engine coolant YAMAHA WR 450F 2016 User Guide

ENGINE
3-12
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EAS2GC1087CHECKING THE COOLANT CIRCULATORY
SYSTEM FOR LEAKS
1. Check:• Coolant level
2. Install: • Radiator cap tester “1”
• Adapter “2”
3. Activate the tester to apply the test pressure.
ECA
NOTICE
• Do not apply such a high pressure as ex- ceeds the test pressure.
• Make sure that a checkup after the cylin-
der head gasket is replaced is made after 3
minutes of warm-up.
• Make sure that coolant is filled up to the
upper level beforehand.
TIP
This model is equipped with an engine auto-
stop system. The engine stops automatically if
left idling for 7 minutes. If the engine stops,
push the start switch or push down the kick-
starter lever to restart the engine.
4. Check:
• Pressure valueNo stay for 5 to 10 seconds at the test pres-
sure value  Correct.
• Radiator
• Radiator hose connections Coolant leaks  Correct or replace.
• Radiator hoses Bulges  Replace
EWA
WARNING
When the radiator cap tester is removed,
coolant will spout; therefore, cover it with a
cloth beforehand.
EAS2GC1088ADJUSTING THE CLUTCH LEVER FREE
PLAY
1. Check:
• Clutch lever free play “a”Out of specification  Regulate.
Radiator cap tester
90890-01325
Mityvac cooling system tester kit YU-24460-A
Radiator cap tester adapter 90890-01352
Pressure tester adapter YU-33984
Radiator cap tester 90890-01325
Mityvac cooling system tester kit YU-24460-A
Radiator cap tester adapter 90890-01352
Pressure tester adapter YU-33984
Test pressure value 196 kPa (1.96 kg/cm
2, 27.9 psi)
Clutch lever free play 7.0–12.0 mm (0.28–0.47 in)

ENGINE REMOVAL
6-3
Removing the electronic parts
OrderPart name Q’tyRemarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case cover
1 Rectifier/regulator 1
2ECU 1
3 Ignition coil 1
4 Neutral switch 1
5 AC magneto coupler 1 Disconnect.
6 Crankshaft position sensor coupler 1 Disconnect.
7 Coolant temperature sens or coupler1 Disconnect.
For installation, reverse the removal proce-
dure.
T.R.
T.R.
T.R.T.R.
7
3
6 5
1 4 2
LT
New
LS

CYLINDER HEAD
6-18
EAS2GC1244
CYLINDER HEAD
Removing the cylinder head
OrderPart name Q’tyRemarks
Refer to “INSTALLING THE CYLINDER
HEAD” on page 6-21.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 6-1.
Radiator hose Disconnect.
Coolant temperature sens or coupler Disconnect.
Throttle body Refer to “THROTTLE BODY” on page 8-7.
Camshaft Refer to “CAMSHAFT” on page 6-11.
Upper engine bracket Refer to “ENGINE REMOVAL” on page 6-1.
1 Bolt (cylinder head) 2
2 Engine ground sub-lead 1
3 Bolt (cylinder head) 4
4 Cylinder head 1
8
6
7
7
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
15 Nm (1.5 m kgf, 11 ft Ibf)T.R.
*
20 Nm (2.0 mkgf, 14 ftIbf)T.
R.
30 Nm (3.0 mkgf, 22 ftIbf)
2
4 3
3
5
1
1
*

CLUTCH
6-43
Removing the right crankcase cover
OrderPart name Q’tyRemarks
Engine guard Refer to “ENGINE REMOVAL” on page 6-1.
Engine oil Drain.
Refer to “CHANGING THE ENGINE OIL” on
page 3-17.
Coolant Drain.
Refer to “CHANGING THE COOLANT” on
page 3-10.
Brake pedal Refer to “ENGINE REMOVAL” on page 6-1.
Clutch cover Refer to “CLUTCH” on page 6-41.
1 Oil filter element cover 1
2 Oil filter element 1
3 Radiator pipe 2 1
4 Kickstarter lever 1
5 Right crankcase cover 1
6 Gaskets 1
7 Dowel pin 2
8Collar 1
For installation, reverse the removal proce-
dure.
T.R.
LS
New
New
67
2
5
4
1
7
8
New
3
LS
New
New
LS
LS
NewNew
LT
LS

