Yamaha 25NMHS v2 Owner's Manual
en
25
OWNERS MANUAL
6L2-28199-1N
U.S.A.Edition LIT-18626-06-57
6L2-9-1N_Hyoushi 4/25/05 5:04 PM Page 1
EMU25060
ZMU01690
Read this owners manual carefully before operating your outboard motor.
6L2-9-1N_Hyoushi 4/25/05 5:04 PM Page 2
Important manual information
EMU31280
To the owner
Thank you for choosing a Yamaha outboard motor. This Owners Manual contains infor- mation needed for proper operation, mainte- nance and care. A thorough understanding of these simple instructions will help you ob- tain 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 Owners Manual particularly important information is distinguished in the following ways.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS INVOLVED!
WARNING
EWM00780
Failure to follow WARNING instructions could result in severe injury or death to the machine operator, a bystander, or a person inspecting or repairing the out-
board motor.
CAUTION:
ECM00700
A CAUTION indicates special precautions that must be taken to avoid damage to the
outboard motor.
NOTE:
A NOTE provides key information to make
procedures easier or clearer.
Yamaha continually seeks advancements in product design and quality. Therefore, while this manual contains the most current prod- uct information available at the time of print- ing, there may be minor discrepancies between your machine and this manual. If there is any question concerning this manu-
al, please consult your Yamaha dealer.
NOTE:
The 25MH and the standard accessories are used as a base for the explanations and illus- trations in this manual. Therefore some
items may not apply to every model.
EMU25110
25 OWNERS MANUAL
2005 by Yamaha Motor Corporation, USA 1st edition, April 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-18626-06-57
Table of contents
General information .......................... 1
Identification numbers record.......... 1
Outboard motor serial 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 .... 4 Other special situations..................... 6
Fueling instructions ......................... 7
Gasoline............................................ 8 Engine oil .......................................... 8
Propeller selection........................... 8 Start-in-gear protection ................... 9
Basic components .......................... 10
Main components.......................... 10
Fuel tank ......................................... 10 Fuel joint ......................................... 11 Fuel gauge ...................................... 11 Fuel tank cap .................................. 11 Air vent screw ................................. 11 Tiller handle .................................... 11 Gear shift lever................................ 11 Throttle grip ..................................... 11 Throttle indicator ............................. 12 Throttle friction adjuster................... 12 Engine stop lanyard switch ............. 12 Engine stop button .......................... 13 Choke knob for pull type ................. 13 Manual starter handle ..................... 13 Steering friction adjuster ................. 13 Trim tab with anode ........................ 14 Trim rod (tilt pin) .............................. 14 Shallow water lever ......................... 14 Tilt lock mechanism......................... 15 Tilt support bar ................................ 15 Top cowling lock lever(s)
(turn type) ..................................... 15
Warning system ............................ 15
Overheat warning............................ 15
Operation ......................................... 17
Installation..................................... 17
Mounting the outboard motor ..........17 Clamping the outboard motor..........18
Breaking in engine ........................ 19
Gasoline and engine oil mixing chart (25:1)....................................19
Procedure for pre-mixed models.....19
Preoperation checks ..................... 20
Fuel .................................................20 Oil ....................................................20 Controls...........................................20 Engine .............................................20
Filling fuel and engine oil .............. 20
Filling fuel for portable tank .............20 Ring Free Fuel Additive...................21 Gasoline and oil mixing (100:1).......21
Operating engine .......................... 22
Feeding fuel (portable tank) ............22 Starting engine ................................23
Warming up engine....................... 25
Choke start models .........................25
Shifting.......................................... 25
Forward (tiller handle and remote control models) .................25
Reverse (manual tilt and hydro tilt models).....................................26
Stopping engine............................ 26
Procedure........................................26
Trimming outboard motor.............. 27
Adjusting trim angle for manual tilt models......................................28
Adjusting boat trim ..........................28
Tilting up and down....................... 29
Procedure for tilting up ....................30 Procedure for tilting down
(manual tilt models).......................30
Cruising in shallow water .............. 31
Cruising in shallow water (manual tilt models).......................31
Cruising in other conditions........... 32
Maintenance .................................... 33
Specifications................................ 33 Transporting and storing
outboard motor ........................... 33
Table of contents
