Yamaha 25 User Manual

Page 1
OWNER’S MANUAL
25
U.S.A.Edition
LIT-18626-06-81
6L2-28199-1P
Page 2
Read this owners manual carefully before operating your outboard motor.
ZMU01690
Page 3
Important manual information

To the owner

Thank you for choosing 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.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS INVOLVED!
EWM00780
WARNING
Failure to follow WARNING instructions could result in severe injury or death the machine operator, a bystander, or a person inspecting or repairing the out­board motor.
ECM00700
CAUTION:
A CAUTION indicates special precautions that must be taken to avoid damage to the outboard motor.
to
al, please consult your Yamaha dealer.
NOTE:
The 25MH, 25EH, 25ER 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.
25
OWNER’S MANUAL
©2005 by Yamaha Motor Corporation, USA
1st edition, June 2005
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Corporation, USA
is expressly prohibited.
Printed in Japan
P/N LIT-18626-06-81
NOTE:
A NOTE 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 there is any question concerning this manu-
Page 4

Table of contents

General information .......................... 1
Identification numbers record........... 1
Outboard motor serial number .......... 1
Key number....................................... 1
Emission control information ............ 1
North American models..................... 1
Safety information ............................ 2
Important labels................................ 3
Warning labels ..................................3
Basic boating rules
(Rules of the road) .........................4
Steering and sailing rules and
sound signals.................................. 4
Rules when encountering vessels .... 5
Other special situations..................... 6
Fueling instructions .......................... 7
Gasoline............................................ 8
Engine oil ..........................................8
Battery requirement.......................... 8
Battery specifications ........................ 8
Without a rectifier or Rectifier
Regulator ........................................ 8
Propeller selection............................ 9
Start-in-gear protection ..................10
Basic components ..........................11
Main components........................... 11
Fuel tank .........................................11
Fuel joint ......................................... 12
Fuel gauge ...................................... 12
Fuel tank cap .................................. 12
Air vent screw ................................. 12
Remote control................................ 12
Remote control lever....................... 12
Neutral interlock trigger................... 13
Neutral throttle lever........................ 13
Choke switch................................... 13
Tiller handle .................................... 13
Gear shift lever................................ 14
Throttle grip..................................... 14
Throttle indicator .............................14
Throttle friction adjuster................... 14
Engine stop lanyard switch .............15
Engine stop button .......................... 15
Choke knob for pull type .................16
Manual starter handle .....................16
Starter button ..................................16
Main switch .....................................16
Steering friction adjuster .................17
Trim tab with anode......................... 17
Trim rod (tilt pin) .............................. 17
Shallow water lever ......................... 18
Tilt lock mechanism......................... 18
Tilt support bar ................................18
Top cowling lock lever(s)
(turn type)...................................... 18
Warning indicator ............................18
Warning system ............................. 19
Overheat warning............................ 19
Operation ......................................... 20
Installation...................................... 20
Mounting the outboard motor .......... 20
Clamping the outboard motor.......... 21
Breaking in engine ......................... 22
Gasoline and engine oil mixing
chart (25:1).................................... 22
Procedure for pre-mixed models..... 22
Preoperation checks ...................... 23
Fuel .................................................23
Oil.................................................... 23
Controls........................................... 23
Engine ............................................. 23
Filling fuel and engine oil ............... 23
Filling fuel for portable tank ............. 23
Ring Free Fuel Additive................... 24
Gasoline and oil mixing (100:1)....... 24
Operating engine ........................... 25
Feeding fuel (portable tank) ............25
Starting engine ................................ 26
Warming up engine........................ 33
Choke start models .........................33
Shifting........................................... 33
Forward (tiller handle and remote
control models) .............................33
Reverse (manual tilt and hydro tilt
models) ......................................... 34
Stopping engine............................. 35
Procedure........................................ 35
Trimming outboard motor............... 36
Adjusting trim angle for manual tilt
models ..........................................36
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Table of contents
Adjusting boat trim ..........................37
Tilting up and down ........................ 38
Procedure for tilting up.................... 38
Procedure for tilting down
(manual tilt models) ...................... 39
Cruising in shallow water ...............39
Cruising in shallow water
(manual tilt models) ...................... 39
Cruising in other conditions............ 41
Maintenance..................................... 42
Specifications ................................. 42
Transporting and storing outboard
motor ............................................ 43
Clamp screw mounting models....... 43
Storing outboard motor ...................44
Procedure ....................................... 44
Lubrication
(except oil injection models) ......... 45
Cleaning and anticorrosion
measures ...................................... 45
Battery care..................................... 45
Cleaning the outboard motor .......... 46
Checking painted surface of
motor............................................. 46
Periodic maintenance..................... 46
Replacement parts.......................... 47
Maintenance chart .......................... 48
Greasing ......................................... 49
Cleaning and adjusting spark
plug ............................................... 50
Checking fuel system...................... 50
Inspecting fuel filter ......................... 51
Cleaning fuel filter ...........................51
Inspecting idling speed ................... 52
Checking wiring and connectors ..... 52
Exhaust leakage ............................. 52
Water leakage................................. 52
Checking propeller .......................... 53
Spline models ................................. 54
Spline models ................................. 54
Changing gear oil............................ 54
Cleaning fuel tank ...........................55
Inspecting and replacing
anode(s)........................................ 56
Checking battery
(for electric start models) ..............56
Connecting the battery .................... 57
Disconnecting the battery................ 58
Checking top cowling ......................58
Coating the boat bottom.................. 58
Trouble Recovery............................ 59
Troubleshooting ............................. 59
Temporary action in emergency .... 62
Impact damage ...............................62
Replacing fuse ................................62
Starter will not operate ....................63
Emergency starting engine .............63
Treatment of submerged motor ..... 65
Procedure........................................ 65
Consumer information ................... 66
Important warranty information for
U.S.A. and Canada...................... 66
YAMAHA MOTOR
CORPORATION, U.S.A. OUTBOARD MOTOR TWO
YEAR LIMITED WARRANTY ...... 68
IMPORTANT WARRANTY
INFORMATION IF YOU USE YOUR YAMAHA OUTSIDE THE
USA OR CANADA ....................... 71
Page 6

General information

Identification numbers record

Outboard motor serial number
The outboard motor serial number is stamped on the label attached to the port side of the clamp bracket or the upper part of the swivel 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
1. Key number

Emission control information

North American models
This engine conforms to U.S. Environmental Protection Agency (EPA) regulations for ma­rine SI engines. See the label affixed to your engine for details.
Approval label of emission control certif­icate
This label is attached to the bottom cowling. Existing Technology; N/A
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
1
ZMU04828
1. Approval label location
Page 7
EMISSION CONTROL INFORMATION
ENGINE FAMILY :
THIS ENGINE CONFORMS TO 2001 U.S. EPA REGULATIONS FOR MARINE SI ENGINES. REFER TO THE OWNERS MANUAL FOR MAINTENANCE SPECIFICATIONS AND ADJUSTMENTS.
g/kW-hr
FELs : SPARK PLUG :
DISPLACEMENT :
ADVERTISED POWER :
IDLE SPEED : SPARK PLUG GAP (mm) :
3
cm
FUEL : GASOLINE VALVE LASH (mm) :
kW
rpm IN NEUTRAL
IN : N/A EX : N/A
ZMU05230
Manufactured date label
This label is attached to the clamp bracket or the swivel bracket.
1
1. Manufactured date label location
ZMU04125

