2016 YAMAHA YZ450F engine coolant

DESCRIPTION
1-4
EASB111009
DESCRIPTION
TIP
Designs and specifications of the vehicle are subject to change without notice. Therefore, please
note that the descriptions in this manual may be different from those for the vehicle you have pur-
chased.1. Clutch lever 10. Radiator
2. Front brake lever 11. Coolant drain bolt
3. Throttle grip 12. Rear brake pedal
4. Radiator cap 13. Air filter
5. Fuel tank cap 14. Drive chain
6. Launch control switch 15. Shift pedal
7. Engine stop switch 16. Oil level check window
8. Fuel tank 17. Starter knob/idle screw
9. Kickstarter lever 18. Front fork
2 1
7
6
89 1054 3
12 11 18 17 16 15 1413

IMPORTANT INFORMATION
1-8
EAS20180
IMPORTANT INFORMATION
EASB111020PREPARATION FOR REMOVAL AND DIS-
ASSEMBLY
1. Before the jobs, completely remove mud,
dust, and the like in order to prevent the en-
try of them into the inside during the jobs.
• Before cleaning with high-pressure water of
washers, cover the following parts.
Air duct
Silencer exhaust port
Drain hole on the cylinder head (right side)
Hole under the water pump housing
2. Use proper special tools and equipment.
See “SPECIAL TOOLS”.
3. During disassembly, check and measure the
required parts, and make a record of them
so that you may refer to the record when in-
stalling them. Moreover, arrange gears, cyl-
inders, pistons, and other parts for each
section so as not to confuse or lose them.4. During disassembly, clean each of the parts,
and store them in trays for each section.
5. Flammable. Keep servicing areas away
from any source of fire.
6. During servicing, take special care not to re-
ceive an injury or a burn on the engine, the
exhaust pipe, the silencer, or the like.
7. If coolant is left adhered to the chassis, paint
and plating will be damaged. Therefore,
rinse it out with water in good time.
EWA
WARNING
Coolant is potentially harmful and should
be handled with special care.
• If it enters your eyes, wash it away with wa-
ter enough and then get medical attention
• If it splashes on your skin or clothes,
quickly wash it away with water and then
with soapy water.
• If it is swallowed, immediately induce vom-
iting and get medical attention.
EASB111021REPLACEMENT PARTS
Make sure that the parts and grease or oil to be
used for repair of the vehicle, including periodic
replacement parts, are new YAMAHA genuine
parts and recommended parts.
Do not use any used parts, because these may
not be genuine though they have similar ap-
pearances or because the quality may be
changed by aging.

MAINTENANCE AFTER BREAK-IN
1-23
EASB111045
MAINTENANCE AFTER BREAK-IN
After a break-in, perform careful maintenance
to get ready for the next practice or race.
Refer to “PRE-OPERATION INSPECTION
AND MAINTENANCE” on page 3-7.
EASB111046MAJOR MAINTENANCE
1. For the engine
• Leaks around the engine
Check for pressure leaks from the cylinder
head or the cylinder, oil leaks from the
crankcase or the case cover, leaks from the
coolant system, and other leaks.
• Check that the valve, the cylinder head, the
cylinder, the piston, and the piston ring fit
one another, and that contact between the
valve and the cylinder head, and that be-
tween the cylinder and the piston are cor-
rect.
• Engine oil change
Drain the oil, and check for dirt and foreign
materials such as metal chips. (If any foreign
material is mixed, disassemble and check
the crankcase.)
Pour the specified amount of the recom-
mended oil.
• AC magneto
Check for looseness in mounted areas of
the rotor and the stator.
Check that the connector is not being dis-
connected.
• Silencer
Check the main body and stay for cracks.
Check for leaks.
• Mounting bolts and nuts
Check for looseness in mounted areas of
parts, as well as engine mounting bolts and
engine brackets.
2. For the chassis
• Check welds and mounted areas of the
frame, the swingarm, the link, the bracket,
and so on, for looseness and cracks.
• Wheel (s)
Check the wheel for runout. Check the
spoke for looseness.
• Brake(s)
Check the brake disc mounting bolt for
looseness.
Check that the reservoir contains the speci-
fied amount of brake fluid. Check for leaks.• Cable
Grease and adjust cables.
•Drive chain
Lubricate the drive chain and adjust its ten-
sion.
• Fuel tank
Clean the inside of the fuel tank. Check for
leaks.
• Suspension
Check for oil leaks in the front fork or the rear
shock absorber. Check that the mounted
conditions are good.
• Sprocket
Check for looseness in the sprocket mount-
ed on the rear wheel.
• Mounting bolts and nuts
Check mounted areas for looseness.
ECA
NOTICE
After a break-in or before each race, always
check the points shown in “TORQUE-
CHECK POINTS” for tightening torques and
retighten them. (Refer to “TORQUE-CHECK
POINTS” on page 1-24.)
• Greasing and oiling
Always grease or oil the specified points.