Clamp screw mounting models ....... 34 Storing outboard motor ................... 34 Procedure ....................................... 35 Lubrication (except oil injection
models) ......................................... 36 Cleaning and anticorrosion
measures ...................................... 36 Cleaning the outboard motor .......... 36 Checking painted surface of
motor............................................. 36
Periodic maintenance.................... 36
Replacement parts .......................... 37 Maintenance chart .......................... 38 Greasing ......................................... 39 Cleaning and adjusting
spark plug ..................................... 39 Checking fuel system...................... 40 Inspecting fuel filter ......................... 41 Cleaning fuel filter ........................... 41 Inspecting idling speed ................... 42 Checking wiring and connectors ..... 42 Exhaust leakage ............................. 42 Water leakage................................. 42 Checking propeller .......................... 42 Removing the propeller ................... 43 Installing the Propeller .................... 44 Changing gear oil ............................ 44 Cleaning fuel tank ........................... 45 Inspecting and replacing
anode(s)........................................ 46 Checking top cowling ...................... 46 Coating the boat bottom.................. 46
Trouble Recovery............................ 47
Troubleshooting ............................ 47 Temporary action in
emergency .................................. 50
Impact damage ............................... 50 Starter will not operate .................... 50 Emergency starting engine ............. 51
Treatment of submerged motor..... 52
Procedure ....................................... 52
Consumer information.................... 54
Important warranty information for U.S.A. and Canada ................ 54
YAMAHA MOTOR
CORPORATION, U.S.A. OUTBOARD MOTOR TWO YEAR LIMITED WARRANTY ..... 56
IMPORTANT WARRANTY INFORMATION IF YOU USE YOUR YAMAHA OUTSIDE THE USA OR CANADA.............. 59
1
General information
EMU25170
Identification numbers record
EMU25182
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 sto- len.
EMU25221
Emission control information
EMU25230
North American models
This engine conforms to U.S. Environmental Protection Agency (EPA) regulations for ma- rine SI engines. See the label affixed to your
engine for details.
EMU30390
Approval label of emission control certif- icate
This label is attached to the bottom cowling. Existing Technology; N/A
EMU25262
Manufactured date label
This label is attached to the clamp bracket or the swivel bracket.
1. Outboard motor serial number location
1. Approval label location
1
ZMU04828
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. FELs : SPARK PLUG : DISPLACEMENT : ADVERTISED POWER :
IDLE SPEED : SPARK PLUG GAP (mm) : FUEL : GASOLINE VALVE LASH (mm) : IN : N/A EX : N/A
cm kW
g/kW-hr rpm IN NEUTRAL
3
ZMU05230
General information
2
EMU25362
Safety information
Before mounting or operating the outboard motor, read this entire manual. Reading it should give you an understanding of the motor and its operation.
Before operating the boat, read any own- ers or operators manuals supplied with it and all labels. Be sure you understand each item before operating.
Do not overpower the boat with this out- board 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 tak- ing drugs. About 50% of all boating fatali- ties involve intoxication.
Have an approved personal flotation de- vice (PFD) on board for every occupant. It is a good idea to wear a PFD whenever boating. At a minimum, children and non- swimmers should always wear PFDs, and everyone should wear PFDs when there are potentially hazardous boating condi- tions.
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 be- fore starting the engine.
This product emits exhaust gases which contain carbon monoxide, a colorless, odorless gas which may cause brain dam- age or death when inhaled. Symptoms in- clude nausea, dizziness, and drowsiness. Keep cockpit and cabin areas well ventilat- ed. Avoid blocking exhaust outlets.
Check throttle, shift, and steering for prop- er 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 acciden- tally 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.
1. Manufactured date label location
1 ZMU04125
General information
3
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 re- turn.
Use common sense and good judgment when boating. Know your abilities, and be sure you understand how your boat han- dles 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 with- out using a funnel or similar device. If nec- essary, 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 fol- lowing:
United States Coast Guard
Consumer Affairs Staff (G-BC) Office of Boating, Public, and Consumer Af-
fairs U.S. Coast Guard Headquarters Washington, D.C. 20593-0001 Boating Safety Hotline: 1-800-368-5647
National Marine Manufacturers Associa- tion (NMMA)
401 N. Michigan Ave. Chicago, Il 60611
Marine Retailers Association of America
155 N. Michigan Ave. Chicago, Il 60601
EMU25382
Important labels
EMU25395
Warning labels
EMU25401
Label
WARNING
EWM01260
Be sure shift control is in neutral before starting engine. (except 2HP)
Do not touch or remove electrical parts
ZMU04780
ZMU03684
General information
4
when starting or during operation.
Keep hands, hair, and clothes away from flywheel and other rotating parts
while engine is running.
EMU25431
Label
WARNING
EWM01300
This engine is equipped with a neutral starting device.
