Yamaha F25AET

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Read this manual carefully before operating thisoutboard motor.

OWNERS MANUAL

F25AFT25BF25C

65W-28199-2D-E0

EMU25052

Read this manual carefully before operating this outboard motor. Keep this manual onboard in a waterproof bag when boating. This manual should stay with the outboard motor if it is sold.

Important manual information

EMU25105

To the owner

Thank you for choosing a Yamaha outboardmotor. This Owners Manual contains infor-mation needed for proper operation, mainte-nance and care. A thorough understandingof these simple instructions will help you ob-tain maximum enjoyment from your newYamaha. If you have any question about theoperation or maintenance of your outboardmotor, please consult a Yamaha dealer.In this Owners Manual particularly importantinformation is distinguished in the followingways.

: This is the safety alert symbol. It isused to alert you to potential personal injuryhazards. Obey all safety messages that fol-low this symbol to avoid possible injury ordeath.

WARNING

EWM00781

A WARNING indicates a hazardous situa-tion which, if not avoided, could result in

death or serious injury.

NOTICE

ECM00701

A NOTICE indicates special precautionsthat must be taken to avoid damage to the

outboard motor or other property.

TIP:

A TIP provides key information to make pro-cedures easier or clearer.

Yamaha continually seeks advancements inproduct design and quality. Therefore, whilethis manual contains the most current prod-uct information available at the time of print-ing, there may be minor discrepanciesbetween your machine and this manual. If

there is any question concerning this manu-al, please consult your Yamaha dealer.To ensure long product life, Yamaha recom-mends that you use the product and performthe specified periodic inspections and main-tenance by correctly following the instruc-tions in the owners manual. Any damageresulting from neglect of these instructions isnot covered by warranty.Some countries have laws or regulations re-stricting users from taking the product out ofthe country where it was purchased, and itmay be impossible to register the product inthe destination country. Additionally, thewarranty may not apply in certain regions.When planning to take the product to anothercountry, consult the dealer where the prod-uct was purchased for further information.If the product was purchased used, pleaseconsult your closest dealer for customer re-registration, and to be eligible for the speci-fied services.TIP:

The F25AMH, F25AET, F25AEHT,FT25BET, F25CMH and the standard acces-sories are used as a base for the explana-tions and illustrations in this manual.Therefore some items may not apply to ev-ery model.

EMU25121

F25A, FT25B, F25COWNERS MANUAL

2008 by Yamaha Motor Co., Ltd.1st Edition, April 2008

All rights reserved.Any reprinting or unauthorized usewithout the written permission of

Yamaha Motor Co., Ltd.is expressly prohibited.

Printed in Japan

Table of contents

Safety information............................. 1

Outboard motor safety .................... 1

Propeller............................................ 1Rotating parts.................................... 1Hot parts ........................................... 1Electric shock.................................... 1Power trim and tilt ............................. 1Engine shut-off cord (lanyard)........... 1Gasoline............................................ 1Gasoline exposure and spills ............ 2Carbon monoxide.............................. 2Modifications ..................................... 2

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

Alcohol and drugs ............................. 2Personal flotation devices ................. 2People in the water ........................... 2Passengers ....................................... 2Overloading....................................... 2Avoid collisions ................................. 3Weather ............................................ 3Passenger training ............................ 3Boating safety publications ............... 3Laws and regulations ........................ 3

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

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

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

EC Declaration of Conformity (DoC)............................................. 4

CE Marking ..................................... 5C-Tick label ..................................... 5Read manuals and labels................ 6

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

Specifications and requirements..... 9

Specifications .................................. 9Installation requirements ............... 11

Boat horsepower rating................... 11Mounting motor ............................... 11

Remote control requirements........ 12Battery requirements..................... 12

Battery specifications ...................... 12Mounting battery ............................. 12Multiple batteries............................. 12Without a rectifier or Rectifier

Regulator ...................................... 12

Propeller selection ........................ 12Start-in-gear protection ................. 13Engine oil requirements ................ 14Fuel requirements ......................... 14

Gasoline ..........................................14

Muddy or acidic water ................... 14Anti-fouling paint ........................... 15Motor disposal requirements......... 15Emergency equipment .................. 15

Components .................................... 16

Components diagram.................... 16

Fuel tank .........................................17Fuel joint..........................................17Fuel gauge ......................................17Fuel tank cap...................................17Air vent screw..................................17Remote control box .........................17Remote control lever .......................17Neutral interlock trigger ...................18Neutral throttle lever ........................18Tiller handle.....................................18Gear shift lever ................................18Throttle grip .....................................19Throttle indicator .............................19Throttle friction adjuster...................19Engine shut-off cord (lanyard) and

clip.................................................20Engine stop button ..........................21Manual starter handle .....................21Starter button ..................................21Main switch .....................................21Steering friction adjuster .................21Steering friction adjuster .................22Power trim and tilt switch on

remote control or tiller handle .......23Power trim and tilt switch on

bottom engine cowling ..................23Trim tab with anode.........................23Trim tab ...........................................24Trim rod (tilt pin) ..............................24Tilt lock mechanism.........................25Tilt support knob..............................25Tilt support bar ................................25Top cowling lock lever(s)

(turn type)......................................26

Table of contents

Flushing device ............................... 26Alert indicator .................................. 26

Instruments and indicators ............ 27

Indicators....................................... 27

Low oil pressure-alert indicator ....... 27

Engine control system.................... 28

Alert system .................................. 28

Overheat alert ................................. 28Low oil pressure alert ...................... 28

Installation ....................................... 30

Installation ..................................... 30

Mounting the outboard motor .......... 30Clamping the outboard motor ......... 31

Operation ......................................... 33

First-time operation ....................... 33

Fill engine oil ................................... 33Breaking in engine .......................... 33Getting to know your boat ............... 33

Checks before starting engine ...... 33

Fuel level......................................... 34Remove cowling.............................. 34Fuel system..................................... 34Controls........................................... 34Engine shut-off cord (lanyard)......... 35Engine oil ........................................ 35Engine............................................. 36Flushing device ............................... 36Install cowling.................................. 36Power trim and tilt system............... 37Battery............................................. 37

Filling fuel ...................................... 37Operating engine........................... 38

Feeding fuel (portable tank) ............ 38Starting engine................................ 39

Checks after starting engine ......... 43

Cooling water .................................. 43

Warming up engine ....................... 43

Manual start and electric start models .......................................... 43

Checks after engine warm-up ....... 43

Shifting ............................................ 43Stop switches.................................. 43

Shifting .......................................... 44Stopping boat ................................ 45

Stopping engine............................ 45

Procedure........................................45

Trimming outboard motor.............. 46

Adjusting trim angle for manual tilt models......................................47

Adjusting trim angle (Power trim and tilt) ..........................................48

Adjusting boat trim ..........................48

Tilting up and down....................... 49

Procedure for tilting up (manual tilt models).....................................50

Procedure for tilting up (power trim and tilt models)..............................50

Procedure for tilting down (manual tilt models)....................................51

Procedure for tilting down (power trim and tilt models).......................52

Shallow water................................ 52

Cruising in shallow water (manual tilt models).....................................52

Power trim and tilt models...............53

Cruising in other conditions........... 54

Maintenance .................................... 55

Transporting and storing outboard motor ........................................... 55

Clamp screw mounting models .......55Storing outboard motor ...................55Procedure........................................56Lubrication.......................................57Flushing power unit .........................57Cleaning the outboard motor...........58Checking painted surface of

motor.............................................58

Periodic maintenance ................... 58

Replacement parts ..........................58Severe operating conditions............59Maintenance chart 1........................60Maintenance chart 2........................62Greasing..........................................63Cleaning and adjusting spark

plug ...............................................64Checking fuel filter...........................65Inspecting idling speed....................65Changing engine oil ........................66Checking wiring and connectors .....67

Table of contents

Checking propeller .......................... 68Removing propeller ......................... 68Installing propeller ........................... 69Changing gear oil ............................ 70Cleaning fuel tank ........................... 71Inspecting and replacing

anode(s)........................................ 71Checking battery (for electric start

models) ......................................... 72Connecting the battery .................... 73Disconnecting the battery ............... 73

Trouble Recovery............................ 74

Troubleshooting ............................ 74Temporary action in emergency.... 77

Impact damage ............................... 77Replacing fuse ................................ 77Power trim and tilt will not

operate.......................................... 78Starter will not operate .................... 78Emergency starting engine ............. 79

Treatment of submerged motor..... 80

1

Safety information

EMU33622

Outboard motor safety

Observe these precautions at all times.

EMU36500

Propeller

People can be injured or killed if they comein contact with the propeller. The propellercan keep moving even when the motor is inneutral, and sharp edges of the propeller cancut even when stationary.

Shut off the engine when a person is in thewater near you.

Keep people out of reach of the propeller,even when the engine is off.

EMU33630

Rotating parts

Hands, feet, hair, jewelry, clothing, PFDstraps, etc. can become entangled with inter-nal rotating parts of the engine, resulting inserious injury or death.Keep the top cowling in place whenever pos-sible. Do not remove or replace the cowlingwith the engine running.Only operate the engine with the cowling re-moved according to the specific instructionsin the manual. Keep hands, feet, hair, jewel-ry, clothing, PFD straps, etc. away from anyexposed moving parts.

