CONTENTS
CHAPTER 1
GENERAL INFOR-
MATION
LOCATION OF
IMPORTANT LABELS ..... 1-1
DESCRIPTION ................. 1-5
CONSUMER
INFORMATION................. 1-6
FEATURES....................... 1-7
INCLUDED PARTS .......... 1-9
IMPORTANT
INFORMATION................. 1-9
HANDLING THE
ELECTRONIC PARTS ... 1-10
CHECKING OF
CONNECTION ................ 1-10
SPECIAL TOOLS ........... 1-12
CONTROL
FUNCTIONS ................... 1-17
STARTING
AND BREAK-IN.............. 1-17
TORQUE-CHECK
POINTS........................... 1-19
CLEANING
AND STORAGE ............. 1-20
CHAPTER 2
SPECIFICATIONS
GENERAL
SPECIFICATIONS ............ 2-1
MAINTENANCE
SPECIFICATIONS ............ 2-3
TIGHTENING
TORQUES ...................... 2-11
LUBRICATION
DIAGRAMS .................... 2-17
CABLE ROUTING
DIAGRAM ....................... 2-18
CHAPTER 3
REGULAR INSPEC-
TION AND AD-
JUSTMENTS
MAINTENANCE
INTERVALS ...................... 3-1
PRE-OPERATION
INSPECTION
AND MAINTENANCE ....... 3-5
ENGINE ............................ 3-6
CHASSIS ........................ 3-14
ELECTRICAL ................. 3-24
CHAPTER 4
ENGINE
SEAT
AND SIDE COVERS ......... 4-1
EXHAUST PIPE
AND SILENCER ............... 4-3
RADIATOR ....................... 4-5
CAMSHAFTS.................... 4-8
CYLINDER HEAD........... 4-13
VALVES AND
VALVE SPRINGS ........... 4-17
CYLINDER
AND PISTON .................. 4-21
CLUTCH ......................... 4-25
OIL FILTER ELEMENT
AND WATER PUMP ....... 4-29
BALANCER .................... 4-33
OIL PUMP ....................... 4-35
KICK SHAFT
AND SHIFT SHAFT ........ 4-38
AC MAGNETO................ 4-43
ENGINE REMOVAL ....... 4-45
CRANKCASE
AND CRANKSHAFT ...... 4-50
TRANSMISSION,
SHIFT CAM
AND SHIFT FORK .......... 4-56
CHAPTER 5
CHASSIS
FRONT WHEEL
AND REAR WHEEL .........5-1
FRONT BRAKE
AND REAR BRAKE..........5-6
FRONT FORK .................5-16
HANDLEBAR..................5-24
STEERING ......................5-28
SWINGARM ....................5-32
REAR
SHOCK ABSORBER ......5-37
CHAPTER 6
FUEL SYSTEM
FUEL TANK ......................6-1
THROTTLE BODY ............6-4
CHAPTER 7
ELECTRICAL
ELECTRICAL
COMPONENTS AND
WIRING DIAGRAM ...........7-1
IGNITION SYSTEM...........7-3
THROTTLE POSITION
SENSOR SYSTEM ...........7-6
FUEL INJECTION
SYSTEM............................7-9
FUEL PUMP SYSTEM ....7-35
ELECTRICAL
COMPONENTS...............7-36
CHAPTER 8
TUNING
CHASSIS ..........................8-1
1-15
SPECIAL TOOLS
Valve guide remover
5.5 mm (0.22 in)
YM-01122This tool is needed to remove and
install the valve guide.
Valve guide installer
5.5 mm (0.22 in)
YM-04015This tool is needed to install the
valve guide.
Valve guide reamer
5.5 mm (0.22 in)
YM-01196This tool is needed to rebore the
new valve guide.
Valve spring compressor attach-
ment
YM-04108, 90890-04108This tool is needed to remove and
install the valve assemblies.
Rotor puller
YM-04151, 90890-04151This tool is used to remove the fly-
wheel magneto.
Crankcase separating tool
YU-A9642
90890-04152These tool is used to remove the
crankshaft from either case.
Dynamic spark tester
YM-34487
Ignition checker
90890-06754This instrument is necessary for
checking the ignition system compo-
nents. Tool name/Part number How to use Illustration
1-19
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 pump to fuel tank
1-20
CLEANING AND STORAGE
CLEANING AND STORAGE
CLEANING
Frequent cleaning of your machine
will enhance its appearance, maintain
good overall performance, and ex-
tend the life of many components.
1. Before washing the machine,
block off the end of the exhaust
pipe to prevent water from enter-
ing. A plastic bag secured with a
rubber band may be used for this
purpose.
2. If the engine is excessively
greasy, apply some degreaser to
it with a paint brush. Do not apply
degreaser to the chain, sprockets,
or wheel axles.