The engine will not start unless the shift
control is in neutral position.
EMU25500
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 agen- cies. You should be aware of these rules, and follow them whenever you encounter another vessel on the water. 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 Owners Manual are condensed, and have been pro- vided for your convenience only. Consult your local U.S. Coast Guard Auxiliary or De- partment of Motor Vehicles for a complete set of rules governing the waters in which you will be using your boat.
EMU25510
Steering and sailing rules and sound signals
Whenever two vessels on the water meet one another, one vessel has the right-of- way; 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-of- way 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 brief- ly 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, In obeying and construing these rules due regard shall be had to all dangers of naviga- tion and collision, and to any special circum- stances, which may render a departure from the above rules necessary in order to avoid immediate danger. In other words, follow the standard rules ex- cept when a collision will occur unless both vessels try to avoid each other. If that is the case, both vessels become Give-Way ves- sels.
EMU25520
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:
General information
5
Meeting:
(you are approaching another ves- sel head-on)
Crossing:
(you are traveling across the oth- er vessels path)
Overtaking:
(you are passing or being 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 shad- ed area must yield to you (they are the Give- Way vessels). Both you and the meeting vessel must alter course to avoid each other.
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-of- way! Both of you should alter course to avoid an accident. You should keep the other ves- sel on your port (left) side. This rule doesnt 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 oth- er 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 direc- tion, provided the other vessel gives you the right-of-way as it should.
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 an- other vessel is passing you, you should maintain your speed and direction so that the other vessel can steer itself around you.
General information
6
EMU25530
Other special situations
There are three other rules you should be aware of when driving your boat around oth- er 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 power- driven vessel is preparing to go around a bend that may obstruct the view of other wa- ter vessels, the operator should sound a pro- longed 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 pro- ceed 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 ves- sels under the International Rules. Vessels with trolling lines are not considered fishing vessels. Fishing vessels have the right-of- way 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-driv- en 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 navi- gate 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 navigat- ing in a particular direction. The markings on these buoys are oriented from the perspec- tive of being entered from seaward (the boat- er is going towards the port). This means that red buoys are passed on the starboard (right) side when proceeding from open wa- ter into port, and black buoys are to port (left) side. When navigating out of port, your posi- tion with respect to the buoys should be re- versed; 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 dis- tinctive shapes and colors to show regulato- ry or advisory information. These markers are white with black letters and orange boarders. They signify speed zones, restrict- ed areas, danger areas, and general infor- mation. Remember, markings may vary by geo- graphic location. Always consult local boat- ing authorities before driving your boat in unfamiliar waters.
General information
7
EMU25540
Fueling instructions
WARNING
EWM00010
GASOLINE AND ITS VAPORS ARE HIGH- LY FLAMMABLE AND EXPLOSIVE!
Do not smoke when refueling, and keep
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
ZMU01708
General information
8
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 electro-
static sparks.
CAUTION:
ECM00010
Use only new clean gasoline which has been stored in clean containers and is not contaminated with water or foreign mat-
ter.
EMU25570
Gasoline
If knocking or pinging occurs, use a different brand of gasoline or premium unleaded fuel.
Gasohol
There are two types of gasohol: gasohol con- taining ethanol and that containing metha- nol. 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.
EMU25650
Engine oil
If the recommended engine oil is not avail- able, another 2-stroke engine oil with an NMMA-certified TC-W3 rating may be used.
EMU25742
Propeller selection
The performance of your outboard motor will be critically affected by your choice of propel- ler, 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 pro- pellers 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 suit- able as it enables the correct engine speed to be maintained. Conversely, a larger-pitch propeller is more suitable for a smaller oper- ating 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 ap- plication.
Recommended gasoline: Regular unleaded gasoline with a min- imum octane rating of 86 (Pump Oc- tane Number) = (R+M)/2
Recommended engine oil: YAMALUBE 2-stroke outboard motor oil
General information
9
NOTE:
Select a propeller which will allow the engine to reach the middle or upper half of the oper- ating 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 in- stallation, see page 42.
EMU25770
Start-in-gear protection
Yamaha outboard motors or Yamaha-ap- proved 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.
1. Propeller diameter in inches 2. Propeller pitch in inches 3. Type of propeller (propeller mark)
ZMU04605
-x 1 2 3
10
Basic components
EMU25795
Main components NOTE:
* May not be exactly as shown; also may not be included as standard equipment on all mod-
els.
25
EMU25802
Fuel tank
If your model was equipped with a portable fuel tank, its function is as follows.