EMU33640

Hot parts

During and after operation, engine parts arehot enough to cause burns. Avoid touchingany parts under the top cowling until the en-gine has cooled.

EMU33650

Electric shock

Do not touch any electrical parts while start-ing or operating the engine. They can causeshock or electrocution.

EMU33660

Power trim and tilt

Body parts can be crushed between the mo-

tor and the clamp bracket when the motor istrimmed or tilted. Keep body parts out of thisarea at all times. Be sure no one is in thisarea before operating the power trim and tiltmechanism.The power trim and tilt switches operateeven when the main switch is off. Keep peo-ple be away from the switches wheneverworking around the motor.Never get under the lower unit while it is tilt-ed, even when the tilt support lever is locked.Severe injury could occur if the outboard mo-tor accidentally falls.

EMU33671

Engine shut-off cord (lanyard)

Attach the engine shut-off cord so that theengine stops if the operator falls overboardor leaves the helm. This prevents the boatfrom running away under power and leavingpeople stranded, or running over people orobjects.Always attach the engine shut-off cord to asecure place on your clothing or your arm orleg while operating. Do not remove it to leavethe helm while the boat is moving. Do not at-tach the cord to clothing that could tearloose, or route the cord where it could be-come entangled, preventing it from function-ing.Do not route the cord where it is likely to beaccidentally pulled out. If the cord is pulledduring operation, the engine will shut off andyou will lose most steering control. The boatcould slow rapidly, throwing people and ob-jects forward.

EMU33810

Gasoline

Gasoline and its vapors are highly flam-mable and explosive.

Always, refuel ac-cording to the procedure on page 38 toreduce the risk of fire and explosion.

Safety information

2

EMU33820

Gasoline exposure and spills

Take care not to spill gasoline. If gasolinespills, wipe it up immediately with dry rags.Dispose of rags properly.If any gasoline spills onto your skin, immedi-ately wash with soap and water. Changeclothing if gasoline spills on it.If you swallow gasoline, inhale a lot of gaso-line vapor, or get gasoline in your eyes, getimmediate medical attention. Never siphonfuel by mouth.

EMU33900

Carbon monoxide

This product emits exhaust gases whichcontain carbon monoxide, a colorless, odor-less gas which may cause brain damage ordeath when inhaled. Symptoms include nau-sea, dizziness, and drowsiness. Keep cock-pit and cabin areas well ventilated. Avoidblocking exhaust outlets.

EMU33780

Modifications

Do not attempt to modify this outboard mo-tor. Modifications to your outboard motormay reduce safety and reliability, and renderthe outboard unsafe or illegal to use.

EMU33740

Boating safety

This section includes a few of the many im-portant safety precautions that you shouldfollow when boating.

EMU33710

Alcohol and drugs

Never operate after drinking alcohol or tak-ing drugs. Intoxication is one of the mostcommon factors contributing to boating fatal-ities.

EMU33720

Personal flotation devices

Have an approved personal flotation device(PFD) on board for every occupant. Yamaha

recommends that you must wear a PFDwhenever boating. At a minimum, childrenand non-swimmers should always wearPFDs, and everyone should wear PFDswhen there are potentially hazardous boat-ing conditions.

EMU33730

People in the water

Always watch carefully for people in the wa-ter, such as swimmers, skiers, or divers,whenever the engine is running. Whensomeone is in the water near the boat, shiftinto neutral and shut off the motor.Stay away from swimming areas. Swimmerscan be hard to see.The propeller can keep moving even whenthe motor is in neutral. Shut off the enginewhen a person is in the water near you.

EMU33750

Passengers

Consult your boat manufacturers instruc-tions for details about appropriate passengerlocations in your boat and be sure all pas-sengers are positioned properly before ac-celerating and when operating above an idlespeed. Standing or sitting in non-designatedlocations may result in being thrown eitheroverboard or within the boat due to waves,wakes, or sudden changes in speed or direc-tion. Even when people are positioned prop-erly, alert your passengers if you must makeany unusual maneuver. Always avoid jump-ing waves or wakes.

EMU33760

Overloading

Do not overload the boat. Consult the boatcapacity plate or boat manufacturer for max-imum weight and number of passengers. Besure that weight is properly distributed ac-cording to the boat manufacturers instruc-tions. Overloading or incorrect weightdistribution can compromise the boats han-

Safety information

3

dling and lead to an accident, capsizing orswamping.

EMU33771

Avoid collisions

Scan constantly

for people, objects, andother boats. Be alert for conditions that limityour visibility or block your vision of others.

Operate defensively

at safe speeds andkeep a safe distance away from people, ob-jects, and other boats.

Do not follow directly behind other boats orwaterskiers.

Avoid sharp turns or other maneuvers thatmake it hard for others to avoid you or un-derstand where you are going.

Avoid areas with submerged objects orshallow water.

Ride within your limits and avoid aggres-sive maneuvers to reduce the risk of lossof control, ejection, and collision.

Take early action

to avoid collisions. Re-member,

boats do not have brakes

, andstopping the engine or reducing throttlecan reduce the ability to steer. If you arenot sure that you can stop in time beforehitting an obstacle, apply throttle and turnin another direction.

EMU33790

Weather

Stay informed about the weather. Checkweather forecasts before boating. Avoid

boating in hazardous weather.

EMU33880

Passenger training

Make sure at least one other passenger istrained to operate the boat in the event of anemergency.

EMU33890

Boating safety publications

Be informed about boating safety. Additionalpublications and information can be obtainedfrom many boating organizations.

EMU33600

Laws and regulations

Know the marine laws and regulations whereyou will be boating- and obey them. Severalsets of rules prevail according to geographiclocation, but all are basically the same as theInternational Rules of the Road.

ZMU06025

4

General information

EMU25171

Identification numbers record

EMU25183

Outboard motor serial number

The outboard motor serial number isstamped on the label attached to the portside of the clamp bracket.Record your outboard motor serial number inthe spaces provided to assist you in orderingspare parts from your Yamaha dealer or forreference in case your outboard motor is sto-len.

EMU25190

Key number

If a main key switch is equipped with the mo-tor, the key identification number is stampedon your key as shown in the illustration.Record this number in the space provided forreference in case you need a new key.

EMU37290

EC Declaration of Conformity (DoC)

This outboard motor conforms to certain por-tions of the European Parliament directiverelating to machinery.Each conformed outboard motor accompa-nied with EC DoC.EC DoC contains the fol-lowing information;

Name of Engine Manufacture

Model name

Product code of model (Approved modelcode)

Code of conformed directives

1. Outboard motor serial number location

1

ZMU02638

1. Key number

General information

5

EMU25203

CE Marking

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

EMU25213

C-Tick label

Engines affixed with this label conform tocertain portion(s) of the Australian RadioCommunications Act.

1. CE marking location

1. CE marking location

ZMU04946

1

ZMU05495

1

ZMU06040

1. C-Tick label location

1. C-Tick label location

1

ZMU04947

ZMU05497

1

ZMU01697

General information

6

EMU33520

Read manuals and labels

Before operating or working on this motor:

Read this manual.

Read any manuals supplied with the boat.

Read all labels on the outboard motor and the boat.If you need any additional information, contact your Yamaha dealer.

EMU33831

Warning labels

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

1

23

ZMU05798

General information

7

EMU33912

Contents of labels

The above warning labels mean as follows.

1

WARNING

EWM01691

Emergency starting does not have start-in-gear protection. Ensure shift control is

in neutral before starting engine.

2

WARNING

EWM01681

Keep hands, hair, and clothing awayfrom rotating parts while the engine isrunning.

Do not touch or remove electrical parts

when starting or during operation.

3

WARNING

EWM01671

Read Owners Manuals and labels.

Wear an approved personal flotationdevice (PFD).

Attach engine shut-off cord (lanyard) toyour PFD, arm, or leg so the enginestops if you accidentally leave thehelm, which could prevent a runaway

boat.

ZMU05706

1 2

3

General information

8

EMU33843

Symbols

The following symbols mean as follows.

Notice/Warning

Read Owners Manual

Hazard caused by continuous rotation

Electrical hazard

Remote control lever/gear shift lever operat-ing direction, dual direction

Engine start/ Engine cranking

ZMU05696

ZMU05664

ZMU05665

ZMU05666

ZMU05667

ZMU05668

9

Specifications and requirements

EMU34520

SpecificationsTIP:

(AL) stated in the specification data belowrepresents the numerical value for the alumi-num propeller installed.Likewise, (SUS) represents the value forstainless steel propeller installed and (PL)for plastic propeller installed.TIP:

* means, select the engine oil referring tothe chart of engine oil paragraph. For furtherinformation, see page 14.