ENGINE SPECIFICATIONS
2-6
Throttle body
Type/quantity 30RA-JX1A/1
ID mark 1SL5 10
Fuel line pressure at idling 324.0 kPa (3.24 kgf/cm
2, 47.0 psi)
Throttle position sensor
Resistance 6.30 k
Output voltage (at idle) 0.48–0.52 V
Fuel injection sensor
Crankshaft position sensor resistance 228–342 
Intake air pressure sensor output voltage 3.57–3.71 V at 101.3 kPa
Intake air temperature sensor resistance 290–390  at 80 °C (176 °F)
Coolant temperature sensor resistance 2.51–2.78 k at 20°C (68°F) 210–221  at
100°C (212°F)
Idling condition
Engine idling speed 1900–2100 r/min
CO% 6.8–9.2 %
Intake vacuum 30.5–37.8 kPa (229–284 mmHg,
9.0–11.2 inHg)
Water temperature 70–80 °C (158–176 °F)
Oil temperature 55–65 °C (131–149 °F)
Throttle grip free play 3.0–5.0 mm (0.12–0.20 in)

TIGHTENING TORQUES
2-13
EASB111056ENGINE TIGHTENING TORQUES
TIP
- marked portion shall be checked for torque tightening after break-in or before each race.
ITEMThread
sizeQ’ty TIGHTENING TORQUES Remarks
Camshaft cap bolt
M6 8 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Cylinder head blind plug
M12 1 28 Nm (2.8 m·kgf, 20 ft·lbf)
Spark plug
M10 1 13 Nm (1.3 m·kgf, 9.4 ft·lbf)
Cylinder head stud bolt (exhaust
pipe)M6 3 7 Nm (0.7 m·kgf, 5.1 ft·lbf)
Cylinder head bolts
M9 4 See TIP.
*1
Cylinder head bolts
M6 2 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Cylinder head cover bolt
M6 3 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil passage plug (cylinder head)
M8 1 15 Nm (1.5 m·kgf, 11 ft·lbf)
Cylinder bolt
M6 1 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil pressure check bolt
M6 2 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Balancer weight plate screw
M6 3 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Balancer driven gear nut M14 1 50 Nm (5.0 m·kgf, 36 ft·lbf)Use a
lock
washer.
Balancer nut M10 1 45 Nm (4.5 m·kgf, 33 ft·lbf)Use a
lock
washer.
Timing chain guide stopper plate
(exhaust side)M6 1 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Timing chain tensioner cap bolt
M6 1 6 Nm (0.6 m·kgf, 4.3 ft·lbf)
Timing chain tensioner bolt
M6 2 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Coolant drain bolt
M6 1 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Radiator hose clamp screw
M6 8 1.5 Nm (0.15 m·kgf, 1.1 ft·lbf)
Radiator bolt
M6 4 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Radiator pipe bolt
M6 1 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Radiator pipe joint bolt
M6 1 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Water pump housing cover bolt
M6 4 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil pump bolt
M5 2 5 Nm (0.5 m·kgf, 3.6 ft·lbf)
Oil pump cover screw
M4 1 2.0 Nm (0.20 m·kgf, 1.4 ft·lbf)
Oil strainer bolt
M6 1 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil passage cover bolt (left crank-
case)M6 1 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Throttle cable cover bolt
M5 1 3.5 Nm (0.35 m·kgf, 2.5 ft·lbf)
Throttle body joint bolt
M6 2 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Throttle body joint clamp bolt
M5 1 3.0 Nm (0.30 m·kgf, 2.2 ft·lbf)
E
LT
M
LT
LT
LT

CABLE ROUTING DIAGRAM
2-34
1. Bracket
2. Condenser
3. Coolant temperature sensor
4. Coupler cover
5. Intake air pressure sensor coupler
6. Intake air temperature sensor coupler
7. Radiator hose
8. Radiator breather hose
9. Joint coupler
10. Plate
11. Tension arm
12. Throttle position sensor lead
13. Ground lead
14. Throttle position sensor coupler
15. Radiator breather hose
16. Cylinder head breather hose
17. Engine guard
18. Crankcase
19. Fuel pump coupler
20. Fuel hose
21. Condenser lead
22. Fuel pump lead
23. Condenser coupler
24. Ground lead terminal
25. Fuel tank
26. Damper
27. Rear frame
28. Main harness
A. Insert the condenser into the bracket as far as it
will go.
B. Attach the coupler cover to the coolant tempera-
ture sensor coupler.
C. Pass the radiator breather hose to the inside of
the radiator hose (the side of the vehicle).
D. Insert and fix the joint coupler to the plate. After
fixing it, attach the cover.
E. Pass the throttle position sensor lead to the out-
side of the tension arm (the outside of the vehi-
cle).
F. After connecting the throttle position sensor cou-
pler, attach the cover.
G. Pass the radiator breather hose to the outside of
the tension arm and the throttle position sensor
lead (the outside of the vehicle), and to the inside
of the radiator hose (the side of the vehicle).
H. Pass the protector of the cylinder head breather
hose until it touches the holder.
I. Pass the cylinder head breather hose between
the engine guard and the crankcase.
J. Install the end of the cylinder head breather hose
with it facing downward.
K. After connecting the fuel pump coupler, attach
the coupler cover.
L. 55 mm (2.17 in) (seat load receiver)
M. Clamp the fuel hose and the fuel pump lead by
the holder. Make sure that the painted part on the
fuel hose is clamped, and face the lock on the
clamp toward the rear top of the vehicle.
N. Do not install the plastic locking tie to the seat
load receiver.
O. Make the lock on the plastic locking tie face the
front of the vehicle, and make the end face the
bottom of the vehicle. Do not cut the end.
P. Install the ground lead terminal between the plate
and the bolt.
Q. Detent
R. Fix the ground lead terminal to the detent in the
plate. For the ground lead terminal, either side
will do.S. Insert the projection on the plastic locking tie into
the hole in the rear frame.
T. Clamp the painted part on the fuel hose by the
plastic clamp. Make the lock on the plastic clamp
face the bottom of the vehicle, and cut the end.

