33630

Rotating parts

Hands, feet, hair, jewelry, clothing, PFD
straps, etc. can become entangled with inter­nal rotating parts of the engine, resulting in
serious injury or death.
Keep the top cowling in place whenever pos­sible. Do not remove or replace the cowling
with the engine running.
Only operate the engine with the cowling re­moved according to the specific instructions
in the manual. Keep hands, feet, hair, jewel­ry, clothing, PFD straps, etc. away from any
exposed moving parts.

EMU33640

Hot parts

During and after operation, engine parts are
hot enough to cause burns. Avoid touching
any parts under the top cowling until the en­gine has cooled.

EMU33650

Electric shock

Do not touch any electrical parts while start­ing or operating the engine. They can cause
shock or electrocution.

EMU33660

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 be 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.
Severe injury could occur if the outboard mo­tor accidentally falls.

EMU33671

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
people stranded, or running over people or
objects.
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 at­tach the cord to clothing that could tear
loose, or route the cord where it could be­come entangled, preventing it from function­ing.
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 ob­jects forward.

EMU33810

Gasoline

Gasoline and its vapors are highly flam­mable and explosive. Always, refuel ac-

cording to the procedure on page 44 to
reduce the risk of fire and explosion.

1

Safety information

EMU33820

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, immedi­ately wash with soap and water. Change
clothing if gasoline spills on it.
If you swallow gasoline, inhale a lot of gaso­line vapor, or get gasoline in your eyes, get
immediate medical attention. Never siphon
fuel by mouth.

EMU33900

Carbon monoxide

This product emits exhaust gases which con­tain 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.

EMU33780

Modifications

Do not attempt to modify this outboard mo­tor. Modifications to your outboard motor
may reduce safety and reliability, and render
the outboard unsafe or illegal to use.

EMU33740

Boating safety

This section includes a few of the many im­portant safety precautions that you should
follow when boating.

EMU33710

Alcohol and drugs

Never operate after drinking alcohol or taking
drugs. Intoxication is one of the most com­mon factors contributing to boating fatalities.

EMU33720

Personal flotation devices

Have an approved personal flotation device
(PFD) on board for every occupant. Yamaha
recommends that you must wear a PFD

whenever boating. At a minimum, children
and non-swimmers should always wear
PFDs, and everyone should wear PFDs
when there are potentially hazardous boat­ing conditions.

EMU33731

People in the water

Always watch carefully for people in the wa­ter, such as swimmers, skiers, or divers,
whenever the engine is running. When
someone 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.

EMU33751

Passengers

Consult your boat manufacturer’s instruc­tions for details about appropriate passenger
locations in your boat and be sure all pas­sengers are positioned properly before ac­celerating 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 direc­tion. Even when people are positioned prop­erly, alert your passengers if you must make
any unusual maneuver. Always avoid jump­ing waves or wakes.

EMU33760

Overloading

Do not overload the boat. Consult the boat
capacity plate or boat manufacturer for max­imum weight and number of passengers. Be
sure that weight is properly distributed ac­cording to the boat manufacturers instruc­tions. Overloading or incorrect weight
distribution can compromise the boats han­dling and lead to an accident, capsizing or

2

Safety information

ZMU06025

swamping.

EMU33772

Avoid collisions

Scan constantly for people, objects, and oth­er 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 un­derstand 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 another direction.

EMU33790

Weather

Stay informed about the weather. Check
weather forecasts before boating. Avoid
boating in hazardous weather.

EMU33880

Passenger training

Make sure at least one other passenger is
trained to operate the boat in the event of an
emergency.

EMU33890

Boating safety publications

Be informed about boating safety. Additional
publications and information can be obtained
from many boating organizations.

EMU33600

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.

3

General information

1

ZMU02931

EMU25171

Identification numbers record

EMU25183

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 sto­len.

1. Outboard motor serial number location

EMU25191

Key number

If a main key switch is equipped with the mo­tor, the key identification number is stamped
on your key as shown in the illustration.
Record this number in the space provided for
reference in case you need a new key.

1. Key number

EMU37290

EC Declaration of Conformity

(DoC)

This outboard motor conforms to certain por­tions of the European Parliament directive
relating to machinery.
Each conformed outboard motor accompa­nied with EC DoC.EC DoC contains the fol­lowing information;

● Name of Engine Manufacture

● Model name

● Product code of model (Approved model

code)

● Code of conformed directives

EMU25203

CE Marking

Outboard motors affixed with this “CE”mark­ing conform with the directives of; 98/37/EC,
94/25/EC - 2003/44/EC and 2004/108/EC.

4

1. CE marking location

1

ZMU04889

ZMU06040

General information

5

General information

ZMU07315

3

2

1

EMU33522

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.

EMU33832

Warning labels

If these labels are damaged or missing, contact your Yamaha dealer for replacements.

40V, 50H

6

General information

WARNING

WARNING

WARNING

ZMU05706

1

2

3

EMU33912

Contents of labels

The above warning labels mean as follows.

1

EWM01691

Emergency starting does not have start­in-gear protection. Ensure shift control is
in neutral before starting engine.

2

EWM01681

● 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.

3

EWM01671

● Read Owner’s Manuals and labels.

● Wear an approved personal flotation

device (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.

7

General information

ZMU05696

ZMU05664

ZMU05665

ZMU05666

ZMU05667

ZMU05668

EMU33843

Symbols

The following symbols mean as follows.

Notice/Warning

Read Owner’s Manual

Electrical hazard

Remote control lever/gear shift lever operat­ing direction, dual direction

Engine start/ Engine cranking

Hazard caused by continuous rotation

8

Specifications and requirements

TIP:

EMU31480

Specifications

“(AL)” stated in the specification data below
represents the numerical value for the alumi­num propeller installed.
Likewise, “(SUS)” represents the value for
stainless steel propeller installed and “(PL)”
for plastic propeller installed.

EMU2821J

Dimension:

Overall length:

40VEO 670 mm (26.4 in)

40VMHO 1281 mm (50.4 in)

50HETO 670 mm (26.4 in)

50HMHO 1281 mm (50.4 in)

Overall width:

40VEO 349 mm (13.7 in)

40VMHO 349 mm (13.7 in)

50HETO 360 mm (14.2 in)

50HMHO 349 mm (13.7 in)

Overall height S:

40VEO 1192 mm (46.9 in)

40VMHO 1223 mm (48.1 in)

50HMHO 1223 mm (48.1 in)

Overall height L:

40VEO 1319 mm (51.9 in)

40VMHO 1350 mm (53.1 in)

50HETO 1319 mm (51.9 in)

Transom height S:

406 mm (16.0 in)

Transom height L:

533 mm (21.0 in)

Weight (AL) S:

40VEO 74.5 kg (164 lb)

40VMHO 75.8 kg (167 lb)

50HMHO 75.0 kg (165 lb)

Weight (AL) L:

40VEO 77.3 kg (170 lb)

40VMHO 77.5 kg (171 lb)

50HETO 88.0 kg (194 lb)

Performance:

Full throttle operating range:

4500–5500 r/min

Maximum output:

40VEO 29.4 kW@5000 r/min
(40 HP@5000 r/min)
40VMHO 29.4 kW@5000 r/min
(40 HP@5000 r/min)
50HETO 36.8 kW@5000 r/min
(50 HP@5000 r/min)
50HMHO 36.8 kW@5000 r/min
(50 HP@5000 r/min)

Idle speed (in neutral):

800 50 r/min

Engine:

Type:

2-stroke L

Displacement:

698.0 cm

Bore  stroke:

67.0  66.0 mm (2.64  2.60 in)

Ignition system:

CDI

Spark plug with resistor (NGK):

40VEO BR7HS-10
40VMHO BR7HS-10
50HETO BR8HS-10
50HMHO BR8HS-10

Spark plug gap:

0.9–1.0 mm (0.035–0.039 in)

Control system:

40VEO Remote control
40VMHO Tiller handle
50HETO Remote control
50HMHO Tiller handle

Starting system:

40VEO Electric starter
40VMHO Manual starter
50HETO Electric starter
50HMHO Manual starter

3

9

Specifications and requirements

WARNING

Starting carburetion system:

40VEO Prime start

40VMHO Choke valve

50HETO Prime start

50HMHO Choke valve

Min. cold cranking amps (CCA/EN):

40VEO 347.0 A

50HETO 347.0 A

Min. rated capacity (20HR/IEC):

40VEO 40.0 Ah

50HETO 40.0 Ah

Alternator output:

40VMHO 80 W

50HMHO 80 W

Maximum generator output:

40VEO 6 A

50HETO 6 A

Drive unit:

Gear positions:

Forward-neutral-reverse

Gear ratio:

1.85 (24/13)

Trim and tilt system:

40VEO Manual tilt

40VMHO Manual tilt

50HETO Power trim and tilt

50HMHO Manual tilt

Propeller mark:

G

Fuel and oil:

Recommended fuel:

Regular unleaded gasoline

Min. research octane:

40VEO 90

40VMHO 90

Fuel tank capacity:

24 L (6.34 US gal, 5.28 Imp.gal),

25 L (6.60 US gal, 5.50 Imp.gal)

Recommended engine oil:

YAMALUBE 2-stroke outboard motor

oil

Recommended engine oil:

TC-W3

Lubrication:

Oil injection

Engine oil tank capacity:

1.5 L (1.59 US qt, 1.32 Imp.qt)

Recommended gear oil:

Hypoid gear oil SAE#90

Gear oil quantity:

0.430 L (0.455 US qt, 0.378 Imp.qt)

Tightening torque for engine:

Spark plug:

25.0 Nm (2.55 kgf-m, 18.4 ft-lb)

Propeller nut:

39.0 Nm (3.98 kgf-m, 28.8 ft-lb)

Noise and vibration level:

Operator sound pressure level (ICOMIA
39/94 and 40/94):

40VEO 89.5 dB(A)

40VMHO 89.5 dB(A)
Sound power level (ICOMIA 39/94 and
40/94):

40VEO 97.4 dB(A)

40VMHO 97.4 dB(A)
Vibration on tiller handle (ICOMIA 38/94):

40VEO Vibration on tiller handle is

under 2.5 m/s

2

40VMHO Vibration on tiller handle is

under 2.5 m/s

EMU33554

2

Installation requirements

EMU33564

Boat horsepower rating

EWM01560

Overpowering a boat can cause severe
instability.

Before installing the outboard motor(s), con­firm that the total horsepower of your out­board motor(s) does not exceed the boats
maximum horsepower rating. See the boat’s

10

Specifications and requirements

WARNING

WARNING

capacity plate or contact the manufacturer.

EMU33571

Mounting motor

EWM01570

● Improper mounting of the outboard mo-

tor could result in hazardous condi­tions such as poor handling, loss of
control, or fire hazards.

● Because the motor is very heavy, spe-

cial equipment and training is required
to mount it safely.

Your dealer or other person experienced in
proper rigging should mount the motor using
correct equipment and complete rigging in­structions. For further information, see page

33.

EMU33581

Remote control requirements

EWM01580

● If the engine starts in gear, the boat can

move suddenly and unexpectedly, pos­sibly 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 dis­continue using the outboard. Contact
your Yamaha dealer.

The remote control unit must be equipped
with a start-in-gear protection device(s). This
device prevents the engine from starting un­less it is in neutral.

EMU25694

Battery requirements

EMU25721

Battery specifications

Minimum cold cranking amps (CCA/EN):

40VEO 347.0 A
50HETO 347.0 A

Minimum rated capacity (20HR/IEC):

40VEO 40.0 Ah
50HETO 40.0 Ah

The engine cannot be started if battery volt­age is too low.

EMU36290

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.

[EWM01820]

EMU36300

Multiple batteries

To connect multiple batteries, such as for
multiple engine configurations or for an ac­cessory battery, consult your Yamaha dealer
about battery selection and correct wiring.

EMU34194

Propeller selection

Next to selecting an outboard motor, select­ing the right propeller is one of the most im­portant purchasing decisions a boater can
make. The type, size, and design of your pro­peller have a direct impact on acceleration,
top speed, fuel economy, and even engine
life. Yamaha designs and manufactures pro­pellers for every Yamaha outboard motor
and every application.
Your outboard motor came with a Yamaha
propeller selected to perform well over a
range of applications, but there may be uses

11

Specifications and requirements

ZMU04606

-

x

123

ZMU04607

-

x

123

where a different propeller would be more
appropriate.
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 boat­load. 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.
To check the propeller, see page 71.

1. Propeller diameter in inches

2. Propeller pitch in inches

3. Type of propeller (propeller mark)

EMU25770

Start-in-gear protection

Yamaha outboard motors or Yamaha-ap­proved remote control units are equipped
with start-in-gear protection device(s). This
feature permits the engine to be started only
when it is in neutral. Always select neutral
before starting the engine.

EMU25651

Engine oil requirements

1. Propeller diameter in inches

2. Propeller pitch in inches

3. Type of propeller (propeller mark)

12

Recommended engine oil:

YAMALUBE 2-stroke outboard motor
oil

If the recommended engine oil is not avail­able, another 2-stroke engine oil with an
NMMA-certified TC-W3 rating may be used.

EMU36360

Fuel requirements

EMU36802

Gasoline

Use a good quality gasoline that meets the
minimum octane rating. If knocking or ping­ing occurs, use a different brand of gasoline
or premium unleaded fuel.