EMU2821C

Dimension:

Overall length: F25AEHT 1151 mm (45.3 in)F25AET 769 mm (30.3 in)F25AMH 1151 mm (45.3 in)F25CMH 1151 mm (45.3 in)FT25BET 712 mm (28.0 in)

Overall width: F25AEHT 406 mm (16.0 in)F25AET 373 mm (14.7 in)F25AMH 406 mm (16.0 in)F25CMH 430 mm (16.9 in)FT25BET 373 mm (14.7 in)

Overall height S: F25CMH 1148 mm (45.2 in)

Overall height L: F25AEHT 1275 mm (50.2 in)F25AET 1275 mm (50.2 in)F25AMH 1275 mm (50.2 in)F25CMH 1275 mm (50.2 in)FT25BET 1311 mm (51.6 in)

Overall height X: FT25BET 1425 mm (56.1 in)

Transom height S: F25CMH 423 mm (16.7 in)

Transom height L: F25AEHT 550 mm (21.7 in)F25AET 550 mm (21.7 in)F25AMH 550 mm (21.7 in)F25CMH 550 mm (21.7 in)FT25BET 528 mm (20.8 in)

Transom height X: FT25BET 642 mm (25.3 in)

Weight (AL) S: F25CMH 62.0 kg (137 lb)

Weight (AL) L: F25AEHT 80.3 kg (177 lb)F25AET 78.0 kg (172 lb)F25AMH 64.0 kg (141 lb)F25CMH 64.0 kg (141 lb)FT25BET 86.7 kg (191 lb)

Weight (AL) X: FT25BET 90.0 kg (198 lb)

Performance:

Full throttle operating range: 50006000 r/min

Maximum output: 18.4 kW@5500 r/min (25 HP@5500 r/min)

Idling speed (in neutral): F25AEHT 925

50 r/minF25AET 925

50 r/minF25AMH 975

50 r/minF25CMH 975

50 r/minFT25BET 975

50 r/min

Engine:

Type: 4-stroke L

Displacement: 498.0 cm

3

Bore

stroke: 65.0

75.0 mm (2.56

2.95 in)Ignition system:

CDISpark plug with resistor (NGK):

DPR6EA-9


10

Spark plug gap: 0.80.9 mm (0.0310.035 in)

Control system: F25AEHT TillerF25AET Remote controlF25AMH TillerF25CMH TillerFT25BET Remote control

Starting system: F25AEHT ElectricF25AET ElectricF25AMH ManualF25CMH ManualFT25BET Electric

Starting carburetion system: Prime start

Valve clearance (cold engine) IN: 0.150.25 mm (0.00590.0098 in)

Valve clearance (cold engine) EX: 0.250.35 mm (0.00980.0138 in)

Min. cold cranking amps (CCA/EN): F25AEHT 347.0 AF25AET 347.0 AFT25BET 347.0 A

Min. rated capacity (20HR/IEC): F25AEHT 40.0 AhF25AET 40.0 AhFT25BET 40.0 Ah

Alternator output: F25AMH 80 WF25CMH 80 W

Maximum generator output: F25AEHT 15.0 AF25AET 15.0 AFT25BET 15.0 A

Drive unit:

Gear positions: Forward-neutral-reverse

Gear ratio: F25AEHT 2.08 (27/13)F25AET 2.08 (27/13)

F25AMH 2.08 (27/13)F25CMH 2.08 (27/13)FT25BET 2.42 (29/12)

Trim and tilt system: F25AEHT Power trim and tiltF25AET Power trim and tiltF25AMH Manual tiltF25CMH Manual tiltFT25BET Power trim and tilt

Propeller mark: F25AEHT FF25AET FF25AMH FF25CMH FFT25BET G

Fuel and oil:

Recommended fuel: Regular unleaded gasoline

Fuel tank capacity: 24 L (6.34 US gal, 5.28 Imp.gal)

Recommended engine oil: 4-stroke outboard motor oil

Recommended engine oil group 1*: SAE 10W-30/10W-40/5W-30 API SE/SF/SG/SH/SJ/SL

Recommended engine oil group 2*: SAE 15W-40/20W-40 API SH/SJ/SL

Lubrication: Wet sump

Engine oil quantity without replacement of oil filter (Oil pan capacity):

F25AEHT 1.7 L (1.80 US qt, 1.50 Imp.qt)F25AET 1.7 L (1.80 US qt, 1.50 Imp.qt)F25AMH 1.7 L (1.80 US qt, 1.50 Imp.qt)F25CMH 1.7 L (1.80 US qt, 1.50 Imp.qt)FT25BET 1.9 L


11

(2.01 US qt, 1.67 Imp.qt)Recommended gear oil:

Hypoid gear oil SAE#90Gear oil quantity:

F25AEHT 0.320 L (0.338 US qt, 0.282 Imp.qt)F25AET 0.320 L (0.338 US qt, 0.282 Imp.qt)F25AMH 0.320 L (0.338 US qt, 0.282 Imp.qt)F25CMH 0.320 L (0.338 US qt, 0.282 Imp.qt)FT25BET 0.430 L (0.455 US qt, 0.378 Imp.qt)

Tightening torque for engine:

Spark plug: 18.0 Nm (1.84 kgf-m, 13.3 ft-lb)

Propeller nut: F25AEHT 35.0 Nm (3.57 kgf-m, 25.8 ft-lb)F25AET 35.0 Nm (3.57 kgf-m, 25.8 ft-lb)F25AMH 35.0 Nm (3.57 kgf-m, 25.8 ft-lb)F25CMH 35.0 Nm (3.57 kgf-m, 25.8 ft-lb)FT25BET 40.0 Nm (4.08 kgf-m, 29.5 ft-lb)

Engine oil drain bolt: F25AEHT 28.0 Nm (2.86 kgf-m, 20.7 ft-lb)F25AET 28.0 Nm (2.86 kgf-m, 20.7 ft-lb)F25AMH 28.0 Nm (2.86 kgf-m, 20.7 ft-lb)F25CMH 28.0 Nm (2.86 kgf-m, 20.7 ft-lb)FT25BET 18.0 Nm (1.84 kgf-m, 13.3 ft-lb)

Engine oil filter: 18.0 Nm (1.84 kgf-m, 13.3 ft-lb)

Noise and vibration level:

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

F25CMH 81.9 dB(A)Vibration on tiller handle (ICOMIA 38/94):

F25CMH Vibration on tiller handle is under 2.5 m/s

2

EMU33553

Installation requirements

EMU33563

Boat horsepower rating

WARNING

EWM01560

Overpowering a boat can cause severe

instability.

Before installing the outboard motor(s), con-firm that the total horsepower of your mo-tor(s) does not exceed the boats maximumhorsepower rating. See the boats capacityplate or contact the manufacturer.

EMU33571

Mounting motor

WARNING

EWM01570

Improper mounting of the outboard mo-tor could result in hazardous condi-tions such as poor handling, loss ofcontrol, or fire hazards.

Because the motor is very heavy, spe-cial equipment and training is required

to mount it safely.

Your dealer or other person experienced inproper rigging should mount the motor usingcorrect equipment and complete rigging in-structions. For further information, see page30.


12

EMU33581

Remote control requirements

WARNING

EWM01580

If the engine starts in gear, the boat canmove suddenly and unexpectedly, pos-sibly causing a collision or throwingpassengers overboard.

If the engine ever starts in gear, thestart-in-gear protection device is notworking correctly and you should dis-continue using the outboard. Contact

your Yamaha dealer.

The remote control unit must be equippedwith a start-in-gear protection device(s). Thisdevice prevents the engine from starting un-less it is in neutral.

EMU25694

Battery requirements

EMU25721

Battery specifications

The engine cannot be started if battery volt-age is too low.

EMU36290

Mounting battery

Mount the battery holder securely in a dry,well-ventilated, vibration-free location in theboat.

WARNING! Do not put flammableitems, or loose heavy or metal objects inthe same compartment as the battery.Fire, explosion or sparks could result.

[EWM01820]

EMU36300

Multiple batteries

To connect multiple batteries, such as formultiple engine configurations or for an ac-cessory battery, consult your Yamaha dealerabout battery selection and correct wiring.

EMU25730

Without a rectifier or Rectifier Regulator

NOTICE

ECM01090

A battery cannot be connected to modelsthat do not have a rectifier or Rectifier

Regulator.

If you wish to use a battery with the modelswithout a rectifier or Rectifier Regulator, in-stall an optional Rectifier Regulator.Using a maintenance-free battery with theabove models can shorten the life of the bat-tery significantly.Install an optional Rectifier Regulator or useaccessories rated to withstand 18 volts orhigher with the above models. Consult yourYamaha dealer for details on installing anoptional Rectifier Regulator.

EMU34191

Propeller selection

Next to selecting an outboard, choosing theright propeller is one of the most importantpurchasing decisions a boater can make.The type, size, and design of your propellerhave a direct impact on acceleration, topspeed, fuel economy, and even engine life.Yamaha designs and manufactures propel-lers for every Yamaha outboard motor andevery application.Your outboard motor came with a Yamahapropeller chosen to perform well over arange of applications, but there may be useswhere a different propeller would be moreappropriate.

