coolant YAMAHA YZ450F 2014 Owner's Manual

RADIATOR
6-1
EAS1SL1294
TIP
This section is intended for those who have basic knowledge and skill concerning the servicing of
Yamaha motorcycles (e.g., Yamaha dealers, service 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.
EAS1SL1295
RADIATOR
Removing the radiator
OrderPart nameQ’tyRemarks
CoolantDrain.Refer to “CHANGING THE COOLANT” on page 3-8.
SeatRefer to “GENERAL CHASSIS” on page 4-1.
Side cover (left/right)Refer to “GENERAL CHASSIS” on page 4-1.
Air scoop (left / right)Refer to “GENERAL CHASSIS” on page 4-1.
Fuel tankRefer to “FUEL TANK” on page 7-1.
Air filter caseRefer to “THROTTLE BODY” on page 7-5.
1Radiator guard2
2Radiator hose clamp8Loosen.
3Right radiator1
11
12
New
New
New
LS
LS

RADIATOR
6-2
4Radiator hose 21
5Radiator hose 31
6Radiator hose 41
7Radiator pipe 21
8Radiator breather hose1
9Left radiator1
10Radiator hose 11
11Radiator pipe 11
12Coolant temperature sensor1
For installation, reverse the removal proce-dure.
Removing the radiator
Order Part name Q’ty Remarks
11
12
New
New
New
LS
LS

RADIATOR
6-3
EAS1SL1296HANDLING NOTEEWA1DX1007
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
EAS1SL1297CHECKING THE RADIATOR
1. Check:
• Radiator fins “1”
Obstructions  Clean.
Apply compressed air to the rear of the radi-
ator.
Damage  Repair or replace.
TIP
Correct any flattened fins with a thin, flat-head
screwdriver.
2. Check:
• Radiator hoses
• Radiator pipes
Crack/damage  Replace.

WATER PUMP
6-4
EAS1SL1298
WATER PUMP
Removing the water pump
OrderPart nameQ’tyRemarks
CoolantDrain.Refer to “CHANGING THE COOLANT” on page 3-8.
Engine oilDrain.Refer to “CHANGING THE ENGINE OIL” on page 3-15.
Right crankcase coverRefer to “CLUTCH” on page 5-37.
1Water pump housing1
2Dowel pin2
3Gasket1
4Collar1
5Pin1
6Impeller shaft assembly1
7Oil seal1
8Bearing1
9Oil seal1
For installation, reverse the removal proce-dure.
7
6
2
2
3
1
854
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R.
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R.
New
New
New
E
9
New
E

WATER PUMP
6-5
EAS1SL1299REMOVING 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”
EAS1SL1300CHECKING THE WATER PUMP
1. Check:
• Water pump housing cover
• Impeller shaft
Cracks/damage/wear  Replace.
EAS1SL1301CHECKING THE BEARING
1. Check:
• Bearing
Rotate the inner race with your finger.
Rough spot/seizure  Replace.
EAS1SL1302INSTALLING THE OIL SEAL
1. Install:
• Oil seals “1”
TIP
• Apply the lithium soap base 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.
EAS1SL1303ASSEMBLING 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
LS
New
4
1
23New
E

WATER PUMP
6-6
2. Install:
• Dowel pin “1”
• Gasket “2”
3. Install:
• Water pump housing “1”
• Water pump housing bolt “2”
• Washer “3”
• Coolant drain bolt “4”
Water pump housing bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Coolant drain bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
New
21
1New
T R..
New
T R..
2
2
43 1
New

8
ELECTRICAL SYSTEM
IGNITION SYSTEM.......................................................................................... 8-2
CIRCUIT DIAGRAM ................................................................................... 8-2
TROUBLESHOOTING ............................................................................... 8-4
CHARGING SYSTEM....................................................................................... 8-6
CIRCUIT DIAGRAM ................................................................................... 8-6
TROUBLE SHOOTING .............................................................................. 8-8
FUEL INJECTION SYSTEM........................................................................... 8-10
CIRCUIT DIAGRAM ................................................................................. 8-10
YAMAHA DIAGNOSTIC TOOL ................................................................ 8-12
TROUBLESHOOTING DETAILS ............................................................. 8-13
FUEL PUMP SYSTEM.................................................................................... 8-32
CIRCUIT DIAGRAM ................................................................................. 8-32
TROUBLESHOOTING ............................................................................. 8-34
ELECTRICAL COMPONENTS....................................................................... 8-36
CHECKING THE SWITCHES .................................................................. 8-38
CHECKING THE IGNITION SPARK GAP................................................ 8-41
CHECKING THE SPARK PLUG CAP ...................................................... 8-41
CHECKING THE IGNITION COIL ............................................................ 8-41
CHECKING THE CRANKSHAFT POSITION SENSOR........................... 8-42
CHECKING THE ECU .............................................................................. 8-43
CHECKING THE STATOR COIL ............................................................. 8-43
CHECKING THE RECTIFIER/REGULATOR ........................................... 8-43
CHECKING THE COOLANT TEMPERATURE SENSOR........................ 8-44
CHECKING THE THROTTLE POSITION SENSOR ................................ 8-44
CHECKING THE THROTTLE POSITION SENSOR 
INPUT VOLTAGE .................................................................................... 8-43
CHECKING THE INTAKE AIR PRESSURE SENSOR ............................ 8-46
CHECKING THE INTAKE AIR TEMPERATURE SENSOR ..................... 8-46
CHECKING THE NEUTRAL SWITCH ..................................................... 8-46
CHECKING THE FUEL INJECTOR ......................................................... 8-47

FUEL INJECTION SYSTEM
8-11
EAS1SL1327
1. Crankshaft position sensor
2. AC magneto
3. Rectifier/regulator
4. Joint connector
5. Condenser
7. Engine stop switch
8. Neutral switch
9. ECU
12.Fuel injector
14.Intake air temperature sensor
15.Coolant temperature sensor
16.Throttle position sensor
17.Intake air pressure sensor

FUEL INJECTION SYSTEM
8-20
TIP
Make sure that the machine is completely cold before checking the coolant temperature sensor.
Fault code21
SymptomCoolant temperature sensor: open or short circuit detected.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.06
Diagnostic tool displayDisplays the coolant temperature.
ProcedureCompare the actually measured coolant temperature with the
Yamaha diagnostic tool display value.
Or-
der
Probable cause of malfunc-
tion and checkMaintenance jobReinstatement method
1Connection of coolant tem-
perature sensor coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected 
Connect the coupler secure
-
ly, or repair/replace the wire
harness.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
2Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected 
Connect the coupler secure
-
ly, or repair/replace the wire
harness.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
3Wire 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
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
4Mounted condition of coolant
temperature sensor.
Check for looseness or
pinching.
Check the mounted condition
for correctness.
Improperly mounted sensor
 Remount or replace the
sensor.Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
5Defective coolant tempera-
ture sensor.
Execute the diagnostic mode.
(Code No. 06)
When the machine is cold,
displayed temperature is
close to the ambient temper
-
ature.
Improper display  Replace
the coolant temperature sen
-
sor.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
6Faulty ECUReplace the ECU.

ELECTRICAL COMPONENTS
8-37
EAS1SL1334
1. Rectifier/regulator
2. Intake air pressure sensor
3. Throttle position sensor
4. Injector
5. Intake air temperature sensor
6. ECU
7. Ignition coil
8. Condenser
9. Neutral switch
10.Coolant temperature sensor