Specifications and requirements

NOTICE

Recommended gasoline:

Regular unleaded gasoline with a min­imum octane rating of 90 (Research
Octane Number).

ECM01981

● Do not use leaded gasoline. Leaded

gasoline can seriously damage the en­gine.

● Avoid getting water and contaminants

in the fuel tank. Contaminated fuel can
cause poor performance or engine
damage. Use only fresh gasoline that
has been stored in clean containers.

EMU36880

Muddy or acidic water

Yamaha strongly recommends that you have
your dealer install the optional chromium­plated water pump kit if you use the outboard
motor in muddy or acidic water conditions.
However, depending on the model it might
not be required.

EMU36330

Anti-fouling paint

A clean hull improves boat performance. The
boat bottom should be kept as clean of ma­rine growth as possible. If necessary, the
boat bottom can be coated with an anti-foul­ing paint approved for your area to inhibit
marine growth.
Do not use anti-fouling paint which includes
copper or graphite. These paints can cause
more rapid engine corrosion.

EMU36341

Motor disposal requirements

Never illegally discard (dump) the motor.
Yamaha recommends consulting the dealer
about discarding the motor.

EMU36352

Emergency equipment

Keep the following items onboard in case
there is trouble with the outboard motor.

● A tool kit with assorted screwdrivers, pli-

ers, wrenches (including metric sizes), and
electrical tape.

● Waterproof flashlight with extra batteries.

● An extra engine shut-off cord (lanyard)

with clip.

● Spare parts, such as an extra set of spark

plugs.

Consult your Yamaha dealer for details.

13

Components

TIP:

17

2
3

4

5
6
7

16

8

9

10

11

12

13

14

15

ZMU03344

2

1

EMU2579V

Components diagram

* May not be exactly as shown; also may not be included as standard equipment on all mod­els (order from dealer).

40VMHO, 50HMHO

1. Manual starter handle

2. Tiller handle*

3. Choke knob

4. Alert indicator

5. Tilt lock lever

6. Clamp screw

7. Trim rod

8. Cooling water inlet

9. Propeller

10. Trim tab (anode)

11. Anti-cavitation plate

12. Anode

13. Tilt support lever

14. Clamp bracket

15. Top cowling

14

16. Fuel tank*

17. Engine shut-off switch

40VEO

7

8

9

10

11

12

13

14

1

15

16

2

3

4

5

6

ZMU06642

1. Oil tank filler cap

2. Alert indicator(s)

3. Tilt lock lever

4. Clamp screw

5. Trim rod

6. Battery cable

7. Propeller

8. Cooling water inlet

9. Trim tab (anode)

10. Anti-cavitation plate

11. Anode

12. Tilt support lever

13. Clamp bracket

14. Top cowling

15. Remote control box (side mount type)*

16. Fuel tank*

Components

15

Components

WARNING

113

14 15 16

17

2

3

4

6
5

7

8

4

9

10

11

12

ZMU06643

50HETO

1. Oil tank filler cap

2. Alert indicator(s)

3. Battery cable

4. Anode(s)

5. Propeller

6. Cooling water inlet

7. Trim tab (anode)

8. Anti-cavitation plate

9. Trim rod

10. Clamp bracket

11. Tilt support lever

12. Top cowling

13. Remote control box (side mount type)*

14. Trim meter*

15. Tachometer*

16. Digital tachometer*

17. Fuel tank*

EMU25802

Fuel tank

If your model was equipped with a portable

16

fuel tank, its function is as follows.

EWM00020

The fuel tank supplied with this engine is
its dedicated fuel reservoir and must not
be used as a fuel storage container. Com­mercial users should conform to relevant
licensing or approval authority regula­tions.

1. Fuel joint

ZMU02284

3

1

4

2

ZMU03157

13

42

2. Fuel gauge

3. Fuel tank cap

4. Air vent screw

1. Fuel joint

2. Fuel gauge

3. Fuel tank cap

4. Air vent screw

EMU25830

Fuel joint

This joint is used to connect the fuel line.

EMU25841

Fuel gauge

This gauge is located on either the fuel tank
cap or on the fuel joint base. It shows the ap­proximate amount of fuel remaining in the
tank.

EMU25850

Fuel tank cap

This cap seals the fuel tank. When removed,

Components

the tank can be filled with fuel. To remove the
cap, turn it counterclockwise.

EMU25860

Air vent screw

This screw is on the fuel tank cap. To loosen
the screw, turn it counterclockwise.

EMU26181

Remote control box

The remote control lever actuates both the
shifter and the throttle. The electrical switch­es are mounted on the remote control box.

1. Power trim and tilt switch

2. Remote control lever

3. Neutral interlock trigger

4. Neutral throttle lever

5. Main switch

6. Engine shut-off switch

7. Throttle friction adjuster

EMU26190

Remote control lever

Moving the lever forward from the neutral po­sition engages forward gear. Pulling the le­ver back from neutral engages reverse. The
engine will continue to run at idle until the le­ver is moved about 35 (a detent can be felt).
Moving the lever farther opens the throttle,
and the engine will begin to accelerate.

17

Components

TIP:

1. Neutral “ ”

2. Forward “ ”

3. Reverse “ ”

4. Shift

5. Fully closed

6. Throttle

7. Fully open

EMU26201

Neutral interlock trigger

To shift out of neutral, first pull the neutral in­terlock trigger up.

1. Neutral interlock trigger

EMU26212

Neutral throttle lever

To open the throttle without shifting into ei­ther forward or reverse, put the remote con­trol lever in the neutral position and lift the
neutral throttle lever.

1. Fully open

2. Fully closed

The neutral throttle lever will operate only
when the remote control lever is in neutral.
The remote control lever will operate only
when the neutral throttle lever is in the closed
position.

EMU25912

Tiller handle

To change direction, move the tiller handle to
the left or right as necessary.

EMU25923

Gear shift lever

Move the gear shift lever forward to engage
the forward gear or rearward to engage the
reverse gear.

18

Components

ZMU03095

1. Forward “ ”

2. Neutral “ ”

3. Reverse “ ”

EMU25941

Throttle grip

The throttle grip is on the tiller handle. Turn
the grip counterclockwise to increase speed
and clockwise to decrease speed.

EMU25961

Throttle indicator

The fuel consumption curve on the throttle
indicator shows the relative amount of fuel
consumed for each throttle position. Choose
the setting that offers the best performance
and fuel economy for the desired operation.

1. Throttle indicator

EMU25976

Throttle friction adjuster

A friction device provides adjustable resis­tance to movement of the throttle grip or the
remote control lever, and can be set accord­ing to operator preference.
To increase resistance, turn the adjuster
clockwise. To decrease resistance, turn the
adjuster counterclockwise. WARNING! Do

not overtighten the friction adjuster. If
there is too much resistance, it could be
difficult to move the remote control lever
or throttle grip, which could result in an
accident.

[EWM00032]

19

Components

When constant speed is desired, tighten the
adjuster to maintain the desired throttle set­ting.

EMU25994

Engine shut-off cord (lanyard) and
clip

The clip must be attached to the engine shut­off switch for the engine to run. The cord
should be attached to a secure place on the
operator’s clothing, or arm or leg. Should the
operator fall overboard or leave the helm, the
cord will pull out the clip, stopping ignition to
the engine. This will prevent the boat from
running away under power. WARNING! At-

tach the engine shut-off cord to a secure
place on your clothing, or your arm or leg
while operating. Do not attach the cord to
clothing that could tear loose. Do not
route the cord where it could become en­tangled, preventing it from functioning.
Avoid accidentally pulling the cord dur­ing normal operation. Loss of engine
power means the loss of most steering
control. Also, without engine power, the
boat could slow rapidly. This could cause
people and objects in the boat to be
thrown forward.

[EWM00122]

1. Cord

2. Clip

3. Engine shut-off switch

1. Cord

2. Clip

3. Engine shut-off switch

EMU26002

Engine stop button

The engine stop button stops the engine
when the button is pushed.

20

Components

WARNING

ZMU03355

ZMU02942

EMU26012

Choke knob for pull type

To supply the engine with the rich fuel mix­ture required to start, pull out this knob.

EMU26073

Manual starter handle

The manual starter handle is used to crank
and start the engine.

EMU26091

Main switch

The main switch controls the ignition system;
its operation is described below.

● “” (off)

With the main switch in the “ ” (off) posi­tion, the electrical circuits are off, and the key
can be removed.

● “” (on)

With the main switch in the “ ” (on) posi­tion, the electrical circuits are on, and the key
cannot be removed.

● “” (start)

With the main switch in the “ ” (start) po-

sition, the starter motor turns to start the en­gine. When the key is released, it returns
automatically to the “ ” (on) position.

EMU26111

Steering friction adjuster

A friction device provides adjustable resis­tance to the steering mechanism, and can be
set according to operator preference. An ad­juster lever is located on the bottom of the
tiller handle bracket.
To increase resistance, turn the lever to the
port side “A”.
To decrease resistance, turn the lever to the
starboard side “B”.

EWM00040

Do not overtighten the friction adjuster. If
there is too much resistance, it could be
difficult to steer, which could result in an
accident.

21

Components

TIP:

WARNING

ZMU02908

● Check the tiller handle for smooth move-

ment when the lever is turned to the star­board side “B”.

● Do not apply lubricants such as grease to

the friction areas of the steering friction ad­juster.

EMU26122

Steering friction adjuster

A friction device provides adjustable resis­tance to the steering mechanism, and can be
set according to operator preference. An ad­justing screw or bolt is located on the swivel
bracket.

there is too much resistance, it could be
difficult to steer, which could result in an
accident.

EMU26143

Power trim and tilt switch on remote
control or tiller handle

The power trim and tilt system adjusts the
outboard motor angle in relation to the tran­som. Pressing the switch “ ” (up) trims the
outboard motor up, and then tilts it up. Press­ing the switch “ ” (down) tilts the outboard
motor down and trims it down. When the
switch is released, the outboard motor will
stop in its current position.
For instructions on using the power trim and
tilt switch, see pages 52 and 55.

To increase resistance, turn the adjuster
clockwise.
To decrease resistance, turn the adjuster
counterclockwise.

EWM00040

Do not overtighten the friction adjuster. If

22

EMU26154

Power trim and tilt switch on bottom
cowling

The power trim and tilt switch is located on
the side of the bottom cowling. Pushing the

Components

WARNING

WARNING

NOTICE

DOWN

UP

ZMU03096

A

B

ZMU03097

1

2

switch “ ” (up) trims the outboard motor up,
and then tilts it up. Pushing the switch “ ”
(down) tilts the outboard motor down and
trims it down. When the switch is released,
the outboard motor will stop in its current po­sition.
For instructions on using the power trim and
tilt switch, see page 55.

EWM01031

Use the power trim and tilt switch located
on the bottom cowling only when the boat
is at a complete stop with the engine off.
Attempting to use this switch while the
boat is moving could increase the risk of
falling overboard and could distract the
operator, increasing the risk of collision
with another boat or an obstacle.

right or left by applying the same amount of
force.
If the boat tends to veer to the left (port side),
turn the trim tab rear end to the port side “A”
in the figure. If the boat tends to veer to the
right (starboard side), turn the trim tab end to
the starboard side “B” in the figure.

ECM00840

The trim tab also serves as an anode to
protect the engine from electrochemical
corrosion. Never paint the trim tab as it
will become ineffective as an anode.

1. Trim tab

2. Bolt

EMU26244

Trim tab with anode

EWM00840

An improperly adjusted trim tab could
cause difficult steering. Always test run
after the trim tab has been installed or re­placed to be sure steering is correct. Be
sure you have tightened the bolt after ad­justing the trim tab.

The trim tab should be adjusted so that the
steering control can be turned to either the

Bolt tightening torque:

18.0 Nm (1.8 kgf-m, 13 ft-lb)

EMU26262

Trim rod (tilt pin)

The position of the trim rod determines the
minimum trim angle of the outboard motor in
relation to the transom.

23

Components

NOTICE

NOTICE

ZMU03098

1

ZMU06790

ZMU03194

ZMU03358

EMU30530

Tilt lock mechanism

The tilt lock mechanism is used to prevent
the outboard motor from lifting out of the wa­ter when in reverse gear.

1. Tilt lock lever

To lock it, set the tilt lock lever in the lock po­sition. To release, push the tilt lock lever in
the release position.

EMU26341

Tilt support lever for power trim and
tilt model

To keep the outboard motor in the tilted up
position, lock the tilt support lever to the
clamp bracket.

ECM00660

Do not use the tilt support lever or knob
when trailering the boat. The outboard
motor could shake loose from the tilt sup­port and fall. If the motor cannot be trail­ered in the normal running position, use
an additional support device to secure it
in the tilt position.

EMU30201

Tilt support lever for manual tilt
model

To keep the outboard motor in the tilted up
position, lock the tilt support lever to the
clamp bracket.

ECM00660

24

Do not use the tilt support lever or knob
when trailering the boat. The outboard
motor could shake loose from the tilt sup­port and fall. If the motor cannot be trail-

ered in the normal running position, use

ZMU02862

1

ZMU03361

1

1

ZMU03360

an additional support device to secure it
in the tilt position.