Minimum cold cranking amps (CCA/EN):F25AEHT 347.0 AF25AET 347.0 AFT25BET 347.0 A

Minimum rated capacity (20HR/IEC):F25AEHT 40.0 AhF25AET 40.0 AhFT25BET 40.0 Ah


13

Your Yamaha dealer can help you select theright propeller for your boating needs. Selecta propeller that will allow the engine to reachthe middle or upper half of the operatingrange at full throttle with the maximum boat-load. Generally, chose a larger pitch propel-ler for a smaller operating load and a smallerpitch propeller for a heavier load. If you carryloads that vary widely, chose the propellerthat lets the engine run in the proper rangefor your maximum load but remember thatyou may need to reduce your throttle settingto stay within the recommended enginespeed range when carrying lighter loads.For instructions on propeller removal and in-stallation, see page 68.

EMU25770

Start-in-gear protection

Yamaha outboard motors or Yamaha-ap-proved remote control units are equippedwith start-in-gear protection device(s). Thisfeature permits the engine to be started onlywhen it is in neutral. Always select neutralbefore starting the engine.

1. Propeller diameter in inches2. Propeller pitch in inches3. Type of propeller (propeller mark)

1. Propeller diameter in inches

ZMU04604

-x1 2 3

ZMU04606

-x1 2 3

2. Propeller pitch in inches3. Type of propeller (propeller mark)

1. Propeller diameter in inches2. Propeller pitch in inches3. Type of propeller (propeller mark)

ZMU04605

-x1 2 3


14

EMU37471

Engine oil requirements

If the recommended engine oil grades arenot available, select an alternative from thefollowing chart according to the averagetemperatures in your area.

EMU36360

Fuel requirements

EMU36770

Gasoline

Use a good quality gasoline that meets theminimum octane rating. If knocking or ping-ing occurs, use a different brand of gasolineor premium unleaded fuel. Yamaha re-comends that you use alcohol-free (seeGasohol) gasoline whenever possible.

NOTICE

ECM01980

Do not use leaded gasoline. Leadedgasoline can seriously damage the en-gine.

Avoid getting water and contaminantsin the fuel tank. Contaminated fuel cancause poor performance or enginedamage. Use only fresh gasoline that

has been stored in clean containers.

Gasohol

There are two types of gasohol: gasohol con-taining ethanol (E10) and that containingmethanol. Ethanol can be used if the ethanolcontent does not exceed 10% and the fuelmeets the minimum octane ratings. All etha-nol blends containing more than 10% etha-nol can cause fuel system damage or causeengine starting and running problems.Yamaha does not recommend gasohol con-taining methanol because it can cause fuelsystem damage or engine performanceproblems.

EMU36880

Muddy or acidic water

Yamaha strongly recommends that you haveyour dealer install the optional chromium-plated water pump kit if you use the outboard

Recommended engine oil:4-stroke motor oil with a combination of the following SAE and API oil classi-fications

Engine oil type SAE:10W-30 or 10W-40

Engine oil grade API:SE, SF, SG, SH, SJ, SL

Engine oil quantity without replacement of oil filter (Oil pan capacity):

F25AEHT 1.7 L (1.80 US qt, 1.50 Imp.qt)F25AET 1.7 L (1.80 US qt, 1.50 Imp.qt)F25AMH 1.7 L (1.80 US qt, 1.50 Imp.qt)F25CMH 1.7 L (1.80 US qt, 1.50 Imp.qt)FT25BET 1.9 L (2.01 US qt, 1.67 Imp.qt)

Recommended gasoline:Regular unleaded gasoline


15

motor in muddy or acidic water conditions.However, depending on the model it mightnot be required.

EMU36330

Anti-fouling paint

A clean hull improves boat performance. Theboat bottom should be kept as clean of ma-rine growth as possible. If necessary, theboat bottom can be coated with an anti-foul-ing paint approved for your area to inhibitmarine growth.Do not use anti-fouling paint which includescopper or graphite. These paints can causemore rapid engine corrosion.

EMU36341

Motor disposal requirements

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

EMU36351

Emergency equipment

Keep the following items onboard in casethere is trouble with the motor.

A tool kit with assorted screwdrivers, pli-ers, wrenches (including metric sizes), andelectrical tape.

Waterproof flashlight with extra batteries.

An extra engine shut-off cord (lanyard)with clip.

Spare parts, such as an extra set of sparkplugs.

Consult your Yamaha dealer for details.

16

Components

EMU2579J

Components diagramTIP:

* May not be exactly as shown; also may not be included as standard equipment on all mod-els.

F25A, FT25B, F25C

27

24

1

3

4

56

109

11

8

7

25

23

1213

14 17

21

1920 18

22

26

215 16

28

ZMU02818

1. Top cowling2. Cooling water pilot hole3. Top cowling lock lever(s)4. Drain screw5. Anti-cavitation plate6. Trim tab7. Propeller8. Cooling water inlet9. Trim rod*10. Clamp bracket11. Power trim and tilt switch*12. Manual starter handle*13. Alert indicator14. Gear shift lever*15. Engine stop button/Engine shut-off switch*

16. Throttle friction adjuster*17. Tiller handle*18. Steering friction lever*19. Transom clamp handle*20. Rope attachment21. Tilt lock lever*22. Flushing device*23. Starter button*24. Tilt support knob*25. Fuel tank*26. Remote control box (side mount type)*27. Remote control cable*28. Clip*

Components

17

EMU25802

Fuel tank

If your model was equipped with a portablefuel tank, its function is as follows.

WARNING

EWM00020

The fuel tank supplied with this engine isits dedicated fuel reservoir and must notbe used as a fuel storage container. Com-mercial users should conform to relevantlicensing or approval authority regula-

tions.

EMU25830

Fuel joint

This joint is used to connect the fuel line.

EMU25841

Fuel gauge

This gauge is located on either the fuel tankcap or on the fuel joint base. It shows the ap-proximate amount of fuel remaining in thetank.

EMU25850

Fuel tank cap

This cap seals the fuel tank. When removed,the tank can be filled with fuel. To remove thecap, turn it counterclockwise.

EMU25860

Air vent screw

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

EMU26181

Remote control box

The remote control lever actuates both theshifter and the throttle. The electrical switch-es are mounted on the remote control box.

EMU26190

Remote control lever

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

1. Fuel joint2. Fuel gauge3. Fuel tank cap4. Air vent screw

ZMU022843

1

4

2

1. Power trim and tilt switch2. Remote control lever3. Neutral interlock trigger4. Neutral throttle lever5. Main switch6. Engine shut-off switch7. Throttle friction adjuster

Components

18

EMU26201

Neutral interlock trigger

To shift out of neutral, first pull the neutral in-terlock trigger up.

EMU26211

Neutral throttle lever

To open the throttle without shifting into ei-ther forward or reverse, put the remote con-trol lever in the neutral position and lift theneutral throttle lever.TIP:

The neutral throttle lever will operate only

when the remote control lever is in neutral.The remote control lever will operate onlywhen the neutral throttle lever is in the closedposition.

EMU25911

Tiller handle

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

EMU25922

Gear shift lever

Pulling the gear shift lever towards you putsthe engine in forward gear so that the boatmoves ahead. Pushing the lever away fromyou puts the engine in reverse gear so thatthe boat moves astern.

1. Neutral 2. Forward 3. Reverse 4. Shift5. Fully closed6. Throttle7. Fully open

1. Neutral interlock trigger

1. Fully open2. Fully closed

ZMU01997

Components

19

EMU25941

Throttle grip

The throttle grip is on the tiller handle. Turnthe grip counterclockwise to increase speedand clockwise to decrease speed.

EMU25961

Throttle indicator

The fuel consumption curve on the throttleindicator shows the relative amount of fuelconsumed for each throttle position. Choosethe setting that offers the best performanceand fuel economy for the desired operation.

EMU25973

Throttle friction adjuster

A friction device provides adjustable resis-tance to movement of the throttle grip or theremote control lever, and can be set accord-ing to operator preference.To increase resistance, turn the adjusterclockwise.

WARNING! Do not overtightenthe friction adjuster. If there is too muchresistance, it could be difficult to movethe remote control lever or throttle grip,which could result in an accident.

[EWM00032]

To decrease resistance, turn the adjustercounterclockwise.

1. Forward 2. Neutral 3. Reverse

ZMU02285

2

1

3R N

F

ZMU01999

1. Throttle indicator

START

1

ZMU02286

Components

20

When constant speed is desired, tighten theadjuster to maintain the desired throttle set-ting.

EMU25993

Engine shut-off cord (lanyard) and clip

The clip must be attached to the engine shut-off switch for the engine to run. The cordshould be attached to a secure place on theoperators clothing, or arm or leg. Should theoperator fall overboard or leave the helm, thecord will pull out the clip, stopping ignition tothe engine. This will prevent the boat fromrunning away under power.

WARNING! At-tach the engine shut-off cord to a secureplace on your clothing, or your arm or legwhile operating. Do not attach the cord toclothing that could tear loose. Do notroute the cord where it could become en-tangled, preventing it from functioning.Avoid accidentally pulling the cord dur-ing normal operation. Loss of enginepower means the loss of most steeringcontrol. Also, without engine power, theboat could slow rapidly. This could causepeople and objects in the boat to bethrown forward.