3
PERIODIC CHECKS AND ADJUSTMENTS
MAINTENANCE INTERVALS.......................................................................... 3-1
MAINTENANCE INTERVALS .................................................................... 3-1
PRE-OPERATION INSPECTION AND MAINTENANCE................................. 3-7
GENERAL INSPECTION AND MAINTENANCE........................................ 3-7
ENGINE............................................................................................................ 3-8
CHECKING THE COOLANT LEVEL .......................................................... 3-8
CHECKING THE COOLING SYSTEM ....................................................... 3-8
CHANGING THE COOLANT...................................................................... 3-8
CHECKING THE RADIATOR CAP ............................................................ 3-9
CHECKING THE RADIATOR CAP VALVE OPENING PRESSURE ......... 3-9
CHECKING THE COOLANT CIRCULATORY SYSTEM FOR LEAKS .... 3-10
ADJUSTING THE CLUTCH LEVER POSITION ...................................... 3-10
ADJUSTING THE CLUTCH LEVER FREE PLAY .................................... 3-11
ADJUSTING THE THROTTLE GRIP FREE PLAY .................................. 3-11
LUBRICATING THE THROTTLE CABLE ................................................ 3-12
CLEANING THE AIR FILTER ELEMENT................................................. 3-12
CHECKING THE THROTTLE BODY JOINT ............................................ 3-13
CHECKING THE BREATHER HOSES .................................................... 3-13
CHECKING THE EXHAUST SYSTEM..................................................... 3-14
CHECKING THE FUEL LINE ................................................................... 3-14
CHECKING THE ENGINE OIL LEVEL..................................................... 3-14
CHANGING THE ENGINE OIL ................................................................ 3-15
ADJUSTING THE ENGINE IDLING SPEED ............................................ 3-16
ADJUSTING THE VALVE CLEARANCE ................................................. 3-17
CHASSIS........................................................................................................ 3-22
BLEEDING THE BRAKE SYSTEM .......................................................... 3-22
CHECKING THE BRAKE HOSE .............................................................. 3-23
ADJUSTING THE FRONT BRAKE .......................................................... 3-23
ADJUSTING THE REAR BRAKE ............................................................. 3-24
CHECKING THE FRONT BRAKE PADS ................................................. 3-24
CHECKING THE REAR BRAKE PADS ................................................... 3-26
CHECKING THE REAR BRAKE PAD INSULATOR ................................ 3-27
CHECKING THE BRAKE FLUID LEVEL.................................................. 3-27
ADJUSTING THE DRIVE CHAIN SLACK ................................................ 3-28
CHECKING THE FRONT FORK LEGS ................................................... 3-29
CHECKING THE FRONT FORK PROTECTOR GUIDE .......................... 3-29
CLEANING THE FRONT FORK OIL SEAL AND DUST SEAL ................ 3-29
AIR BLEEDING FROM FRONT FORK .................................................... 3-30
ADJUSTING THE FRONT FORK LEGS .................................................. 3-30
CHECKING THE SWINGARM OPERATION ........................................... 3-31
CHECKING THE REAR SUSPENSION ................................................... 3-31
ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLY ................... 3-31
CHECKING THE TIRES ........................................................................... 3-34
CHECKING AND TIGHTENING THE SPOKES ....................................... 3-34
CHECKING THE WHEELS ...................................................................... 3-34

MAINTENANCE INTERVALS
3-2
PISTON RING
Inspect Check the end gap of the pis-
ton ring.
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.
CYLINDER HEAD Check the coolant passages
for corrosion.
Inspect carbon deposits and
eliminate them.
Inspect and clean Check for warpage, and re-
place the gasket.
CYLINDER
Inspect and clean Inspect score marks.
Replace Inspect wear.
ENGINE OIL
Inspect Check the engine oil amount.
Replace
OIL FILTER ELE-
MENT
Replace
OIL STRAINER
Clean
CLUTCH
Inspect and adjust Inspect housing, friction plate,
clutch plate and spring.
Replace
TRANSMISSION
Inspect
Replace bearings
SHIFT FORK, SHIFT
CAM, GUIDE BAR
Inspect Inspect wear.ITEMAfter
break-
inEvery
race
(about
2.5
hours)Every
third
(about
7.5
hours)Every
fifth
(about
12.5
hours)As re-
quiredRemarks