EMU26373

Cowling lock lever(s) (turn type)

To remove the engine top cowling, turn the
cowling lock lever(s) and lift off the cowling.
When installing the cowling, check to be sure
it fits properly in the rubber seal. Then lock
the cowling again by returning the cowling
lock lever(s) to the lock position.

1. Cowling lock lever(s)

Components

1. Alert indicator(s)

EMU26303

Alert indicator

If the engine develops a condition which is
cause for alert, the indicator lights up. For
details on how to read the alert indicator, see
page 30.

1. Alert indicator

25

Instruments and indicators

NOTICE

NOTICE

1

ZMU03360

ZMU03361

1

ZMU03361

1

EMU36014

Indicators

EMU26291

Alert indicator for three indicators

If the engine develops a condition which is
cause for alert, the indicator on the front of
the bottom cowling lights up. The three indi­cators mounted on the bottom cowling also
indicate the engine oil level. For details on
how to read the alert indicators, see page 30.

1. Overheat-alert indicator

EMU37560

Oil level-alert indicator

If the oil level falls below the lower limit, this
indicator will light up. For further information,
see page 30.

ECM00030

Do not operate the engine without oil. Se-

1. Alert indicator(s)

EMU36033

Overheat-alert indicator

If the engine temperature rises too high, this
indicator will light up. For further information
on reading the indicator, see page 30.

ECM00052

rious engine damage will occur.

Do not continue to run the engine if the
overheat-alert indicator is on. Serious en­gine damage will occur.

26

1. Oil level-alert indicator

EMU26493

Digital tachometer

The tachometer shows the engine speed
and has the following functions.
All segments of the display will light momen­tarily after the main switch is turned on and
will return to normal thereafter.

Instruments and indicators

TIP:

1

3

5

6

7

4

2

ZMU01891

ZMU01869

ZMU01870

1. Tachometer

2. Trim meter

3. Hour meter

4. Oil level indicator

5. Overheat-alert indicator

6. Set button

7. Mode button

The water separator and engine trouble-alert
indicators only operate when the engine is
equipped with the appropriate functions.

EMU36050

Tachometer

The tachometer displays engine speed in
hundreds of revolutions per minute (r/min).
For example, if the tachometer display reads
“22” then the engine speed is 2200 r/min.

EMU26621

Trim meter

This meter shows the trim angle of your out­board motor.

● Memorize the trim angles that work best

for your boat under different conditions.
Adjust the trim angle to the desired using
the power trim and tilt switch.

● If the trim angle of your motor exceeds the

trim operating range, the top segment on
the trim meter display will blink.

EMU26651

Hour meter

This meter shows the number of hours the
engine has been run. It can be set to show
the total number of hours or the number of
hours for the current trip. The display can
also be turned on and off.

To change the display format, press the
“ ” (mode) button. The display can show
total hours or trip hours, or turn off.
To reset the trip hours, simultaneously press
the “ ” (set) and “ ” (mode) buttons for
more than 1 second while the trip hours are
displayed. This resets the trip counter to 0
(zero).
The total number of hours the engine has
been run cannot be reset.

EMU26551

Oil level indicator (digital type)

This indicator shows the engine oil level. If
the oil level falls below the lower limit, the

27

Instruments and indicators

NOTICE

NOTICE

NOTICE

1

ZMU01867

1

ZMU01868

ZMU04577

1

2

ZMU04580

1

alert indicator will start to blink. For further in­formation, see page 31.

ECM00030

Do not operate the engine without oil. Se­rious engine damage will occur.

1. Oil level indicator

EMU26583

Overheat-alert indicator

If the engine temperature rises too high, the
alert indicator will start to blink. For further in­formation on reading the indicator, see page

30.

ECM00052

EMU26471

Analog tachometer

This gauge shows the engine speed and has
the following functions.

1. Tachometer

2. Oil level indicator

EMU26541

Oil level indicators (three indicators)

The indicators on the gauge show the status
of the oil level. For details on how to read the
indicators, see page 43.

ECM00030

Do not operate the engine without oil. Se­rious engine damage will occur.

Do not continue to run the engine if the
overheat-alert indicator is on. Serious en­gine damage will occur.

1. Overheat-alert indicator

28

1. Oil level indicators

EMU26574

Overheat-alert indicator

If the engine temperature rises too high, this

Instruments and indicators

NOTICE

ZMU03361

1

ZMU04581

indicator will flash. For further information on
reading the indicator, see page 30.

ECM00052

Do not continue to run the engine if the
overheat-alert indicator is on. Serious en­gine damage will occur.

1. Overheat-alert indicator

EMU26611

Analog trim meter

This gauge shows the trim angle of your out­board motor.

Memorize the trim angles that work best for
your boat under different conditions. Adjust
the trim angle to the desired setting with the
power trim and tilt switch.

29

Engine control system

NOTICE

ZMU04766

ZMU03364
ZMU01757

ZMU03025

ZMU03026

EMU26803

Alert system

ECM00091

Do not continue to operate the engine if a
alert device has activated. Consult your
Yamaha dealer if the problem cannot be
located and corrected.

EMU2681C

Overheat alert

This engine has an overheat-alert device. If
the engine temperature rises too high, the
alert device will activate.

● The engine speed will automatically de-

crease to about 2000 r/min.

● The buzzer will sound (if equipped on the

tiller handle, remote control box, or main
switch panel).

● The overheat-alert indicator will light or

blink.

30

If the alert system has activated, stop the en­gine and check the cooling water inlets:

● Check trim angle to be sure that the cool-

ing water inlet is submerged.

● Check the cooling water inlet for clogging.

EMU26848

TIP:

ZMU04586

ZMU03364

ZMU03363

ZMU03942

Oil level alert and oil filter clogging
alert

Oil injection models

This engine has an oil level alert system. If
the oil level falls below the lower limit, the
alert system will activate.

Activation of alert device

● Engine speed will automatically decrease

to about 2000 r/min.

Engine control system

● The oil level-alert indicator will light or

blink.

● The buzzer will sound (if equipped on the

tiller handle, remote control box, or main
switch panel).

If the alert system has been activated, stop
the engine and check for the cause.

The alert for oil filter clogging is similar to the
alerts for low oil level and overheating. To
make troubleshooting easier, check for en­gine overheating first, then oil level, and fi­nally oil filter clogging.

31

Engine control system

1

ZMU06661

1

ZMU06662

1. Oil filter

1. Oil filter

32

EMU26902

WARNING

ZMU01760

1

Installation

The information presented in this section is
intended as reference only. It is not possible
to provide complete instructions for every
possible boat and motor combination. Proper
mounting depends in part on experience and
the specific boat and motor combination.

EWM01590

Installation

● Overpowering a boat could cause se-

vere instability. Do not install an out­board motor with more horsepower
than the maximum rating on the capac­ity plate of the boat. If the boat does not
have a capacity plate, consult the boat
manufacturer.

● Improper mounting of the outboard mo-

tor could result in hazardous condi­tions such as poor handling, loss of
control, or fire hazards. For permanent­ly mounted models, your dealer or oth­er person experienced in proper rigging
should mount the motor.

EMU33470

Mounting the outboard motor

The outboard motor should be mounted so
that the boat is well balanced. Otherwise, the
boat could be hard to steer. For single-en­gine boats, mount the outboard motor on the
centerline (keel line) of the boat.

1. Center line (keel line)

EMU26933

Mounting height (boat bottom)

The mounting height of your outboard motor
affects its efficiency and reliability. If it is
mounted too high, propeller ventilation may
occur, which will reduce propulsion due to
excessive propeller slip, and the water in­takes for the cooling system may not get ad­equate water supply, which can cause
engine overheating. If the engine is mounted
too low, water resistance (drag) will increase,
thereby reducing engine efficiency and per­formance.
Most commonly, outboard motor should be
mounted so that the anti-cavitation plate is in
alignment with the bottom of the boat. The
optimum mounting height of the outboard
motor is affected by the boat/motor combina­tion and the desired use. Test runs at differ­ent heights can help determine the optimum
mounting height. Consult your Yamaha deal­er or boat manufacturer for further informa­tion on determining the proper mounting
height.

33

Installation

NOTICE

ZMU01762

ZMU02012

ZMU02013

ECM01634

● Make sure that the idle hole is high

enough to prevent water from entering
the engine even if the boat is stationary
with the maximum load.

● Incorrect engine height or obstructions

to the smooth flow of water (such as the
design or condition of the boat, or ac­cessories, such as transom ladders or
depth finder transducers) can create
airborne water spray while the boat is
cruising. If the outboard motor is oper­ated continuously in the presence of
airborne water spray, enough water
could enter the engine through the air
intake opening in the top cowling to
cause severe engine damage. Remove
the cause of the airborne water spray.

EMU26973

Clamping the outboard motor

1. Place the outboard motor on the tran­som so that it is positioned as close to
the center as possible. Tighten the tran­som clamp screws evenly and securely.
Occasionally check the clamp screws for
tightness during operation of the out­board motor because they could be­come loose due to engine vibration.

WARNING! Loose clamp screws
could allow the outboard motor to fall

off or move on the transom. This
could cause loss of control and seri­ous injury. Make sure the clamp
screws are tightened securely. Occa­sionally check the screws for tight­ness during operation.

[EWM00642]

2. If the restraint cable attachment is
equipped on your engine, a restraint ca­ble or chain should be used. Attach one
end to the restraint cable attachment
and the other to a secure mounting point
on the boat. Otherwise the engine could
be completely lost if it accidentally falls
off the transom.

3. Secure the clamp bracket to the transom
using the bolts provided with the out­board (if packed). For details, consult
your Yamaha dealer. WARNING! Avoid

using bolts, nuts or washers other
than those contained in the engine
packaging. If used, they must be of at

34

least the same quality of material and

ZMU03185

1

1

strength and must be tightened se­curely. After tightening, test run the
engine and check their tightness.

[EWM00651]

1. Bolts

Installation

35

Operation

NOTICE

NOTICE

WARNING

EMU36381

First-time operation

EMU27020

Breaking in engine

Your new engine requires a period of break­in to allow mating surfaces of moving parts to
wear in evenly. Correct break-in will help en­sure proper performance and longer engine
life.

ECM00140

● Failure to follow the break-in procedure

could result in reduced engine life or
even severe engine damage.

● Premix fuel must be used during break-

in in addition to oil in the oil injection
system.

EMU27060

Gasoline and engine oil mixing chart
(50:1)

1. : Gasoline

2. : Engine oil

ECM00150

Be sure to mix gasoline and oil complete­ly, otherwise the engine may be dam­aged.

EMU30311

Procedure for oil injection models

Run the engine under load (in gear with a
propeller installed) for 10 hours as follows.

1. First 10 minutes:
Run the engine at the lowest possible

speed. A fast idle in neutral is best.

2. Next 50 minutes:
Do not exceed half throttle (approxi­mately 3000 r/min). Vary engine speed
occasionally. If you have an easy-plan­ing boat, accelerate at full throttle onto
plane, then immediately reduce the
throttle to 3000 r/min or less.

3. Next two hours:
Accelerate at full throttle onto plane,
then reduce engine speed to three-quar­ter throttle (approximately 4000 r/min).
Vary engine speed occasionally. Run at
full throttle for one minute, then allow
about 10 minutes of operation at three­quarter throttle or less to let the engine
cool.

4. Remaining seven hours:
Run the engine at any speed. However,
avoid operating at full throttle for more
than 5 minutes at a time.

5. After the first 10 hours:
Operate the engine normally. Use only
straight gasoline in the fuel tank. The
Yamaha oil injection system provides
proper lubrication for normal operation.

EMU36400

Getting to know your boat

Different boats handle differently. Operate
cautiously while you learn how your boat
handles under different conditions and with
different trim angles (see page 52).

EMU36413

Checks before starting engine

EWM01921

If any item in “Checks before starting en­gine” is not working properly, have it in­spected and repaired before operating
the outboard motor. Otherwise, an acci­dent could occur.

36

Operation

NOTICE

WARNING

WARNING

ZMU06084

ZMU06150

ECM00120

Do not start the engine out of water. Over­heating and serious engine damage can
occur.

EMU37141

Fuel level

Be sure you have plenty of fuel for your trip.
A good rule is to use 1/3 of your fuel to get to
the destination, 1/3 to return, and to keep 1/3
as an emergency reserve. With the boat lev­el on a trailer or in the water, check the fuel
level. For fuel filling instructions, see page

40.

EMU36571

Remove the top cowling

For the following checks, remove the top
cowling from the bottom cowling. To remove
the top cowling, release the cowling lock le­ver and lift off the top cowling.

sion.

● Check for fuel leakage regularly.

● If any fuel leakage is found, the fuel

system must be repaired by a qualified
mechanic. Improper repairs can make
the outboard unsafe to operate.

EMU36451

Check for fuel leaks

● Check for fuel leaks or gasoline fumes in

the boat.

● Check for fuel leakage from the fuel sys-

tem.

● Check the fuel tank and fuel lines for

cracks, swellings, or other damages.

EMU37321

Checking the fuel filter

Check that the fuel filter is clean and free of
water. If any water is found in the fuel, or if a
significant amount of debris is found, the fuel
tank should be checked and cleaned by a
Yamaha dealer.