Safety information

Before mounting or operating the outboard motor, read this entire manual. Reading it
General information
should give you an understanding of the motor and its operation. Before operating the boat, read any own-
er’s or operator’s manuals supplied with it and all labels. Be sure you understand each item before operating.
Do not overpower the boat with this out­board motor. Overpowering the boat could result in loss of control. The rated power of the outboard should be equal to or less than the rated horsepower capacity of the boat. If the rated horsepower capacity of the boat is unknown, consult the dealer or boat manufacturer. Do not modify the outboard. Modifications
could make the motor unfit or unsafe to use. Incorrect propeller selection and incorrect
use may not only cause engine damage, but also adversely affect fuel consumption. Consult your dealer for correct use.
Never operate after drinking alcohol or tak­ing drugs. About 50% of all boating fatali­ties involve intoxication.
Have an approved personal flotation de­vice (PFD) on board for every occupant. It is a good idea to wear a PFD whenever boating. At a minimum, children and non­swimmers should always wear PFDs, and everyone should wear PFDs when there are potentially hazardous boating condi­tions. Gasoline is highly flammable, and its va-
pors are flammable and explosive. Handle and store gasoline carefully. Make sure there are no gas fumes or leaking fuel be­fore starting the engine.
This product emits exhaust gases which contain carbon monoxide, a colorless, odorless gas which may cause brain dam­age or death when inhaled. Symptoms in-
2
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General information
clude nausea, dizziness, and drowsiness. Keep cockpit and cabin areas well ventilat­ed. Avoid blocking exhaust outlets.
Check throttle, shift, and steering for prop­er operation before starting the engine. Attach the engine stop switch lanyard cord
to a secure place on your clothing, or your arm or leg while operating. If you acciden­tally leave the helm, the cord will pull from the switch, stopping the engine.
Know the marine laws and regulations where you will be boatingand obey them. For basic boating rules, see “Rules of the road on page 4. Stay informed about the weather. Check
weather forecasts before boating. Avoid boating in hazardous weather. Tell someone where you are going: leave
a Float Plan with a responsible person. Be sure to cancel the Float Plan when you re­turn.
Use common sense and good judgment when boating. Know your abilities, and be sure you understand how your boat han­dles under the different boating conditions you may encounter. Operate within your limits, and the limits of your boat. Always operate at safe speeds, and keep a careful watch for obstacles and other traffic. Always watch carefully for swimmers dur-
ing the engine operation.
Stay away from swimming areas. When a swimmer is in the water near you
shift into neutral and shut off the engine.
Do not illegally discard empty containers used to replace or replenish oil. For the correct processing of empty containers, consult the dealer where you purchased the oil.
When replacing oils used to lubricate the product (engine or gear oil), be sure to
wipe away any spilt oil. Never pour oil with­out using a funnel or similar device. If nec­essary, verify the necessary replacement procedure with the dealer.
Never illegally discard (dump) the product. Yamaha recommends consulting the deal-
er on discarding the product. Be informed about boating safety. Additional publications and information can be obtained from many organizations, including the fol­lowing:
United States Coast Guard
Consumer Affairs Staff (G-BC) Office of Boating, Public, and Consumer Af­fairs U.S. Coast Guard Headquarters Washington, D.C. 20593-0001 Boating Safety Hotline: 1-800-368-5647
National Marine Manufacturers Associa­tion (NMMA)
401 N. Michigan Ave. Chicago, Il 60611
Marine Retailers Association of America
155 N. Michigan Ave. Chicago, Il 60601
Important labels
Warning labels
ZMU04780
3
Page 9
ZMU03684
Label
EWM01260
WARNING
Be sure shift control is in neutral before starting engine. (except 2HP) Do not touch or remove electrical parts
when starting or during operation.
Keep hands, hair, and clothes away from flywheel and other rotating parts while engine is running.
Label
EWM01300
WARNING
This engine is equipped with a neutral starting device. The engine will not start unless the shift
control is in neutral position.
Basic boating rules (Rules of
the road)
Just as there are rules which apply when you are driving on streets and high ways, there are waterway rules which apply when you are driving your boat. These rules are used internationally, and are also enforced by the United States Coast Guard and local agen­cies. You should be aware of these rules, and follow them whenever you encounter another vessel on the water.
General information
Several sets of rules prevail according to geographic location, but are all basically the same as the International Rules of the Road. The rules presented here in your Owner’s Manual are condensed, and have been pro­vided for your convenience only. Consult your local U.S. Coast Guard Auxiliary or De­partment of Motor Vehicles for a complete set of rules governing the waters in which you will be using your boat.
Steering and sailing rules and sound signals
Whenever two vessels on the water meet one another, one vessel has the right-of­way; it is called the “stand-on” vessel. The vessel which does not have the right-of-way is called the “give-way” or “burdened” vessel. These rules determine which vessel has the right-of-way, and what each vessel should do.
Stand-on vessel
The vessel with the right-of-way has the duty to continue its course and speed, except to avoid an immediate collision. When you maintain your direction and speed, the other vessel will be able to determine how best to avoid you.
Give-way vessel
The vessel which does not have the right-of­way has the duty to take positive and timely action to stay out of the way of the Stand-On vessel. Normally, you should not cross in front of the vessel with the right-of-way. You should slow down or change directions brief­ly and pass behind the other vessel. You should always move in such a way that the operator of the other vessel can see what you are doing.
The general prudential rule
This rule is called Rule 2 in the International Rules and says,
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General information
In obeying and construing these rules due regard shall be had to all dangers of naviga­tion and collision, and to any special circum­stances, which may render a departure from the above rules necessary in order to avoid immediate danger. In other words, follow the standard rules ex­cept when a collision will occur unless both vessels try to avoid each other. If that is the case, both vessels become “Give-Way” ves­sels.
Rules when encountering vessels
There are three main situations which you may encounter with other vessels which could lead to a collision unless the Steering Rules are followed:
Meeting:
sel head-on)
Crossing:
er vessels path)
Overtaking:
passed by another vessel) In the following illustration, your boat is in the center. You should give the right-of-way to any vessels shown in white area (you are the Give-Way vessel). Any vessels in the shad­ed area must yield to you (they are the Give­Way vessels). Both you and the meeting vessel must alter course to avoid each other.
(you are approaching another ves-
(you are traveling across the oth-
(you are passing or being
Meeting
If you are meeting another power vessel head on, and are close enough to run the risk of collision, neither of you has the right-of­way! Both of you should alter course to avoid an accident. You should keep the other ves­sel on your port (left) side. This rule doesn’t apply if both of you will clear one another if you continue on your set course and speed.
Crossing
When two power driven vessels are crossing each others path close enough to run the risk of collision, the vessel which has the oth­er on the starboard (right) side must keep out of the way of the other. If the other vessel is on your right, you must keep out of its way; you are the Give-Way vessel. If the other vessel is on your port (left) side, remember that you should maintain course and direc­tion, provided the other vessel gives you the right-of-way as it should.
5
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General information
Overtaking
If you are passing another vessel, you are the Give-Way vessel. This means that the other vessel is expected to maintain its course and speed. You must stay out of its way until you are clear of it. Likewise, if an­other vessel is passing you, you should maintain your speed and direction so that the other vessel can steer itself around you.
Other special situations
There are three other rules you should be aware of when driving your boat around oth­er vessels.
Narrow channels and bends
When navigating in narrow channels, you should keep to the right when it is safe and practical to do so. If the operator of a power­driven vessel is preparing to go around a bend that may obstruct the view of other wa­ter vessels, the operator should sound a pro­longed blast on the whistle (4 to 6 seconds). If another vessel is around the bend, it too should sound the whistle. Even if no reply is heard, however, the vessel should still pro­ceed around the bend with caution. If you navigate such waters with your boat, you will need to carry a portable air horn, available from local marine supply stores.
Fishing vessel right-of-way
All vessels which are fishing with nets, lines or trawls are considered to be fishing ves­sels under the International Rules. Vessels with trolling lines are not considered fishing vessels. Fishing vessels have the right-of­way regardless of position. Fishing vessels cannot, however, impede the passage of other vessels in narrow channels.
Sailing vessel right-of-way
Sailing vessels should normally be given the right-of-way. The exceptions to this are:
1. When the sailing vessel is overtaking
the power-driven vessel, the power-driv­en vessel has the right-of-way.
2. Sailing vessels should keep clear of any
fishing vessel.
3. In a narrow channel, a sailing vessel
should not hamper the safe passage of a power-driven vessel which can navi­gate only in such a channel.
Reading buoys and other markers
The waters of the United states are marked for safe navigation by the lateral system of buoyage. Simply put, buoys and markers have an arrangement of shapes, colors, numbers and lights to show which side of the buoy a boater should pass on when navigat­ing in a particular direction. The markings on these buoys are oriented from the perspec­tive of being entered from seaward (the boat­er is going towards the port). This means that red buoys are passed on the starboard (right) side when proceeding from open wa­ter into port, and black buoys are to port (left) side. When navigating out of port, your posi­tion with respect to the buoys should be re­versed; red buoys should be to port and black buoys to starboard. Many bodies of water used by boaters are entirely within the boundaries of a particular state. The Uniform State Waterway Marking System has been devised for these waters. This system uses buoys and signs with dis­tinctive shapes and colors to show regulato­ry or advisory information. These markers are white with black letters and orange boarders. They signify speed zones, restrict­ed areas, danger areas, and general infor­mation. Remember, markings may vary by geo­graphic location. Always consult local boat­ing authorities before driving your boat in unfamiliar waters.
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General information

Fueling instructions

EWM00010
WARNING
GASOLINE AND ITS VAPORS ARE HIGH­LY FLAMMABLE AND EXPLOSIVE!
Do not smoke when refueling, and keep
7
ZMU01708
away from sparks, flames, or other
sources of ignition.
Stop engine before refueling.
Refuel in a well-ventilated area. Refuel
portable fuel tanks off the boat.
Take care not to spill gasoline. If gaso-
line spills, wipe it up immediately with
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General information
dry rags.
Do not overfill the fuel tank. Tighten the filler cap securely after re-
fueling.
If you should swallow some gasoline, inhale a lot of gasoline vapor, or get gasoline in your eyes, get immediate medical attention. If any gasoline spills onto your skin, im-
mediately wash with soap and water. Change clothing if gasoline spills on it. Touch the fuel nozzle to the filler open-
ing or funnel to help prevent electro­static sparks.
ECM00010
CAUTION:
Use only new clean gasoline which has been stored in clean containers and is not contaminated with water or foreign mat­ter.
Gasoline
If knocking or pinging occurs, use a different brand of gasoline or premium unleaded fuel.
Recommended gasoline:
Regular unleaded gasoline with a min­imum octane rating of 86 (Pump Oc­tane Number) = (R+M)/2
Gasohol
There are two types of gasohol: gasohol con­taining ethanol and that containing metha­nol. Gasohol containing ethanol can be used if ethanol content does not exceed 10% and the fuel meets minimum octane ratings. Yamaha does not recommended gasohol containing methanol because it can cause fuel system damage or engine performance problems.
Engine oil
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.