WARNING
EWM00020
The fuel tank supplied with this engine is its dedicated fuel reservoir and must not
13 12
11
18 15
14
7
8
1
3
2
4
6 5
9
10
16
17
ZMU04829
1. Top cowling lock lever 2. Choke knob 3. Gear shift lever 4. Tiller handle 5. Throttle friction adjuster 6. Engine stop button/Engine stop lanyard switch 7. Transom clamp handle 8. Tilt lock lever 9. Trim rod 10. Cooling water inlet 11. Propeller 12. Trim tab (anode) 13. Anti-cavitation plate
14. Clamp bracket 15. Rope attachment 16. Shallow water lever 17. Top cowling 18. Fuel tank*
Basic components
11
be used as a fuel storage container. Com- mercial users should conform to relevant licensing 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 tank cap or on the fuel joint base. It shows the ap- proximate amount of fuel remaining in the tank.
EMU25850
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.
EMU25860
Air vent screw
This screw is on the fuel tank cap. To loosen the screw, turn it counterclockwise.
EMU25911
Tiller handle
To change direction, move the tiller handle to the left or right as necessary.
EMU25922
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.
EMU25941
Throttle grip
The throttle grip is on the tiller handle. Turn the grip counterclockwise to increase speed and clockwise to decrease speed.
1. Fuel joint 2. Fuel gauge 3. Fuel tank cap 4. Air vent screw
ZMU03157
1 3 4 2
1. Forward
2. Neutral
3. Reverse
ZMU02846
2
1
3 R N
F
ZMU03687
Basic components
12
EMU25961
Throttle indicator
The fuel consumption curve on the throttle indicator shows the relative amount of fuel consumed for each throttle position. Choose the setting that offers the best performance and fuel economy for the desired operation.
EMU25970
Throttle friction adjuster
A friction device provides adjustable resis- tance to movement of the throttle grip or the remote control lever, and can be set accord- ing to operator preference. To increase resistance, turn the adjuster clockwise. To decrease resistance, turn the adjuster counterclockwise.
WARNING
EWM00030
Do not overtighten the friction adjuster. If
there is too much resistance, it could be difficult to move throttle lever or grip,
which could result in an accident.
When constant speed is desired, tighten the adjuster to maintain the desired throttle set- ting.
EMU25990
Engine stop lanyard switch
The lock plate must be attached to the en- gine 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 un- der power.
WARNING
EWM00120
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 entan- gled, preventing it from functioning.
Avoid accidentally pulling the lanyard during normal operation. Loss of en- gine power means the loss of most steering control. Also, without engine power, the boat could slow rapidly. This
1. Throttle indicator
ZMU02848
ZMU02849
1
ZMU03688
Basic components
13
could cause people and objects in the
boat to be thrown forward.
NOTE:
The engine cannot be started with the lock
plate removed.
EMU26001
Engine stop button
To open the ignition circuit and stop the en- gine, push this button.
EMU26011
Choke knob for pull type
To supply the engine with the rich fuel mix- ture required to start, pull out this knob.
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 quickly to crank the engine.
EMU26122
Steering friction adjuster
A friction device provides adjustable resis- tance to the steering mechanism, and can be set according to operator preference. An ad- justing screw or bolt is located on the swivel bracket.
1. Lanyard 2. Lock plate
2 1
ZMU03689
ZMU03690
ZMU04127
Basic components
14
To increase resistance, turn the adjuster clockwise. To decrease resistance, turn the adjuster counterclockwise.
WARNING
EWM00040
Do not overtighten the friction adjuster. If there is too much resistance, it could be difficult to steer, which could result in an
accident.
EMU26241
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.
WARNING
EWM00840
An improperly adjusted trim tab could cause difficult steering. Always test run after the trim tab has been installed or re- placed to be sure steering is correct. Be sure you have tightened the bolt after ad-
justing 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.
CAUTION:
ECM00840
The trim tab also serves as an anode to protect the engine from electrochemical corrosion. Never paint the trim tab as it
will become ineffective as an anode.
EMU26261
Trim rod (tilt pin)
The position of the trim rod determines the minimum trim angle of the outboard motor in relation to the transom.
EMU26270
Shallow water lever
Lifting this lever will tilt the motor up partially to provide more clearance when operating in shallow water.
ZMU02908
1. Trim tab 2. Bolt
ZMU02822
1
2
A
B
ZMU02929
Basic components
15
EMU30530
Tilt lock mechanism
The tilt lock mechanism is used to prevent the 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 in the release position.