RADIATOR
7-1
EAS2GC1328
TIP
This section is intended for those who have basic knowledge and skill concerning the servicing of
Yamaha motorcycles (e.g., Yamaha dealers, serv ice engineers, etc.). Those who have little knowl-
edge and skill concerning servicing are requested not to undertake inspection, adjustment, disas-
sembly, or reassembly only by reference to this manual. It may lead to servicing trouble and
mechanical damage.
EAS2GC1329
RADIATOR
Removing the radiator
OrderPart name Q’tyRemarks
Coolant Drain.
Refer to “CHANGING THE COOLANT” on
page 3-10.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case Refer to “THROTTLE BODY” on page 8-7.
1 Radiator guard 2
2 Radiator hose clamp 8 Loosen.
3 Radiator fan 1
12
13
New
New
New
LS
LS
3
4 58 Nm (0.8 m kgf, 5.8 ft Ibf)T.R.
6
7
8 9
10
11 2
2
2
2
2
2
2
1
1

WATER PUMP
7-4
EAS2GC1332
WATER PUMP
Removing the water pump
OrderPart name Q’tyRemarks
Coolant Drain.
Refer to “CHANGING THE COOLANT” on
page 3-10.
Engine oil Drain.
Refer to “CHANGING THE ENGINE OIL” on
page 3-17.
Right crankcase cover Refer to “CLUTCH” on page 6-41.
1 Water pump housing 1
2 Dowel pin 2
3Gasket 1
4Collar 1
5Pin 1
6 Impeller shaft assembly 1
7 Oil seal 1
8 Bearing 1
9 Oil seal 1
For installation, reverse the removal proce-
dure.
LS
LS
7
6
2 2
3
1
854
New
New
New
E
9
New
E
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

WATER PUMP
7-5
EAS2GC1333REMOVING THE OIL SEAL
TIP
• Remove the oil seal when the coolant level changes frequently more than usual, coolant
has discolored, or engine oil has become
milky.
• Do not use the removed oil seal.
1. Remove:• Oil seals “1”
EAS2GC1334CHECKING THE WATER PUMP
1. Check:
• Water pump housing cover
• Impeller shaftCracks/damage/wear  Replace.
EAS2GC1335CHECKING THE BEARING
1. Check:
• BearingRotate the inner race with your finger.
Rough spot/seizure  Replace.
EAS2GC1336INSTALLING THE OIL SEAL
1. Install:
• Oil seals “1”
TIP
• Apply the lithium-soap-based grease on the oil seal lip.
• Install the oil seal with its manufacture’s marks or numbers facing the right crankcase
cover “2”. 2. Install:
• Bearing “1”
TIP
Install the bearing by pressing its outer race
parallel.
EAS2GC1337ASSEMBLING THE WATER PUMP
1. Install:
• Impeller shaft assembly “1”
•Pin “2”
• Collar “3”
• Circlip “4”
TIP
• Take care so that the oil seal lip is not dam-aged or the spring does not slip off its posi-
tion.
• When installing the impeller shaft, apply the engine oil to the oil seal lip, the bearing, and
the impeller shaft.
1
1
New
1
1New
New
LS
LS2
New
4
1
23New
E

COOLING SYSTEM
9-25
1. Joint connector
2. Joint connector
3. Joint connector
7. Main relay
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
22.ECU (engine control unit)
27.Radiator fan motor relay
28.Radiator fan motor fuse
29.Radiator fan motor
30.Joint connector
32.Coolant temperature sensor
48.Frame ground
50.Negative battery lead

FUEL INJECTION SYSTEM
9-29
1. Joint connector
2. Joint connector
3. Joint connector
4. AC magneto
7. Main relay
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
15.Indicator light
16.Engine trouble warning light
22.ECU (engine control unit)
25.Injector
30.Joint connector
31.Intake air temperature sensor
32.Coolant temperature sensor
33.Throttle position sensor
34.Intake air pressure sensor
35.Lean angle sensor
36.Engine stop switch
37.Neutral switch
38.Diode
39.Starting circuit cut-off relay
40.Clutch switch
42.Joint connector
48.Frame ground
50.Negative battery lead

FUEL INJECTION SYSTEM
9-42
TIP
• Make sure that the engine is completely cool before checking the coolant temperature sensor.
• Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. 21
Item Coolant temperature sensor: open or short circuit detected.
Fail-safe system Able to start engine
Able to drive vehicle
Diagnostic code No. 06
Diagnostic tool display Displays the coolant temperature.
Procedure Compare the actually measured coolant temperature with the
Yamaha diagnostic tool display value.
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 Connection of coolant tem- perature sensor coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins). Improperly connected

Connect the coupler securely
or repair/replace the wire har-
ness. Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 2.
2 Connection of wire harness ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins). Improperly connected

Connect the coupler securely
or repair/replace the wire har-
ness. Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 3.
3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between coolant temperature
sensor coupler and ECU cou-
pler.
green/white–green/white
black/blue–black/blue Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Installed condition of coolant temperature sensor.
Check for looseness or
pinching. Improperly installed sensor

Reinstall or replace the
sensor. Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 5.