Battery requirement

ECM01060
CAUTION:
Do not use a battery that does not meet the specified capacity. If a battery which does not meet specifications is used, the electric system could perform poorly or be overloaded, causing electric system damage.
For electric start models, choose a battery which meets the following specifications.
Battery specifications
Minimum cold cranking amps (CCA/ SAE):
25EH 245.0 A
25ER 245.0 A Minimum marine cranking amps (MCA/ ABYC):
25EH 323.0 A
25ER 323.0 A Minimum reserve capacity (RC/SAE):
25EH 52 minutes
25ER 52 minutes
Without a rectifier or Rectifier Regulator
ECM01090
CAUTION:
A battery cannot be connected to models
8
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General information
that do not have a rectifier or Rectifier Regulator.
If you wish to use a battery with the models without a rectifier or Rectifier Regulator, in­stall an optional Rectifier Regulator. Using a maintenance-free battery with the above models can shorten the life of the bat­tery significantly. Install an optional Rectifier Regulator or use accessories rated to withstand 18 volts or higher with the above models. Consult your Yamaha dealer for details on installing an optional Rectifier Regulator.

Propeller selection

The performance of your outboard motor will be critically affected by your choice of propel­ler, as an incorrect choice could adversely affect performance and could also seriously damage the motor. Engine speed depends on the propeller size and boat load. If engine speed is too high or too low for good engine performance, this will have an adverse effect on the engine. Yamaha outboard motors are fitted with pro­pellers chosen to perform well over a range of applications, but there may be uses where a propeller with a different pitch would be more appropriate. For a greater operating load, a smaller-pitch propeller is more suit­able as it enables the correct engine speed to be maintained. Conversely, a larger-pitch propeller is more suitable for a smaller oper­ating load. Yamaha dealers stock a range of propellers, and can advise you and install a propeller on your outboard that is best suited to your ap­plication.
x
-
123
ZMU04605
1. Propeller diameter in inches
2. Propeller pitch in inches
3. Type of propeller (propeller mark)
x
-
123
ZMU04604
1. Propeller diameter in inches
2. Propeller pitch in inches
3. Type of propeller (propeller mark)
NOTE:
Select a propeller which will allow the engine to reach the middle or upper half of the oper­ating range at full throttle with the maximum boat load. If operating conditions such as light boat loads then allow the engine r/min to rise above the maximum recommended range, reduce the throttle setting to maintain the engine in the proper operating range.
For instructions on propeller removal and in­stallation, see page 53.
9
Page 15

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.
General information
10
Page 16

Basic components

Main components

NOTE:
* May not be exactly as shown; also may not be included as standard equipment on all mod­els.
25
19
18 17 16
11
15 14
13
1. Manual starter handle*
2. Choke knob
3. Warning indicator
4. Starter button*
5. Gear shift lever*
6. Tiller handle*
7. Throttle friction adjuster*
8. Engine stop button/Engine stop lanyard switch*
9. Transom clamp handle
10. Tilt lock lever
11. Trim rod
12. Cooling water inlet
13. Propeller
14. Trim tab (anode)
1 2 3 4 5
6 7
8
1
2 3
9
9
20
10
12
15. Anti-cavitation plate
16. Clamp bracket
17. Rope attachment
18. Shallow water lever
19. Top cowling
20. Remote control box (side mount type)*
21. Fuel tank*

Fuel tank

If your model was equipped with a portable
21
ZMU04829
11
Page 17
Basic components
fuel tank, its function is as follows.
EWM00020
WARNING
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.
13
1. Fuel joint
2. Fuel gauge
3. Fuel tank cap
4. Air vent screw
42
ZMU03157
Fuel joint
This joint is used to connect the fuel line.
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.
Fuel tank cap
This cap seals the fuel tank. When removed, the tank can be filled with fuel. To remove the cap, turn it counterclockwise.
Air vent screw
This screw is on the fuel tank cap. To loosen the screw, turn it counterclockwise.

Remote control

The remote control lever actuates both the shifter and the throttle. The electrical switch­es are mounted on the remote control box.
1. Remote control lever
2. Neutral interlock trigger
3. Neutral throttle lever
4. Main switch / choke switch
5. Engine stop lanyard switch
6. Throttle friction adjuster
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.
1. Neutral “”
12
Page 18
Basic components
2. Forward “”
3. Reverse “”
4. Shift
5. Fully closed
6. Throttle
7. Fully open
Neutral interlock trigger
To shift out of neutral, first pull the neutral in­terlock trigger up.
1. Neutral interlock trigger
1. Fully open
2. Fully closed

Choke switch

To activate the choke system, press in the main switch while the key is turned to the “” (on) or “” (start) position. The choke system will then supply the rich fuel mixture required to start the engine. When the key is released, the choke will switch off automatically.
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.
NOTE:
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.
13
Tiller handle
To change direction, move the tiller handle to the left or right as necessary.
Page 19
Basic components
ZMU02846

Gear shift lever

Pulling the gear shift lever towards you puts the engine in forward gear so that the boat moves ahead. Pushing the lever away from you puts the engine in reverse gear so that the boat moves astern.
R
3
N
2
F 1
ZMU03687
1. Forward “”
2. Neutral “”
3. Reverse “”

Throttle grip

The throttle grip is on the tiller handle. Turn the grip counterclockwise to increase speed and clockwise to decrease speed.
ZMU02848
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
ZMU02849
1. Throttle indicator
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.
EWM00030
WARNING
Do not overtighten the friction adjuster. If
14
Page 20
Basic components
there is too much resistance, it could be difficult to move throttle lever or grip, which could result in an accident.
ZMU03688
When constant speed is desired, tighten the adjuster to maintain the desired throttle set­ting.

Engine stop lanyard switch

The lock plate must be attached to the en­gine stop switch for the engine to run. The lanyard should be attached to a secure place on the operators clothing, or arm or leg. Should the operator fall overboard or leave the helm, the lanyard will pull out the lock plate, stopping ignition to the engine. This will prevent the boat from running away un­der power.
EWM00120
WARNING
Attach the engine stop switch lanyard
to a secure place on your clothing, or your arm or leg while operating. Do not attach the lanyard to clothing
that could tear loose. Do not route the lanyard where it could become entan­gled, preventing it from functioning.
Avoid accidentally pulling the lanyard 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.
NOTE:
The engine cannot be started with the lock plate removed.
1. Lanyard
2. Lock plate
2
1
ZMU03689
1. Lanyard
2. Lock plate
Engine stop button
To open the ignition circuit and stop the en­gine, push this button.
15
Page 21
ZMU03690

Choke knob for pull type

To supply the engine with the rich fuel mix­ture required to start, pull out this knob.
ZMU04127
Manual starter handle
To start the engine, first gently pull the han­dle out until resistance is felt. From that posi­tion, then pull the handle straight out quickly to crank the engine.
Basic components
Starter button
To start the engine with the electric starter, push the starter button.
ZMU04856

Main switch

The main switch controls the ignition system; its operation is described below.
“”
(off)
With the main switch in the “” (off) posi- tion, the electrical circuits are off, and the key can be removed.
“”
(on)
With the main switch in the “” (on) posi- tion, the electrical circuits are on, and the key cannot be removed.
“”
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.
(start)
16
Page 22
Basic components
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.
ZMU02908
To increase resistance, turn the adjuster clockwise. To decrease resistance, turn the adjuster counterclockwise.
EWM00040
WARNING
Do not overtighten the friction adjuster. If there is too much resistance, it could be difficult to steer, which could result in an accident.
Trim tab with anode
The trim tab should be adjusted so that the steering control can be turned to either the right or left by applying the same amount of force.
EWM00840
WARNING
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.
If the boat tends to veer the left (port side), turn the trim tab rear end to the port side “A” in the figure. If the boat tends to veer the right (starboard side), turn the trim tab end to the starboard side B in the figure.
ECM00840
CAUTION:
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
A
B
2
ZMU02822
1. Trim tab
2. Bolt
Trim rod (tilt pin)
The position of the trim rod determines the minimum trim angle of the outboard motor in relation to the transom.
ZMU02929
17
Page 23
Shallow water lever
Lifting this lever will tilt the motor up partially to provide more clearance when operating in shallow water.
ZMU04111
Tilt lock mechanism
The tilt lock mechanism is used to prevent the outboard motor from lifting out of the wa­ter when in reverse gear.
Basic components
ZMU03699
Top cowling lock lever(s) (turn type)
To remove the engine top cowling, turn the 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 lever(s) to the lock position.
1
ZMU03695
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.
Tilt support bar
The tilt support bar keeps the outboard motor in the tilted up position.
1
1. Top cowling lock lever(s)
ZMU03701
Warning indicator
If the engine develops a condition which is cause for warning, the indicator lights up. For details on how to read the warning indicator, see page 19.
18
Page 24
Basic components
ZMU03703

Warning system

ECM00090
CAUTION:
Do not continue to operate the engine if a warning device has activated. Consult your Yamaha dealer if the problem can­not be located and corrected.

