Page 8 of 754

5. GASOLINE IS HIGHLY FLAMMABLE.
Always turn off the engine while refu-
eling. Take care to not spill any gaso-
line on the engine or exhaust system.
Never refuel in the vicinity of an open
flame, or while smoking.
6. GASOLINE CAN CAUSE INJURY.
If you should swallow some gasoline,
inhale excess gasoline vapors, or
allow any gasoline to get into your
eyes, contact a doctor immediately. If
any gasoline spills onto your skin or
clothing, immediately wash skin areas
with soap and water, and change your
clothes.
7. ONLY OPERATE THE MACHINE IN AN
AREA WITH ADEQUATE VENTILA-
TION.
Never start the engine or let it run for
any length of time in an enclosed area.
Exhaust fumes are poisonous. These
fumes contain carbon monoxide,
which by itself is odorless and color-
less. Carbon monoxide is a dangerous
gas which can cause unconscious-
ness or can be lethal.
8. PARK THE MACHINE CAREFULLY;
TURN OFF THE ENGINE.
Always turn off the engine if you are
going to leave the machine. Do not
park the machine on a slope or soft
ground as it may fall over.
9. THE ENGINE, EXHAUST PIPE, MUF-
FLER, AND OIL TANK WILL BE VERY
HOT AFTER THE ENGINE HAS BEEN
RUN.
Be careful not to touch them or to
allow any clothing item to contact
them during inspection or repair.
10. PROPERLY SECURE THE MACHINE
BEFORE TRANSPORTING IT.
When transporting the machine in
another vehicle, always be sure it is
properly secured and in an upright
position and that the fuel cock is in
the “OFF” position. Otherwise, fuel
may leak out of the carburetor or fuel
tank.
Page 74 of 754

1 - 21
GEN
INFO
CLEANING AND STORAGE
8. Automotive wax may be applied to all
painted or chromed surfaces. Avoid com-
bination cleaner-waxes, as they may con-
tain abrasives.
9. After completing the above, start the
engine and allow it to idle for several min-
utes.
EC1B2001
STORAGE
If your machine is to be stored for 60 days or
more, some preventive measures must be
taken to avoid deterioration. After cleaning the
machine thoroughly, prepare it for storage as
follows:
1. Drain the fuel tank, fuel lines, and the car-
buretor float bowl.
2. Remove the spark plug, pour a table-
spoon of SAE 10W-30 motor oil in the
spark plug hole, and reinstall the plug.
With the engine stop switch pushed in,
kick the engine over several times to coat
the cylinder walls with oil.
3. Remove the drive chain, clean it thor-
oughly with solvent, and lubricate it. Rein-
stall the chain or store it in a plastic bag
tied to the frame.
4. Lubricate all control cables.
5. Block the frame up to raise the wheels off
the ground.
6. Tie a plastic bag over the exhaust pipe
outlet to prevent moisture from entering.
7. If the machine is to be stored in a humid
or salt-air environment, coat all exposed
metal surfaces with a film of light oil. Do
not apply oil to rubber parts or the seat
cover.
NOTE:
Make any necessary repairs before the
machine is stored.
Page 76 of 754

SPEC
2 - 1
GENERAL SPECIFICATIONS
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: WR450FS (USA)
WR450F (EUROPE)
WR450F(S) (CDN, AUS, NZ, ZA)
Model code number: 5TJ5 (USA)
5TJ6 (EUROPE)
5TJ7 (CDN, AUS, NZ, ZA)
Dimensions:
Overall length 2,171 mm (85.5 in)
Overall width 827 mm (32.6 in)
Overall height 1,303 mm (51.3 in)
Seat height 998 mm (39.3 in)
Wheelbase 1,485 mm (58.5 in)
Minimum ground clearance 371 mm (14.6 in)
Dry weight:
Without oil and fuel 112.5 kg (248 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 449 cm
3
(15.8 Imp oz, 15.2 US oz)
Bore
×
stroke 95.0
×
63.4 mm (3.74
×
2.50 in)
Compression ratio 12.5 : 1
Starting system Kick and electric starter
Lubrication system: Dry sump
Oil type or grade:
Engine oil (For USA and CDN)
At 5 ˚C (40 ˚F) or higher
Å
Yamalube 4 (20W-40) or SAE 20W-40 type SG
motor oil (Non-Friction modified)
At 15 ˚C (60 ˚F) or lower
ı
Yamalube 4 (10W-30) or SAE 10W-30 type SG
motor oil (Non-Friction modified) and/or
Yamalube 4-R (15W-50) (Non-Friction modi-
fied)
(Except for USA and CDN)
API “SG” or higher grade
-20
-4-10
140
3010
5020
6830
8640 50
104
122°CTemp.
°F
10W-30
10W-40
20W-40
20W-50
15W-40
Page 93 of 754

