Yamaha Wr 450 F Owners Manual

							2 - 24
SPECCABLE ROUTING DIAGRAM
ÏFasten the wire harness, TPS
lead (in the wire harness),
starter motor lead and negative
battery lead to the frame with a
plastic locking tie and cut off
the tie end.
ÌMake sure that the TPS cou-
pler does not go out the chas-
sis.
ÓFasten the TPS lead to the
frame with a plastic band.
ÈFasten the neutral switch lead
and oil hose together with the
plastic locking ties and cut off
the tie ends.
ÔPass the cylinder head
breather hose through the hose
holder.Fasten the neutral switch lead
to the frame with a plastic band
ends outward.
ÒFasten the neutral switch lead
and AC magneto lead to the
frame with a plastic band.
˜Pass the cylinder head
breather hose on the outside of
the radiator hose 1 and on the
inside of the radiator pipe (radi-
ator hose 4).
ˆPass the oil tank breather hose
on the outside of the AC mag-
neto lead, neutral switch lead,
lights switch lead, wire harness
and cylinder head breather
hose.ØPass the wire harness on the
outside of the neutral switch
lead and AC magneto lead.
∏Fit the brake hose into the
guides on the protector.
ŒPass the wire harness through
the cable guide.
ÂFasten the AC magneto lead,
neutral switch lead and lights
switch lead to the cable guide
at their protecting tube with a
plastic locking tie and cut off
the tie end.
ÍPass the carburetor breather
hoses, overflow hose and cool-
ant reservoir tank breather
hose so that the hoses do not
contact the rear shock
absorber. 
						

							2 - 25
SPECCABLE ROUTING DIAGRAM
1Hot starter cable
2Clutch cable
3Throttle cable (return)
4Throttle cable (pull)
5Ignition coil
6Negative battery lead
7Starter motor lead
8Coolant reservoir tank
breather hose
9Rectifier/regulator
0Cable holder
ACoolant reservoir hose
BRectifier/regulator lead
CClamp
DCDI unit lead
ECDI unit 
FCDI unit band
GCDI unit stay (frame)
HCable bracketIRectifier/regulator bracket
ÅPass the throttle cables, clutch
cable and hot starter cable through
the cable guides.
ıPass the throttle cables, clutch
cable and hot starter cable between
the radiator and frame, then over
the middle radiator mounting boss.
ÇPass the throttle cables and clutch
cable on the outside of the ignition
coil.
ÎPass the carburetor breather hose
(throttle cable cover) through the
hose holder.
‰Fasten the coolant reservoir tank
breather hose and carburetor
breather hoses together with a
plastic locking tie.ÏFasten the grommet of the clutch
cable with the cable holder.
ÌFasten the CDI unit lead to the
frame with a plastic locking tie ends
at the lower of the frame and cut off
the tie end.
ÓInsert the CDI unit band over the
CDI unit stay (frame) as far as pos-
sible.
ÈFasten the starter motor lead and
negative battery lead to the cable
bracket in its slot with a plastic lock-
ing tie and cut off the tie end.
ÔFasten the rectifier/regulator lead to
the rectifier/regulator bracket with a
plastic locking tie and cut off the tie
end. 
						

							2 - 26
SPECCABLE ROUTING DIAGRAM
1Master cylinder
2Brake hose holder 
3Brake hoseÅInstall the brake hose so that its
pipe portion directs as shown and
lightly touches the projection on
the caliper.
ıPass the brake hose into the
brake hose holders.
ÇIf the brake hose contacts the
spring (rear shock absorber), cor-
rect its twist.
ÎInstall the brake hose so that its
pipe portion directs as shown and
lightly touches the projection on
the master cylinder. 
						

							2 - 27
SPECCABLE ROUTING DIAGRAM
1Starter motor lead
2Negative battery lead
3Wire harness
4Clamp
5Taillight lead
6Coolant reservoir tank
breather hose
7Coolant reservoir hose
8Positive battery lead
9Starting circuit cut-off 
relay
0BatteryÅPosition the starter motor lead,
negative battery lead and wire
harness in the tank damper slit.
ıFasten the wire harness to the
frame with a plastic locking tie and
cut off the tie end.
ÇDo not allow the taillight lead to
slacken.
ÎPass the starter motor lead and
negative battery lead over the car-
buretor.
‰Fasten the coolant reservoir tank
breather hose, coolant reservoir
hose and rectifier/regulator lead to
the frame with a plastic band.ÏFasten the coolant reservoir tank
breather hose and coolant reser-
voir hose to the frame with a plas-
tic band.
ÌPass the coolant reservoir hose
on the outside of the coolant res-
ervoir tank breather hose. 
						