Overheat warning

This engine has an overheat warning device. If the engine temperature rises too high, the warning device will activate.
Activation of warning device
The engine speed will automatically de-
crease to about 2000 r/min.
If equipped with an overheat warning indi­cator, it will light.
If the warning system has activated, stop the engine and check the cooling water inlet for clogging.
ZMU03706
The buzzer will sound (if equipped on the tiller handle, remote control box, or main switch panel).
19
Page 25

Operation

Installation

ECM00110
CAUTION:
Incorrect engine height or obstructions to smooth water flow (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. Severe engine damage may result if the motor is operated continuously in the presence of airborne water spray.
NOTE:
During water testing check the buoyancy of the boat, at rest, with its maximum load. Check that the static water level on the ex­haust housing is low enough to prevent wa­ter entry into the powerhead, when water rises due to waves when the outboard is not running.
Mounting the outboard motor
EWM00820
WARNING
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.
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.
EWM00830
WARNING
Improper mounting of the outboard mo­tor could result in hazardous conditions such as poor handling, loss of control, or fire hazards. Observe the following:
For permanently mounted models, your dealer or other person experienced in proper rigging should mount the motor. If you are mounting the motor yourself, you should be trained by an experi­enced person.
For portable models, your dealer or oth­er person experienced in proper out­board motor mounting should show you how to mount your motor.
Mount the outboard motor on the center line (keel line) of the boat, and ensure that the boat itself is well balanced. Otherwise the boat will be hard to steer. For boats without a keel or which are asymmetrical, consult your dealer.
1
1. Center line (keel line)
Mounting height
To run your boat at optimum efficiency, the water resistance (drag) of the boat and out­board motor must be made as little as possi­ble. The mounting height of the outboard
ZMU01760
20
Page 26
Operation
motor greatly affects the water resistance. If the mounting height is too high, cavitation tends to occur, thus reducing the propulsion; and if the propeller tips cut the air, the engine speed will rise abnormally and cause the en­gine to overheat. If the mounting height is too low, the water resistance will increase and thereby reduce engine efficiency. Mount the outboard motor so that the anti-cavitation plate is between the bottom of the boat and a level 25 mm (1 in.) below it.
0–25mm (0–1in.)
ZMU02011
NOTE:
The optimum mounting height of the out-
board motor is affected by the boat and 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.
For instructions on setting the trim angle of the outboard motor, see page 36.
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 be-
come loose due to engine vibration.
EWM00640
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 tran­som screws are tightened securely. Oc­casionally check the screws for tightness during operation.
ZMU02012
2. If the engine restraint cable attachment is equipped on your engine, an engine restraint cable or chain should be used. Attach one end to the engine 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.
ZMU02013
3. Secure the clamp bracket to the transom using the bolts provided with the out-
21
Page 27
Operation
board (if packed). For details, consult your Yamaha dealer.
EWM00650
WARNING
Avoid using bolts, nuts or washers other than those contained in the engine pack­aging. If used, they must be of at least the same quality of material and strength and must be tightened securely. After tighten­ing, test run the engine and check their tightness.
1
ZMU02637
1. Bolts

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.
ECM00800
CAUTION:
Failure to follow the break-in procedure could result in reduced engine life or even severe engine damage.
Gasoline and engine oil mixing chart (25:1)
1. : Gasoline
2. : Engine oil
ECM00150
CAUTION:
Be sure to mix gasoline and oil complete­ly, otherwise the engine may be dam­aged.
Procedure for pre-mixed models
Run the engine under load (in gear with a propeller installed) 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. Second hour: 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
22
Page 28
Operation
cool.
4. Third through tenth hours: Avoid operating at full throttle for more than 5 minutes at a time. Let the engine cool between full-throttle runs. Vary en­gine speed occasionally.
5. After the first 10 hours: Operate the engine normally. Use the standard premix ratio of gasoline and oil. For details on mixing fuel and oil, see page 23.
Preoperation checks
EWM00080
WARNING
If any item in the preoperation check is not working properly, have it inspected and repaired before operating the out­board motor. Otherwise an accident could occur.
ECM00120
CAUTION:
Do not start the engine out of water. Over­heating and serious engine damage can occur.
Fuel
Check to be sure you have plenty of fuel
for your trip.
Make sure there are no fuel leaks or gaso­line fumes. Check fuel line connections to be sure they
are tight (if equipped Yamaha fuel tank or boat tank). Be sure the fuel tank is positioned on a se-
cure, flat surface, and that the fuel line is not twisted or flattened, or likely to contact sharp objects (if equipped Yamaha fuel tank or boat tank).
Oil
Check to be sure you have plenty of oil for your trip.
Controls
Check throttle, shift, and steering for prop­er operation before starting the engine.
The controls should work smoothly, with­out binding or unusual free play. Look for loose or damaged connections.
Check operation of the starter and stop switches when the outboard motor is in the water.
Engine
Check the engine and engine mounting.
Look for loose or damaged fasteners.
Check the propeller for damage.

Filling fuel and engine oil

Filling fuel for portable tank
EWM00060
WARNING
Gasoline and its vapors are highly flam­mable and explosive. Keep away from sparks, cigarettes, flames, or other sources of ignition.
1. Remove the fuel tank cap.
2. Fill the fuel tank carefully.
3. Close the cap securely after refueling. Wipe up any spilled fuel.
Fuel tank capacity (if equipped Yamaha fuel tank):
25 L (6.60 US gal) (5.50 Imp.gal)
23
Page 29
ZMU03012
Ring Free Fuel Additive
Gasoline is a precise blend of many different substances, each chosen to give certain characteristics. Gasoline blends have been changing in recent years in response to con­cerns about pollution and resulting emis­sions regulations. One of the most obvious changes has been the elimination of lead from most fuels. As gasoline has changed, the amount of ad­ditives such as aromatics and oxygenates has increased. These additives are impor­tant for the engines in passenger cars, but they can have detrimental effects in marine engines, because of increased deposits in the combustion chamber. When enough de­posits collect, piston rings begin sticking. Performance drops and engine wear in­creases dramatically. While many additives available may reduce deposits, Yamaha recommends the use of
Ring Free Fuel Additive
your Yamaha dealer.
tive
has repeatedly proven its ability to clean combustion deposits from inside the engine, notably the critical piston-ring-land area, and fuel system components. Follow product la­beling for use instructions.
, available from
Ring Free Fuel Addi-
Operation
Gasoline and oil mixing (100:1)
Gasoline to engine
oil ratio
Break-in period See page 22
After break-in 100:1
If equipped with a portable fuel tank
1. Pour oil into the portable fuel tank, and then add gasoline.
1. Engine oil
2. Gasoline
2. Replace the fuel tank cap and close tightly.
3. Shake the fuel tank to mix the fuel thor­oughly.
4. Make sure that the oil and gasoline are mixed.
If equipped with a built-in fuel tank
1. Pour oil into a clean fuel can, and then add gasoline.
24
Page 30
Operation
2. Replace the fuel can cap and close tight­ly.
3. Shake the fuel can to mix the fuel thor­oughly.
4. Make sure that the oil and gasoline are mixed.
5. Pour the gasoline and oil mixture into the built-in fuel tank.
ECM00810
CAUTION:
Avoid using any oil other than the spec­ified type.
Use a thoroughly blended fuel-oil mix­ture.
If the mixture is not thoroughly mixed, or if the mixing ratio is incorrect, the following problems could occur. Low oil ratio: Lack of oil could cause major engine trouble, such as piston seizure.
High oil ratio: Too much oil could cause fouled spark plugs, smoky exhaust, and heavy carbon deposits.
NOTE:
If using a permanently installed tank, pour the oil gradually as the gasoline is being add­ed to the tank.