EMU36442

Fuel system

EWM00060

Gasoline and its vapors are highly flam­mable and explosive. Keep away from
sparks, cigarettes, flames, or other sourc­es of ignition.

EWM00910

Leaking fuel can result in fire or explo-

EMU36902

Controls

Tiller handle models:

● Move the tiller handle fully to the left and

right to make sure operation is smooth.

● Turn the throttle grip from the fully closed

to the fully open position. Make sure that it
turns smoothly and that it completely re­turns to the fully closed position.

● Look for loose or damaged connections of

the throttle and shift cables.

37

Operation

Remote control models:

● Turn the steering wheel full-right and full-

left. Make sure operation is smooth and
unrestricted throughout the whole range
with no binding or excessive free play.

● Operate the throttle levers several times to

make sure there is no hesitation in their
travel. Operation should be smooth over
the complete range of motion, and each le­ver should return completely to the idle po­sition.

● Look for loose or damaged connections of

the throttle and shift cables.

EMU36483

Engine shut-off cord (lanyard)

Inspect the engine shut-off cord and clip for
damage, such as cuts, breaks, and wear.

1. Cord

2. Clip

3. Engine shut-off switch

1. Cord

2. Clip

3. Engine shut-off switch

EMU27120

Oil

● Check to be sure you have plenty of oil for

your trip.

EMU27153

Engine

● Check the engine and engine mounting.

● Look for loose or damaged fasteners.

● Check the propeller for damage.

● Check for engine oil leaks.

EMU27181

Operation after long period of
storage

Oil injection models

When operating the engine after a long peri­od (12 months) of storage, proceed as fol­lows:

1. Use a 50:1 gasoline to oil mixture to start
the engine.

2. Start the engine. Leave it idling. WARN-

ING! Do not touch or remove electri­cal parts when starting or during
operation. Keep hands, hair, and
clothes away from the flywheel and
other rotating parts while the engine
is running.

3. Watch for oil flowing through the oil feed
pipes. After any air in the oil lines has

[EWM01331]

38

been expelled, the oil injection system

NOTICE

WARNING

ZMU03367

ZMU06109

ZMU04678

should supply oil normally. If no oil is
flowing after 10 minutes of idling, consult
your Yamaha dealer.

ECM01260

Be sure to take the above steps when op­erating the engine after a long period of
storage. Otherwise engine seizure could
occur.

EMU36954

Install top cowling

1. Be sure that the cowling lock lever is re­leased.

2. Be sure that the rubber seal is seated all
the way around the top cowling.

3. Place the top cowling on the bottom
cowling.

4. Check to be sure the rubber seal is seat­ed correctly between the top cowling
and the bottom cowling.

5. Move the lever to lock the cowling as
shown. NOTICE: If the top cowling is

not installed correctly, water spray
under the top cowling can damage
the engine, or the top cowling can
blow off at high speeds.

[ECM01991]

Operation

After installing, check the fitting of the top
cowling by pushing it with both hands. If the
top cowling is loose, have it repaired by your
Yamaha dealer.

EMU34581

Power trim and tilt system

EWM01930

● Never get under the lower unit while it

is tilted, even when the tilt support lever
is locked. Severe injury could occur if
the outboard motor accidentally falls.

● Body parts can be crushed between the

motor and the clamp bracket when the
motor is trimmed or tilted.

● Be sure no one is near the outboard

motor before performing this check.

1. Check the power trim and tilt unit for any
sign of oil leaks.

39

Operation

WARNING

1

ZMU07311

ZMU06621

ZMU02301

1. Trim and tilt rod

2. Operate each of the power trim and tilt
switches to check that all switches work.

3. Tilt the outboard motor up and check
that the trim and tilt rod is pushed out
completely.

4. Check that the trim and tilt rod is free of
corrosion or other flaws.

5. Tilt the outboard motor down. Check that
the trim and tilt rod operates smoothly.

EMU36582

Battery

Check that the battery is in good condition,
and fully charged. Check that the battery
connections are clean, secure and covered
by insulating covers. The electrical contacts
of the battery and cables must be clean and
properly connected or the battery will not
start the engine.
Refer to the battery manufacturer’s instruc­tions for checks for your particular battery.

EMU27234

Filling fuel and engine oil

EMU27248

Filling fuel for portable tank

EWM01830

● Gasoline and its vapors are highly flam-

mable and explosive. Always refuel ac­cording to this procedure to reduce the
risk of fire and explosion.

● Gasoline is poisonous and can cause

injury or death. Handle gasoline with
care. Never siphon gasoline by mouth.
If you should swallow some gasoline or
inhale a lot of gasoline vapor, or get
some gasoline in your eyes, see your
doctor immediately. If gasoline spills
on your skin, wash with soap and wa­ter. If gasoline spills on your clothing,
change your clothes.

1. Be sure the engine is stopped.

2. Disconnect the fuel line from the fuel
tank and tighten the air vent screw on
the fuel tank cap.

3. Remove the portable tank from the boat.

4. Be sure you are in a well-ventilated out­door area, either securely moored or
trailered.

5. Do not smoke and keep away from
sparks, flames, static electric discharge,

40

Operation

WARNING

WARNING

ZMU02834

1

2

ZMU03368

or other sources of ignition.

6. If you use a portable container to store
and dispense fuel, use only an approved
GASOLINE container.

7. Touch the fuel nozzle to the filler open­ing or funnel to help prevent electrostatic
sparks.

8. Fill the fuel tank, but do not overfill.

WARNING! Do not overfill. Otherwise
fuel can expand and overflow if the
temperature increases.

[EWM02610]

Fuel tank capacity:

24 L (6.34 US gal, 5.28 Imp.gal),
25 L (6.60 US gal, 5.50 Imp.gal)

9. Tighten the filler cap securely.

10. Wipe up any spilled gasoline immediate­ly with dry rags. Dispose rags properly
according to local laws or regulations.

EMU27301

Filling oil for manual starter model

EWM00530

Do not add gasoline into the oil tank. Fire
or explosion could result.

This engine uses the Yamaha oil injection
system, which provides superior lubrication
by ensuring the proper oil ratio for all operat­ing conditions. No fuel premixing is needed.
Simply pour gasoline into the fuel tank and

oil into the oil tank. Convenient indicator seg­ments indicate the status of the oil supply.
For details on reading the indicator seg­ments, see page 43.
To fill the engine oil tank, proceed as follows:

Engine oil tank capacity:

1.5 L (1.59 US qt, 1.32 Imp.qt)

1. Remove the top cowling.

2. Open the oil tank filler cap by pulling the
tab.

3. Slowly fill the engine oil into the engine
oil tank.

1. Engine oil tank

2. Oil tank filler cap

4. After filling, replace the cap securely.

EMU27311

Filling oil for electric start models

EWM00530

Do not add gasoline into the oil tank. Fire
or explosion could result.

This engine uses the Yamaha oil injection
system, which provides superior lubrication
by ensuring the proper oil ratio for all operat­ing conditions. No fuel premixing is needed.
Simply pour gasoline into the fuel tank and
oil into the oil tank. Convenient indicator seg­ments indicate the status of the oil supply.

41

Operation

ZMU03369

ZMU03370

ZMU03371

2

1

For details on reading the indicator seg­ments, see page 43.
To fill the engine oil tank, proceed as follows:

Engine oil tank capacity:

1.5 L (1.59 US qt, 1.32 Imp.qt)

1. Turn the oil filler access cap on the top
cowling counterclockwise and open it.

2. Open the oil tank filler cap by pulling the
tab on the cap.

1. Oil filler access cap

2. Oil tank filler cap

4. After filling, replace the all caps secure­ly.

3. Slowly pour the engine oil into the en­gine oil tank.

42

EMU27321

Oil level indicator operation

The various functions of the oil level system are as follows:

EMU27342

Manual start models

Oil level-alert indicator Engine oil tank Remarks

more than

3

OFF

Red

ON

Electric start models

Oil level-alert

indicator

(digital

tachometer)

Oil level-alert

tachometer/b

indicator

(analog

ottom

cowling)

Green

Engine oil tank Remarks

200 cm
(0.21 US qt,

0.181 Imp qt)

3

200 cm
(0.21 US qt,

0.181 Imp qt)
or less

more than 450

3

(0.48 US qt,

cm

0.40 Imp qt)

Operation

No refilling necessary.

● Buzzer sounds in

remote control box
and engine speed is
limited to about 2000
r/min to help con­serve oil.

● Check oil filter for

clogging.

● Add oil; see page

41.

No refilling necessary.

Yellow

from 450 cm

3

(0.48 US qt, 0.40
Imp qt) down to

3

200 cm
(0.21 US qt, 0.18
Imp qt)

Add oil; see page 41.

43

Operation

WARNING

ZMU02295

ZMU03100

Oil level-alert

indicator

(digital

tachometer)

EMU27452

Oil level-alert

indicator

(analog

tachometer/b

ottom

cowling)

Red

Engine oil tank Remarks

Operating engine

EWM00420

● Before starting the engine, make sure

that the boat is tightly moored and that
you can steer clear of any obstructions.
Be sure there are no swimmers in the
water near you.

● When the air vent screw is loosened,

gasoline vapor will be released. Gaso­line is highly flammable, and its vapors
are flammable and explosive. Refrain
from smoking, and keep away from
open flames and sparks while loosen­ing the air vent screw.

● This product emits exhaust gases

which contain carbon monoxide, a col­orless, odorless gas which could cause
brain damage or death when inhaled.
Symptoms include nausea, dizziness,
and drowsiness. Keep cockpit and cab­in areas well ventilated. Avoid blocking
exhaust outlets.

EMU35704

Sending fuel (portable tank)

1. If there is an air vent screw on the fuel
tank cap, loosen it 2 or 3 turns.

● Buzzer sounds in

remote control box

3

200 cm
(0.21 US qt, 0.18
Imp qt) or less

and engine speed is
limited to about 2000
r/min to help con­serve oil.

● Check oil filter for

clogging.

2. If there is a fuel joint on the motor, align
the fuel joint on the fuel line with the fuel
joint on the motor and firmly connect the
fuel line to the joint while pinching the
joint. Then firmly connect the other end
of the fuel line to the joint on the fuel
tank.

44

TIP:

Wipe up any spilled gasoline immediately

WARNING

WARNING

TIP:

ZMU02024

with dry rags. Dispose rags properly accord­ing to local laws or regulations.

3. If a steering friction adjuster is provided
on your outboard motor, securely attach
the fuel line to the fuel line clamp.

4. Squeeze the primer pump, with the ar­row pointing up, until you feel it become
firm. During engine operation place the
tank horizontally, otherwise fuel cannot
be drawn from the fuel tank.

Operation

Be sure there are no swimmers in the wa­ter near you.

EMU27508

Manual start models (tiller control)

EWM01840

● Failure to attached engine shut-off cord

could result in a runaway boat if opera­tor is ejected. Attach the engine shut­off cord to a secure place on your cloth­ing, or your arm or leg while operating.
Do not attach the cord to clothing that
could tear loose. Do not route the cord
where it could become entangled, pre­venting it from functioning.

● Avoid accidentally pulling the cord dur-

ing normal operation. Loss of engine
power means the loss of most steering
control. Also, without engine power,
the boat could slow rapidly. This could
cause people and objects in the boat to
be thrown forward.

1. Place the gear shift lever in neutral.

1. Arrow

EMU27494

Starting engine

EWM01600

Before starting the engine, make sure
that the boat is tightly moored and that
you can steer clear of any obstructions.

The start-in-gear protection device prevents
the engine from starting except when in neu­tral.

2. Attach the engine shut-off cord to a se­cure place on your clothing, or your arm
or leg. Then install the clip on the other

45

Operation

TIP:

TIP:

ZMU07239

ZMU03389

ZMU03279

end of the cord into the engine shut-off
switch.

3. Place the throttle grip in the “ ”
(start) position.

(start) position while the engine is running,
the engine will run poorly or stall.

5. Pull the manual starter handle slowly un­til you feel resistance. Then give a
strong pull straight out to crank and start
the engine. Repeat if necessary.

6. After the engine starts, slowly return the
manual starter handle to its original posi­tion before releasing it.

7. Slowly return the throttle grip to the fully
closed position.

4. Pull out / turn the choke knob fully. After
the engine starts, replace / return the
knob to the home position.

● It is not necessary to use the choke when

starting a warm engine.

● If the choke knob is left in the “ ”

46

● When the engine is cold, it needs to be

warmed up. For further information, see
page 49.

● If the engine does not start on the first try,

repeat the procedure. If the engine fails to
start after 4 or 5 tries, open the throttle a
small amount (between 1/8 and 1/4) and
try again. Also if the engine is warm and
fails to start, open the throttle a same

Operation

WARNING

TIP:

amount and try to start the engine again. If
the engine still fails to start, see page 77.

EMU27595

Electric start / prime start models

EWM01840

● Failure to attached engine shut-off cord

could result in a runaway boat if opera­tor is ejected. Attach the engine shut­off cord to a secure place on your cloth­ing, or your arm or leg while operating.
Do not attach the cord to clothing that
could tear loose. Do not route the cord
where it could become entangled, pre­venting it from functioning.