							2 - 28
SPECCABLE ROUTING DIAGRAM
1Throttle cable 
2Brake hose 
3Clamp
4Lights switch lead
5Hot starter cable
6Clutch cable
7Hose guide
8Clutch switch lead
9“ENGINE STOP” button
lead
0Trip meter cable
AMain switch lead
BTrip meter
CMain switch
DLights switch
EStart switch leadÅFasten the start switch lead and
lights switch lead to the handlebar
with a plastic band.
ıFasten the “ENGINE STOP” but-
ton lead and clutch switch lead to
the handlebar with the plastic
bands.
ÇPass the brake hose through the
hose guide.
ÎPass the start switch lead in front
of the main switch lead.
‰Fasten the start switch lead to the
handlebar with a plastic band.
ÏPass the hot starter cable and
lights switch lead between the
handle crown and coupler
bracket.ÌPass the throttle cables and clutch
cable between the handle crown
and trip meter. 
						

							 
3 - 1
INSP
ADJ
 
MAINTENANCE INTERVALS 
EC300000 
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
Inspect
Replace 
● 
  
● 
  
● 
  
● 
 The engine must be cold.
Check the valve seats 
and valve stems for wear.
VALVE SPRINGS
Inspect
Replace 
● 
  
● 
 Check the free length and 
the tilt.
VALVE LIFTERS
Inspect
Replace 
● 
  
● 
 Check for scratches and 
wear.
CAMSHAFTS
Inspect
Replace 
● 
  
● 
 Inspect the camshaft sur-
face.
Inspect the decompres-
sion system
CAMSHAFT SPROCKETS
Inspect
Replace 
● 
  
● 
 Check for wear on the 
teeth and for damage.
PISTON
Inspect 
Clean
Replace 
● 
  
● 
  
● 
  
● 
 Inspect crack
Inspect carbon deposits 
and eliminate them.
PISTON RING
Inspect
Replace 
● 
  
● 
  
● 
 Check ring end gap
PISTON PIN
Inspect
Replace 
● 
  
● 
 
CYLINDER HEAD
Inspect and clean 
● 
 Inspect carbon deposits 
and eliminate them.
Change gasket
CYLINDER
Inspect and clean
Replace 
● 
  
● 
 Inspect score marks
Inspect wear
CLUTCH
Inspect and adjust
Replace 
● 
  
● 
  
● 
 Inspect housing, friction 
plate, clutch plate and 
spring
TRANSMISSION
Inspect
Replace bearing 
● 
  
● 
  
						

							 
3 - 2
INSP
ADJ
 
MAINTENANCE INTERVALS 
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect 
● 
 Inspect wear
ROTOR NUT
Retighten 
● 
  
● 
 
MUFFLER
Inspect and retighten
Clean
Replace 
● 
  
● 
  
● 
  
● 
  * Whichever comes first
*SPARK ARRESTER
Clean 
(Every 
six 
months) 
● 
CRANK
Inspect and clean 
● 
  
● 
 
CARBURETOR
Inspect, adjust and clean 
● 
  
● 
 
SPARK PLUG
Inspect and clean
Replace 
● 
  
● 
  
● 
 
DRIVE CHAIN
Lubricate, slack, alignment
Replace 
● 
  
● 
  
● 
 Use chain lube
Chain slack: 40 ~ 50 mm 
(1.57 ~ 1.97 in)
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses 
● 
  
● 
  
● 
  
● 
  
● 
  Every two years
OUTSIDE NUTS AND BOLTS
Retighten 
● 
  
● 
 Refer to “STARTING 
AND BREAK-IN” section 
in the CHAPTER 1.
AIR FILTER
Clean and lubricate
Replace 
● 
  
● 
  
● 
 Use foam air-filter oil or 
equivalent oil
OIL FILTER
Replace 
● 
  
● 
 
OIL STRAINER (frame)
Clean 
● 
 
FRAME
Clean and inspect 
● 
  
● 
 
FUEL TANK, COCK
Clean and inspect 
● 
  
● 
 
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper 
bolts, master cylinder bolts and union 
bolts
Replace pads
Replace brake fluid 
● 
  