Operating engine

Feeding fuel (portable tank)
EWM00420
WARNING
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.
1. If there is an air vent screw on the fuel tank cap, loosen it 2 or 3 turns.
ZMU02022
2. If there is a fuel joint on the motor, firmly connect the fuel line to the joint. Then firmly connect the other end of the fuel line to the joint on the fuel tank.
ZMU04113
25
Page 31
Operation
N
ZMU02024
3. If a steering friction adjuster is provided on your outboard motor, securely attach the fuel line to the fuel line clamp.
NOTE:
During engine operation place the tank hori­zontally, otherwise fuel cannot be drawn from the fuel tank.
4. Squeeze the primer pump with the outlet end up until you feel it become firm.
ZMU02025
Starting engine
Manual start models (tiller control)
1. Place the gear shift lever in neutral.
ZMU03714
NOTE:
The start-in-gear protection device prevents the engine from starting except when in neu­tral.
2. Attach the engine stop switch lanyard to a secure place on your clothing, or your arm or leg. Then install the lock plate on the other end of the lanyard into the en­gine stop switch.
EWM00120
WARNING
Attach the engine stop switch lanyard to a secure place on your clothing, or your arm or leg while operating.
Do not attach the lanyard to clothing that could tear loose. Do not route the lanyard where it could become entan­gled, preventing it from functioning. Avoid accidentally pulling the lanyard
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.
26
Page 32
Operation
5. Pull the manual starter handle slowly un-
ZMU03744
3. Place the throttle grip in the “” (start) position.
6. After the engine starts, slowly return the
7. Slowly return the throttle grip to the fully
ZMU02954
the engine will run poorly or stall.
til you feel resistance. Then give a strong pull straight out to crank and start the engine. Repeat if necessary.
manual starter handle to its original po­sition before releasing it.
closed position.
4. Pull out / turn the choke knob fully. After the engine starts, replace / return the knob to the home position.
ZMU04114
NOTE:
It is not necessary to use the choke when
starting a warm engine. If the choke knob is left in the “”
(start) position while the engine is running,
27
ZMU02030
NOTE:
When the engine is cold, it needs to be warmed up. For further information, see page 33.
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
Page 33
amount and try to start the engine again. If the engine still fails to start, see page 59.
Electric start models
1. Place the gear shift lever in neutral.
N
ZMU03714
NOTE:
The start-in-gear protection device prevents the engine from starting except when in neu­tral.
2. Attach the engine stop switch lanyard to a secure place on your clothing, or your arm or leg. Then install the lock plate on the other end of the lanyard into the en­gine stop switch.
EWM00120
WARNING
Attach the engine stop switch lanyard to a secure place on your clothing, or your arm or leg while operating.
Do not attach the lanyard to clothing that could tear loose. Do not route the lanyard where it could become entan­gled, preventing it from functioning.
Avoid accidentally pulling the lanyard 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.
Operation
ZMU03744
3. Place the throttle grip in the “” (start) position. After the engine starts, return the throttle to the fully closed po­sition.
ZMU02959
4. Pull out / turn the choke knob fully. After the engine starts, replace / return the knob to the home position.
ZMU04116
NOTE:
It is not necessary to use the choke when
starting a warm engine.
28
Page 34
Operation
If the choke knob is left in the “” (start) position while the engine is running, the engine will run poorly or stall.
5. Push the starter button to start the mo­tor. (Repeat if necessary.)
ZMU04856
6. Immediately after the engine starts, re­lease the starter button to allow it to re­turn to its original position.
7. Slowly return the throttle grip to the fully closed position so that the engine does not stall.
ECM00160
CAUTION:
Never push the starter button 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, release the starter button, wait 10 sec­onds, then crank the engine again.
ZMU02962
NOTE:
When the engine is cold, it needs to be
warmed up. For further information, see page 33. 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 amount and try to start the engine again. If the engine still fails to start, see page 59.
Manual start models (remote control)
1. Place the remote control lever in neutral.
N
ZMU03087
NOTE:
The start-in-gear protection device prevents the engine from starting except when in neu­tral.
29
2. Attach the engine stop switch lanyard to
Page 35
a secure place on your clothing, or your arm or leg. Then install the lock plate on the other end of the lanyard into the en­gine stop switch.
EWM00120
WARNING
Attach the engine stop switch lanyard
to a secure place on your clothing, or your arm or leg while operating. Do not attach the lanyard to clothing
that could tear loose. Do not route the lanyard where it could become entan­gled, preventing it from functioning.
Avoid accidentally pulling the lanyard 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.
Operation
N
ZMU03200
NOTE:
As a starting point, lift the lever just until you feel resistance, then lift slightly more.
The neutral throttle lever can only be used when the remote control lever is in neutral.
4. Pull out / turn the choke knob fully. After the engine starts, replace / return the knob to the home position.
ZMU03088
3. Open the throttle slightly without shifting using the neutral throttle lever. You may need to change the throttle opening slightly depending on engine tempera­ture. After the engine starts, return the throttle to the original position.
ZMU03717
NOTE:
It is not necessary to use the choke when starting a warm engine.
If the choke knob is left in the “” (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.
30
Page 36
Operation
ZMU03008
6. After the engine starts, slowly return the manual starter handle to its original po­sition before releasing it.
NOTE:
When the engine is cold, it needs to be warmed up. For further information, see page 33.
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 and try again. Also if the en­gine is warm and fails to start, open the throttle a small amount and try to start the engine again. If the engine still fails to start, see page 59.
Electric start / remote control models
1. Place the remote control lever in neutral.
the engine from starting except when in neu­tral.
2. Attach the engine stop switch lanyard to a secure place on your clothing, or your arm or leg. Then install the lock plate on the other end of the lanyard into the en­gine stop switch.
EWM00120
WARNING
Attach the engine stop switch lanyard to a secure place on your clothing, or your arm or leg while operating.
Do not attach the lanyard to clothing that could tear loose. Do not route the lanyard where it could become entan­gled, preventing it from functioning. Avoid accidentally pulling the lanyard
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.
NOTE:
The start-in-gear protection device prevents
31
3. Turn the main switch to “” (on).
Page 37
OFF
ON
pressed in.
Operation
ON
STARTOFF
ZMU01880
4. Open the throttle slightly without shifting using the neutral throttle lever or free ac­celerator. You may need to change the throttle opening slightly depending on engine temperature. After the engine starts, return the throttle to the original position.
N
ZMU02314
NOTE:
On remote controls equipped with a neu­tral throttle lever, a good starting point is to lift the lever just until you feel resistance, then lift slightly more.
The neutral throttle lever or free accelera­tor can only be used when the remote con­trol lever is in neutral.
5. Press in and hold the main switch to op­erate the remote choke system. The re­mote choke switch automatically returns to its normal position when you release your hand. Therefore keep the switch
ZMU02315
NOTE:
It is not necessary to use the choke when starting a warm engine. Push in the main switch fully, or the remote
choke system will not operate.
6. Turn the main switch to “” (start), and hold it for a maximum of 5 seconds.
ON
STARTOFF
ZMU03753
7. Immediately after the engine starts, re­lease the main switch and allow it to re­turn to “” (on).
ECM00191
CAUTION:
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 im-
32
Page 38
Operation
possible 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.

Warming up engine

Choke start models
1. 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.
2. Check for a steady flow of water from the cooling water pilot hole.
ECM00511
CAUTION:
A continuous flow of water from the cool­ing water pilot hole shows that the water pump is pumping water through the cool­ing passages. If water is not flowing out of the 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.

Shifting

EWM00180
WARNING
Before shifting, make sure there are no swimmers or obstacles in the water near you.
ECM00220
CAUTION:
To change the boat direction or shifting position from forward to reverse or vice­versa, first close the throttle so that the engine idles (or runs at low speeds).
Forward (tiller handle and remote control models)
Tiller control models
1. Place the throttle grip in the fully closed position.
ZMU02030
2. Move the gear shift lever quickly and firmly from neutral to forward.
33
ZMU02856
Page 39
Operation
N
F
ZMU03718
Remote control models
1. Pull up the neutral interlock trigger (if equipped) and move the remote control lever quickly and firmly from neutral to forward.
Reverse (manual tilt and hydro tilt models)
EWM00190
WARNING
When operating in reverse, go slowly. Do not open the throttle more than half. Oth­erwise the boat could become unstable, which could result in loss of control and an accident.
ZMU02030
2. On models equipped with a tilt lock le­ver, check that it is in the lock/down po­sition.
ZMU03719
3. Move the gear shift lever quickly and firmly from neutral to reverse.
R
N
ZMU03720
Tiller control models
1. Place the throttle grip in the fully closed position.
Remote control models
1. Check that the tilt lock lever is in the lock position.
34
Page 40
Operation
ZMU03721
2. Pull up the neutral interlock trigger (if equipped) and move the remote control lever quickly and firmly from neutral to reverse.

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.
Procedure
1. Push and hold the engine stop button or turn the main switch to “” (off).
ZMU03690
2. After stopping the engine, disconnect the fuel line if there is a fuel joint on the outboard motor.
ZMU04121
3. Tighten the air vent screw on the fuel tank cap (if equipped).
35
Page 41
ZMU02041
4. Remove the key if the boat will be left unattended.
NOTE:
The engine can also be stopped by pulling the lanyard and removing the lock plate from the engine stop switch, then turning the main switch to “” (off).

Trimming outboard motor

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.
EWM00740
WARNING
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 to steer, slow down and/or readjust the trim angle.
Operation
1
ZMU02858
1. Trim operating angle
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. Remove the trim rod from the clamp bracket while slightly tilting the outboard motor up.
36
Page 42
Operation
1
ZMU02909
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
WARNING
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 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. The trim tab can also be adjusted to help offset this effect. When the bow of the boat is down, it is easier to accelerate from a standing start onto plane.
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 “por- poise (hop in the water), which could throw the operator and passengers overboard.
NOTE:
The outboard motor trim angle can be changed approximately 4 degrees by shifting the trim rod one hole.
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
37
Bow Down
Too much trim-in causes the boat to “plow” through the water, decreasing fuel economy
Page 43
Operation
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.
NOTE:
Depending on the type of boat, the outboard motor trim angle may have little effect on the trim of the boat when operating.

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 casing from damage by colli­sion with obstructions, and also to reduce salt corrosion.
EWM00220
WARNING
Be sure all people are clear of the out­board motor when tilting up and down, also be careful not to pinch any body parts between the drive unit and engine bracket.
EWM00250
WARNING
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
CAUTION:
Before tilting the outboard motor, stop the engine by following the procedure on page 35. 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.
Procedure for tilting up
Manual tilt models
1. Place the gear shift lever in neutral.
N
ZMU03724
2. Disconnect the fuel line if a fuel joint is provided on the outboard motor.
38
Page 44
Operation
ZMU03725
3. Place the tilt lock lever in the release po­sition.
ZMU03726
4. 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.
Procedure for tilting down (manual tilt models)
1. Place the tilt lock lever in the release/ down position or return the shallow wa­ter lever to its original position.
ZMU03747
ZMU03731
2. Slightly tilt the engine up until the tilt sup­port bar is automatically released.
3. Slowly tilt the engine down.