● Avoid accidentally pulling the cord dur-

ing normal operation. Loss of engine
power means the loss of most steering
control. Also, without engine power,
the boat could slow rapidly. This could
cause people and objects in the boat to
be thrown forward.

1. Place the gear shift lever in neutral.

switch.

3. Place the throttle grip in the “ ”
(start) position. After the engine starts,
return the throttle to the fully closed po­sition.

The start-in-gear protection device prevents
the engine from starting except when in neu­tral.

2. Attach the engine shut-off cord to a se­cure place on your clothing, or your arm
or leg. Then install the clip on the other
end of the cord into the engine shut-off

4. Turn the main switch to “ ” (start),
and hold it for a maximum of 5 seconds.

5. Immediately after the engine starts, re­lease the main switch and allow it to re­turn to “ ” (on). NOTICE: Never turn

the main switch to “ ” (start)

47

Operation

TIP:

WARNING

TIP:

while the engine is running. Do not
keep the starter motor turning for
more than 5 seconds. If the starter
motor is turned continuously for
more than 5 seconds, the battery will
be quickly discharged, thus making it
impossible to start the engine. The
starter can also be damaged. If the
engine will not start after 5 seconds
of cranking, return the main switch to
“ ” (on), wait 10 seconds, then
crank the engine again.

● When the engine is cold, it needs to be

warmed up. For further information, see
page 49.

● If the engine is warm and fails to start,

open the throttle slightly and try to start the
engine again. If the engine still fails to
start, see page 77.

EMU27664

Electric start and remote control models

EWM01840

[ECM00192]

The start-in-gear protection device prevents
the engine from starting except when in neu­tral.

2. Attach the engine shut-off cord to a se­cure place on your clothing, or your arm
or leg. Then install the clip on the other
end of the cord into the engine shut-off
switch.

● Failure to attached engine shut-off cord

could result in a runaway boat if opera­tor is ejected. Attach the engine shut­off cord to a secure place on your cloth­ing, or your arm or leg while operating.
Do not attach the cord to clothing that
could tear loose. Do not route the cord
where it could become entangled, pre­venting it from functioning.

● Avoid accidentally pulling the cord dur-

ing normal operation. Loss of engine
power means the loss of most steering
control. Also, without engine power,
the boat could slow rapidly. This could
cause people and objects in the boat to
be thrown forward.

1. Place the remote control lever in neutral.

48

3. Turn the main switch to “ ” (on).

4. Turn the main switch to “ ” (start),
and hold it for a maximum of 5 seconds.

5. Immediately after the engine starts, re-

TIP:

NOTICE

ZMU03391

lease the main switch and allow it to re­turn to “ ” (on). NOTICE: Never turn

the main switch to “ ” (start)
while the engine is running. Do not
keep the starter motor turning for
more than 5 seconds. If the starter
motor is turned continuously for
more than 5 seconds, the battery will
be quickly discharged, thus making it
impossible to start the engine. The
starter can also be damaged. If the
engine will not start after 5 seconds
of cranking, return the main switch to
“ ” (on), wait 10 seconds, then
crank the engine again.

● When the engine is cold, it needs to be

[ECM00192]

warmed up. For further information, see
page 49.

● If the engine is warm and fails to start,

open the throttle slightly and try to start the
engine again. If the engine still fails to
start, see page 77.

EMU36510

Checks after starting engine

EMU36522

Cooling water

Check for a steady flow of water from the
cooling water pilot hole. A continuous flow of
water from the pilot hole indicates that the

Operation

water pump is pumping water through the
cooling water passages. If the cooling water
passages are frozen, it may take a while for
water to start flowing out of the pilot hole.

ECM01810

If water is not flowing out of the pilot hole
at all times while the engine is running,
overheating and serious damage could
occur. Stop the engine and check wheth­er the cooling water inlet on the lower
case or the cooling water pilot hole is
blocked. Consult your Yamaha dealer if
the problem cannot be located and cor­rected.

EMU27670

Warming up engine

EMU27683

Choke start models

After starting the engine, allow it to idle for 3
minutes to warm up. Failure to do so will
shorten engine life. Gradually return the
choke knob to its home position as the en­gine warms up.

EMU27704

Electric start and prime start models

After starting the engine, allow it to idle for 3
minutes to warm up. Failure to do so will
shorten engine life.

49

Operation

WARNING

NOTICE

ZMU03399

EMU36531

Checks after engine warm up

EMU36541

Shifting

While the boat is tightly moored, and without
applying throttle, confirm that the engine
shifts smoothly into forward and reverse, and
back to neutral.

EMU31721

Stop switches

● Confirm that turning the main switch to the

“ ” (off) position stops the engine.

● Confirm that removing the clip from the en-

gine shut-off switch stops the engine.

● Confirm that the engine cannot be started

with the clip removed from the engine
shut-off switch.

EMU34530

Shifting

EWM00180

Before shifting, make sure there are no
swimmers or obstacles in the water near
you.

ECM01610

1. Neutral interlock trigger

2. Move the remote control lever / gear
shift lever firmly and crisply forward (for
forward gear) or backward (for reverse
gear) [about 35 (a detent can felt) for re­mote control models]. Be sure to check
that the tilt lock lever is in the lock/down
position (if equipped) before operating in
reverse.

Warm up the engine before shifting into
gear. Until the engine is warm, the idle
speed may be higher than normal. High
idle speed can prevent you from shifting
back to neutral. If this occurs, stop the
engine, shift to neutral, then restart the
engine and allow it to warm up.

To shift out of neutral

1. Pull the neutral interlock trigger up (if
equipped).

50

To shift from in gear (forward/reverse) to

WARNING

neutral

1. Close the throttle so that the engine
slows to idle speed.

Operation

EMU31742

Stopping boat

EWM01510

2. After the engine is at idle speed in gear
move the remote control lever / gear
shift lever firmly and crisply into the neu­tral position.

● Do not use the reverse function to slow

down or stop the boat as it could cause
you to lose control, be ejected, or im­pact the steering wheel or other parts of
the boat. This could increase the risk of
serious injury. It could also damage the
shift mechanism.

● Do not shift into reverse while traveling

at planing speeds. Loss of control, boat
swamping, or damage to the boat could
occur.

The boat is not equipped with a separate
braking system. Water resistance stops it af­ter the throttle lever is moved back to idle.
The stopping distance varies depending on
gross weight, water surface conditions, and
wind direction.

51

Operation

TIP:

WARNING

ZMU03108

ZMU02301

EMU27821

Stopping engine

Before stopping the engine, first let it cool off
for a few minutes at idle or low speed. Stop­ping the engine immediately after operating
at high speed is not recommended.

EMU27847

Procedure

1. Push and hold the engine stop button or
turn the main switch to “ ” (off).

the fuel line if there is a fuel joint on the
outboard motor.

3. Tighten the air vent screw on the fuel
tank cap (if equipped).

2. After stopping the engine, disconnect

52

4. Remove the key if the boat will be left un­attended.

The engine can also be stopped by pulling
the cord and removing the clip from the en­gine shut-off switch, then turning the main
switch to “ ” (off).

EMU27862

Trimming outboard motor

EWM00740

Excessive trim for the operating condi­tions (either trim up or trim down) can
cause boat instability and can make
steering the boat more difficult. This in­creases the possibility of an accident. If
the boat begins to feel unstable or is hard

Operation

WARNING

TIP:

ZMU03109

1

to steer, slow down and/or readjust the
trim angle.

The trim angle of the outboard motor helps
determine the position of the bow of the boat
in the water. Correct trim angle will help im­prove performance and fuel economy while
reducing strain on the engine. Correct trim
angle depends upon the combination of
boat, engine, and propeller. Correct trim is
also affected by variables such as the load in
the boat, sea conditions, and running speed.

1. Trim operating angle

EMU27872

Adjusting trim angle for manual tilt
models

There are 4 or 5 holes provided in the clamp
bracket to adjust the outboard motor trim an­gle.

1. Stop the engine.

2. Tilt the outboard motor up, and then re-

move the trim rod from the clamp brack­et.

1. Trim rod

3. Reposition the rod in the desired hole.

To raise the bow (“trim-out”), move the rod
away from the transom.
To lower the bow (“trim-in”), move the rod to­ward the transom.
Make test runs with the trim set to different
angles to find the position that works best for
your boat and operating conditions.

EWM00400

● Stop the engine before adjusting the

trim angle.

● Use care to avoid being pinched when

removing or installing the rod.

● Use caution when trying a trim position

for the first time. Increase speed gradu­ally and watch for any signs of instabil­ity or control problems. Improper trim
angle can cause loss of control.

The outboard motor trim angle can be
changed approximately 4 degrees by shifting
the trim rod one hole.

53

Operation

WARNING

DOWN

UP

ZMU05675

1

EMU27886

Adjusting trim angle (Power trim and
tilt)

EWM00753

● Be sure all people are clear of the out-

board motor when adjusting the trim
angle. Body parts can be crushed be­tween the motor and the clamp bracket
when the motor is trimmed or tilted.

● Use caution when trying a trim position

for the first time. Increase speed gradu­ally and watch for any signs of instabil­ity or control problems. Improper trim
angle can cause loss of control.

● If equipped with a power trim and tilt

switch located on the bottom cowling,
use the switch only when the boat is at
a complete stop with the engine off. Do
not adjust the trim angle with this
switch while the boat is moving.

Adjust the outboard motor trim angle using
the power trim and tilt switch.

1. Power trim and tilt switch

1. Power trim and tilt switch

1. Power trim and tilt switch

54

To raise the bow (trim-out), press the switch
“” (up).
To lower the bow (trim-in), press the switch
“ ” (down).
Make test runs with the trim set to different
angles to find the position that works best for
your boat and operating conditions.

EMU27912

Adjusting boat trim

When the boat is on plane, a bow-up attitude
results in less drag, greater stability and effi­ciency. This is generally when the keel line of
the boat is up about 3 to 5 degrees. With the
bow up, the boat may have a greater tenden­cy to steer to one side or the other. Compen­sate for this as you steer. When the bow of
the boat is down, it is easier to accelerate

from a standing start onto plane.

TIP:

WARNING

WARNING

NOTICE

Operation

Bow Up

Too much trim-out puts the bow of the boat
too high in the water. Performance and econ­omy are decreased because the hull of the
boat is pushing the water and there is more
air drag. Excessive trim-out can also cause
the propeller to ventilate, which reduces per­formance further, and the boat may “por­poise” (hop in the water), which could throw
the operator and passengers overboard.

Bow Down

Too much trim-in causes the boat to “plow”
through the water, decreasing fuel economy
and making it hard to increase speed. Oper­ating with excessive trim-in at higher speeds
also makes the boat unstable. Resistance at
the bow is greatly increased, heightening the
danger of “bow steering” and making opera­tion difficult and dangerous.

Depending on the type of boat, the outboard
motor trim angle may have little effect on the
trim of the boat when operating.

EMU27935

Tilting up and down

If the engine will be stopped for some time or
if the boat is moored in shallows, the out­board motor should be tilted up to protect the
propeller and lower casing from damage by
collision with obstructions, and also to re­duce salt corrosion.

EWM00222

Make sure that no one is near the out­board motor when tilting the outboard
motor up or down. Otherwise, body parts
could be crushed between the outboard
motor and the clamp bracket.

EWM00250

Leaking fuel is a fire hazard. If there is a
fuel joint on the outboard motor, discon­nect the fuel line or close the fuel cock if
the engine will be tilted for more than a
few minutes. Otherwise fuel may leak.

ECM00241

● Before tilting the outboard motor, stop

the engine by following the procedure

55

Operation

ZMU03405

ZMU03358

on page 52. Never tilt the outboard mo­tor while the engine is running. Severe
damage from overheating can result.

● Do not tilt up the engine by pushing the

tiller handle (if equipped) because this
could break the handle.

EMU27955

Procedure for tilting up (manual tilt
models)

1. Place the remote control lever / gear
shift lever in neutral.

3. Hold the rear of the top cowling with one
hand, tilt the engine up, and turn the tilt
support lever to the lock position and
support the engine. NOTICE: Do not

use the tilt support lever or knob
when trailering the boat. The out­board motor could shake loose from
the tilt support and fall. If the motor
cannot be trailered in the normal run­ning position, use an additional sup­port device to secure it in the tilt
position. For more detailed informa­tion, see page 61.

[ECM01641]

2. Place the tilt lock lever in the release po­sition.

56

EMU32724

Procedure for tilting up (power trim
and tilt models)

1. Place the remote control lever / gear
shift lever in neutral.

Operation

UP

ZMU01935

UP
DN

UP

ZMU04993

2. Press the power trim and tilt switch “ ”
(up) until the outboard motor has tilted
up completely.

3. Pull the tilt support lever toward you to
support the engine. WARNING! After

tilting the outboard motor, be sure to
support it with the tilt support knob or
tilt support lever. Otherwise the out­board motor could fall back down
suddenly if oil in the power trim and
tilt unit or in the power tilt unit loses
pressure.

[EWM00262] NOTICE: Do not use

the tilt support lever or knob when
trailering the boat. The outboard mo­tor could shake loose from the tilt
support and fall. If the motor cannot
be trailered in the normal running po­sition, use an additional support de­vice to secure it in the tilt position.
For more detailed information, see
page 61.