SPEC
2 - 18
MAINTENANCE SPECIFICATIONS
EC212300
ELECTRICAL
Item Standard Limit
Ignition system:
Advancer type Electrical ----
C.D.I.:
Pickup coil resistance (color) 248 ~ 372 Ω at 20 ˚C (68 ˚F)
(White – Red)----
CDI unit-model/manufacturer 5TJ50/YAMAHA (For USA)
5TJ60/YAMAHA
(Except for USA)----
----
Ignition coil:
Model/manufacturer 5TA-10/DENSO ----
Minimum spark gap 6 mm (0.24 in) ----
Primary winding resistance 0.08 ~ 0.10 Ω at 20 ˚C (68 ˚F) ----
Secondary winding resistance 4.6 ~ 6.8 kΩ at 20 ˚C (68 ˚F) ----
Charging system:
System type AC magneto ----
Model (stator)/manufacturer 5TJ-01/YAMAHA ----
Normal output 14 V/120 W at 5,000 r/min ----
Charging coil resistance (color) 0.288 ~ 0.432 Ω at 20 ˚C (68 ˚F)
(White – Ground)----
Lighting coil resistance (color) 0.224 ~ 0.336 Ω at 20 ˚C (68 ˚F)
(Yellow – Ground)----
Rectifier/regulator:
Regulator type Semiconductor short circuit ----
Model/manufacture SH712AA/SHINDENGEN ----
Regulated voltage (AC) 13.0 ~ 14.0 V ----
Regulated voltage (DC) 14.1 ~ 14.9 V ----
Rectifier capacity (AC) 12 A ----
Rectifier capacity (DC) 8 A ----
Electric starting system:
Type Constant mesh ----
Starter motor:
Model/manufacturer 5TJ01/YAMAHA ----
Operation voltage 12 V ----
Output 0.48 kW ----
Armature coil resistance 0.0117 ~ 0.0143 Ω at 20 ˚C
(68 ˚F)----
Brush overall length 7 mm (0.28 in) 3.5 mm
(0.14 in)
Brash quantity 2 pcs. ----
Spring force 3.92 ~ 5.88 N
(400 ~ 600 g, 14.1 ~ 21.2 oz)----
Commutator diameter 17.6 mm (0.69 in) 16.6 mm
(0.65 in)
Mica undercut (depth) 1.5 mm (0.06 in) ----
Page 656 of 754

6 - 6
–+ELECIGNITION SYSTEM
3. Inspect:
Secondary coil resistance
Out of specification → Replace.
4. Inspect:
Sealed portion of ignition coil a
Spark plug terminal pin b
Threaded portion of spark plug c
Wear → Replace.
AC MAGNETO INSPECTION
1. Inspect:
Pick-up coil resistance
Out of specification → Replace. Tester (+) lead → Orange lead 1
Tester (–) lead → Spark plug terminal 2
Secondary coil
resistanceTester selector
position
4.6 ~ 6.8 kΩ at
20 ˚C (68 ˚F)kΩ × 1
Tester (+) lead → Red lead 1
Tester (–) lead → White lead 2
Pick-up coil
resistanceTester selector
position
248 ~ 372 Ω at
20 ˚C (68 ˚F)Ω × 100
RW
12
NEUTRAL SWITCH INSPECTION
1. Inspect:
Neutral switch conduct
No continuity while in neutral → Replace.
Continuity while in gear → Replace.
EC628000
CDI UNIT INSPECTION
Check all electrical components. If no fault is
found, replace the CDI unit. Then check the
electrical components again.Tester (+) lead → Sky blue lead 1
Tester (–) lead → Ground 2
Sb
1GroundTester selec-
tor position
NEUTRALΩ × 1IN GEAR
–+ Ω×1
1
2L/W Sb
Page 674 of 754
6 - 14
–+ELECELECTRIC STARTING SYSTEM
INSPECTION AND REPAIR
1. Check:
Commutator
Dirt → Clean with 600 grit sandpaper.
2. Measure:
Commutator diameter a
Out of specification → Replace the
starter motor.
3. Measure:
Mica undercut a
Out of specification → Scrape the mica
to the proper measurement with a hack-
saw blade which has been grounded to
fit the commutator.
NOTE:
The mica must be undercut to ensure proper
operation of the commutator.
Min. commutator diameter
16.6 mm (0.65 in)
Mica undercut
1.5 mm (0.06 in)
4. Measure:
Armature assembly resistances (com-
mutator and insulation)
Out of specification → Replace the
starter motor.
Measure the armature assembly resis-
tances with the pocket tester.
Pocket tester
YU-03112-C/90890-03112
Armature assembly
Commutator resistance 1
0.0117 ~ 0.0143 Ω at 20 ˚C
(68 ˚F)
Insulation resistance 2
Above 1 MΩ at 20˚C (68 ˚F)
If any resistance is out of specification,
replace the starter motor.
Page 684 of 754
6 - 18
–+ELECCHARGING SYSTEM
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
Couplers and leads connection
Rust/dust/looseness/short-circuit →
Repair or replace.
CHARGING VOLTAGE INSPECTION
1. Start the engine.
2. Inspect:
Charging voltage
Out of specification → If no failure is
found in checking the source coil resis-
tance, replace the rectifier/regulator.
Tester (+) lead → Red lead 1
Tester (–) lead → Black lead 2
Charging
voltageTester selector
position
14.1 ~ 14.9 V at
5,000 r/minDCV-20
R
BW Y1
2
3. Inspect:
Charging coil resistance
Out of specification → Replace.
Tester (+) lead → White lead 1
Tester (–) lead → Ground 2
Charging coil
resistanceTester selector
position
0.288 ~ 0.432 Ω
at 20 ˚C (68 ˚F)Ω × 1
Page 702 of 754
6 - 25
–+ELECLIGHTING SYSTEM
AC MAGNETO INSPECTION
1. Inspect:
Lighting coil resistance
Out of specification → Replace.
RECTIFIER/REGULATOR INSPECTION
1. Connect the battery leads.
2. Start the engine.
3. Turn on the headlight and taillight by turn-
ing on the lights switch.
4. Inspect:
Out-put voltage
Out of specification → Replace rectifier/
regulator. Tester (+) lead → Yellow lead 1
Tester (–) lead → Ground 2
Lighting coil
resistanceTester selector
position
0.224 ~ 0.336 Ω
at 20 ˚C (68 ˚F)Ω × 1
Tester (+) lead → Yellow lead 1
Tester (–) lead → Black lead 2
Out-put voltageTester selector
position
13.0 ~ 14.0 V at
5,000 r/minACV-20
R
BW
Y1
2