2008 YAMAHA WR 450F water pump

CONTENTS
CHAPTER 1
GENERAL INFOR-
MATION
DESCRIPTION ................. 1-1
MACHINE
IDENTIFICATION ............. 1-2
INCLUDED PARTS .......... 1-2
IMPORTANT
INFORMATION................. 1-2
CHECKING OF CONNEC-
TION ................................. 1-3
SPECIAL TOOLS ............. 1-4
CONTROL FUNCTIONS .. 1-8
MULTI-FUNCTION
DISPLAY .......................... 1-9
STARTING AND
BREAK-IN ...................... 1-14
TORQUE-CHECK
POINTS........................... 1-16
CLEANING AND
STORAGE ...................... 1-17
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICA-
TIONS ............................... 2-1
MAINTENANCE
SPECIFICATIONS ............ 2-4
TIGHTENING
TORQUES ...................... 2-13
LUBRICATION
DIAGRAMS .................... 2-19
CABLE ROUTING
DIAGRAM ....................... 2-21
CHAPTER 3
REGULAR INSPEC-
TION AND AD-
JUSTMENTS
MAINTENANCE
INTERVALS ...................... 3-1
PRE-OPERATION
INSPECTION AND
MAINTENANCE................ 3-5
ENGINE ............................ 3-6
CHASSIS ........................ 3-17
ELECTRICAL ................. 3-27
CHAPTER 4
TUNING
ENGINE ............................ 4-1
CHASSIS .......................... 4-5
CHAPTER 5
ENGINE
RADIATOR ....................... 5-1
CARBURETOR................. 5-4
AIR INDICTOIN
SYSTEM ......................... 5-13
CAMSHAFTS.................. 5-15
CYLINDER HEAD........... 5-20
VALVES AND VALVE
SPRINGS ........................ 5-23
CYLINDER AND
PISTON ........................... 5-27
CLUTCH ......................... 5-30
OIL FILTER ELEMENT
AND WATER PUMP ....... 5-34
BALANCER .................... 5-38
OIL PUMP ....................... 5-40
KICK SHAFT AND SHIFT
SHAFT ............................ 5-43
AC MAGNETO AND
STARTER CLUTCH ....... 5-48
ENGINE REMOVAL ....... 5-53CRANKCASE AND
CRANKSHAFT ...............5-57
TRANSMISSION, SHIFT
CAM AND SHIFT
FORK ..............................5-63
CHAPTER 6
CHASSIS
FRONT WHEEL AND
REAR WHEEL ..................6-1
FRONT BRAKE AND
REAR BRAKE ..................6-6
FRONT FORK .................6-16
HANDLEBAR..................6-23
STEERING ......................6-27
SWINGARM ....................6-31
REAR SHOCK
ABSORBER ....................6-36
CHAPTER 7
ELECTRICAL
ELECTRICAL COMPO-
NENTS AND WIRING DIA-
GRAM ...............................7-1
IGNITION SYSTEM...........7-3
ELECTRIC STARTING
SYSTEM............................7-5
CHARGING SYSTEM .....7-13
THROTTLE POSITION
SENSOR SYSTEM .........7-15
LIGHTING SYSTEM .......7-18
SIGNALING SYSTEM.....7-20