[ECM01641]

57

Operation

ZMU03115

ZMU06644

ZMU02569

DN

ZMU01936

UP
DN

DOWN

ZMU03410

4. Models equipped with trim rods: Once
the outboard motor is supported with the
tilt support lever, press the power trim
and tilt switch “ ” (down) to retract the
trim rods. NOTICE: Make sure that the

trim rods retracts completely during
mooring. This protects the rods from
marine growth and corrosion, which
could damage the power trim and tilt
mechanism.

EMU30411

Procedure for tilting down (manual
tilt models)

1. Slightly tilt the engine up.

2. On models equipped with a tilt support
lever, return it to the release position.

[ECM00252]

(up) until the outboard motor is support­ed by the tilt rod and the tilt support lever
becomes free.

2. Release the tilt support lever.

3. Push the power trim and tilt switch “ ”
(down) to lower the outboard motor to
the desired position.

3. Slowly tilt the engine down.

EMU33121

Procedure for tilting down (power
trim and tilt models)

1. Push the power trim and tilt switch “ ”

58

Operation

NOTICE

UP

ZMU01935

UP
DN

UP

ZMU03412

EMU28061

Shallow water

EMU32851

Power trim and tilt models

The outboard motor can be tilted up partially
to allow operation in shallow water.

ECM00260

Do not tilt the outboard motor up so that
the cooling water inlet on the lower unit is
above the surface of the water when set­ting up for and cruising in shallow water.
Otherwise severe damage from overheat­ing can result.

EMU32913

Procedure for power trim and tilt models

1. Place the remote control lever / gear
shift lever in neutral.

2. Slightly tilt the outboard motor up to the
desired position using the power trim
and tilt switch. WARNING! Using the

power trim and tilt switch on the bot­tom cowling while the boat is moving
or engine is on could increase the
risk of falling overboard and could
distract the operator, increasing the
risk of collision with another boat or
an obstacle.

[EWM01850]

59

Operation

3. To return the outboard motor to the nor­mal running position, press the power
trim and tilt switch and slowly tilt the out­board motor down.

EMU28195

Cruising in other conditions

Cruising in salt water

After operating in salt water, flush the cooling
water passages with fresh water to prevent
them from becoming clogged. Also rinse the
outside of the outboard motor with fresh wa­ter.

Cruising in muddy, turbid, or acidic water

Yamaha strongly recommends that you use
the optional chromium-plated water pump kit
(see page 13) if you use the outboard motor
in acidic water or water with a lot of sediment
in it, such as muddy or turbid (cloudy) water.
After operating in such water, flush the cool­ing passages with fresh water to prevent cor­rosion. Also rinse the outside of the outboard
motor with fresh water.

60

Maintenance

WARNING

NOTICE

TIP:

ZMU03122

EMU2822A

Transporting and storing

outboard motor

EWM02620

● USE CARE when transporting fuel tank,

whether in a boat or car.

● DO NOT fill fuel container to maximum

capacity. Gasoline will expand consid­erably as it warms up and can build up
pressure in the fuel container. This can
cause fuel leakage and a potential fire
hazard.

● Leaking fuel is a fire hazard. When

transporting and storing the outboard
motor, disconnect the fuel line from the
outboard motor to prevent fuel from
leaking.

● Never get under the outboard motor

while it is tilted. Severe injury could oc­cur if the outboard motor accidentally
falls.

● Do not use the tilt support lever or knob

when trailering the boat. The outboard
motor could shake loose from the tilt
support and fall. If the outboard motor
cannot be trailered in the normal run­ning position, use an additional sup­port device to secure it in the tilt
position.

ECM02440

● Disconnect the fuel line from the outboard

motor.

● Tighten the fuel tank cap and its air vent

screw.

● When the outboard motor is tilted pro-

longed time for mooring or trailering the
boat, disconnect the fuel line from the out­board motor. Tighten the fuel tank cap and

its air vent screw.
The outboard motor should be transported
and stored in the normal running position. If
there is insufficient road clearance in this po­sition, then trailer the outboard motor in the
tilt position using a motor support device
such as a transom saver bar. Consult your
Yamaha dealer for further details.

EMU28236

Clamp screw mounting models

When transporting or storing the outboard
motor while removed from a boat, keep the
outboard motor in the attitude shown.

When storing the outboard motor for pro­longed time, fuel must be drained from
the fuel tank. The deteriorated fuel could
clog the fuel line causing engine start dif­ficulty or malfunction.

When storing or transporting the outboard
motor, make sure to follow the procedure list­ed below.

Place a towel or something similar under the
outboard motor to protect it from damage.

EMU30272

Storing outboard motor

When storing your Yamaha outboard motor
for prolonged periods of time (2 months or
longer), several important procedures must
be performed to prevent excessive damage.
It is advisable to have your outboard motor

61

Maintenance

NOTICE

NOTICE

ZMU02051

1

2

serviced by an authorized Yamaha dealer
prior to storage. However, you, the owner,
with a minimum of tools, can perform the fol­lowing procedures.

ECM01411

● Do not place the outboard motor on its

side before the cooling water has
drained from it completely, otherwise
water may enter the cylinder through
the exhaust port and cause engine trou­ble.

● Store the outboard motor in a dry, well-

ventilated place, not in direct sunlight.

EMU28305

Procedure

EMU28335

Flushing in a test tank

ECM00301

Before starting the engine, make sure to
supply water to the cooling water passag­es. Otherwise, the engine could overheat
and be damaged.

1. Wash the outboard motor body using
fresh water. NOTICE: Do not spray wa-

ter into the air intake.

ther information, see page 63.

2. Disconnect the fuel line from the motor
or shut off the fuel cock, if equipped.

3. Remove the engine top cowling and si­lencer cover. Remove the propeller.

4. Install the outboard motor on the test
tank. Fill the tank with fresh water to
above the level of the anti-cavitation
plate. NOTICE: If the fresh water level

is below the level of the anti-cavita­tion plate, or if the water supply is in­sufficient, engine seizure may occur.

[ECM00291]

[ECM01840] For fur-

1. Water surface

2. Lowest water level

5. Cooling system flushing is essential to
prevent the cooling system from clog­ging up with salt, sand, or dirt. In addi­tion, fogging/lubricating of the engine is
mandatory to prevent excessive engine
damage due to rust. Perform the flush­ing and fogging at the same time.

WARNING! Do not touch or remove
electrical parts when starting or dur­ing operation. Keep hands, hair, and
clothes away from the flywheel and
other rotating parts while the engine
is running.

[EWM00091]

6. Run the engine at a fast idle for a few
minutes in neutral position.

7. Just prior to turning off the engine, quick­ly spray “Fogging Oil” alternately into
each carburetor or the fogging hole of
the silencer cover, if equipped. When
properly done, the engine will smoke ex­cessively and almost stall.

8. Remove the outboard motor from the
test tank.

9. Install the silencer cover/cap of fogging
hole and top cowling.

10. If the “Fogging Oil” is not available, run
the engine at a fast idle until the fuel sys­tem becomes empty and the engine

62

stops.

TIP:

TIP:

WARNING

ZMU03223

11. Drain the cooling water completely out of
the motor. Clean the body thoroughly.

12. If the “Fogging Oil” is not available, re­move the spark plug(s). Pour a tea­spoonful of clean engine oil into each
cylinder. Crank several times manually.
Replace the spark plug(s).

13. Drain the fuel from the fuel tank.

Maintenance

Store the fuel tank in a dry, well-ventilated
place, not in direct sunlight.

EMU28411

Lubrication (oil injection models)

1. Install the spark plug(s) and torque to
proper specification. For information on
spark plug installation, see page 69.

2. Fill the oil tanks. This prevents the for­mation of condensation. For models with
a remote oil tank, it may be necessary to
manually override the control unit to
completely fill the engine oil tank.

3. Change the gear oil. For instructions,
see page 73. Inspect the oil for the pres­ence of water which indicates a leaky
seal. Seal replacement should be per­formed by an authorized Yamaha dealer
prior to use.

4. Grease all grease fittings. For further de­tails, see page 68.

For long-term storage, fogging the engine
with oil is recommended. Contact your
Yamaha dealer for information about fogging
oil and procedures for your engine.

EMU28451

Cleaning the outboard motor

After use, wash the exterior of the outboard
motor with fresh water. Flush the cooling
system with fresh water.

EMU28461

Checking painted surface of
outboard motor

Check the outboard motor for scratches,
nicks, or flaking paint. Areas with damaged
paint are more likely to corrode. If necessary,
clean and paint the areas. A touch-up paint is
available from your Yamaha dealer.

EMU2847C

Periodic maintenance

EWM01871

These procedures require mechanical
skills, tools, and supplies. If you do not
have the proper skills, tools, or supplies
to perform a maintenance procedure,
have a Yamaha dealer or other qualified
mechanic do the work.
The procedures involve disassembling
the motor and exposing dangerous parts.
To reduce the risk of injury from moving,
hot, or electrical parts:

● Turn off the engine and keep the key(s)

and engine shut-off cord (lanyard) with
you when you perform maintenance un­less otherwise specified.

● The power trim and tilt switches oper-

ate even when the ignition key is off.
Keep people away from the switches
whenever working around the motor.
When the motor is tilted, keep away

63

Maintenance

from the area under it or between it and
the clamp bracket. Be sure no one is in
this area before operating the power
trim and tilt mechanism.

● Allow the engine to cool before han-

dling hot parts or fluids.

● Always completely reassemble the mo-

tor before operation.

EMU28511

Replacement parts

If replacement parts are necessary, use only
genuine Yamaha parts or parts of equivalent
design and quality. Any part of inferior quality
may malfunction, and the resulting loss of
control could endanger the operator and
passengers. Yamaha genuine parts and ac­cessories are available from your Yamaha
dealer.

EMU34151

Severe operating conditions

Severe operating conditions involve one or
more of the following types of operation on a
regular basis:

● Operating continuously at or near maxi-

mum engine speed (rpm) for many hours

● Operating continuously at a low engine

speed (rpm) for many hours

● Operating without sufficient time for engine

to warm up and cool down

● Frequent quick acceleration and decelera-

tion

● Frequent shifting

● Frequently starting and stopping the en-

gine(s)

● Operation that fluctuates often between

light and heavy cargo loads
Outboard motors operating under any of
these above conditions require more fre­quent maintenance. Yamaha recommends
that you do this service twice as often as
specified in the maintenance chart. For ex-

ample, if a particular service should be done
at 50 hours, do it instead at 25 hours. This
will help prevent more rapid deterioration of
engine components.

64

Maintenance

TIP:

EMU34446

Maintenance chart 1

● Refer to the sections in this chapter for explanations of each owner-specific action.

● The maintenance cycle on these charts assume usage of 100 hours per year and regular

flushing of the cooling water passages. Maintenance frequency should be adjusted when

operating the engine under adverse conditions such as extended trolling.

● Disassembly or repairs may be necessary depending on the outcome of maintenance

checks.

● Expendable or consumable parts and lubricants will lose their effectiveness over time and

through normal usage regardless of the warranty period.

● When operating in salt water, muddy, other turbid (cloudy), acidic water, the engine should

be flushed with clean water after each use.
The “ ” symbol indicates the check-ups which you may carry out yourself.
The “ ” symbol indicates work to be carried out by your Yamaha dealer.

Initial Every

Item Actions

Anode(s) (external)

Anode(s) (cylinder
head, thermostat
cover)

Anodes (exhaust cover,
cooling water passage
cover, Rectifier Regula­tor cover)

Battery (electrolyte
level, terminal)

Battery (electrolyte
level, terminal)

Cooling water leakage

Cowling lock lever Inspection

Engine starting condi­tion/noise

Engine idle
speed/noise

Fuel filter (can be dis­assembled)

Fuel line (High pres­sure)

Inspection or replace­ment as necessary

Inspection or replace­ment as necessary

Replacement

Inspection

Fill, charging or replac­ing as necessary

Inspection or replace­ment as necessary

Inspection

Inspection

Inspection or replace­ment as necessary

Inspection

20 hours

(3

months)

100

hours (1

year)

300

hours (3

years)

500

hours (5

years)

65

Maintenance

Item Actions

Fuel line (High pres­sure)

Fuel line (Low pres­sure)

Fuel line (Low pres­sure)

Fuel pump

Fuel/engine oil leakage Inspection

Gear oil Replacement

Greasing points Greasing

Impeller/water pump
housing

Impeller/water pump
housing

Oil tank water drain Inspection or cleaning

Oil injection pump/oil
feed pump

Power trim and tilt
unit/Operation, noise
and oil leakage

Propeller/propeller
nut/cotter pin

Shift link/shift cable

Spark plug(s)

Spark plug caps/spark
plug wires

Water from the cooling
water pilot hole

Throttle link/throttle
cable/throttle pick-up
timing

Thermostat

Cooling water inlet Inspection

Inspection or replace­ment as necessary

Inspection

Inspection or replace­ment as necessary

Inspection or replace­ment as necessary

Inspection or replace­ment as necessary

Replacement

Inspection or Adjust­ment

Inspection

Inspection or replace­ment as necessary

Inspection, adjustment
or replacement as nec­essary

Inspection or replace­ment as necessary

Inspection or replace­ment as necessary

Inspection

Inspection, adjustment
or replacement as nec­essary

Inspection or replace­ment as necessary

Initial Every

20 hours

(3

months)

100

hours (1

year)

hours (3

years)

300

500

hours (5

years)

66

Item Actions

Main switch/stop
switch/choke switch

Wire harness connec­tions/wire coupler con­nections

(Yamaha) Meter/gauge Inspection

Fuel tank (Yamaha por­table tank)

EMU34451

Inspection or replace­ment as necessary

Inspection or replace­ment as necessary

Inspection and clean­ing as necessary

Maintenance chart 2

Maintenance

Initial Every

20 hours

(3

months)

100

hours (1

year)

hours (3

years)

300

500

hours (5

years)

Item Actions

Exhaust guide/exhaust
manifold

Every

1000 hours

Inspection or replace­ment as necessary

67

Maintenance

ZMU03415

EMU28943

Greasing

Yamaha grease A (water resistant grease)
Yamaha grease D (corrosion resistant grease; for propeller shaft)

40VMHO, 50HMHO

68

40VEO, 50HETO

ZMU03414

Maintenance

EMU28957

Cleaning and adjusting spark plug

The spark plug is an important engine com­ponent and is easy to inspect. The condition
of the spark plug can indicate something
about the condition of the engine. For exam­ple, if the center electrode porcelain is very
white, this could indicate an intake air leak or
carburetion problem in that cylinder. Do not
attempt to diagnose any problems yourself.
Instead, take the outboard motor to a
Yamaha dealer. You should periodically re­move and inspect the spark plug because

heat and deposits will cause the spark plug
to slowly break down and erode.