Cruising in shallow water

The outboard motor can be tilted up partially to allow operation in shallow water.
Cruising in shallow water (manual tilt models)
EWM00710
WARNING
Place the gear shift in neutral before us­ing the shallow water cruising system.
Run the boat at the lowest possible speed when using the shallow water cruising system. The tilt lock mecha­nism does not work while the shallow water cruising system is being used. Hitting an underwater obstacle could cause the outboard motor to lift out of
39
Page 45
Operation
the water, resulting in loss of control.
Do not rotate the outboard motor 180° and operate the boat in reverse. Place the gear shift in reverse to operate the boat in reverse. Use extra care when operating in re-
verse. Too much reverse thrust can cause the outboard motor to lift out of the water, increasing the chance of ac­cident and personal injury.
Return the outboard motor to its normal position as soon as the boat is back in deeper water.
ECM00260
CAUTION:
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.
N
ZMU03745
N
ZMU03525
2. Push the tilt lock lever down to release it.
ZMU02868
Procedure
1. Place the gear shift lever in neutral.
ZMU03746
3. Pull up the shallow water lever.
40
Page 46
Operation
ZMU03728
4. Slightly tilt the outboard motor up. The tilt support bar will lock automatically, supporting the outboard motor in a par­tially raised position.
NOTE:
This outboard motor has 2 positions for shal­low water cruising.
5. To return the outboard motor to the nor­mal running position, place the tilt lock lever and shallow water lever to the lock position.
ZMU03729
ZMU03731
6. Slightly tilt the outboard motor up until the tilt support bar automatically returns to the free position.
7. Slowly lower the outboard motor to the normal position.
Cruising in other conditions
Cruising in salt water
After operating in salt water, wash out the cooling water passages with fresh water to prevent them from becoming clogged with salt deposits.
NOTE:
For cooling system flushing instructions, see page 43.
Cruising in turbid water
Yamaha strongly recommends that you use the optional chromium-plated water pump kit (not available for some models) if you use the outboard motor in turbid (muddy) water conditions.
41
Page 47
Maintenance

Specifications

Dimension:
Overall length:
25EH 936 mm (36.9 in) 25ER 615 mm (24.2 in) 25MH 936 mm (36.9 in)
Overall width:
25EH 358 mm (14.1 in) 25ER 304 mm (12.0 in) 25MH 358 mm (14.1 in)
Overall height S:
1068 mm (42.0 in)
Overall height L:
1195 mm (47.0 in)
Transom height S:
419 mm (16.5 in)
Transom height L:
546 mm (21.5 in)
Weight (AL) S:
25EH 50.5 kg (111 lb) 25ER 49.5 kg (109 lb) 25MH 48.0 kg (106 lb)
Weight (AL) L:
25EH 52.0 kg (115 lb) 25ER 51.0 kg (112 lb) 25MH 49.5 kg (109 lb)
Performance:
Full throttle operating range:
5000–6000 r/min
Maximum output:
18.4 kW@5500 r/min (25 HP@5500 r/min)
Idling speed (in neutral):
750 ±50 r/min
Engine:
Type:
2-stroke L
Displacement:
395.0 cm
Bore × stroke:
3
(24.10 cu.in)
67.0 × 56.0 mm (2.64 × 2.20 in)
Ignition system:
CDI
Spark plug (NGK):
B7HS-10
Spark plug gap:
0.9–1.0 mm (0.035–0.039 in)
Control system:
25EH Tiller 25ER Remote control 25MH Tiller
Starting system:
25EH Manual and electric 25ER Manual and electric 25MH Manual
Starting carburetion system:
Choke valve
Min. cold cranking amps (CCA/SAE):
25EH 245.0 A 25ER 245.0 A
Min. marine cranking amps (MCA/ABYC):
25EH 323.0 A 25ER 323.0 A
Min. reserve capacity (RC/SAE):
25EH 52 minutes 25ER 52 minutes
Alternator output:
25MH 80 W
Alternator output for battery DC:
25EH 6.0 A 25ER 6.0 A
Drive unit:
Gear positions:
Forward-neutral-reverse
Gear ratio:
2.08 (27/13)
Trim and tilt system:
Manual tilt
Propeller mark:
F
Fuel and oil:
42
Page 48

Maintenance

Recommended fuel:
Regular unleaded gasoline
Min. pump octane:
86
Fuel tank capacity:
25 L (6.60 US gal) (5.50 Imp.gal)
Recommended engine oil:
YAMALUBE 2-stroke outboard motor oil
Fuel:oil ratio:
Regular gasoline:
100 :1
Lubrication:
Pre-mixed fuel and oil
Recommended gear oil:
Hypoid gear oil SAE#90
Gear oil quantity:
370.0 cm
3
(12.51 US oz) (13.05
Imp.oz)
Tightening torque for engine:
Spark plug:
25.0 Nm (18.4 ft-lb) (2.55 kgf-m)
Propeller nut:
35.0 Nm (25.8 ft-lb) (3.57 kgf-m)
Transporting and storing
outboard motor
EWM00690
WARNING
Leaking fuel is a fire hazard. When
transporting and storing the outboard motor, close the air vent screw and fuel cock to prevent fuel from leaking. 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.
EWM00700
WARNING
Never get under the lower unit while it is tilted, even if a motor support bar is used. Severe injury could occur if the outboard motor accidentally falls.
ECM00660
CAUTION:
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.
The outboard motor should be trailered 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.
ZMU02870
Clamp screw mounting models
When transporting or storing the outboard motor while removed from a boat, keep the outboard motor in the attitude shown.
43
Page 49
ZMU02869
NOTE:
Place a towel or something similar under the outboard motor to protect it from damage.
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 serviced by an authorized Yamaha dealer prior to storage. However, you, the owner, with a minimum of tools, can perform the fol­lowing procedures.
ECM01411
CAUTION:
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, well­ventilated place, not in direct sunlight.
Procedure
Flushing in a test tank
1. Wash the outboard motor body using fresh water. For further information, see page 46.
Maintenance
2. Fill the fuel tank with fresh fuel and add one ounce of Yamaha Fuel Conditioner and Stabilizer (Part No. LUB-FUELC­12-00) to each gallon of fuel.
NOTE:
The use of Yamaha Fuel Conditioner and Stabilizer eliminates the need to drain the fuel system. Consult your Yamaha dealer or other qualified mechanic if the fuel system is to be drained instead.
3. Remove the engine top cowling and si­lencer cover.
4. Install the outboard motor on the test tank.
1
2
ZMU02051
1. Water surface
2. Lowest water level
5. Fill the tank with fresh water to above the level of the anti-cavitation plate.
ECM00300
CAUTION:
Do not run the engine without supplying it with cooling water. Either the engine water pump will be damaged or the en­gine will be damaged from overheating. Before starting the engine, be sure to supply water to the cooling water passag-
44
Page 50
Maintenance
es.
ECM00290
CAUTION:
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.
6. Cooling system flushing is essential to prevent the cooling system from clog­ging up with salt, sand, or dirt. In addi­tion, fogging of the engine is mandatory to prevent excessive engine damage due to rust. Perform the flushing and fogging at the same time.
EWM00090
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.
7. Run the engine at a fast idle for 10–15 minutes in neutral position.
8. Just prior to turning off the engine, quick­ly spray Yamaha Stor-Rite Engine Fogging Oil (Part No. LUB-STRRT-12-
00) 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.
9. Remove the outboard motor from the test tank.
10. Drain the cooling water completely out of the motor. Clean the body thoroughly.
11. Install the silencer cover/cap and top cowling.
Lubrication (except oil injection models)
1. Grease the spark plug threads and in­stall the spark plug(s) and torque to proper specification. For information on spark plug installation, see page 50.
2. Change the gear oil. For instructions, see page 54. Inspect the oil for the pres­ence of water that indicates a leaky seal. Seal replacement should be performed by an authorized Yamaha dealer prior to use.
3. Grease all grease fittings. For further de­tails, see page 49.
Cleaning and anticorrosion measures
1. Wash down the exterior of the outboard motor with fresh water and dry off com­pletely.
2. Spray the outboard motor exterior with Yamaha Silicone Protectant (Part No. LUB-SILCNE-13-00).
3. Wax the cowling with a non-abrasive wax such as Yamaha Silicone Wax (Part No. ACC-11000-15-02).
Battery care
EWM00330
WARNING
Battery electrolytic fluid is dangerous; it contains sulfuric acid and therefore is poisonous and highly caustic. Always follow these preventive mea­sures:
Avoid bodily contact with electrolytic
fluid as it can cause severe burns or permanent eye injury. Wear protective eye gear when han-
45
Page 51
Maintenance
dling or working near batteries.
Antidote (EXTERNAL):
SKIN - Flush with water.
EYES - Flush with water for 15 minutes and get immediate medical attention.
Antidote (INTERNAL):
Drink large quantities of water or milk followed by milk of magnesia, beaten egg, or vegetable oil. Get immediate
medical attention. Batteries also generate explosive hydro­gen gas; therefore, you should always follow these preventive measures:
Charge batteries in a well-ventilated ar-
ea.
Keep batteries away from fire, sparks,
or open flames (for example: welding
equipment, lighted cigarettes, and so
on.)
DO NOT SMOKE when charging or han-
dling batteries. KEEP BATTERIES AND ELECTROLYTIC FLUID OUT OF REACH OF CHILDREN.
Batteries vary among manufacturers. There­fore the following procedures may not al­ways apply. Consult your battery manufacturers instructions. Procedure
1. Disconnect and remove the battery from
the boat. Always disconnect the black negative cable first to prevent the risk of shorting.
2. Clean the battery casing and terminals.
Fill each cell to the upper level with dis­tilled water.
3. Store the battery on a level surface in a
cool, dry, well-ventilated place out of di­rect sunlight.
4. Once a month, check the specific gravity
of the electrolyte and recharge as re­quired to prolong battery life.
Cleaning the outboard motor
After use, wash the exterior of the outboard motor with fresh water. Flush the cooling system with fresh water.
ZMU02871
NOTE:
For cooling system flushing instructions, see page 43.
Checking painted surface of motor
Check the 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.