EMU26330
Tilt support bar
The tilt support bar keeps the outboard motor in the tilted up position.
EMU26372
Top cowling lock lever(s) (turn type)
To remove the engine top cowling, turn the lock lever(s) and lift off the cowling. When in- stalling 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.
EMU26801
Warning system
CAUTION:
ECM00090
Do not continue to operate the engine if a warning device has activated. Consult your Yamaha dealer if the problem can-
not be located and corrected.
EMU26813
Overheat warning
This engine has an overheat warning device.
1. Tilt lock lever
ZMU04111
1
ZMU03695
1. Top cowling lock lever(s)
ZMU03699
ZMU037011
Basic components
16
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.
The overheat warning indicator will light (if equipped on the bottom cowling or the ta- chometer).
The buzzer will sound (if equipped on the tiller handle, remote control box, or main switch panel).
If the warning system has activated, stop the engine and check the cooling water inlet for clogging.
17
Operation
EMU26901
Installation
CAUTION:
ECM00110
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 ex- haust housing is low enough to prevent wa- ter entry into the powerhead, when water rises due to waves when the outboard is not
running.
EMU26910
Mounting the outboard motor
WARNING
EWM00820
Overpowering a boat could cause se- vere instability. Do not install an out- board motor with more horsepower than the maximum rating on the capac- ity plate of the boat. If the boat does not have a capacity plate, consult the boat manufacturer.
The information presented in this sec- tion is intended as reference only. It is not possible to provide complete in- structions for every possible boat and motor combination. Proper mounting depends in part on experience and the
specific boat and motor combination.
WARNING
EWM00830
Improper mounting of the outboard mo- tor 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 experi- enced person.
For portable models, your dealer or oth- er person experienced in proper out- board 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.
EMU26920
Mounting height
To run your boat at optimum efficiency, the water resistance (drag) of the boat and out- board motor must be made as little as possi- ble. The mounting height of the outboard
1. Center line (keel line)
ZMU017601
Operation
18
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 en- gine 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.
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 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 of
the outboard motor, see page 27.
EMU26970
Clamping the outboard motor
1. Place the outboard motor on the tran- som so that it is positioned as close to the center as possible. Tighten the tran- som clamp screws evenly and securely. Occasionally check the clamp screws for tightness during operation of the out- board motor because they could be-
come loose due to engine vibration.
WARNING
EWM00640
Loose clamp screws could allow the out- board motor to fall off or move on the transom. This could cause loss of control and serious injury. Make sure the tran- som screws are tightened securely. Oc- casionally check the screws for tightness
during operation.
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 se- cure mounting point on the boat. Other- wise the engine could be completely lost if it accidentally falls off the transom.
3. Secure the clamp bracket to the transom using the bolts provided with the out-
ZMU02011
025mm (01in.)
ZMU02012
ZMU02013
Operation
19
board (if packed). For details, consult your Yamaha dealer.
WARNING
EWM00650
Avoid using bolts, nuts or washers other than those contained in the engine pack- aging. If used, they must be of at least the same quality of material and strength and must be tightened securely. After tighten- ing, test run the engine and check their
tightness.
EMU30172
Breaking in engine
Your new engine requires a period of break- in to allow mating surfaces of moving parts to wear in evenly. Correct break-in will help en- sure proper performance and longer engine life.
CAUTION:
ECM00800
Failure to follow the break-in procedure could result in reduced engine life or
even severe engine damage.
EMU27050
Gasoline and engine oil mixing chart (25:1)
CAUTION:
ECM00150
Be sure to mix gasoline and oil complete- ly, otherwise the engine may be dam-
aged.
EMU27073
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 (approxi- mately 3000 r/min). Vary engine speed occasionally. If you have an easy-plan- ing 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-quar- ter throttle (approximately 4000 r/min). Vary engine speed occasionally. Run at full throttle for one minute, then allow about 10 minutes of operation at three- quarter throttle or less to let the engine
1. Bolts
ZMU02637
1
1. : Gasoline
2. : Engine oil
Operation
20
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 en- gine 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 20.
EMU27101
Preoperation checks
WARNING
EWM00080
If any item in the preoperation check is not working properly, have it inspected and repaired before operating the out- board motor. Otherwise an accident
could occur.
CAUTION:
ECM00120
Do not start the engine out of water. Over- heating and serious engine damage can
occur.
EMU27110
Fuel
Check to be sure you have plenty of fuel for your trip.
Make sure there are no fuel leaks or gaso- line fumes.