3. Rinse the dirt and degreaser off
with a garden hose; use only
enough pressure to do the job.
Do not use high-pressure washers
or steam-jet cleaners since they
cause water seepage and deterio-
ration seals.
4. After the majority of the dirt has
been hosed off, wash all surfaces
with warm water and a mild deter-
gent. Use an old toothbrush to
clean hard-to-reach places.
5. Rinse the machine off immediate-
ly with clean water, and dry all
surfaces with a soft towel or cloth.
6. Immediately after washing, re-
move excess water from the
chain with a paper towel and lubri-
cate the chain to prevent rust.
7. Clean the seat with a vinyl uphol-
stery cleaner to keep the cover
pliable and glossy.
8. Automotive wax may be applied
to all painted or chromed surfac-
es. Avoid combination cleaner-
waxes, as they may contain abra-
sives.
9. After completing the above, start
the engine and allow it to idle for
several minutes.STORAGE
If your machine is to be stored for 60
days or more, some preventive mea-
sures must be taken to avoid deterio-
ration. After cleaning the machine
thoroughly, prepare it for storage as
follows:
1. Fill up the fuel tank and add fuel
stabilizer (if available) to prevent
the fuel tank from rusting and the
fuel from deteriorating.
2. Remove the spark plug, pour a ta-
blespoon of SAE 10W-40 motor
oil in the spark plug hole, and re-
install the plug. With the engine
stop switch pushed in, kick the en-
gine over several times to coat the
cylinder walls with oil.
3. Remove the drive chain, clean it
thoroughly with solvent, and lubri-
cate it. Reinstall 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 cov-
er.
Make any necessary repairs before
the machine is stored.
2-1
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model name: YZ450FD (USA, CDN, AUS, NZ)
YZ450F (EUROPE, ZA)
Model code number: 33DD (USA,CDN)
33DE (EUROPE)
33DG (AUS, NZ, ZA)
Dimensions: USA, CDN EUROPE AUS, NZ, ZA
Overall length 2,195 mm (86.42
in)2,191 mm (86.26
in)2,195 mm (86.42
in)
Overall width 825 mm (32.48 in)←←
Overall height 1,312 mm (51.65
in)1,311 mm (51.61
in)←
Seat height 999 mm (39.33 in)←998 mm (39.29 in)
Wheelbase 1,492 mm (58.74
in)1,487 mm (58.54
in)←
Minimum ground clearance 383 mm (15.08 in)←384 mm (15.12 in)
Weight:
Curb weight 111 kg (245 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder
Displacement 449.7 cm
3 (15.8 Imp oz, 15.2 US oz)
Bore × stroke 97.0 × 60.8 mm (3.82 × 2.39 in)
Compression ratio 12.5 : 1
Starting system Kickstarter
Lubrication system: Dry sump
Oil type or grade:
Engine oil
Recommended brand: YAMALUBE
SAE10W-30, SAE10W-40, SAE10W-50,
SAE15W-40, SAE20W-40 or SAE20W-50
API service SG type or higher,
JASO standard MA
Oil capacity:
Engine oil
Periodic oil change 0.95 L (0.84 Imp qt, 1.00 US qt)
With oil filter replacement 1.0 L (0.88 Imp qt, 1.06 US qt)
Total amount 1.2 L (1.06 Imp qt, 1.27 US qt)
Coolant capacity (including all routes): 1.13 L (0.99 Imp qt, 1.19 US qt)
Air filter: Wet type element
2
2-3
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINEWheel travel:
Front wheel travel 310 mm (12.2 in)
Rear wheel travel 315 mm (12.4 in) (For USA, CDN)
312 mm (12.3 in) (For EUROPE, AUS, NZ, ZA)
Electrical:
Ignition system TCI
Item Standard Limit
Cylinder head:
Warp limit ---- 0.05 mm (0.002
in)
Cylinder:
Bore size 97.00–97.01 mm (3.8189–3.8193 in) ----
Out of round limit ---- 0.05 mm (0.002
in)
Camshaft:
Drive method Chain drive (Left) ----
Camshaft cap inside diameter 22.000–22.021 mm (0.8661–0.8670 in) ----
Camshaft outside diameter 21.959–21.972 mm (0.8645–0.8650 in) ----
Shaft-to-cap clearance 0.028–0.062 mm (0.0011–0.0024 in) 0.08 mm (0.003
in)
Cam dimensions
Intake "A" 37.750–37.850 mm (1.4862–1.4902 in) 37.650 mm
(1.4823 in)
Intake "B" 28.129–28.229 mm (1.1074–1.1114 in) 28.029 mm
(1.1035 in)
Exhaust "A" 33.540–33.640 mm (1.3205–1.3244 in) 33.440 mm
(1.3165 in)
Exhaust "B" 24.769–24.869 mm (0.9752–0.9791 in) 24.669 mm
(0.9712 in)
Camshaft runout limit ---- 0.03 mm
