2012 YAMAHA YZ450F oil

2-11
TIGHTENING TORQUES
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque tightening after break-in or before each race.
ItemThread
sizeQ'ty Tightening torque Remarks
Spark plug M10S 1 13 Nm (1.3 m•kg, 9.4 ft•lb)
Camshaft cap M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head blind plug screw M12 2 28 Nm (2.8 m•kg, 20 ft•lb)
Oil passage plug M8 1 15 Nm (1.5 m•kg, 11 ft•lb)
Cylinder head (stud bolt) M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
Cylinder head (bolt) M10 4 Refer to TIP.
*1
Cylinder head (bolt) M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head cover M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Timing chain tensioner M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Timing chain tensioner cap bolt M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Timing chain guide stopper plate (exhaust
side)M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Exhaust pipe (nut) M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Exhaust pipe and frame M8 1 20 Nm (2.0 m•kg, 14 ft•lb)
△Silencer M8 2 30 Nm (3.0 m•kg, 22 ft•lb)
Silencer clamp (front) M8 1 12 Nm (1.2 m•kg, 8.7 ft•lb)
Silencer clamp (rear) M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Starter knob/Idle screw M12 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Throttle body joint M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Throttle body joint clamp M5 1 3 Nm (0.3 m•kg, 2.2 ft•lb)
△Air filter case M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
Air filter joint and air filter case M4 9 1 Nm (0.1 m•kg, 0.7 ft•lb)
Air filter case cover M5 2 5 Nm (0.5 m•kg, 3.6 ft•lb)
Air filter joint clamp M4 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Throttle cable adjust bolt and locknut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Throttle cable (pull) M10 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Throttle cable (return) M10 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Throttle cable cover M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Air duct M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
Radiator M6 4 10 Nm (1.0 m•kg, 7.2 ft•lb)
Radiator hose clamp M6 8 2 Nm (0.2 m•kg, 1.4 ft•lb)
Radiator pipe 1 M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Radiator pipe 2 M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Impeller M8 1 14 Nm (1.4 m•kg, 10 ft•lb)
Water pump housing cover M6 4 10 Nm (1.0 m•kg, 7.2 ft•lb)
Coolant drain bolt M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil pump cover M4 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Oil pump M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil pump drive gear shaft M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)

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

2-15
TIGHTENING TORQUES
1. First, tighten the steering ring nut approximately 38 Nm (3.8 m•kg, 27 ft•lb) by using the steering nut wrench, then loosen
the steering ring nut one turn.
2. Retighten the steering ring nut 7 Nm (0.7 m•kg, 5.1 ft•lb).
ELECTRICALSeat M8 2 22 Nm (2.2 m•kg, 16 ft•lb)
△Side cover M6 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
Heat protector M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Air scoop and air duct M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Radiator and radiator guard M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Air scoop and radiator guard M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Front fender M6 4 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Rear fender (front) M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Rear fender (rear) M6 2 18 Nm (1.8 m•kg, 13 ft•lb)
△Mud flap — 2 1 Nm (0.1 m•kg, 0.7 ft•lb)
△Number plate M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)Item
Thread
sizeQ'ty Tightening torque Remarks
ItemThread
sizeQ'ty Tightening torque Remarks
Stator M5 3 8 Nm (0.8 m•kg, 5.8 ft•lb)
Rotor M12 1 65 Nm (6.5 m•kg, 47 ft•lb)
Crankshaft position sensor M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Throttle position sensor M5 1 3 Nm (0.3 m•kg, 2.2 ft•lb)
Injector M5 2 3 Nm (0.3 m•kg, 2.2 ft•lb)
Ignition coil M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Coolant temperature sensor M10 1 16 Nm (1.6 m•kg, 11 ft•lb)
Rectifier/regulator M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Ignition coil bracket M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Intake air pressure sensor M5 1 5 Nm (0.5 m•kg, 3.6 ft•lb)
Atmospheric pressure sensor M5 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Atmospheric pressure sensor bracket M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Condenser bracket M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Ground lead M5 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
△ECU M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
ECU bracket M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)

2-17
LUBRICATION DIAGRAMS
LUBRICATION DIAGRAMS
1. Oil strainer
2. Oil check bolt
3. Scavenging pump
4. Oil feed pump
5. Oil filter element
6. Crankshaft
7. Oil nozzle
8. Exhaust camshaft
9. Intake camshaft10. Main axle
11. Drive axle
12. Oil level check window
13. Oil tank

2-21
CABLE ROUTING DIAGRAM
1. Clutch cable
2. Throttle cable (return)
3. Throttle cable (pull)
4. Cable holder
5. Clamp
6. Rectifier/regulator
7. Ignition coil
8. Ignition coil coupler
9. AC magneto coupler
10. Radiator hose 2
11. Ground lead terminal
12. Plug cap
13. Ignition coil bracket
14. Clamp (lock)
15. Clamp (clip)
16. AC magneto lead
17. ECU bracket
18. Cylinder head cover installing
boltA. Pass the clutch cable, throttle
cables, and engine stop switch
lead through the cable holder.
Pass the clutch cable through
the lower guide only.
B. Route the engine stop switch
lead to the inside of the clip.
C. Fasten the rectifier/regulator
lead and engine stop switch lead
(wire harness end).
D. Insert the projection on the en-
gine stop switch coupler into the
hole in the bracket.
E. Insert the projection on the recti-
fier/regulator coupler into the
hole in the bracket.
F. Position the ignition coil bracket
to the outside of the ignition coil,
and insert the bolts from the igni-
tion coil side.
G. Fasten the AC magneto lead to
the ignition coil bracket with a
plastic locking tie, making sure
to position the tie above the low-
er mounting portion of the brack-
et. Face the buckle of the plastic
locking tie forward, and then cut
off the excess end of the tie.
H. Route the ignition coil lead be-
tween the condenser and the ig-
nition coil.
I. Fit the clip portion of the clamp
into the ignition coil bracket and
fasten the clutch cable with the
locking portion of the clamp.
J. Route the clutch cable to the
outside of the AC magneto lead.
K. Route the throttle cables under
radiator hose 2, making sure not
to twist the cables.
L. Route the AC magneto lead to
the inside of the throttle cables
and clutch cable.
M. Install the ground lead terminal
between the ECU bracket and
the cable holder, making sure to
position the terminal between
the stoppers.
N. Push in the spark plug cap com-
pletely, making sure that there is
no gap between the cylinder
head cover and the cap.
O. Pass the high tension cord so
that it may not go right over the
cylinder head cover installing
bolt when viewed directly from
above.
P. Apply sealant to the slit and in-
ner surface of the grommet, and
then install the grommet at the
position shown.