1-2
MACHINE IDENTIFICATION
MACHINE IDENTIFICATION
There are two significant reasons for
knowing the serial number of your
machine:
1. When ordering parts, you can
give the number to your Yamaha
dealer for positive identification of
the model you own.
2. If your machine is stolen, the au-
thorities will need the number to
search for and identify your ma-
chine.
VEHICLE IDENTIFICATION
NUMBER
The vehicle identification number "1"
is stamped on the right of the steering
head pipe.
ENGINE SERIAL NUMBER
The engine serial number "1" is
stamped into the elevated part of the
right-side of the engine.
MODEL LABEL
The model label "1" is affixed to the
frame under the rider's seat. This in-
formation will be needed to order
spare parts.
INCLUDED PARTS
VALVE JOINT
This valve joint "1" prevents fuel from
flowing out and is installed to the fuel
tank breather hose.
In this installation, make sure the
arrow faces the fuel tank and also
downward.
SPARK PLUG WRENCH
This spark plug wrench "1" is used to
remove and install the spark plug.
NIPPLE WRENCH
This nipple wrench "1" is used to
tighten the spoke.
JET NEEDLE PULL-UP TOOL
The jet needle pull-up tool "1" is used
to pull the jet needle out of the carbu-
retor.
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL
AND DISASSEMBLY
1. Remove all dirt, mud, dust, and
foreign material before removal
and disassembly.
• When washing the machine with
high pressured water, cover the
parts follows.
Silencer exhaust port
Side cover air intake port
Water pump housing hole at the
bottom
Drain hole on the cylinder head
(right side)
All electrical components2. Use proper tools and cleaning
equipment. Refer to "SPECIAL
TOOLS" section.
3. When disassembling the ma-
chine, keep mated parts together.
They include gears, cylinders,
pistons, and other mated parts
that have been "mated" through
normal wear. Mated parts must
be reused as an assembly or re-
placed.
4. During the machine disassembly,
clean all parts and place them in
trays in the order of disassembly.
This will speed up assembly time
and help assure that all parts are
correctly reinstalled.
5. Keep away from fire.

2-9
MAINTENANCE SPECIFICATIONS
Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.09–0.17 mm (0.0035–0.0067 in) 0.24 mm (0.009
in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm
(0.0067 in)
Bypass valve setting pressure 40–80 kPa (0.4–0.8 kg/cm
2, 5.69–11.38
psi)----
Cooling:
Radiator core size
Width 120.2 mm (4.73 in) ----
Height (Left/Right) 260 mm (10.24 in)/240 mm (9.45 in) ----
Thickness 22 mm (0.87 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity (total) 0.57 L (0.50 Imp qt, 0.60 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit

2-14
TIGHTENING TORQUES
Radiator pipe 1, 2 M10 × 1.0 2 10 1.0 7.2
Impeller M8 × 1.25 1 14 1.4 10
Water pump housing cover M6 × 1.0 3 10 1.0 7.2
Coolant drain bolt M6 × 1.0 1 10 1.0 7.2
Oil pump cover M4 × 0.7 1 2 0.2 1.4
Oil pump M6 × 1.0 2 10 1.0 7.2
Oil pump drive gear shaft M6 × 1.0 1 10 1.0 7.2
Engine oil drain bolt (oil filter) M6 × 1.0 1 10 1.0 7.2
Oil filter cover M6 × 1.0 2 10 1.0 7.2
Oil check bolt (cylinder head) M6 × 1.0 1 10 1.0 7.2
△Oil hose clamp — 2 2 0.2 1.4
Crankshaft end accessing screw M27 × 1.5 1 10 1.0 7.2
Timing mark accessing screw M14 × 1.5 1 6 0.6 4.3
Clutch cover M6 × 1.0 7 10 1.0 7.2
Crankcase cover (right) M6 × 1.0 8 10 1.0 7.2
Crankcase cover (right) M6 × 1.0 2 12 1.2 8.7
Crankcase cover (left) M6 × 1.0 8 10 1.0 7.2
Idle gear cover (starter motor) M6 × 1.0 2 10 1.0 7.2
Crankcase M6 × 1.0 12 12 1.2 8.7
Clutch cable holder M6 × 1.0 1 10 1.0 7.2
Oil drain bolt (crankcase right) M6 × 1.25 1 20 2.0 14
Oil drain bolt (crankcase left) M6 × 1.0 1 20 2.0 14
Oil check bolt (crankcase) M6 × 1.0 1 10 1.0 7.2
Oil strainer M6 × 1.0 1 10 1.0 7.2
Crankcase bearing stopper M6 × 1.0 4 14 1.4 10
Crankcase bearing stopper M6 × 1.0 8 10 1.0 7.2
Drive axle oil seal stopper M6 × 1.0 2 10 1.0 7.2
Ratchet wheel guide M6 × 1.0 2 12 1.2 8.7
Kickstarter crank M8 × 1.25 1 33 3.3 24
Screw (kickstarter crank) M6 × 1.0 1 7 0.7 5.1
Starter clutch M6 × 1.0 6 16 1.6 11
Primary drive gear M20 × 1.0 1 110 11.0 80
Clutch boss M20 × 1.0 1 75 7.5 54
Clutch cable adjust bolt and locknut M8 × 1.0 1 4 0.4 2.9
Clutch spring M6 × 1.0 6 10 1.0 7.2
Balancer M10 × 1.0 1 45 4.5 32
Balancer driven gear M14 × 1.0 1 50 5.0 36
Balancer weight plate M6 × 1.0 3 10 1.0 7.2
Drive sprocket M20 × 1.0 1 75 7.5 54
Drive chain sprocket cover M6 × 1.0 2 8 0.8 5.8
Shift pedal M6 × 1.0 1 12 1.2 8.7
Shift guide M6 × 1.0 2 10 1.0 7.2
Stopper lever M6 × 1.0 1 10 1.0 7.2
Segment M8 × 1.25 1 30 3.0 22Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb

4-1
ENGINE
TUNING
ENGINE
CARBURETOR SETTING
• The air/fuel mixture will vary de-
pending on atmospheric conditions.
Therefore, it is necessary to take
into consideration the air pressure,
ambient temperature, humidity,
etc., when adjusting the carburetor.
• Perform a test run to check for prop-
er engine performance (e.g., throt-
tle response) and spark plug(-s)
discoloration or fouling. Use these
readings to determine the best pos-
sible carburetor setting.
It is recommended to keep a record of
all carburetor settings and external
conditions (e.g., atmospheric condi-
tions, track/surface conditions, lap
times) to make future carburetor set-
ting easier.
• The carburetor is a part of the
fuel line. Therefore, be sure to in-
stall it in a wellventilated area,
away from flammable objects
and any sources of fire.
• Never look into the carburetor in-
take. Flames may shoot out from
the pipe if the engine backfires
while it is being started. Gasoline
may be discharged from the ac-
celerator pump nozzle when the
carburetor has been removed.
• The carburetor is extremely sen-
sitive to foreign matter (dirt,
sand, water, etc.). During instal-
lation, do not allow foreign mat-
ter to get into the carburetor.
• Always handle the carburetor
and its components carefully.
Even slight scratches, bends or
damage to carburetor parts may
prevent the carburetor from
functioning correctly. Carefully
perform all servicing with the ap-
propriate tools and without ap-
plying excessive force.
• When the engine is stopped or
when riding at no load, do not
open and close the throttle un-
necessarily. Otherwise, too
much fuel may be discharged,
starting may become difficult or
the engine may not run well.• After installing the carburetor,
check that the throttle operates
correctly and opens and closes
smoothly.
ATMOSPHERIC CONDITIONS AND
CARBURETOR SETTINGS
The air density (i.e., concentration of
oxygen in the air) determines the rich-
ness or leanness of the air/fuel mix-
ture.
• Higher temperature expands the air
with its resultant reduced density.
• Higher humidity reduces the
amount of oxygen in the air by so
much of the water vapor in the
same air.
• Lower atmospheric pressure (at a
high altitude) reduces the density of
the air.
EFFECT OF SETTING PARTS IN
RELATION TO THROTTLE VALVE
OPENING
A. Closed
B. Fully open
1. Pilot jet
2. Throttle valve cutaway
3. Jet needle
4. Main jetCONSTRUCTION OF
CARBURETOR AND SETTING
PARTS
The FLATCR carburetor has a prima-
ry main jet. This type of main jet is
perfect for racing machines since it
supplies an even flow of fuel, even at
full load. Use the main jet and the jet
needle to set the carburetor.
1. Jet needle
2. Pilot air jet
3. Needle jet
4. Main jet
5. Pilot jet
ADJUSTING THE MAIN JET
The richness of the air-fuel mixture at
full throttle can be set by changing the
main jet "1".
If the air-fuel mixture is too rich or too
lean, the engine power will drop, re-
sulting in poor acceleration.
Effects of changing the main jet
(reference)
A. Idle
B. Fully open
1. #165
2. #160
3. #162 Air
tem
p.Hu-
midi-
tyAir
pres-
sure
(alti-
tude)Mix-
tureSet-
ting
High HighLow
(high)Rich-
erLean-
er
Low LowHigh
(low)Lean-
erRich-
er
Standard main jet#162
* #160
* For EUROPE