Periodic maintenance

EWM01070
WARNING
Be sure to turn off the engine when you perform maintenance unless otherwise specified. If you or the owner is not famil­iar with machine servicing, this work should be done by your Yamaha dealer or other qualified mechanic.
Maintenance, replacement, or repair of the emission control devices and sys­tems may be performed by any marine engine repair establishment or individual. All warranty repairs, however, including those to the emission control system,
46
Page 52
Maintenance
must be performed by an authorized Yamaha marine dealership.
A service manual is available for purchase through your Yamaha dealer for owners who have the mechanical skills, tools, and other equipment necessary to perform mainte­nance not covered by this owners manual.
Replacement parts
If replacement parts are necessary, use only genuine Yamaha parts or parts of the same type and of equivalent strength and materi­als. 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.
47
Page 53
Maintenance

Maintenance chart

Frequency of maintenance operations may be adjusted according to the operating condi­tions, but the following table gives general guidelines. Refer to the sections in this chapter for explanations of each owner-specific action.
NOTE:
When operating in salt water, turbid or muddy 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) (internal)
Battery Inspection / charging
Cooling water pas­sages
Cowling clamp Inspection
Fuel lter (can be dis­assembled)
Fuel system Inspection
Fuel tank (Yamaha por­table tank)
Gear oil Change
Greasing points Greasing
Idling speed (carbure­tor models)
Propeller and cotter pin
Shift link / shift cable Inspection / adjustment
Thermostat
Throttle link / throttle cable / throttle pick-up timing
Water pump
Inspection / replace­ment
Inspection / replace­ment
Cleaning
Inspection / cleaning
Inspection / cleaning
Inspection
Inspection / replace­ment
Inspection / replace­ment
Inspection / adjustment
Inspection / replace­ment
10 hours
(1 month)
50 hours
(3
months)
100
hours (6
months)
200
hours (1
year)
48
Page 54
Maintenance
Item Actions
Spark plug(s)
Greasing
Yamaha marine grease (Water resistant grease)
25
Cleaning / adjustment / replacement
10 hours
(1 month)
Initial Every
50 hours
(3
months)
100
hours (6
months)
200
hours (1
year)
49
ZMU03734
Page 55

Cleaning and adjusting spark plug

EWM00560
WARNING
When removing or installing a spark plug, be careful not to damage the insulator. A damaged insulator could allow external sparks, which could lead to explosion or fire.
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. 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.
Standard spark plug:
B7HS-10
Before fitting the spark plug, measure the electrode gap with a wire thickness gauge; adjust the gap to specification if necessary.
Maintenance
1. Spark plug gap
2. Spark plug I.D. mark (NGK)
Spark plug gap:
0.9–1.0 mm (0.035–0.039 in)
When fitting the plug, always clean the gas­ket surface and use a new gasket. Wipe off any dirt from the threads and screw in the spark plug to the correct torque.
Spark plug torque:
25.0 Nm (18.4 ft-lb) (2.55 kgf-m)
NOTE:
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.

Checking fuel system

EWM00060
WARNING
Gasoline and its vapors are highly flam­mable and explosive. Keep away from sparks, cigarettes, flames, or other
50
Page 56
Maintenance
sources of ignition.
EWM00910
WARNING
Leaking fuel can result in fire or explo­sion.
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.
Check the fuel lines for leaks, crack, or mal­function. If a problem is found, your Yamaha dealer or other qualified mechanic should re­pair it immediately.
ZMU04772
cool.
There will be fuel in the fuel filter. Keep away from sparks, cigarettes, flames or other sources of ignition.
This procedure will allow some fuel to spill. Catch fuel in a rag. Wipe up any spilled fuel immediately.
The fuel filter must be reassembled carefully with the O-ring, filter cup, and hoses in place. Improper assembly or replacement could result in a fuel leak, which could result in a fire or explosion hazard.
Cleaning fuel filter
1. Remove the nut holding the fuel filter as­sembly if equipped.
1
Checkpoints
Fuel system parts leakage
Fuel line joint leakage Fuel line cracks or other damage
Fuel connector leakage
Inspecting fuel filter
EWM00310
WARNING
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. Do not perform this procedure on a hot
or running engine. Allow the engine to
51
ZMU03812
1. Nut
2. Unscrew the filter cup, catching any spilled fuel in a rag.
3. Remove the filter element, and wash it in solvent. Allow it to dry. Inspect the filter element and O-ring to make sure they are in good condition. Replace them if necessary. If any water is found in the fuel, the Yamaha portable fuel tank or other fuel tanks should be checked and cleaned.
Page 57
2
4
1
1. Filter cup
2. Filter element
3. Filter housing
4. O-ring
3
ZMU02079
Maintenance
on whether testing is conducted with the flushing attachment, in a test tank, or with the outboard motor in the water.
1. Start the engine and allow it to warm up fully in neutral until it is running smooth­ly.
NOTE:
Correct idling speed inspection is only possi­ble if the engine is fully warmed up. If not warmed up fully, the idle speed will measure higher than normal. If you have difficulty ver­ifying the idle speed, or the idle speed re­quires adjustment, consult a Yamaha dealer or other qualified mechanic.
4. Reinstall the filter element in the cup. Make sure the O-ring is in position in the cup. Firmly screw the cup onto the filter housing.
5. Attach the filter assembly to the bracket so that the fuel hoses are attached to the filter assembly.
6. Run the engine and check the filter and lines for leaks.

Inspecting idling speed

EWM00451
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.
ECM00490
CAUTION:
This procedure must be performed while the outboard motor is in the water. A flushing attachment or test tank can be used.
A diagnostic tachometer should be used for this procedure. Results may vary depending
2. Verify whether the idle speed is set to specification. For idle speed specifica­tions, see page 42.

Checking wiring and connectors

Check that each grounding wire is properly secured.
Check that each connector is engaged se­curely.
ZMU03737
Exhaust leakage
Start the engine and check that no exhaust leaks from the joints between the exhaust cover, cylinder head, and body cylinder.
Water leakage
Start the engine and check that no water
52
Page 58
Maintenance
leaks from the joints between the exhaust cover, cylinder head, and body cylinder.

Checking propeller

EWM00321
WARNING
You could be seriously injured if the en­gine accidentally starts when you are near the propeller.
Before inspecting, removing, or install­ing the propeller, remove the spark plug caps from the spark plugs. Also, place the shift control in neutral, turn the main switch to “” (off) and re- move the key, and remove the lanyard from the engine stop switch. Turn off the battery cut-off switch if your boat has one.
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.
ZMU01897
Checkpoints
Check each of the propeller blades for wear, erosion from cavitation or ventila­tion, or other damage.
Check the propeller shaft for damage.
Check the splines / shear pin for wear or damage.
Check for fish line tangled around the pro­peller shaft.
53
ZMU02876
Check the propeller shaft oil seal for dam-
age.
NOTE:
If the shear pin equipped: it is designed to break if the propeller hits a hard underwater obstacle to help protect the propeller and drive mechanism. The propeller will then spin freely on the shaft. If this happens, the shear pin must be replaced.
Page 59
Maintenance
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).
1
2
3
4
6
1. Cotter pin
2. Propeller nut
3. Washer
4. Spacer
5. Propeller
6. Thrust washer
5
ZMU02829
3. Remove the propeller and thrust wash­er.
Spline models
ECM00340
CAUTION:
Be sure to install the thrust washer be­fore installing the propeller, otherwise the lower case and propeller boss could be damaged. Be 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, and propeller on the propeller shaft.
3. Install the spacer (if equipped) and the washer. Tighten the propeller nut to the specified torque.
4. Align the propeller nut with the propeller shaft hole. Insert a new cotter pin in the hole and bend the cotter pin ends.
ZMU02063
NOTE:
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.
Changing gear oil
EWM00800
WARNING
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
54
Page 60
Maintenance
gear case.
3. Remove the gear oil drain screw.
2
1
ZMU03738
1. Gear oil drain screw
2. Oil level plug
NOTE:
If the magnetic gear oil drain screw equipped: remove all metal particles from the screw before installing it.
4. Remove the oil level plug to allow the oil to drain completely.
ECM00710
CAUTION:
Inspect the used oil after it has been drained. If the oil is milky, water is getting into the gear case which can cause gear damage. Consult a Yamaha dealer for re­pair of the lower unit seals.
NOTE:
For disposal of used oil consult your Yamaha dealer.
5. With the outboard motor in a vertical po­sition, and using a flexible or pressur­ized filling device, inject the gear oil into
the gear oil drain screw hole.
Recommended gear oil:
Hypoid gear oil SAE#90
Gear oil quantity:
370.0 cm
3
(12.51 US oz) (13.05
Imp.oz)
ZMU03739
6. When the oil begins to flow out of the oil level plug hole, insert and tighten the oil level plug.
7. Insert and tighten the gear oil drain screw.
Cleaning fuel tank
EWM00920
WARNING
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 when cleaning the fuel tank.
Remove the fuel tank from the boat be­fore cleaning it. Work only outdoors in an area with good ventilation.
Wipe up any spilled fuel immediately.
Reassemble the fuel tank carefully. Im­proper assembly can result in a fuel leak, which could result in a fire or ex-
55
Page 61
Maintenance
plosion hazard.
Dispose of old gasoline according to lo­cal 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.
ZMU02066
4. Clean the filter (located on the end of the suction pipe) in a suitable cleaning sol­vent. Allow the filter to dry.
5. Replace the gasket with a new one. Re­install the fuel joint assembly and tighten the screws firmly.

