2005 YAMAHA YFZ450 check engine

EBU00150
1-CONTENTS
LOCATION OF THE WARNING
AND SPECIFICATION LABELS .............. 1-1
SAFETY INFORMATION ......................... 2-1
DESCRIPTION AND MACHINE
IDENTIFICATION .................................... 3-1
Identification number records ............... 3-3
Key identification number ..................... 3-5
Vehicle identification number ............... 3-5
Model label ........................................... 3-7
CONTROL FUNCTIONS ......................... 4-1
Main switch........................................... 4-1
Indicator and warning lights.................. 4-3
Handlebar switches .............................. 4-7
Throttle lever ...................................... 4-11
Speed limiter ...................................... 4-13
Clutch lever ........................................ 4-15
Brake lever ......................................... 4-17
Brake pedal ........................................ 4-17
Parking brake lever ............................ 4-19
Shift pedal .......................................... 4-21
Fuel tank cap ...................................... 4-21
1234
Fuel cock............................................ 4-23
Starter (choke) .................................. 4-25
Seat.................................................... 4-27
Front shock absorber adjustment ...... 4-29
Rear shock absorber adjustment ....... 4-39
PRE-OPERATION CHECKS ................... 5-1
Front and rear brakes .......................... 5-5
Fuel ...................................................... 5-9
Engine oil ........................................... 5-13
Coolant............................................... 5-15
Chain.................................................. 5-17
Throttle lever ...................................... 5-17
Fittings and fasteners......................... 5-19
Lights ................................................. 5-19
Switches............................................. 5-19
Tires ................................................... 5-21
How to measure tire pressure ............ 5-25
Tire wear limit..................................... 5-27
5
U5TG61.book Page 1 Friday, April 2, 2004 11:28 AM

OPERATION ............................................6-1
Starting a cold engine ...........................6-3
Starting a warm engine .........................6-9
Warming up...........................................6-9
Shifting ................................................6-11
To start out and accelerate .................6-13
To decelerate ......................................6-17
Engine break-in ...................................6-19
Parking ................................................6-23
Parking on a slope ..............................6-25
Accessories and loading .....................6-29
RIDING YOUR ATV..................................7-1
Getting to know your ATV .....................7-3
Ride with care and good judgement .....7-5
Be careful where you ride ...................7-27
Turning your ATV ................................7-41
Climbing uphill.....................................7-47
Riding downhill ....................................7-57
Crossing a slope .................................7-61
Crossing through shallow water ..........7-65
Riding over rough terrain ....................7-69
Sliding and skidding ............................7-71
What to do if ........................................7-75
What to do...........................................7-75
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ......................................... 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Panel removal and installation............ 8-17
Engine oil and oil filter element........... 8-23
Cooling system ................................... 8-41
Changing the coolant.......................... 8-45
Spark plug inspection ......................... 8-53
Air filter element cleaning ................... 8-65
Carburetor adjustment ........................ 8-73
Idle speed adjustment ........................ 8-75
Valve clearance adjustment ............... 8-75
Throttle lever adjustment .................... 8-77
Front brake pad inspection ................. 8-79
Rear brake pad inspection.................. 8-81
Brake fluid level inspection ................. 8-83
Brake fluid replacement ...................... 8-87
Front brake lever free play.................. 8-89
Brake pedal height adjustment ........... 8-91
Parking brake adjustment ................... 8-93
Adjusting the rear brake light switch ... 8-97
Clutch lever free play adjustment ....... 8-99
Drive chain slack check .................... 8-101
Drive chain slack adjustment ............ 8-103
Lubricating the drive chain................ 8-107
Cable inspection and lubrication....... 8-111
8
U5TG61.book Page 2 Friday, April 2, 2004 11:28 AM

4-3 1. Neutral indicator light “N”
2. Coolant temperature warning light “”
1. Témoin de point mort “N”
2. Témoin d’avertissement de la température du liquide de
refroidissement “”
1. Luz de control de punto muerto “N”
2. Luz de aviso de la temperatura del refrigerante “”
EBU08020
Indicator and warning lights
EBU06030
Neutral indicator light “N”
This indicator light comes on when the transmis-
sion is in neutral.
EBU13850
Coolant temperature warning light “”
When the coolant temperature reaches a specified
level, this light comes on to warn that the coolant
temperature is too hot. If the light comes on during
operation, stop the engine as soon as it is safe to
do so and allow the engine to cool down for about
10 minutes.
The electrical circuit of the warning light can be
checked according to the following procedures.
1. Set the engine stop switch to “RUN” and turn
the key to “ON”.
2. Shift the transmission into the neutral position
or pull the clutch lever.
U5TG61.book Page 3 Friday, April 2, 2004 11:28 AM

4-5
3. Push the start switch. If the warning light
does not come on while the start switch is
pushed, have a Yamaha dealer check the
electrical circuit.CAUTION:_

The engine may overheat if the ATV is
overloaded. If this happens, reduce the
load to specification.