5-34
OIL FILTER ELEMENT AND WATER PUMP
OIL FILTER ELEMENT AND WATER PUMP
REMOVING THE OIL FILTER ELEMENT AND WATER PUMP
Order Part name Q'ty Remarks
Right engine guard Refer to "ENGINE REMOVAL" section.
Drain the engine oil. Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
Drain the coolant. Refer to "CHANGING THE COOLANT" sec-
tion.
Exhaust pipe Refer to "EXHAUST PIPE AND SILENCER"
section.
Brake pedal Refer to "ENGINE REMOVAL" section.
Clutch cover Refer to "CLUTCH" section.
1 Oil filter element cover 1
2 Oil filter element 1
3 Coolant pipe 2 1
4 Water pump housing 1
5Pin 2
6 Oil tank breather hose 1
7 Kickstarter crank 1
8 Right crankcase cover 1
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
33 Nm (3.3 m kg, 24 ft lb)
14 Nm (1.4 m kg, 10 ft lb)
12 Nm (1.2 m kg, 8.7 ft lb)

5-35
OIL FILTER ELEMENT AND WATER PUMP
9 Gasket 1
10 Dowel pin/O-ring 3/1
11 Impeller 1 Refer to removal section.
12 Washer 1 Refer to removal section.
13 Impeller shaft 1 Refer to removal section.
14 Oil seal 1 1 Refer to removal section.
15 Oil seal 2 1 Refer to removal section.
16 Bearing 1 Refer to removal section. Order Part name Q'ty Remarks
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
10 Nm (1.0 m kg, 7.2 ft lb)
33 Nm (3.3 m kg, 24 ft lb)
14 Nm (1.4 m kg, 10 ft lb)
12 Nm (1.2 m kg, 8.7 ft lb)

5-36
OIL FILTER ELEMENT AND WATER PUMP
REMOVING THE IMPELLER
SHAFT
1. Remove:
• Impeller "1"
• Washer "2"
• Impeller shaft "3"
Hold the impeller shaft on its width
across the flats "a" with spanners,
etc. and remove the impeller.
REMOVING THE OIL SEAL
It is not necessary to disassemble the
water pump, unless there is an abnor-
mality such as excessive change in
coolant level, discoloration of coolant,
or milky transmission oil.
1. Remove:
• Bearing "1"
• Oil seal "2"
CHECKING THE IMPELLER SHAFT
1. Inspect:
• Impeller shaft "1"
Bend/wear/damage→Replace.
Fur deposits→Clean.CHECKING THE BEARING
1. Inspect:
•Bearing
Rotate inner race with a finger.
Rough spot/seizure→Replace.
CHECKING THE OIL SEAL
1. Inspect:
• Oil seal "1"
Wear/damage→Replace.
INSTALLING THE OIL SEAL
1. Install:
• Oil seal "1"
• Apply the lithium soap base grease
on the oil seal lip.
• Install the oil seal with its manufac-
ture's marks or numbers facing the
right crankcase cover "2".
2. Install:
•Bearing "1"
Install the bearing by pressing its out-
er race parallel.
INSTALLING THE IMPELLER
SHAFT
1. Install:
• Impeller shaft "1"
• Washer "2"
• Impeller "3"
• Take care so that the oil seal lip is
not damaged or the spring does not
slip off its position.
• When installing the impeller shaft,
apply the engine oil on the oil seal
lip, bearing and impeller shaft. And
install the shaft while turning it.
• Hold the impeller shaft on its width
across the flats "a" with spanners,
etc. and install the impeller.
INSTALLING THE RIGHT
CRANKCASE COVER
1. Install:
• Dowel pin "1"
• O-ring "2"
•Collar "3"
• Gasket "4"
Apply the lithium soap base grease
on the O-ring.
Impeller:
14 Nm (1.4 m•kg, 10
ft•lb)