2008 YAMAHA WR 450F check oil

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

1-3
CHECKING OF CONNECTION
ALL REPLACEMENT PARTS
1. We recommend to use Yamaha
genuine parts for all replace-
ments. Use oil and/or grease rec-
ommended by Yamaha for
assembly and adjustment.
GASKETS, OIL SEALS AND O-
RINGS
1. All gaskets, oil seals, and O-rings
should be replaced when an en-
gine is overhauled. All gasket sur-
faces, oil seal lips, and O-rings
must be cleaned.
2. Properly oil all mating parts and
bearings during reassembly. Ap-
ply grease to the oil seal lips.
LOCK WASHERS/PLATES AND
COTTER PINS
1. All lock washers/plates "1" and
cotter pins must be replaced
when they are removed. Lock
tab(s) should be bent along the
bolt or nut flat(s) after the bolt or
nut has been properly tightened.
BEARINGS AND OIL SEALS
1. Install the bearing(s) "1" and oil
seal(s) "2" with their manufactur-
er's marks or numbers facing out-
ward. (In other words, the
stamped letters must be on the
side exposed to view.) When in-
stalling oil seal(s), apply a light
coating of lightweight lithium base
grease to the seal lip(s). Oil the
bearings liberally when installing.
Do not use compressed air to spin
the bearings dry. This causes dam-
age to the bearing surfaces.
CIRCLIPS
1. All circlips should be inspected
carefully before reassembly. Al-
ways replace piston pin clips after
one use. Replace distorted cir-
clips. When installing a circlip "1",
make sure that the sharp-edged
corner "2" is positioned opposite
to the thrust "3" it receives. See
the sectional view.
CHECKING OF
CONNECTION
Dealing with stains, rust, moisture,
etc. on the connector.
1. Disconnect:
• Connector
2. Dry each terminal with an air
blower.
3. Connect and disconnect the con-
nector two or three times.
4. Pull the lead to check that it will
not come off.
5. If the terminal comes off, bend up
the pin "1" and reinsert the termi-
nal into the connector.
6. Connect:
• Connector
The two connectors "click" together.
7. Check for continuity with a tester.
• If there in no continuity, clean the
terminals.
• Be sure to perform the steps 1 to 7
listed above when checking the
wire harness.
• For a field remedy, use a contact re-
vitalizer available on the market.
• Use the tester on the connector as
shown.

1-5
SPECIAL TOOLS
Damper rod holder
YM-01494, 90890-01494Use this tool to remove and install
the damper rod.
Fork seal driver
YM-A0948, 90890-01502 This tool is used when install the fork
oil seal.
Sheave holder
YS-1880-A, 90890-01701This tool is used for when loosening
or tightening the flywheel magneto
securing nut.
Pocket tester
YU-3112-C, 90890-03112 Use this tool to inspect the coil resis-
tance, output voltage and amper-
age.
Timing light
YM-33277-A, 90890-03141 This tool is necessary for checking
ignition timing.
Valve spring compressor
YM-4019, 90890-04019 This tool is needed to remove and
install the valve assemblies. Tool name/Part number How to use Illustration

1-14
STARTING AND BREAK-IN
STARTING AND BREAK-IN
FUEL
Always use the recommended fuel as
stated below. Also, be sure to use
new gasoline the day of a race.
Use only unleaded gasoline. The
use of leaded gasoline will cause
severe damage to the engine inter-
nal parts such as valves, piston
rings, and exhaust system, etc.
If knocking or pinging occurs, use a
different brand of gasoline or higher
octane grade.
• For refueling, be sure to stop the
engine and use enough care not
to spill any fuel. Also be sure to
avoid refueling close to a fire.
• Refuel after the engine, exhaust
pipe, etc. have cooled off.
HANDLING NOTE
Never start or run the engine in a
closed area. The exhaust fumes
are poisonous; they can cause
loss of consciousness and death
in a very short time. Always oper-
ate the machine in a well-ventilated
area.
• The carburetor on this machine
has a built-in accelerator pump.
Therefore, when starting the en-
gine, do not operate the throttle
or the spark plug will foul.
• Unlike a two-stroke engine, this
engine cannot be kick started
when the throttle is open be-
cause the kickstarter may kick
back. Also, if the throttle is open
the air/fuel mixture may be too
lean for the engine to start.
• Before starting the machine, per-
form the checks in the pre-opera-
tion check list.
AIR FILTER MAINTENANCE
According to "CLEANING THE AIR
FILTER ELEMENT" section in the
CHAPTER 3, apply the foam-air-filter
oil or its equivalent to the element.
(Excess oil in the element may ad-
versely affect engine starting.)
STARTING A COLD ENGINE
This model is equipped with an igni-
tion circuit cut-off system. The engine
can be started under the following
conditions.
• When the transmission is in neutral.
• When the clutch is disengaged with
the transmission in any position.
However, it is recommended to shift
into neutral before starting the en-
gine.
1. Inspect the coolant level.
2. Turn the fuel cock to "ON".
3. Push on the main switch to "ON".
4. Shift the transmission into neutral.
5. Fully open the cold starter knob
"1".
6. Start the engine by pushing the
start switch or by kicking the kick-
starter crank.
If the engine fails to start by pushing
the start switch, release the switch,
wait a few seconds, and then try
again. Each starting attempt should
be as short as possible to preserve
the battery. Do not crank the engine
more than 10 seconds on any one at-
tempt. If the engine does not start
with the starter motor, try using the
kickstarter crank.
• If the starter motor will not turn
when pushing the start switch,
stop pushing it immediately and
kick start the engine in order to
avoid the load on the motor.
• Do not open the throttle while
kicking the kickstarter crank.
Otherwise, the kickstarter crank
may kick back.
7. Return the cold starter knob to its
original position and run the en-
gine at 3,000–5,000 r/min for 1 or
2 minutes.
Since this model is equipped with an
accelerator pump, if the engine is
raced (the throttle opened and
closed), the air/fuel mixture will be too
rich and the engine may stall. Also
unlike a two-stroke engine, this model
can idle.
Do not warm up the engine for ex-
tended periods of time.
STARTING A WARM ENGINE
Do not operate the cold starter knob
and throttle. Pull the hot starter lever
"1" and start the engine by pushing
the start switch or by kicking the kick-
starter crank forcefully with a firm
stroke. As soon as the engine starts,
Release the hot starter lever to close
the air passage.
Restarting an engine after a fall
Pull the hot starter lever and start the
engine. As soon as the engine starts,
Release the hot starter lever to close
the air passage. Recommended fuel:
Premium unleaded
gasoline only with a re-
search octane number
of 95 or higher.