[EWM00122]

ZMU02001

1. Cord2. Clip3. Engine shut-off switch


21

3

ZMU02003

Components

21

EMU26001

Engine stop button

To open the ignition circuit and stop the en-gine, push this button.

EMU26070

Manual starter handle

To start the engine, first gently pull the han-dle out until resistance is felt. From that posi-tion, then pull the handle straight out quicklyto crank the engine.

EMU26080

Starter button

To start the engine with the electric starter,push the starter button.

EMU26090

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 keycan be removed.

(on)

With the main switch in the (on) posi-tion, the electrical circuits are on, and the keycannot be removed.

(start)

With the main switch in the (start) po-sition, the starter motor turns to start the en-gine. When the key is released, it returnsautomatically to the (on) position.

EMU31432

Steering friction adjuster

A friction device provides adjustable resis-tance to the steering mechanism, and can be

ZMU02083

ZMU02287

ZMU02809

Components

22

set according to operator preference. An ad-juster lever is located on the bottom of thetiller handle bracket.To increase resistance, turn the lever to theport side A.To decrease resistance, turn the lever to thestarboard side B.

WARNING

EWM00040

Do not overtighten the friction adjuster. Ifthere is too much resistance, it could bedifficult to steer, which could result in an

accident.

If the resistance does not increase evenwhen the lever is turned to the port side A,make sure that the nut is tightened to thespecified torque.

TIP:

Steering movement is blocked when theadjuster lever is set to the A position.

Check the tiller handle for smooth move-ment when the lever is turned to the star-board side B.

Do not apply lubricants such as grease tothe friction areas of the steering friction ad-juster.

EMU26122

Steering friction adjuster

A friction device provides adjustable resis-tance to the steering mechanism, and can beset according to operator preference. An ad-justing screw or bolt is located on the swivelbracket.

To increase resistance, turn the adjusterclockwise.To decrease resistance, turn the adjustercounterclockwise.

WARNING

EWM00040

Do not overtighten the friction adjuster. Ifthere is too much resistance, it could bedifficult to steer, which could result in an

accident.

1. Nut

ZMU02810

B

A

Nut tightening torque:3.9 Nm (0.4 kgf-m, 2.9 ft-lb)

ZMU02288

Components

23

EMU26143

Power trim and tilt switch on remote control or tiller handle

The power trim and tilt system adjusts theoutboard motor angle in relation to the tran-som. Pressing the switch (up) trims theoutboard motor up, and then tilts it up. Press-ing the switch (down) tilts the outboardmotor down and trims it down. When theswitch is released, the outboard motor willstop in its current position.For instructions on using the power trim andtilt switch, see pages 46 and 49.

EMU26153

Power trim and tilt switch on bottom engine cowling

The power trim and tilt switch is located onthe side of the bottom engine cowling. Press-ing the switch (up) trims the outboardmotor up, and then tilts it up. Pressing theswitch (down) tilts the outboard motordown and trims it down. When the switch isreleased, the outboard motor will stop in itscurrent position.For instructions on using the power trim andtilt switch, see page 49.

WARNING

EWM01030

Use the power trim and tilt switch locatedon the bottom engine cowling only whenthe boat is at a complete stop with the en-

gine off. Attempting to use this switchwhile the boat is moving could increasethe risk of falling overboard and coulddistract the operator, increasing the riskof collision with another boat or an obsta-

cle.

EMU26244

Trim tab with anode

WARNING

EWM00840

An improperly adjusted trim tab couldcause difficult steering. Always test runafter the trim tab has been installed or re-placed to be sure steering is correct. Besure you have tightened the bolt after ad-

justing the trim tab.

The trim tab should be adjusted so that thesteering control can be turned to either theright or left by applying the same amount offorce.If the boat tends to veer to the left (port side),turn the trim tab rear end to the port side Ain the figure. If the boat tends to veer to theright (starboard side), turn the trim tab end tothe starboard side B in the figure.

NOTICE

ECM00840

The trim tab also serves as an anode toprotect the engine from electrochemicalcorrosion. Never paint the trim tab as it

ZMU02811

UPDN

Components

24

will become ineffective as an anode.

EMU26253

Trim tab

WARNING

EWM00840

An improperly adjusted trim tab couldcause difficult steering. Always test runafter the trim tab has been installed or re-placed to be sure steering is correct. Besure you have tightened the bolt after ad-

justing the trim tab.

The trim tab should be adjusted so that thesteering control can be turned to either theright or left by applying the same amount offorce.If the boat tends to veer to the left (port side),turn the trim tab rear end to the port side Ain the figure.If the boat tends to veer to the right (star-board side), turn the trim tab end to the star-board side B in the figure.

EMU26261

Trim rod (tilt pin)

The position of the trim rod determines theminimum trim angle of the outboard motor inrelation to the transom.

1. Trim tab2. Bolt

Bolt tightening torque:18.0 Nm (1.8 kgf-m, 13 ft-lb)

ZMU02822

1

2

A

B

1. Trim tab2. Bolt

Bolt tightening torque:8.0 Nm (0.8 kgf-m, 5.8 ft-lb)

1

2

ZMU02289

A

B

ZMU02889

Components

25

EMU30530

Tilt lock mechanism

The tilt lock mechanism is used to preventthe outboard motor from lifting out of the wa-ter when in reverse gear.

To lock it, set the tilt lock lever in the lock po-sition. To release, push the tilt lock lever inthe release position.

EMU26321

Tilt support knob

To keep the outboard motor in the tilted upposition, push the tilt support knob under theswivel bracket.

NOTICE

ECM00660

Do not use the tilt support lever or knobwhen trailering the boat. The outboardmotor could shake loose from the tilt sup-port and fall. If the motor cannot be trail-

ered in the normal running position, usean additional support device to secure it

in the tilt position.

EMU26332

Tilt support bar

The tilt support bar keeps the outboard motorin the tilted up position.

NOTICE

ECM01660

Do not use the tilt support bar whentrailering the boat. The outboard motorcould shake loose from the tilt supportand fall. If the motor cannot be trailered inthe normal running position, use an addi-tional support device to secure it in the

tilt position.

1. Tilt lock lever

ZMU02291

1

ZMU02812

ZMU02292

Components

26

EMU26372

Top cowling lock lever(s) (turn type)

To remove the engine top cowling, turn thelock lever(s) and lift off the cowling. When in-stalling the cowling, check to be sure it fitsproperly in the rubber seal. Then lock thecowling again by returning the lever(s) to thelock position.

EMU26460

Flushing device

This device is used to clean the cooling wa-ter passages of the motor using a gardenhose and tap water.TIP:

For details on usage, see page 57.

EMU26303

Alert indicator

If the engine develops a condition which iscause for alert, the indicator lights up. Fordetails on how to read the alert indicator, seepage 28.

1. Top cowling lock lever(s)

1. Flushing device

ZMU02009

1

ZMU02813

1

ZMU02293

27

Instruments and indicators

EMU36014

Indicators

EMU36023

Low oil pressure-alert indicator

If oil pressure drops too low, this indicator willlight up. For further information, see page 28.

NOTICE

ECM00022

Do not continue to run the engine if thelow oil pressure-alert indicator is onand the engine oil level is lower. Seri-ous engine damage will occur.

The low oil pressure-alert indicatordoes not indicate the engine oil level.Use the oil dipstick to check the re-maining oil quantity. For further infor-

mation, see page 35.

ZMU02294

28

Engine control system

EMU26803

Alert system

NOTICE

ECM00091

Do not continue to operate the engine if aalert device has activated. Consult yourYamaha dealer if the problem cannot be

located and corrected.

EMU2681A

Overheat alert

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

The engine speed will automatically de-crease to about 2000 r/min.

The overheat-alert indicator will light orblink.

The buzzer will sound (if equipped on thetiller handle, remote control box, or mainswitch panel).

If the alert system has activated, stop the en-gine and check the cooling water inlets:

Check trim angle to be sure that the cool-ing water inlet is submerged.

Check the cooling water inlet for clogging.

EMU3016A

Low oil pressure alert

If the oil pressure drops too low, the alert de-vice will activate.

The engine speed will automatically de-crease to about 2000 r/min. If equippedwith a low oil pressure-alert indicator, it willlight or blink.

The buzzer will sound (if equipped on thetiller handle, remote control box, or mainswitch panel).

ZMU02360

ZMU02294

ZMU02360

Engine control system

29

If the alert system has activated, stop the en-gine as soon as it is safe to do so. Check theoil level and add oil as needed. If the oil levelis correct and the alert device does notswitch off, consult your Yamaha dealer.

30

Installation

EMU26902

Installation

The information presented in this section isintended as reference only. It is not possibleto provide complete instructions for everypossible boat and motor combination. Prop-er mounting depends in part on experienceand the specific boat and motor combination.

WARNING

EWM01590

Overpowering a boat could cause se-vere instability. Do not install an out-board motor with more horsepowerthan the maximum rating on the capac-ity plate of the boat. If the boat does nothave a capacity plate, consult the boatmanufacturer.