● 
  
● 
  
● 
  
● 
  
● 
  
● 
  
● 
  
● 
  
● 
  
● 
  
● 
  Every one year ItemAfter 
break-inEvery 
race 
Every 
third 
(or 
500 km)Every 
fifth 
(or 
1,000 km) 
As re-
quiredRemarks 
 
 
3  
						

							 
3 - 3
INSP
ADJ
 
MAINTENANCE INTERVALS 
* marked: For USA 
FRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal 
● 
  
● 
  
● 
  
● 
  
● 
 Suspension oil “01”
FRONT FORK OIL SEAL AND DUST 
SEAL
Clean and lube 
● 
  
● 
  Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten 
● 
  
● 
  
● 
  
● 
  
● 
  
(After 
rain ride) 
● 
 Molybdenum disulfide 
grease
CHAIN GUARD AND ROLLERS
Inspect
● ● 
SWINGARM
Inspect, lube and retighten
● ● Molybdenum disulfide 
grease
RELAY ARM, CONNECTING ROD
Inspect, lube and retighten
● ● Molybdenum disulfide 
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
● ● 
● 
● Lithium base grease
TIRE, WHEELS
Inspect air pressure, wheel run-out, 
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate
● 
● 
● 
● 
● 
● 
●
Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Lubricate
● 
● 
● 
● Yamaha cable lube or 
SAE 10W-30 motor oil
HOT STARTER, CLUTCH LEVER
Inspect free play
●
BATTERY
Check terminal for looseness and 
corrosion
●
ItemAfter 
break-inEvery 
race
Every 
third 
(or 
500 km)Every 
fifth 
(or 
1,000 km)As re-
quiredRemarks 
						

							3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE 
Item Routine Page
CoolantCheck that coolant is filled up to the radiator filler cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the 
fuel line for leakage.P.1-14
Engine oilCheck that the oil level is correct. Check the crankcase and 
frame oil line for leakage.P.3-14 ~ 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the 
clutch operates smoothly.P.3-10
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly 
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
Brakes Check the play of front brake and effect of front and rear brake. P.3-26 ~ 32
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-33 ~ 36
WheelsCheck for excessive wear and tire pressure. Check for loose 
spokes and have no excessive play.P.3-44 ~ 45
SteeringCheck that the handlebar can be turned smoothly and have no 
excessive play.P.3-45 ~ 46
Front forks and rear shock 
absorberCheck that they operate smoothly and there is no oil leakage. P.3-36 ~ 43
Cables (wires)Check that the clutch and throttle cables move smoothly. Check 
that they are not caught when the handlebars are turned or 
when the front forks travel up and down.—
Muffler Check that the muffler is tightly mounted and has no cracks.—
Sprocket Check that the driven sprocket tightening bolt is not loose. P.3-33
Lubrication Check for smooth operation. Lubricate if necessary. P.3-47
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-19
Lead connectorsCheck that the AC magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course 
and weather or by taking into account the results of test runs 
before racing? Are inspection and maintenance completely 
done?P.7-1 ~ 21 
						

							3 - 5
INSP
ADJ
EC350000
ENGINE
COOLANT LEVEL INSPECTION
WARNING
Do not remove the radiator cap 1, drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury.
When the engine has cooled, place a thick
towel over the radiator cap, slowly rotate
the cap counterclockwise to the detent.
This procedure allows any residual pres-
sure to escape. When the hissing sound
has stopped, press down on the cap while
turning counterclockwise and remove it.
CAUTION:
Hard water or salt water is harmful to the
engine parts. You may use distilled water, if
you can’t get soft water.
1. Place the machine on a level place, and
hold it in an upright position.
2. Inspect:
Coolant level
Coolant level should be between the
maximum a and minimum b marks.
Coolant level is below the “LOW” level
line → Add soft water (tap water) up to
the proper level.
3. Start the engine and let it warm up for
several minutes.
4. Turn off the engine and check the coolant
level again.
NOTE:
Before checking the coolant level, wait a few
minutes until the coolant settles.
LOWFULLCOOLANT
a
b
COOLANT REPLACEMENT
WARNING
Do not remove the radiator cap when the
engine is hot.
ENGINE/COOLANT LEVEL INSPECTION/
COOLANT REPLACEMENT