(0.0012 in)
2-9
MAINTENANCE SPECIFICATIONS
CHASSISItem Standard Limit
Steering system: Steering bearing type Taper roller bearing ----
Front suspension: USA, CDN EUROPE, AUS, NZ, ZA Front fork travel 310 mm (12.2 in) ←----
Fork spring free length 470.0 mm (18.5 in) ←465.0 mm
(18.3 in)
Spring rate, STD K = 4.6 N/mm (0.469 kg/ mm, 26.3 lb/in)←
----
Optional spring Yes← ----
Oil capacity 551 cm
3 (19.4 lmp oz,
18.63 US oz) ←
----
Oil grade Suspension oil "S1"←----
Inner tube outer diameter 48 mm (1.89 in)← ----
Front fork top end 0 mm (0 in)←----
Rear suspension: USA, CDN EUROPE, AUS, NZ, ZA
Shock absorber travel 132.0 mm (5.20 in)←----
Spring free length 260.0 mm (10.24 in)←254.8 mm
(10.03 in)
Fitting length 250.0 mm (9.84 in) 246.0 mm (9.69 in) ----
Preload length
in) ←
Spring rate, STD K = 56.0 N/mm (5.7 kg/
mm, 319.2 lb/in) K = 54.0 N/mm (5.5 kg/
mm, 308.0 lb/in)----
Optional spring Yes← ----
Enclosed gas pressure 1,000 kPa (10 kg/cm
2,
142 psi) ←
----
Swingarm: Swingarm free play limitEnd ---- 1.0 mm (0.04 in)
Wheel: Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/materia l 21 × 1.60/Aluminum ----
Rear rim size/materia l 19 × 2.15/Aluminum ----
Rim runout limit: Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain: Type/manufacturer DID5 20DMA2 SDH/DAIDO ----
Number of links 113 links + joint ----
Chain slack 50–60 mm (2.0–2.4 in) ----
Chain length (15 links) ---- 242.9 mm (9.563 in)
2-12
TIGHTENING TORQUES
*1: Tighten the cylinder head bolts to 30 Nm (3.0 m•kg, 22 ft•lb) in the proper tightening sequence, remove and retighten
the cylinder head bolts to 20 Nm (2.0 m•kg, 14 ft•lb) in the proper tightening sequence, and then tighten the cylinder head
bolts further to reach the specified angle 150° in the proper tightening sequence.
Oil filter element cover M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil pressure check bolt M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankshaft end accessing screw M36 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Timing mark accessing screw M14 1 6 Nm (0.6 m•kg, 4.3 ft•lb)
Clutch cover M6 7 10 Nm (1.0 m•kg, 7.2 ft•lb)
Right crankcase cover M6 9 10 Nm (1.0 m•kg, 7.2 ft•lb)
Left crankcase cover M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase M6 13 12 Nm (1.2 m•kg, 8.7 ft•lb)
Clutch cable holder M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil drain bolt M8 1 20 Nm (2.0 m•kg, 14 ft•lb)
Oil drain bolt M8 1 20 Nm (2.0 m•kg, 14 ft•lb)
Oil check bolt (crankcase) M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil strainer M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil nozzle M5 1 8 Nm (0.8 m•kg, 5.8 ft•lb)
Crankcase bearing stopper M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase bearing stopper (crankshaft) M8 4 22 Nm (2.2 m•kg, 16 ft•lb) Stake.
Drive axle oil seal stopper M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Kick shaft ratchet wheel guide M62 12 Nm (1.2 m•kg, 8.7 ft•lb)Lock washer
Kickstarter crank M8 1 33 Nm (3.3 m•kg, 24 ft•lb)
Screw (kickstarter crank) M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Primary drive gear M20 1 100 Nm (10.0 m•kg, 72 ft•lb)
Clutch boss M20 1 75 Nm (7.5 m•kg, 54 ft•lb)
Clutch cable locknut M8 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Clutch cable adjust bolt and locknut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Clutch spring M6 6 10 Nm (1.0 m•kg, 7.2 ft•lb)
Balancer M10 1 45 Nm (4.5 m•kg, 32 ft•lb) Lock washer
Balancer shaft driven gear M14 1 50 Nm (5.0 m•kg, 36 ft•lb) Lock washer
Balancer weight M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Drive sprocket M20 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Drive chain sprocket cover M6 27 Nm (0.7 m•kg, 5.1 ft•lb)
Shift pedal M6 1 12 Nm (1.2 m•kg, 8.7 ft•lb)
Shift guide M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Stopper lever M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Segment M8 1 30 Nm (3.0 m•kg, 22 ft•lb)Item
Thread
sizeQ'ty Tightening torque Remarks