Improper mounting of the outboard mo-tor could result in hazardous condi-tions such as poor handling, loss ofcontrol, or fire hazards. For permanent-ly mounted models, your dealer or oth-er person experienced in proper

rigging should mount the motor.

EMU33470

Mounting the outboard motor

The outboard motor should be mounted sothat the boat is well balanced. Otherwise, theboat could be hard to steer. For single-en-gine boats, mount the outboard motor on thecenterline (keel line) of the boat.

EMU26921

Mounting height

To run your boat at optimum efficiency, thewater resistance (drag) of the boat and out-board motor must be made as little as possi-ble. The mounting height of the outboardmotor greatly affects the water resistance. Ifthe mounting height is too high, cavitationtends to occur, thus reducing the propulsion;and if the propeller tips cut the air, the enginespeed will rise abnormally and cause the en-gine to overheat. If the mounting height is toolow, the water resistance will increase andthereby reduce engine efficiency. Mount theoutboard motor so that the anti-cavitationplate is between the bottom of the boat anda level 25 mm (1 in.) below it.

1. Center line (keel line)

ZMU017601

Installation

31

NOTICE

ECM01630

During water testing, check the buoy-ancy of the boat, at rest, with its maxi-mum load. Check that the static waterlevel on the exhaust housing is lowenough to prevent water entry into thepower head when water rises due towaves when the outboard is not run-ning.

Incorrect engine height or obstructionsto the smooth flow of water (such as thedesign or condition of the boat, or ac-cessories such as transom ladders ordepth finder transducers) can createairborne water spray while the boat iscruising. If the motor is operated con-tinuously in the presence of airbornewater spray, enough water could enterthe engine through the intake openingon the cowling to cause severe enginedamage. Eliminate the cause of the air-

borne water spray.

TIP:

The optimum mounting height of the out-board motor is affected by the boat andmotor combination and the desired use.Test runs at different heights can help de-termine the optimum mounting height.Consult your Yamaha dealer or boat man-

ufacturer for further information on deter-mining the proper mounting height.

For instructions on setting the trim angle ofthe outboard motor, see page 46.

EMU26971

Clamping the outboard motor

1. Place the outboard motor on the tran-som so that it is positioned as close tothe center as possible. Tighten the tran-som clamp screws evenly and securely.Occasionally check the clamp screwsfor tightness during operation of the out-board motor because they could be-come loose due to engine vibration.

WARNING! Loose clamp screwscould allow the outboard motor to falloff or move on the transom. Thiscould cause loss of control and seri-ous injury. Make sure the transomscrews are tightened securely. Occa-sionally check the screws for tight-ness during operation.

[EWM00641]

2. If the engine restraint cable attachmentis equipped on your engine, an enginerestraint cable or chain should be used.Attach one end to the engine restraintcable attachment and the other to a se-cure mounting point on the boat. Other-wise the engine could be completely lostif it accidentally falls off the transom.

ZMU02011025mm(01in.)

ZMU02012

Installation

32

3. Secure the clamp bracket to the transomusing the bolts provided with the out-board (if packed). For details, consultyour Yamaha dealer.

WARNING! Avoidusing bolts, nuts or washers otherthan those contained in the enginepackaging. If used, they must be of atleast the same quality of material andstrength and must be tightened se-curely. After tightening, test run theengine and check their tightness.

[EWM00651]

1. Bolts

ZMU02013

ZMU02637

1

33

Operation

EMU36380

First-time operation

EMU36390

Fill engine oil

The engine is shipped from the factory with-out engine oil. If your dealer did not fill the oil,you must fill it before starting the engine.

NO-TICE:

Check that the engine is filled withoil before first-time operation to avoid se-vere engine damage.

[ECM01780]

The engine is shipped with the followingsticker, which should be removed after en-gine oil is filled for the first time. For more in-formation on checking the engine oil level,see page 35.

EMU30174

Breaking in engine

Your new engine requires a period of break-in to allow mating surfaces of moving parts towear in evenly. Correct break-in will help en-sure proper performance and longer enginelife.

NOTICE:

Failure to follow the break-inprocedure could result in reduced enginelife or even severe engine damage.

[ECM00801]

EMU27084

Procedure for 4-stroke models

Your new engine requires a period of 10hours break-in to allow mating surfaces ofmoving parts to wear in evenly. Correctbreak-in will help ensure proper performanceand longer engine life.

TIP:

Failure to follow the break-in procedurecould result in reduced engine life or evensevere engine damage. Run the engine inthe water, under load (in gear with a propel-ler installed) as follows. For ten hours forbreaking in engine avoid extended idling,rough water and crowded areas.1. For the first hour of operation:

Run the engine at varying speeds up to2000 r/min or approximately half throttle.

2. For the second hour of operation:Increase engine speed as much as nec-essary to put the boat on plane (butavoid full-throttle operation), then backoff on the throttle while keeping the boatat a planing speed.

3. Remaining eight hours:Run the engine at any speed. However,avoid operating at full throttle for morethan 5 minutes at a time.

4. After the first 10 hours:Operate the engine normally.

EMU36400

Getting to know your boat

Different boats handle differently. Operatecautiously while you learn how your boathandles under different conditions and withdifferent trim angles (see page 46).

EMU36412

Checks before starting engineWARNING

EWM01920

If any item in the checks before startingengine is not working properly, have it in-spected and repaired before operatingthe outboard motor. Otherwise an acci-

dent could occur.

NOTICE

ECM00120

Do not start the engine out of water. Over-

ZMU01710

Operation

34

heating and serious engine damage can

occur.

EMU36560

Fuel level

Be sure you have plenty of fuel for your trip.A good rule is to use 1/3 of your fuel to get tothe destination, 1/3 to return, and to keep 1/3 as an emergency reserve. With the boatlevel on a trailer or in the water, check thefuel level. For fuel filling instructions, seepage 37.

EMU36570

Remove cowling

For the following checks, remove the topcowling from the engine. To remove the en-gine top cowling, release the lock lever andlift off the cowling.

EMU36442

Fuel system

WARNING

EWM00060

Gasoline and its vapors are highly flam-mable and explosive. Keep away fromsparks, cigarettes, flames, or other

sources of ignition.

WARNING

EWM00910

Leaking fuel can result in fire or explo-sion.

Check for fuel leakage regularly.

If any fuel leakage is found, the fuel

system must be repaired by a qualifiedmechanic. Improper repairs can make

the outboard unsafe to operate.

EMU36450

Check for fuel leaks

Check under top cowling and in the boatfor fuel leaks or gasoline fumes.

Check fuel line connections to be sure theyare tight.

Check fuel lines for cracks, swelling, orother damage.

EMU37320

Check the fuel filter

Check that the fuel filter is clean and free ofwater. If any water is found in the fuel, or if asignificant amount of debris is found, the fueltank should be checked and cleaned by aYamaha dealer.

EMU36900

Controls

Tiller handle models:

Turn the tiller handle fully to the left andright to make sure operation is smooth.

Turn the throttle grip from the fully closedto the fully open position. Make sure that itturns smoothly and that it completely re-turns to the fully closed position.

Look for loose or damaged connections ofthe throttle and shift cables under the en-gine cowling.

Remote control models:

ZMU06090ZMU06230

Operation

35

Turn the steering wheel full-right and full-left. Make sure operation is smooth andunrestricted throughout the whole rangewith no binding or excessive free play.

Operate the throttle levers several times tomake sure there is no hesitation in theirtravel. Operation should be smooth overthe complete range of motion, and each le-ver should return completely to the idle po-sition.

Look for loose or damaged connections ofthe throttle and shift cables under the en-gine cowling.

EMU36481

Engine shut-off cord (lanyard)

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

EMU27165

Engine oil

1. Put the outboard motor in an upright po-sition (not tilted).

NOTICE:

If the motoris not level, the oil level indicated onthe dipstick may not be accurate.

[ECM01790]

2. Remove the top cowling.3. Remove oil dipstick and wipe it clean.4. Insert the dipstick and remove it again.

Be sure to completely insert the dipstickinto the dipstick guide, otherwise the oillevel measurement will be incorrect.

5. Check the oil level using the dipstick tobe sure the level falls between the upperand lower marks. Fill with oil if it is belowthe lower mark, or drain to the specifiedlevel if it is above the upper mark.



21

3

ZMU02003

Operation

36

EMU27151

Engine

Check the engine and engine mounting.

Look for loose or damaged fasteners.

Check the propeller for damage.

Check for oil leaks.

EMU36490

Flushing device

Check that flushing devices garden hoseconnector is securely screwed on to the fit-ting on the bottom cowling.

NOTICE:

If theflushing device is not properly connect-ed, cooling water can leak out and the en-gine can overheat during operation.

[ECM01800]

EMU36952

Install cowling

1. Be sure that a cowling lock lever is re-leased.

2. Be sure that the rubber seal is seated allthe way around the engine.

3. Place the cowling on top of the seal.4. Check to be sure the rubber seal fits cor-

rectly all the way around the engine.5. Move the lever to lock the cowling as

shown.