1-16
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Concerning the tightening torque, refer to "TIGHTENING TORQUES" section in the CHAPTER 2.
Frame construction Frame to rear frame
Combined seat and fuel tank Fuel tank to frame
Exhaust system Silencer to rear frame
Engine mounting Frame to engine
Engine bracket to engine
Engine bracket to frame
Steering Steering stem to handlebar Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Suspension Front Steering stem to front fork Front fork to upper bracket
Front fork to lower bracket
Rear For link type Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Installation of rear shock absorber Rear shock absorber to frame
Installation of swingarm Tightening of pivot shaft
Wheel Installation of wheel Front Tightening of wheel axle
Tightening of axle holder
Rear Tightening of wheel axle
Wheel to rear wheel sprocket
Brake Front Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handlebar
Tightening of bleed screw
Tightening of brake hose holder
Rear Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Tightening of brake hose holder
Fuel system Fuel tank to fuel cock
Lubrication system Tightening of oil hose clamp

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

3-1
MAINTENANCE INTERVALS
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind that such factors as
weather, terrain, geographical location, and individual usage will alter the required maintenance and lubrication intervals. If
you are a doubt as to what intervals to follow in maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-
inEvery
race
Every
third
(or 500
km)Every
fifth (or
1,000
km)
As re-
quiredRemarks
ENGINE OIL
Replace●●
VALVES
Check the valve clearances●●The engine must be cold.
Inspect●Check the valve seats and valve
stems for wear.
Replace●
VALVE SPRINGS
Inspect●Check the free length and the tilt.
Replace●
VALVE LIFTERS
Inspect●Check for scratches and wear.
Replace●
CAMSHAFTS Inspect the camshaft surface.
Inspect●Inspect the decompression system.
Replace●
CAMSHAFT SPROCKETS
Inspect●Check for wear on the teeth and for
damage.
Replace●
PISTON
Inspect●●Inspect crack.
Clean●Inspect carbon deposits and eliminate
them.
Replace●
PISTON RING
Inspect●Check ring end gap.
Replace●●
PISTON PIN
Inspect●
Replace●
CYLINDER HEAD Inspect carbon deposits and eliminate
them.
Inspect and clean●Change gasket.
CYLINDER
Inspect and clean●Inspect score marks.
Replace●Inspect wear.

3-2
MAINTENANCE INTERVALS
CLUTCH
Inspect and adjust●●Inspect housing, friction plate, clutch
plate and spring.
Replace●
TRANSMISSION
Inspect●
Replace bearing●
SHIFT FORK, SHIFT CAM,
GUIDE BAR
Inspect●Inspect wear.
ROTOR NUT
Retighten●●
MUFFLER
Inspect and retighten●●
Clean●
Replace●
CRANK
Inspect and clean●●
CARBURETOR
Inspect, adjust and clean●●
AIR INDUCTION SYSTEM
Inspect and clean●● ●●
SPARK PLUG
Inspect and clean●●
Replace●
DRIVE CHAIN Use chain lube.
Lubricate, slack, alignment●●Chain slack: 48–58 mm (1.9–2.3 in)
Replace●
COOLING SYSTEM
Check coolant level and leakage●●
Check radiator cap operation●
Replace coolant●Every two years
Inspect hoses●
OUTSIDE NUTS AND BOLTS
Retighten●●Refer to "STARTING AND BREAK-
IN" section in the CHAPTER 1.
AIR FILTER
Clean and lubricate●●Use foam air-filter oil or equivalent oil.
Replace●
OIL FILTER
Replace●●
FRAME
Clean and inspect●● ItemAfter
break-
inEvery
race
Every
third
(or 500
km)Every
fifth (or
1,000
km)
As re-
quiredRemarks
3