2-23
CABLE ROUTING DIAGRAM
1. Tension pipe
2. Coolant temperature sensor
coupler
3. Front engine bracket
4. Fuel pump coupler
5. Fuel pump
6. Intake air temperature sensor
coupler
7. Radiator hose 2
8. Radiator breather hose
9. Radiator hose 1
10. Radiator hose 4
11. Radiator pipe 2
12. Radiator hose 3
13. Cylinder head breather hose
14. Frame
15. ECU (electronic control unit)
16. ECU bracket
17. Main harness
18. AC magneto lead
19. Throttle position sensor lead
20. Condenser lead
21. Coolant temperature sensor
lead
22. Ignition coil lead
23. CondenserA. Fasten the wire harness at the
positioning tape to the ECU
bracket with a plastic locking tie.
Face the buckle of the plastic
locking tie downward, and then
cut off the excess end of the tie.
B. Install the cover onto the wire
harness coupler.
C. Route the condenser lead, throt-
tle position sensor lead, coolant
temperature sensor lead, igni-
tion coil lead, and AC magneto
lead under radiator hose 2.
D. Connect the vacuum hose to the
atmospheric pressure sensor,
and then fasten the hose with
the clamp. Make sure to face the
moving part of the sensor rear-
ward.
E. After connecting the condenser
coupler, install the coupler cover
onto the coupler.
F. After connecting the throttle po-
sition sensor coupler, install the
coupler cover onto the coupler.
G. Fasten the AC magneto lead,
condenser lead, throttle position
sensor lead, coolant tempera-
ture sensor lead, and ignition
coil lead to the frame with the
plastic band, making sure to po-
sition the band between the igni-
tion coil bracket and the tension
pipe. Face the buckle of the
plastic band to the right with the
end pointing rearward.
H. Point the end of the vacuum
hose rearward.
I. Fit the bracket into the hole in
the rubber portion of the con-
denser.
J. Fasten the radiator breather
hose to the frame with the plas-
tic band, making sure to position
the band above the front engine
bracket. Face the buckle of the
plastic band outward with the
end pointing rearward.
K. After connecting the coolant
temperature sensor coupler, in-
stall the coupler cover onto the
coupler.L. Route the radiator breather hose
between the down tubes.
M. Fasten the fuel hose and fuel
pump lead with the plastic band,
making sure to position the band
between the bend in the fuel
hose protector and the end of
the protector. Point the end of
the plastic band upward.
N. Insert the projection on the joint
coupler into the hole in the
bracket, and then install the cou-
pler cover onto the coupler.
O. Route the atmospheric pressure
sensor lead, intake air pressure
sensor lead, intake air tempera-
ture sensor lead, fuel injector
lead, and fuel pump lead above
radiator hose 2. Position the
joint coupler above radiator
hose 2.
P. Route the radiator breather hose
to the inside of radiator hose 1
and the front engine bracket.
Q. Hose installation position
(1.3–3.3 mm, 0.05–0.13 in)
R. Clip installation position (0–2.0
mm, 0–0.08 in)
S. Install the washer so that it con-
tacts the bolt head.
T. Install the collar so that the
flange on the collar contacts the
ECU bracket.
U. 6 mm (0.24 in) or less

2-24
CABLE ROUTING DIAGRAM
1. Ignition coil coupler
2. Coolant temperature sensor
lead
3. Atmospheric pressure sensor
coupler
4. Intake air temperature sensor
lead
5. Clamp
6. Intake air pressure sensor cou-
pler
7. Cover8Fuel hose
9. Fuel pump lead
10. Fuel injector coupler
11. Throttle body
12. High tension code
13. Throttle cable
14. AC magneto leadA. Route the fuel pump lead to the
outside of the fuel hose and
above the cover.
B. Route the spark plug wire be-
tween the throttle cables and the
throttle body. When installing
the air filter, be sure not to pinch
the spark plug wire.
C. Route the AC magneto lead to
the inside of the throttle cables.

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.
• Periodic inspection is essential in making full use of the machine performance. The service life of the parts varies sub-
stantially according to the environment in which the machine runs (e.g., rain, dirt, etc.). Therefore, earlier inspection is
required by reference to the list below..
ItemAfter
break-
inEvery
race
(about
2.5
hours)
Every
third
(about
7.5
hours)Every
fifth
(about
12.5
hours)
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●●Replace the piston, piston pin, piston
pin clip, and piston ring all as a set.
PISTON RING
Inspect●Check ring end gap.
Replace●●Replace the piston, piston pin, piston
pin clip, and piston ring all as a set.
PISTON PIN
Inspect●
Replace●●Replace the piston, piston pin, piston
pin clip, and piston ring all as a set.
3