NOTICE:

If the cowling is notinstalled correctly, water spray underthe cowling can damage the engine,or the cowling can blow off at highspeeds.

[ECM01990]

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

1. Oil dipstick

1. Lower level mark2. Oil dipstick3. Upper level mark

ZMU02833

1

ZMU02082

1 3 2

1. Fitting2. Flushing device

ZMU06046

21

ZMU06115

Operation

37

Yamaha dealer.

EMU34581

Power trim and tilt system

WARNING

EWM01930

Never get under the lower unit while itis tilted, even when the tilt support leveris locked. Severe injury could occur ifthe outboard motor accidentally falls.

Body parts can be crushed between themotor and the clamp bracket when themotor is trimmed or tilted.

Be sure no one is near the outboard

motor before performing this check.

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

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

3. Tilt the outboard motor up and check

that the trim and tilt rod is pushed outcompletely.

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

5. Tilt the outboard motor down. Checkthat the trim and tilt rod operatessmoothly.

EMU36581

Battery

Check that the battery is in good condition,and fully charged. Check that the batteryconnections are clean, secure and coveredby insulating covers. The electrical contactsof the battery and cables must be clean andproperly connected or the battery will notstart the engine.Refer to the battery manufacturers instruc-tions for checks for your particular battery.

EMU27436

Filling fuelWARNING

EWM01830

Gasoline and its vapors are highly flam-mable and explosive. Always refuel ac-cording to this procedure to reduce therisk of fire and explosion.

Gasoline is poisonous and can causeinjury or death. Handle gasoline withcare. Never siphon gasoline by mouth.If you should swallow some gasoline orinhale a lot of gasoline vapor, or getsome gasoline in your eyes, see yourdoctor immediately. If gasoline spillson your skin, wash with soap and wa-ter. If gasoline spills on your clothing,

change your clothes.

1. Stop the engine.2. Remove the portable tank from the boat.3. Be sure you are in a well-ventilated out-

door area, either securely moored ortrailered.

1. Trim and tilt rod

ZMU02068

ZMU02828

1

Operation

38

4. Do not smoke and keep away fromsparks, flames, static electric discharge,or other sources of ignition.

5. If you use a portable container to storeand dispense fuel, use only an approvedGASOLINE container.

6. Touch the fuel nozzle to the filler open-ing or funnel to help prevent electrostaticsparks.

7. Fill the fuel tank, but do not overfill. Fuelcan expand and overflow if the tempera-ture increases.

8. Tighten the filler cap securely.9. Wipe up any spilled gasoline immediate-

ly with dry rags. Dispose rags properly.According to local laws or regulations.

EMU27451

Operating engine

EMU27464

Feeding fuel (portable tank)WARNING

EWM00420

Before starting the engine, make surethat the boat is tightly moored and thatyou can steer clear of any obstructions.Be sure there are no swimmers in thewater near you.

When the air vent screw is loosened,

gasoline vapor will be released. Gaso-line is highly flammable, and its vaporsare flammable and explosive. Refrainfrom smoking, and keep away fromopen flames and sparks while loosen-ing the air vent screw.

This product emits exhaust gaseswhich contain carbon monoxide, a col-orless, odorless gas which could causebrain damage or death when inhaled.Symptoms include nausea, dizziness,and drowsiness. Keep cockpit and cab-in areas well ventilated. Avoid blocking

exhaust outlets.

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

2. If there is a fuel joint on the motor, firmlyconnect the fuel line to the joint. Thenfirmly connect the other end of the fuelline to the joint on the fuel tank.

Fuel tank capacity:24 L (6.34 US gal, 5.28 Imp.gal)

ZMU02834

ZMU02295

ZMU02296

Operation

39

3. Squeeze the primer pump, with the ar-row pointing up, until you feel it becomefirm. During engine operation place thetank horizontally, otherwise fuel cannotbe drawn from the fuel tank.

EMU27492

Starting engine

WARNING

EWM01600

Before starting the engine, make surethat the boat is tightly moored and thatyou can steer clear of any obstructions.Be sure there are no swimmers in the wa-

ter near you.

EMU27545

Starting engine

WARNING

EWM01840

Failure to attached engine shut-off cord

could result in a runaway boat if opera-tor is ejected. Attach the engine shut-off cord to a secure place on your cloth-ing, or your arm or leg while operating.Do not attach the cord to clothing thatcould tear loose. Do not route the cordwhere it could become entangled, pre-venting it from functioning.

Avoid accidentally pulling the cord dur-ing normal operation. Loss of enginepower means the loss of most steeringcontrol. Also, without engine power,the boat could slow rapidly. This couldcause people and objects in the boat to

be thrown forward.

1. Place the gear shift lever in neutral.

TIP:

The start-in-gear protection device preventsthe engine from starting except when in neu-tral.2. Attach the engine shut-off cord to a se-

cure place on your clothing, or your armor leg. Then install the clip on the otherend of the cord into the engine shut-offswitch.

1. Arrow

ZMU02024

ZMU02025

ZMU02304

N

Operation

40

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

4. Pull the manual starter handle slowly un-til you feel resistance. Then give astrong pull straight out to crank and startthe engine. Repeat if necessary.

5. After the engine starts, slowly return themanual starter handle to its original po-sition before releasing it.

TIP:

When the engine is cold, it needs to bewarmed up. For further information, seepage 43.

If the engine is warm and fails to start,open the throttle slightly and try to start theengine again. If the engine still fails tostart, see page 74.

6. Slowly return the throttle grip to the fullyclosed position.

EMU27604

Electric start/prime start models

WARNING

EWM01840

Failure to attached engine shut-off cordcould result in a runaway boat if opera-tor is ejected. Attach the engine shut-off cord to a secure place on your cloth-ing, or your arm or leg while operating.Do not attach the cord to clothing thatcould tear loose. Do not route the cordwhere it could become entangled, pre-venting it from functioning.


be thrown forward.


ZMU02026

START

START

ZMU02335

ZMU02336

ZMU02304

N

Operation

41

TIP:



3. Place the throttle grip in the (start) position. After the engine starts,return the throttle to the fully closed po-sition.

4. Push the starter button to start the en-gine.

5. Immediately after the engine starts, re-lease the starter button and allow it to re-turn to its original position.

NOTICE:

Never push the starter button whilethe engine is running. Do not keepthe starter motor turning for morethan 5 seconds. If the starter motor isturned continuously for more than 5seconds, the battery will be quicklydischarged, thus making it impossi-ble to start the engine. The starter canalso be damaged. If the engine willnot start after 5 seconds of cranking,release the starter button, wait 10seconds, then crank the engineagain.

[ECM00161]

TIP:

When the engine is cold, it needs to bewarmed up. For further information, seepage 43.


6. Slowly return the throttle grip to the fullyclosed position.

ZMU02026

START

START

ZMU02335

ZMU02809

Operation

42

EMU27664

Electric start and remote control models

WARNING

EWM01840

Failure to attached engine shut-off cordcould result in a runaway boat if opera-tor is ejected. Attach the engine shut-off cord to a secure place on your cloth-ing, or your arm or leg while operating.Do not attach the cord to clothing thatcould tear loose. Do not route the cordwhere it could become entangled, pre-venting it from functioning.


be thrown forward.

1. Place the remote control lever in neutral.

TIP:



3. Turn the main switch to (on).4. Turn the main switch to (start),

and hold it for a maximum of 5 seconds.

5. Immediately after the engine starts, re-lease the main switch and allow it to re-turn to (on).

NOTICE:

Never turnthe main switch to (start)while the engine is running. Do notkeep the starter motor turning formore than 5 seconds. If the startermotor is turned continuously formore than 5 seconds, the battery willbe quickly discharged, thus making itimpossible to start the engine. Thestarter can also be damaged. If theengine will not start after 5 secondsof cranking, return the main switch to (on), wait 10 seconds, thencrank the engine again.

[ECM00192]

TIP:

When the engine is cold, it needs to be

Operation

43

warmed up. For further information, seepage 43.


EMU36510

Checks after starting engine

EMU36520

Cooling water

Check for a steady flow of water from thecooling water pilot hole. A continuous flow ofwater from the pilot hole shows that the wa-ter pump is pumping water through the cool-ing passages. If the cooling passages arefrozen, it may take a while for water to startflowing out of the pilot hole.

NOTICE

ECM01810

If water is not flowing out of the pilot holeat all times while the engine is running,overheating and serious damage couldoccur. Stop the engine and check wheth-er the cooling water inlet on the lowercase or the cooling water pilot hole isblocked. Consult your Yamaha dealer ifthe problem cannot be located and cor-

rected.

Check that no water leaks from the joints be-tween the exhaust cover, cylinder head, andbody cylinder.

EMU27670

Warming up engine

EMU27715

Manual start and electric start models

1. After starting the engine, allow it to idlefor 3 minutes to warm up. Failure to doso will shorten engine life.

2. Be sure the low oil pressure-alert indica-tor goes off after starting the engine.

NOTICE:

If the low oil pressure-alertindicator blinks after the enginestarts, stop the engine. Otherwise se-rious engine damage could occur.Check the oil level and add oil if nec-essary. Consult your Yamaha dealerif the cause for the low oil pressure-alert indicator cannot be found.