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
CAUTION:
Do not paint anodes, as this would render them ineffective.
NOTE:
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.
ZMU02924
Checking battery (for electric start models)
EWM00330
WARNING
Battery electrolytic fluid is dangerous; it contains sulfuric acid and therefore is poisonous and highly caustic. Always follow these preventive mea­sures:
Avoid bodily contact with electrolytic
fluid as it can cause severe burns or permanent eye injury. Wear protective eye gear when han-
dling or working near batteries.
Antidote (EXTERNAL):
SKIN - Flush with water.
EYES - Flush with water for 15 minutes and get immediate medical attention.
Antidote (INTERNAL):
Drink large quantities of water or milk followed by milk of magnesia, beaten egg, or vegetable oil. Get immediate
56
Page 62
Maintenance
medical attention. Batteries also generate explosive hydro­gen gas; therefore, you should always follow these preventive measures:
Charge batteries in a well-ventilated ar-
ea.
Keep batteries away from fire, sparks,
or open flames (for example: welding
equipment, lighted cigarettes, and so
on.)
DO NOT SMOKE when charging or han-
dling batteries. KEEP BATTERIES AND ELECTROLYTIC FLUID OUT OF REACH OF CHILDREN.
ECM00360
CAUTION:
A poorly maintained battery will quickly
deteriorate.
Ordinary tap water contains minerals
harmful to a battery, and should not be
used for topping up.
1. Check the electrolyte level at least once
a month. Fill to the manufacturers rec­ommended level when necessary. Top up only with distilled water (or pure de­ionized water suitable to use in batter­ies).
use the boat for a month or more, re­move the battery from the boat and store it in a cool, dark place. Completely re­charge the battery before using it.
3. If the battery will be stored for longer than a month, check the specific gravity of the fluid at least once a month and re­charge the battery when it is low.
NOTE:
Consult a Yamaha dealer when charging or re-charging batteries.
Connecting the battery
EWM00570
WARNING
Mount the battery holder securely in a dry, well-ventilated, vibration-free loca­tion in the boat. Install a fully charged bat­tery in the holder.
ECM01121
CAUTION:
Make sure the main switch (on applica­ble models) is “” (off) before work- ing on the battery.
Reversal of the battery cables will dam­age the electrical parts.
Connect the red battery cable first when installing the battery and discon­nect the black battery cable first when removing it. Otherwise, the electrical parts can be damaged.
The electrical contacts of the battery and cables must be clean and properly connected, or the battery will not start the engine.
2. Always keep the battery in a good state of charge. Installing a voltmeter will help you monitor your battery. If you will not
57
Connect the red battery cable to the POSI­TIVE (+) terminal first. Then connect the black battery cable to the NEGATIVE (-) ter­minal.
Page 63
1. Red cable
2. Black cable
3. Battery
Disconnecting the battery
Disconnect the BLACK cable from the NEG­ATIVE (-) terminal first. Then disconnect the RED cable from the POSITIVE (+) terminal.
Checking top cowling
Check the fitting of the top cowling by push­ing it with both hands. If it is loose have it re­paired by your Yamaha dealer.
Maintenance
Do not use anti-fouling paint which includes copper or graphite. These paints can cause more rapid engine corrosion.
ZMU01943
ZMU04677
Coating the boat bottom
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.
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Trouble Recovery

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 warning 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 26.
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 stop switch lanyard not at­tached? A. Attach lanyard.
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.
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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 warning system activated? A. Find and correct cause of warning.
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.
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.
Warning 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 specified engine oil not being used? A. Check and replace oil as specified.
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?
Q. Is heat range of spark plug incorrect? A. Inspect spark plug and replace it with rec­ommended type.
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?
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Trouble Recovery
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.
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. Are weeds or other foreign matter tangled 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 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. Has warning system activated? A. Find and correct cause of warning.
Q. Is boat bottom fouled with marine growth? A. Clean boat bottom.
Q. Are spark plug(s) fouled or of incorrect type? A. Inspect spark plug(s). Clean or replace with recommended type.
61
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. Is air vent screw closed? A. Open the air vent screw.
Q. Is fuel pump damaged? A. Have serviced by a Yamaha dealer.
Page 67
Q. Is fuel joint connection incorrect? A. Connect correctly.
Trouble Recovery
damaged by a collision while operating or trailering. Damage could make the out­board motor unsafe to operate.
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.
Temporary action in
emergency
Impact damage
EWM00870
WARNING
The outboard motor can be seriously
If the outboard motor hits an object in the wa­ter, follow the procedure below.
1. Stop the engine immediately.
2. Inspect the control system and all com­ponents for damage. Also inspect the boat for damage.
3. Whether damage is found or not, return to the nearest harbor slowly and careful­ly.
4. Have a Yamaha dealer inspect the out­board motor before operating it again.
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.
EWM00630
WARNING
Be sure to use the specified fuse. An in­correct fuse or a piece of wire could allow excessive current flow. This could cause electric system damage and a fire hazard.
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Trouble Recovery
1
2
ZMU04839
1. Fuse holder
2. Fuse (10 A)
NOTE:
Consult your Yamaha dealer if the new fuse immediately blows again.
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.
EWM01020
WARNING
Use this procedure only in an emergen­cy and only to return to 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 stop switch lanyard
to a secure place on your clothing, or your arm or leg while operating. Do not attach the lanyard to clothing
that could tear loose. Do not route the cord where it could become entangled, preventing it from functioning.
Avoid accidentally pulling the lanyard 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.
Be 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 fly­wheel 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.
Emergency starting engine
1. Remove the top cowling.
2. Remove the start-in-gear protection ca­ble from the starter, if equipped.
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Trouble Recovery
1
ZMU03740
1. Start-in-gear protection cable
3. Remove the starter/flywheel cover after removing the bolt(s).
ZMU03741
4. Prepare the engine for starting. For fur­ther information, see page 26. Be sure the engine is in neutral and that the en­gine stop switch lanyard lock plate is at­tached to the engine stop switch. The main switch must be “” (on), if equipped.
ZMU02334
ON STARTOFF
ZMU01906
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.
ZMU03742
ZMU04119
6. Insert the knotted end of the emergency 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
64
Page 70
Trouble Recovery
and start the engine. Repeat if neces­sary.
ZMU01910
ZMU02928

Treatment of submerged motor

If the outboard motor is submerged, immedi­ately take it to a Yamaha dealer. Otherwise some corrosion may begin almost immedi­ately. If you cannot immediately take the outboard motor to a Yamaha dealer, follow the proce­dure below in order to minimize engine dam­age.
Procedure
1. Thoroughly wash away mud, salt, sea­weed, and so on, with fresh water.
3. Drain the fuel from the carburetor, fuel filter, and fuel line.
4. Feed fogging oil or engine oil through the carburetor(s) and spark plug holes while cranking with the manual starter or emergency starter rope.
ZMU01911
5. Take the outboard motor to a Yamaha dealer as soon as possible.
ECM00400
CAUTION:
Do not attempt to run the outboard motor until it has been completely inspected.
ZMU01909
2. Remove the spark plugs and face the spark plug holes downward to allow any water, mud, or contaminants to drain.
65
Page 71

Consumer information

Important warranty information for U.S.A. and Canada
66
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Consumer information
67
Page 73
Consumer information
YAMAHA MOTOR CORPORATION, U.S.A.
OUTBOARD MOTOR TWO YEAR LIMITED WARRANTY
68
Page 74
Consumer information
69
Page 75
Consumer information
70
Page 76
Consumer information
IMPORTANT WARRANTY INFORMATION IF YOU USE YOUR
YAMAHA OUTSIDE THE USA OR CANADA
71
Page 77
Printed in Japan June 2005–0.2
× 1 !
Printed on recycled paper
Page 78
YAMAHA MOTOR CO., LTD. MADE IN JAPAN PAYS D'ORIGINE JAPON
OUTBOARD MOTOR WARRANTY REGISTRATION
ENREGISTREMENT DE LA GARANTIE DU MOTEUR HORS-BORD
Please complete and mail this card. This information is necessary to accurately register your unit for warranty.
Veuillez signer ci-dessous pour attester que le montage et l’inspection ont été faits dans le respect des directives d’inspection et
OUTBOARD MOTOR MODEL AND SERIAL NUMBER (From I.D. label on clamp bracket)
MODÉLE ET NO. DE SÉRIE DU MOTEUR HORS-BORD (sur l’étiquette d’identification de la presse de fixation)
DATE SOLD
DATE DE LIVRAISON
OWNER’S NAME
NOM DU PROPRIÉTAIRE
ADDRESS
ADRESSE
PHONE NUMBER ( )
NUMÉRO DE TÉLÉPHONE
que la marche à suivre pour la garantie et l’entretien a été expliquée à l’acheteur au détail.
(For Dealer Use Only)
(A l’usage du concessionnaire)
YAMAHA DEALER NUMBER
NO. DU CONCESSIONNAIRE YAMAHA
DEALER NAME
NOM DU CONCESSIONNAIRE
USAGE (Check One)
UTILISATION
MONTH DAY YEAR
MOIS JOUR ANNÉE
FIRST LAST
PRÉNOM NOM DE FAMILLE
STREET
RUE
CITY STATE/PROVINCE ZIP
VILLE PROVINCE CODE POSTAL
(En cocher un.)
PLEASURE
LOISIR
COMMERCIAL
COMMERCIAL
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