1. Remove the spark plug caps from the
spark plugs.

2. Remove the spark plug. If electrode ero­sion becomes excessive, or if carbon
and other deposits are excessive, you
should replace the spark plug with an­other of the correct type. WARNING!

When removing or installing a spark
plug, be careful not to damage the in­sulator. A damaged insulator could

69

Maintenance

TIP:

WARNING

NOTICE

ZMU06150

allow external sparks, which could
lead to explosion or fire.

[EWM00561]

Standard spark plug:

40VEO B7HS-10
40VMHO B7HS-10
50HETO B8HS-10
50HMHO B8HS-10

3. Be sure to use the specified spark plug,
otherwise the engine may not operate
properly. Before fitting the spark plug,
measure the electrode gap with a wire
thickness gauge; replace it if out of spec­ification.

1. Spark plug gap

2. Spark plug part number

3. Spark plug I.D. mark (NGK)

Spark plug gap:

0.9–1.0 mm (0.035–0.039 in)

4. When fitting the plug, wipe off any dirt
from the threads, and then screw it in to
the correct torque.

Spark plug torque:

25.0 Nm (2.55 kgf-m, 18.4 ft-lb)

If a torque-wrench is not available when you
are fitting a spark plug, a good estimate of

the correct torque is 1/4 to 1/2 a turn past fin­ger-tight. Have the spark plug adjusted to the
correct torque as soon as possible with a
torque-wrench.

EMU37450

Checking fuel filter

Check the fuel filter periodically. If any water
or foreign matter is found in the filter, clean or
replace it. For cleaning or replacement of the
fuel filter, consult your Yamaha dealer.

EMU29044

Inspecting idle speed

EWM00451

● Do not touch or remove electrical parts

when starting or during operation.

● Keep hands, hair, and clothes away

from the flywheel and other rotating
parts while the engine is running.

ECM00490

This procedure must be performed while
the outboard motor is in the water. A
flushing attachment or test tank can be
used.

If the boat is not equipped with a tachometer
for the outboard motor, use a diagnostic ta­chometer for this procedure. Results may
vary depending on whether testing is con­ducted with the flushing attachment, in a test
tank, or with the outboard motor in the water.

70

Maintenance

WARNING

1

2

ZMU03416

1

2

ZMU04989

ZMU03240

1. Start the engine and allow it to warm up
fully in neutral until it is running smooth­ly.

2. Once the engine has warmed up, verify
whether the idle speed is set to specifi­cation. For idle speed specifications, see
page 9. If you have difficulty verifying the
idle speed, or the idle speed requires ad­justment, consult a Yamaha dealer or
other qualified mechanic.

EMU29061

Checking water in engine oil tank

A translucent water drain hose is connected
from the bottom of the oil tank to the filler
neck. If water or foreign matter collects in this
hose, consult a Yamaha dealer.

1. Drain hose

2. Filler neck side

EMU29114

Inspecting wiring and connectors

● Inspect that each connector is engaged

securely.

● Inspect that each ground lead is properly

secured.

EMU32112

Checking propeller

EWM01881

You could be seriously injured if the en­gine accidentally starts when you are
near the propeller. Before inspecting, re­moving, or installing the propeller, place
the shift control in neutral, turn the main
switch to “ ” (off) and remove the key,
and remove the clip from the engine shut­off switch. Turn off the battery cut-off
switch if your boat has one.

1. Drain hose

2. Filler neck side

Do not use your hand to hold the propeller
when loosening or tightening the propeller
nut. Put a wood block between the anti-cavi­tation plate and the propeller to prevent the
propeller from turning.

71

Maintenance

NOTICE

ZMU01897

ZMU03131

1

2

3

5

6

4

Checkpoints

● Check each of the propeller blades for ero-

sion from cavitation or ventilation, or other
damage.

● Check the propeller shaft for damage.

● Check the splines for wear or damage.

● Check for fish line tangled around the pro-

peller shaft.

● Check the propeller shaft oil seal for dam-

age.

EMU30662

Removing propeller

EMU29197

Spline models

1. Straighten the cotter pin and pull it out
using a pair of pliers.

2. Remove the propeller nut, washer, and
spacer (if equipped). WARNING! Do

not use your hand to hold the propel­ler when loosening the propeller nut.

[EWM01890]

1. Cotter pin

2. Propeller nut

3. Washer

4. Spacer

5. Propeller

6. Thrust washer

3. Remove the propeller, washer (if
equipped), and thrust washer.

EMU30672

Installing propeller

EMU29234

Spline models

ECM00501

Make sure to use a new cotter pin and
bend the ends over securely. Otherwise,
the propeller could come off during oper­ation and be lost.

1. Apply Yamaha marine grease or a corro­sion resistant grease to the propeller
shaft.

2. Install the spacer (if equipped), thrust
washer, washer (if equipped), and pro­peller on the propeller shaft. NOTICE:

Make sure to install the thrust washer
before installing the propeller. Other­wise, the lower case and propeller
boss could be damaged.

3. Install the spacer (if equipped) and the
washer. Tighten the propeller nut to the
specified torque.

[ECM01881]

72

Maintenance

TIP:

WARNING

TIP:

TIP:

ZMU03133

2

1

Propeller nut tightening torque:

39.0 Nm (3.98 kgf-m, 28.8 ft-lb)

4. Align the propeller nut with the propeller
shaft hole. Insert a new cotter pin in the
hole and bend the cotter pin ends. NO-

TICE: Do not reuse the cotter pin.
Otherwise, the propeller can come off
during operation.

[ECM01891]

If the propeller nut does not align with the
propeller shaft hole after tightening to the
specified torque, tighten the nut further to
align it with the hole.

EMU29289

Changing gear oil

EWM00800

● Be sure the outboard motor is securely

fastened to the transom or a stable
stand. You could be severely injured if
the outboard motor falls on you.

● Never get under the lower unit while it

is tilted, even when the tilt support lever
or knob is locked. Severe injury could
occur if the outboard motor accidental­ly falls.

1. Tilt the outboard motor so that the gear
oil drain screw is at the lowest point pos­sible.

2. Place a suitable container under the

gear case.

3. Remove the gear oil drain screw and
gasket. NOTICE: If there is an exces-

sive quantity of metal particles on the
magnetic gear oil drain screw, this
can indicate lower unit problem. Con­sult your Yamaha dealer.

1. Gear oil drain screw

2. Oil level plug

● If a magnetic gear oil drain screw is

[ECM01900]

equipped, remove all metal particles from
the screw before installing it.

● Always use new gaskets. Do not reuse the

removed gaskets.

4. Remove the oil level plug and gasket to
allow the oil to drain completely. NO-

TICE: Check the used gear oil after it
has been drained. If the gear oil is
milky or contains water or a large
amount of metal particles, the gear
case may be damaged. Have a
Yamaha dealer check and repair the
outboard motor.

[ECM00713]

For disposal of used oil, consult your
Yamaha dealer.

5. Put the outboard motor in a vertical posi­tion. Using a flexible or pressurized fill­ing device, inject the gear oil into the

73

Maintenance

WARNING

ZMU03132

ZMU02324

ZMU03232

gear oil drain screw hole.

Recommended gear oil:

Hypoid gear oil SAE#90

Gear oil quantity:

0.430 L (0.455 US qt, 0.378 Imp.qt)

6. Put a new gasket on the oil level plug.
When the oil begins to flow out of the oil
level plug hole, insert and tighten the oil
level plug.

Tightening torque:

9 Nm (0.9 kgf-m, 6.6 ft-lb)

7. Put a new gasket on the gear oil drain
screw. Insert and tighten the gear oil
drain screw.

when cleaning the fuel tank.

● Remove the fuel tank from the boat be-

fore cleaning it. Work only outdoors in
an area with good ventilation.

● Wipe up any spilled fuel immediately.

● Reassemble the fuel tank carefully. Im-

proper assembly can result in a fuel
leak, which could result in a fire or ex­plosion hazard.

● Dispose of old gasoline according to lo-

cal regulations.

1. Empty the fuel tank into an approved
container.

2. Pour a small amount of suitable solvent
into the tank. Install the cap and shake
the tank. Drain the solvent completely.

3. Remove the screws holding the fuel joint
assembly. Pull the assembly out of the
tank.

Tightening torque:

9 Nm (0.9 kgf-m, 6.6 ft-lb)

EMU29302

Cleaning fuel tank

EWM00920

Gasoline is highly flammable, and its va­pors are flammable and explosive.

● If you have any question about properly

doing this procedure, consult your
Yamaha dealer.

● Keep away from sparks, cigarettes,

flames, or other sources of ignition

74

4. Clean the filter (located on the end of the

suction pipe) in a suitable cleaning sol-

NOTICE

TIP:

WARNING

NOTICE

ZMU03134

ZMU03135

ZMU03418

vent. Allow the filter to dry.

5. Replace the gasket with a new one. Re­install the fuel joint assembly and tighten
the screws firmly.

EMU29313

Inspecting and replacing anode(s)

Yamaha outboard motors are protected from
corrosion by sacrificial anodes. Inspect the
external anodes periodically. Remove scales
from the surfaces of the anodes. Consult a
Yamaha dealer for replacement of external
anodes.

ECM00720

Do not paint anodes, as this would render
them ineffective.

Maintenance

Inspect ground leads attached to external
anodes on equipped models. Consult a
Yamaha dealer for inspection and replace­ment of internal anodes attached to the pow­er unit.

EMU29323

Checking battery (for electric start
models)

EWM01902

Battery electrolyte is poisonous and
caustic, and batteries generate explosive
hydrogen gas. When working near the
battery:

● Wear protective eye gear and rubber

gloves.

● Do not smoke or bring any other source

of ignition near the battery.

The procedure for checking the battery var­ies for different batteries. This procedure
contains typical checks that apply to many
batteries, but you should always refer to the
battery manufacturer’s instructions.

ECM01920

A poorly maintained battery will quickly
deteriorate.

1. Check the electrolyte level.

75

Maintenance

WARNING

NOTICE

ZMU01811

1

2

3

2. Check the battery’s charge. If your boat
is equipped with the digital speedome­ter, the voltmeter and low battery alert
functions will help you monitor the bat­tery’s charge. If the battery needs charg­ing, consult your Yamaha dealer.

3. Check the battery connections. They
should be clean, secure, and covered by
an insulating cover. WARNING! Bad

connections can produce shorting or
arcing and cause an explosion.

[EWM01912]

EMU29334

Connecting the battery

EWM00572

Mount the battery holder securely in a
dry, well-ventilated, vibration-free loca­tion in the boat. Install a fully charged bat­tery in the holder.

ECM01124

Do not reverse the battery cables. Other­wise, the electrical parts could be dam­aged.

1. Make sure the main switch (on applica­ble models) is “ ” (off) before working
on the battery.

2. Connect the red battery cable to the
POSITIVE (+) terminal first. Then con-

nect the black battery cable to the NEG­ATIVE (-) terminal.

1. Red cable

2. Black cable

3. Battery

3. The electrical contacts of the battery and
cables must be clean and properly con­nected, or the battery will not start the
engine.

EMU29371

Disconnecting the battery

1. Turn off the battery cut-off switch (if
equipped) and main switch. NOTICE: If

they are left on, the electrical system
can be damaged.

2. Disconnect the negative cable(s) from
the negative (-) terminal. NOTICE: Al-

ways disconnect all negative (-) ca­bles first to avoid a short circuit and
damage to the electrical system.