[ECM01830]

EMU36530

Checks after engine warm-up

EMU36540

Shifting

While tightly moored, and without applyingthrottle, confirm that the engine shiftssmoothly into forward and reverse, and backto neutral.

EMU36980

Stop switches

Turn the main switch to , or press theengine stop button and make sure the en-gine stops.

Confirm that removing the clip from the en-gine shut-off switch stops the engine.

Confirm that the engine cannot be startedwith the clip removed from the engineshut-off switch.

ZMU02034

Operation

44

EMU34530

ShiftingWARNING

EWM00180

Before shifting, make sure there are noswimmers or obstacles in the water near

you.

NOTICE

ECM01610

Warm up the engine before shifting intogear. Until the engine is warm, the idlespeed may be higher than normal. Highidle speed can prevent you from shiftingback to neutral. If this occurs, stop theengine, shift to neutral, then restart the

engine and allow it to warm up.

To shift out of neutral1. Pull the neutral interlock trigger up (if

equipped).

2. Move the remote control lever / gearshift lever firmly and crisply forward (forforward gear) or backward (for reversegear) [about 35 (a detent can felt) for re-mote control models]. Be sure to checkthat the tilt lock lever is in the lock/downposition (if equipped) before operating inreverse.

To shift from in gear (forward/reverse) toneutral1. Close the throttle so that the engine

slows to idle speed.

1. Neutral interlock trigger

ZMU02299

ZMU05737

R N

F

Operation

45

2. After the engine is at idle speed in gearmove the remote control lever / gearshift lever firmly and crisply into the neu-tral position.

EMU31742

Stopping boatWARNING

EWM01510

Do not use the reverse function to slowdown or stop the boat as it could causeyou to lose control, be ejected, or im-pact the steering wheel or other parts ofthe boat. This could increase the risk ofserious injury. It could also damage theshift mechanism.

Do not shift into reverse while travelingat planing speeds. Loss of control, boatswamping, or damage to the boat could

occur.

The boat is not equipped with a separatebraking system. Water resistance stops it af-ter the throttle lever is moved back to idle.The stopping distance varies depending ongross weight, water surface conditions, andwind direction.

EMU27821

Stopping engine

Before stopping the engine, first let it cool offfor a few minutes at idle or low speed. Stop-ping the engine immediately after operatingat high speed is not recommended.

EMU27845

Procedure

1. Push and hold the engine stop button orturn the main switch to (off).

ZMU02030

ZMU02304

N

Operation

46

2. After stopping the engine, disconnectthe fuel line if there is a fuel joint on theoutboard motor.

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

4. Remove the key if the boat will be leftunattended.

TIP:

The engine can also be stopped by pullingthe cord and removing the clip from the en-gine shut-off switch, then turning the mainswitch to (off).

EMU27862

Trimming outboard motorWARNING

EWM00740

Excessive trim for the operating condi-tions (either trim up or trim down) cancause boat instability and can makesteering the boat more difficult. This in-creases the possibility of an accident. Ifthe boat begins to feel unstable or is hardto steer, slow down and/or readjust the

trim angle.

The trim angle of the outboard motor helpsdetermine the position of the bow of the boatin the water. Correct trim angle will help im-prove performance and fuel economy whilereducing strain on the engine. Correct trimangle depends upon the combination ofboat, engine, and propeller. Correct trim isalso affected by variables such as the load inthe boat, sea conditions, and running speed.

ZMU02083

ZMU02302

ZMU02301

Operation

47

EMU27872

Adjusting trim angle for manual tilt models

There are 4 or 5 holes provided in the clampbracket to adjust the outboard motor trim an-gle.1. Stop the engine.2. Tilt the outboard motor up, and then re-

move the trim rod from the clamp brack-et.

3. Reposition the rod in the desired hole.To raise the bow (trim-out), move the rodaway from the transom.To lower the bow (trim-in), move the rod to-ward the transom.Make test runs with the trim set to differentangles to find the position that works best foryour boat and operating conditions.

WARNING

EWM00400

Stop the engine before adjusting thetrim angle.

Use care to avoid being pinched whenremoving or installing the rod.

Use caution when trying a trim positionfor the first time. Increase speed gradu-ally and watch for any signs of instabil-ity or control problems. Improper trim

angle can cause loss of control.

TIP:

The outboard motor trim angle can bechanged approximately 4 degrees by shiftingthe trim rod one hole.

1. Trim operating angle

ZMU02641

1

1. Trim rod

ZMU02890

1

Operation

48

EMU27885

Adjusting trim angle (Power trim and tilt)

WARNING

EWM00753

Be sure all people are clear of the out-board motor when adjusting the trimangle. Body parts can be crushed be-tween the motor and the clamp bracketwhen the motor is trimmed or tilted.

Use caution when trying a trim positionfor the first time. Increase speed gradu-ally and watch for any signs of instabil-ity or control problems. Improper trimangle can cause loss of control.

If equipped with a power trim and tiltswitch located on the bottom cowling,use the switch only when the boat is ata complete stop with the engine off. Donot adjust the trim angle with this

switch while the boat is moving.

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

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

EMU27911

Adjusting boat trim

When the boat is on plane, a bow-up attituderesults in less drag, greater stability and effi-ciency. This is generally when the keel line ofthe boat is up about 3 to 5 degrees. With thebow up, the boat may have a greater tenden-cy to steer to one side or the other. Compen-sate for this as you steer. The trim tab canalso be adjusted to help offset this effect.When the bow of the boat is down, it is easierto accelerate from a standing start ontoplane.

1. Power trim and tilt switch

ZMU02811

UPDN

Operation

49

Bow Up

Too much trim-out puts the bow of the boattoo high in the water. Performance and econ-omy are decreased because the hull of theboat is pushing the water and there is moreair drag. Excessive trim-out can also causethe propeller to ventilate, which reduces per-formance further, and the boat may por-poise (hop in the water), which could throwthe operator and passengers overboard.

Bow Down

Too much trim-in causes the boat to plowthrough the water, decreasing fuel economyand making it hard to increase speed. Oper-ating with excessive trim-in at higher speedsalso makes the boat unstable. Resistance atthe bow is greatly increased, heightening thedanger of bow steering and making opera-tion difficult and dangerous.

TIP:

Depending on the type of boat, the outboard

motor trim angle may have little effect on thetrim of the boat when operating.

EMU27934

Tilting up and down

If the engine will be stopped for some time orif the boat is moored in shallows, the out-board motor should be tilted up to protect thepropeller and lower casing from damage bycollision with obstructions, and also to re-duce salt corrosion.

WARNING

EWM00221

Be sure all people are clear of the out-board motor when tilting up and down,Body parts can be crushed between themotor and the clamp bracket when the

motor is trimmed or tilted.

WARNING

EWM00250

Leaking fuel is a fire hazard. If there is afuel joint on the outboard motor, discon-nect the fuel line or close the fuel cock ifthe engine will be tilted for more than a

few minutes. Otherwise fuel may leak.

NOTICE

ECM00241

Before tilting the outboard motor, stopthe engine by following the procedureon page 45. Never tilt the outboard mo-tor while the engine is running. Severedamage from overheating can result.

Do not tilt up the engine by pushing thetiller handle (if equipped) because this

could break the handle.

Operation

50

EMU32661

Procedure for tilting up (manual tilt models)


2. Place the tilt lock lever (if equipped) inthe release/up position.

3. Pull up the shallow water lever (ifequipped).

4. Hold the rear of the top cowling with onehand and tilt the engine up fully.

5. Push the tilt support knob into the clampbracket. Or the tilt support bar will turn tothe lock position automatically.

NO-TICE:

Do not use the tilt support leveror knob when trailering the boat. Theoutboard motor could shake loosefrom the tilt support and fall. If themotor cannot be trailered in the nor-mal running position, use an addi-tional support device to secure it inthe tilt position. For more detailed in-

formation, see page 55.

[ECM01641]

EMU32723

Procedure for tilting up (power trim and tilt models)

1. Place the remote control lever / gearshift lever in neutral.

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

ZMU02304

N

ZMU02305

ZMU02292

ZMU02304

N

Operation

51

3. Push the tilt support knob into the clampbracket to support the engine.

WARNING! After tilting the outboardmotor, be sure to support it with thetilt support knob or tilt support lever.Otherwise the outboard motor couldfall back down suddenly if oil in thepower trim and tilt unit or in the pow-er tilt unit loses pressure.

[EWM00262]

NO-TICE:

Do not use the tilt support leveror knob when trailering the boat. Theoutboard motor could shake loosefrom the tilt support and fall. If themotor cannot be trailered in the nor-mal running position, use an addi-tional support device to secure it inthe tilt position. For more detailed in-formation, see page 55.

[ECM01641]

4. Models equipped with trim rods: Oncethe outboard motor is supported with thetilt support lever, press the power trimand tilt switch (down) to retract thetrim rods.

NOTICE:

Be

Yamaha F25AET

Documents

whilethis manual

yamaha dealer

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