Restart after making sure that the light is
off. Continuous use while the light is on
may cause damage to the engine.
_
U5TG61.book Page 5 Friday, April 2, 2004 11:28 AM

4-11 1. Throttle lever
1. Levier d’accélération
1. Palanca de aceleración
EBU00630
Throttle lever
Once the engine is running, movement of the
throttle lever will increase the engine speed.
Regulate the speed of the machine by varying the
throttle position. Because the throttle is spring-
loaded, the machine will decelerate, and the en-
gine will return to an idle any time the hand is re-
moved from the throttle lever.
Before starting the engine, check the throttle to be
sure it is operating smoothly. Make sure it returns
to the idle position as soon as the lever is released.
WARNING
_ Malfunction of the throttle could make it diffi-
cult to speed up or slow down when you need
to. This could cause an accident. Check the
operation of the throttle lever before you start
the engine. If the throttle does not work
smoothly, check for the cause. Correct the
problem before riding the ATV or consult a
Yamaha dealer. _
U5TG61.book Page 11 Friday, April 2, 2004 11:28 AM

5-1
EBU01130
1-PRE-OPERATION CHECKS
Before using this machine, check the following points:
ITEM ROUTINE PAGE
Front brakeCheck operation, lever free play, fluid level and fluid leakage.
Fill with DOT 4 brake fluid if necessary.5-5–5-7, 8-79,
8-83–8-89
Rear brakeCheck operation, fluid level and fluid leakage.
Fill with DOT 4 brake fluid if necessary.5-5–5-7,
8-81–8-87, 8-91
ClutchCheck operation, condition and lever free play. 8-99
Parking brakeCheck operation, condition and cable length. 8-93–8-95
FuelCheck fuel level.
Fill with fuel if necessary.5-9–5-11
Engine oilCheck oil level.
Fill with oil if necessary.5-13, 8-23–8-39
Coolant reservoirCheck coolant level in reservoir.
Fill with coolant if necessary.5-15–5-17,
8-41–8-51
Drive chainCheck chain slack and condition.
Adjust if necessary.5-17, 8-101–8-109
ThrottleCheck for proper throttle cable operation and free play. 5-17, 8-77
Wheels and tiresCheck tire pressure, wear and damage.5-21–5-27,
8-121–8-123
Fittings and fastenersCheck all fittings and fasteners. 5-19
Lights and switchesCheck for proper operation.5-19, 8-97,
8-133–8-141
U5TG61.book Page 1 Friday, April 2, 2004 11:28 AM

5-15
EBU13160
Coolant
Check the coolant level in the coolant reservoir
when the engine is cold. (The coolant level will
vary with engine temperature.) The coolant level is
satisfactory if it is between the minimum and max-
imum level marks on the coolant reservoir. If the
coolant level is at or below the minimum level
mark, add distilled water to bring the level up to the
maximum level mark. Change the coolant every
two years. (See pages 8-41–8-51 for details.)CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you cannot get
distilled water. _
Coolant reservoir capacity
(up to the maximum level mark):
0.29 L
U5TG61.book Page 15 Friday, April 2, 2004 11:28 AM

5-17
WARNING
_ Wait for the engine and radiator to cool before
removing the radiator cap. You could be
burned by hot fluid and steam blown out under
pressure. Always put a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap. _
EBU04980
Chain
Check the general condition of the chain and
check the chain slack before every ride. Lubricate
and adjust the chain as necessary. (See pages
8-101–8-109 for details.)
EBU10830
Throttle lever
Check to see that the throttle lever operates cor-
rectly. It must open smoothly and spring back to
the idle position when released. Have a Yamaha
dealer repair as necessary for proper operation.
U5TG61.book Page 17 Friday, April 2, 2004 11:28 AM