[ECM01940]

3. Disconnect the positive cable(s) and re­move the battery from the boat.

4. Clean, maintain, and store the battery
according to the manufacturer’s instruc­tions.

[ECM01930]

76

Trouble Recovery

EMU29427

Troubleshooting

A problem in the fuel, compression, or igni­tion systems can cause poor starting, loss of
power, or other problems. This section de­scribes basic checks and possible remedies,
and covers all Yamaha outboard motors.
Therefore some items may not apply to your
model.
If your outboard motor requires repair, bring
it to your Yamaha dealer.
If the engine trouble-alert indicator is flash­ing, consult your Yamaha dealer.

Starter will not operate.

Q. Is battery capacity weak or low?
A. Check battery condition. Use battery of
recommended capacity.

Q. Are battery connections loose or corrod­ed?
A. Tighten battery cables and clean battery
terminals.

Q. Is fuse for electric start relay or electric cir­cuit blown?
A. Check for cause of electric overload and
repair. Replace fuse with one of correct am­perage.

Q. Are starter components faulty?
A. Have serviced by a Yamaha dealer.

Q. Is shift lever in gear?
A. Shift to neutral.

Engine will not start (starter operates).

Q. Is fuel tank empty?
A. Fill tank with clean, fresh fuel.

Q. Is fuel contaminated or stale?

A. Fill tank with clean, fresh fuel.

Q. Is fuel filter clogged?
A. Clean or replace filter.

Q. Is starting procedure incorrect?
A. See page 45.

Q. Has fuel pump malfunctioned?
A. Have serviced by a Yamaha dealer.

Q. Are spark plug(s) fouled or of incorrect
type?
A. Inspect spark plug(s). Clean or replace
with recommended type.

Q. Are spark plug cap(s) fitted incorrectly?
A. Check and re-fit cap(s).

Q. Is ignition wiring damaged or poorly con­nected?
A. Check wires for wear or breaks. Tighten
all loose connections. Replace worn or bro­ken wires.

Q. Are ignition parts faulty?
A. Have serviced by a Yamaha dealer.

Q. Is engine shut-off cord (lanyard) not at­tached?
A. Attach cord.

Q. Are engine inner parts damaged?
A. Have serviced by a Yamaha dealer.

Engine idles irregularly or stalls.

Q. Are spark plug(s) fouled or of incorrect
type?
A. Inspect spark plug(s). Clean or replace
with recommended type.

77

Trouble Recovery

Q. Is fuel system obstructed?
A. Check for pinched or kinked fuel line or
other obstructions in fuel system.

Q. Is fuel contaminated or stale?
A. Fill tank with clean, fresh fuel.

Q. Is fuel filter clogged?
A. Clean or replace filter.

Q. Have ignition parts failed?
A. Have serviced by a Yamaha dealer.

Q. Has alert system activated?
A. Find and correct cause of alert.

Q. Is spark plug gap incorrect?
A. Inspect and adjust as specified.

Q. Is ignition wiring damaged or poorly con­nected?
A. Check wires for wear or breaks. Tighten
all loose connections. Replace worn or bro­ken wires.

Q. Is specified engine oil not being used?
A. Check and replace oil as specified.

A. Return to home position.

Q. Is motor angle too high?
A. Return to normal operating position.

Q. Is carburetor clogged?
A. Have serviced by a Yamaha dealer.

Q. Is fuel joint connection incorrect?
A. Connect correctly.

Q. Is throttle valve adjustment incorrect?
A. Have serviced by a Yamaha dealer.

Q. Is battery cable disconnected?
A. Connect securely.

Alert buzzer sounds or indicator lights.

Q. Is cooling system clogged?
A. Check water intake for restriction.

Q. Is engine oil level low?
A. Fill oil tank with specified engine oil.

Q. Is heat range of spark plug incorrect?
A. Inspect spark plug and replace it with rec­ommended type.

Q. Is thermostat faulty or clogged?
A. Have serviced by a Yamaha dealer.

Q. Are carburetor adjustments incorrect?
A. Have serviced by a Yamaha dealer.

Q. Is fuel pump damaged?
A. Have serviced by a Yamaha dealer.

Q. Is air vent screw on fuel tank closed?
A. Open air vent screw.

Q. Is choke knob pulled out?

78

Q. Is specified engine oil not being used?
A. Check and replace oil with specified type.

Q. Is engine oil contaminated or deteriorat­ed?
A. Replace oil with fresh, specified type.

Q. Is oil filter clogged?
A. Have serviced by a Yamaha dealer.

Q. Has oil feed/injection pump malfunc­tioned?
A. Have serviced by a Yamaha dealer.

Q. Is load on boat improperly distributed?
A. Distribute load to place boat on an even
plane.

Q. Is water pump or thermostat faulty?
A. Have serviced by a Yamaha dealer.

Trouble Recovery

on gear housing?
A. Remove foreign matter and clean lower
unit.

Q. Is fuel system obstructed?
A. Check for pinched or kinked fuel line or
other obstructions in fuel system.

Q. Is there excess water in fuel filter cup?
A. Drain filter cup.

Engine power loss.

Q. Is propeller damaged?
A. Have propeller repaired or replaced.

Q. Is propeller pitch or diameter incorrect?
A. Install correct propeller to operate out­board at its recommended speed (r/min)
range.

Q. Is trim angle incorrect?
A. Adjust trim angle to achieve most efficient
operation.

Q. Is motor mounted at incorrect height on
transom?
A. Have motor adjusted to proper transom
height.

Q. Has alert system activated?
A. Find and correct cause of alert.

Q. Is boat bottom fouled with marine growth?
A. Clean boat bottom.

Q. Is fuel filter clogged?
A. Clean or replace filter.

Q. Is fuel contaminated or stale?
A. Fill tank with clean, fresh fuel.

Q. Is spark plug gap incorrect?
A. Inspect and adjust as specified.

Q. Is ignition wiring damaged or poorly con­nected?
A. Check wires for wear or breaks. Tighten
all loose connections. Replace worn or bro­ken wires.

Q. Have electrical parts failed?
A. Have serviced by a Yamaha dealer.

Q. Is specified fuel not being used?
A. Replace fuel with specified type.

Q. Is specified engine oil not being used?
A. Check and replace oil with specified type.

Q. Is thermostat faulty or clogged?
A. Have serviced by a Yamaha dealer.

Q. Are spark plug(s) fouled or of incorrect
type?
A. Inspect spark plug(s). Clean or replace
with recommended type.

Q. Are weeds or other foreign matter tangled

Q. Is air vent screw closed?
A. Open the air vent screw.

Q. Is fuel pump damaged?
A. Have serviced by a Yamaha dealer.

79

Trouble Recovery

WARNING

WARNING

Q. Is fuel joint connection incorrect?
A. Connect correctly.

Q. Is heat range of spark plug incorrect?
A. Inspect spark plug and replace it with rec­ommended type.

Q. Is high pressure fuel pump drive belt bro­ken?
A. Have serviced by a Yamaha dealer.

Q. Is engine not responding properly to shift
lever position?
A. Have serviced by a Yamaha dealer.

Engine vibrates excessively.

Q. Is propeller damaged?
A. Have propeller repaired or replaced.

Q. Is propeller shaft damaged?
A. Have serviced by a Yamaha dealer.

Q. Are weeds or other foreign matter tangled
on propeller?
A. Remove and clean propeller.

Q. Is motor mounting bolt loose?
A. Tighten bolt.

Q. Is steering pivot loose or damaged?
A. Tighten or have serviced by a Yamaha
dealer.

EMU29433

Temporary action in

emergency

EMU29441

Impact damage

EWM00870

trailering. Damage could make the out­board motor unsafe to operate.

If the outboard motor hits an object i n the wa­ter, follow the procedure below.

1. Stop the engine immediately.

2. Check the control system and all compo­nents for damage. Also, check the boat
for damage.

3. Whether damage is found or not, return
to the nearest harbor slowly and careful­ly.

4. Have a Yamaha dealer check the out­board motor before operating it again.

EMU29463

Replacing fuse

If the fuse has blown on an electric start mod­el, open the fuse holder and replace the fuse
with a new one of the proper amperage.

EWM00631

Substituting an incorrect fuse or a piece
of wire could allow excessive current
flow. This could cause electric system
damage and a fire hazard.

The outboard motor can be seriously
damaged by a collision while operating or

80

WARNING

1. Fuse holder

1

2

3

ZMU03421

1

ZMU03422

2. Fuse (20 A)

3. Spare fuse (20 A)

Consult your Yamaha dealer if the new fuse
immediately blows again.

EMU29524

Power trim and tilt will not operate

If the engine cannot be tilted up or down with
the power trim and tilt because of a dis­charged battery or a failure with the power
trim and tilt unit, the engine can be tilted
manually.

1. Loosen the manual valve screw by turn­ing it counterclockwise until it stops.

1. Manual valve screw

2. Put the engine in the desired position,
then tighten the manual valve screw by
turning it clockwise.

Trouble Recovery

EMU29533

Starter will not operate

If the starter mechanism does not operate
(the engine cannot be cranked with the start­er), the engine can be started with an emer­gency starter rope.

EWM01022

● Use this procedure only in an emergen-

cy to return to the nearest port for re­pairs.

● When the emergency starter rope is

used to start the engine, the start-in­gear protection device does not oper­ate. Make sure the remote control lever
is in neutral. Otherwise the boat could
unexpectedly start to move, which
could result in an accident.

● Attach the engine shut-off cord to a se-

cure place on your clothing, or your
arm or leg while operating the boat.

● Do not attach the cord to clothing that

could tear loose. Do not route the cord
where it could become entangled, pre­venting it from functioning.

● Avoid accidentally pulling the cord dur-

ing normal operation. Loss of engine
power means the loss of most steering
control. Also, without engine power,
the boat could slow rapidly. This could
cause people and objects in the boat to
be thrown forward.

● Make sure no one is standing behind

you when pulling the starter rope. It
could whip behind you and injure
someone.

● An unguarded, rotating flywheel is very

dangerous. Keep loose clothing and
other objects away when starting the
engine. Use the emergency starter rope
only as instructed. Do not touch the fly-

81

Trouble Recovery

ZMU03425

ZMU03139

ZMU03140

ON STARTOFF

ZMU01906

wheel or other moving parts when the
engine is running. Do not install the
starter mechanism or top cowling after
the engine is running.

● Do not touch the ignition coil, spark

plug wire, spark plug cap, or other elec­trical components when starting or op­erating the motor. You could get an
electrical shock.

EMU29562

Emergency starting engine

1. Remove the top cowling.

2. Remove the start-in-gear protection ca­ble from the starter, if equipped.

equipped.

3. Remove the starter/flywheel cover after
removing the bolt(s).

4. Prepare the engine for starting. For fur­ther information, see page 45. Be sure
the engine is in neutral and that the clip
is attached to the engine shut-off switch.
The main switch must be “ ” (on), if

82

5. If equipped the choke knob, pull out it
when the engine is cold. After the engine
starts, gradually return the choke knob
to its home position as the engine warms
up.

6. Insert the knotted end of the emergency

WARNING

ZMU03355

ZMU03429

ZMU03141

OPEN

CLOSE

ZMU03142

starter rope into the notch in the flywheel
rotor and wind the rope several turns
around the flywheel clockwise.

7. Give a strong pull straight out to crank
and start the engine. Repeat if neces­sary.

Trouble Recovery

flywheel or other moving parts when the
engine is running.

1. Adjust the trim angle so that the drive
shaft is at right angles to the water sur­face or is trimmed in.

2. On models equipped with an emergency
starter valve, open it. The valve is locat­ed behind the silencer cover on the front
of the engine.

3. Squeeze the primer pump two or three
times to feed fuel.

EMU29671

Engine fails to operate

EMU29706

Cold engine fails to start

If the engine fails to start when it is cold, use
the following procedure.

EWM00410

When starting or operating the engine, do
not touch the ignition coil, spark plug
wire, spark plug cap, or other electrical
parts carrying high voltage. Keep loose
clothing and other objects away from the
engine when starting it. Do not touch the

4. Open the throttle slightly without shifting
using the throttle grip, neutral throttle le­ver or free accelerator. It is necessary to
change the throttle opening slightly de­pending on the engine temperature. Af­ter the engine starts, return the throttle to
its original position.

83

Trouble Recovery

TIP:

N

ZMU03143

ON STARTOFF

ZMU03144

ZMU03335

ON

START

OFF

ZMU03145

OPEN

CLOSE

5. Turn the main switch to “ ” (on).

6. Turn the main switch to “ ” (start).

NOTICE: Never turn the main switch
to “ ” (start) while the engine is
running. Do not keep the starter mo­tor turning for more than 5 seconds. If
the starter motor is turned continu­ously for more than 5 seconds, the
battery will be quickly discharged,
thus making it impossible to start the
engine. The starter can also be dam­aged. If the engine will not start after
5 seconds of cranking, return the
main switch to “ ” (on), wait 10 sec­onds, then crank the engine again.

[ECM00192]

7. After the engine starts, close the emer­gency starter valve (if used), then return
the throttle to its original position.

When the starter mechanism malfunctions,
see page 81.

EMU33501

Treatment of submerged motor

If the outboard motor is submerged, immedi­ately take it to a Yamaha dealer. Otherwise
some corrosion may begin almost immedi­ately. NOTICE: Do not attempt to run the

outboard motor until it has been com­pletely inspected.

[ECM00401]

84

YAMAHA MOTOR CO., LTD.

Printed in Japan
April 2010–0.2  1 !

Printed on recycled paper