2016 YAMAHA WR 450F stop start

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
3-16
3. Check:• Tightening torques
4. Install: • Exhaust pipe protector
EAS2GC1095CHECKING THE FUEL LINE
1. Remove:• Seat
• Side cover (left/right)
• Air scoop (left/right)Refer to “GENERAL CHASSIS” on page 5-
1.
• Fuel tank Refer to “FUEL TANK” on page 8-1.
2. Check:
• Fuel hose “1”Crack/damage  Replace.
Loose connection  Connect properly. 3. Install:
• Fuel tank
Refer to “FUEL TANK” on page 8-1.
• Air scoop (left/right)
• Seat
• Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GC1096CHECKING THE ENGINE OIL LEVEL
1. Stand the vehicle upright on a level surface.
2. Start the engine, warm this up for 2–3 min- utes, and then stop the engine and wait
about 1 minute.
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.
3. Check:
• Oil levelMake sure that the engine oil level is above
the minimum level mark “a” shown for the oil
level check window “1”, and that the engine
oil does not come out by removing the oil
check bolt “2”.
The minimum level mark “a” or below  Add
the engine oil until its level exceeds the min-
imum level mark “a”.
Engine oil coming out of the oil check bolt 
Drain it until its last drop is out.
ECA33DD018
Exhaust pipe bolt 1 and nut “1” 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Exhaust pipe 1 and exhaust pipe
2 bolt “2” 12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Exhaust pipe 2 and silencer bolt
“3” 12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Silencer and silencer bracket bolt
“4” 30 Nm (3.0 m·kgf, 22 ft·lbf)
Exhaust pipe protector screw 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
LOCTITE®
T R..
2
1
4
3
T R..
1
12
a

ENGINE
3-17
NOTICE
• Since engine oil also lubricates the clutch, the wrong oil types or additives could
cause clutch slippage. Therefore, do not
add any chemical additives.
• Do not allow foreign material to enter the
crankcase.
EAS2GC1097CHANGING THE ENGINE OIL
Stand the vehicle upright on a level surface.
1. Start the engine, warm this up for 3 minutes, and then stop the engine and wait about 5
minutes.
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.
2. Place an oil pan under the drain bolt.
3. Remove:• Engine guard “1”
• Oil filler cap “2”
• Drain bolt (with gasket) “3” 4. If the oil filter element is also to be replaced,
perform the following procedure.
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a. Remove the oil filter element cover “1” and oil filter element “2”.
b. Replace the O-ring “3”.
c. Install the new oil filter element and the oil fil- ter element cover.
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5. To check the oil strainer, perform the follow-ing procedure.
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a. Remove the oil strainer “1”.
b. Check the oil strainer.Damage  Replace.
Clogging due to dirt  Wash with kerosene.
Recommended brand
YAMALUBE
Type SAE 10W-40, SAE 10W-50, SAE
15W-40, SAE 20W-40 or SAE
20W-50
Recommended engine oil grade API service SG type or higher,
JASO standard MA
Oil filter element cover bolt10 Nm (1.0 m·kgf, 7.2 ft·lbf)
12
3
1
3 2
New
T R..

ENGINE
3-19
EAS2GC1098ADJUSTING THE ENGINE IDLING SPEED
TIP
• Because the air pressure is lower at high alti-tudes, the air-fuel mixture will become richer.
If the idling speed is low, turn the starter knob/
idle screw a few clicks counterclockwise to in-
crease the speed before the adjustment.
• Before adjusting the engine idling speed, make sure that the air filter element is not
clogged, the engine compression is proper,
and the throttle grip free play is proper.
• Adjust the engine idling speed with the starter
knob/idle screw pushed in completely.
1. Start the engine, and warm this up until the oil has reached the specified temperature.
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.
2. Attach the pocket tester with temperature probe “1” to the oil drain bolt.
3. Install: • Digital tachometer
TIP
Get the high tension cord “1” of the ignition coil
pinched in the detector “a” of the digital tachom-
eter.
4. Measure:• Engine idling speed
Out of specification  Regulate.
5. Adjust: • Engine idling speed
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a. Turn the starter knob/idle screw “1” in the di- rection of “a” or “b” to make an adjustment.
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Oil temperature70–80 °C (158–176 °F)
Digital tachometer 90890-06760
Digital tachometer YU-39951-B
1
Engine idling speed 1900–2100 r/min
Direction “a” Engine idling speed  De-
creases.
Direction “b” Engine idling speed  In-
creases.
1
1
a
a
1
b
a

HANDLEBAR
5-33
EAS2GC1193
HANDLEBAR
Removing the handlebar
OrderPart name Q’tyRemarks
1 Clutch cable 1 Disconnect.
2 Clutch switch 1
3 Clutch lever holder 1
4 Engine stop switch 1
5 Brake master cylinder 1
6 Throttle cable cap 1
7 Throttle cable (pull) 1 Disconnect.
8 Throttle cable (return) 1 Disconnect.
9 Right grip 1
10 Tube guide 1
11 Start switch 1
12 Left grip 1
13 Handlebar upper holder 2
14 Handlebar 1

CRANKCASE
6-69
EAS2GC1310
CRANKCASE
Separating the crankcase
OrderPart name Q’tyRemarks
Engine Refer to “ENGINE REMOVAL” on page 6-1.
Piston Refer to “CYLINDER AND PISTON” on page
6-31.
Balancer Refer to “OIL PUMP AND BALANCER
GEAR” on page 6-57.
Kick shaft assembly Refer to “KICKSTATER” on page 6-50.
Segment Refer to “SHIFT SHAFT” on page 6-53.
Stator Refer to “GENERATOR AND STARTER
CLUTCH” on page 6-63.
1 Timing chain guide (exhaust side) 1
2 Timing chain guide stopper plate 1
3 Timing chain 1
4 Bolt [L = 45 mm (1.77 in)] 6
5 Bolt [L = 60 mm (2.36 in)] 4
6 Bolt [L = 75 mm (2.95 in)] 2
7 Right crankcase 1
8 Left crankcase 1
9 Dowel pin 2
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.12 Nm (1.2 m kgf, 8.7 ft Ibf)T.R.
3
1
5
2 6410
5
5
4
4 4 46
9 7
8
11
9
LT
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
12 Nm (1.2 m kgf, 8.7 ft Ibf)T.R.
12 Nm (1.2 m kgf, 8.7 ft Ibf)T.R.
LT

THROTTLE BODY
8-10
EAS2GC1352CHECKING THE INJECTOR
1. Check:• InjectorsObstruction  Replace, and check the fuel
pump and the fuel injection system.
Refer to “FUEL INJECTION SYSTEM” on
page 9-28.
Deposits  Replace.
Damage  Replace.
2. Check:
• Injector resistanceRefer to “CHECKING THE FUEL INJEC-
TOR” on page 9-81.
EAS2GC1353CHECKING THE THROTTLE BODY
1. Check:• Throttle bodyCracks/damage  Replace.
2. Check:
• Fuel passagesObstructions  Clean.
ECA
NOTICE
• Before removing the throttle body, clean
the area around the throttle body to pre-
vent dirt and other foreign material from
falling into the engine.
• If the throttle body is subject to strong shocks or dropped during cleaning, re-
place it.
• Do not use any caustic carburetor clean- ing solution.
• Do not directly push the throttle valves to open them.
• Do not loosen the throttle valve stopper screw “1”, throttle valve pulley nut “2”, or
throttle valve screw “3”. A loss of perfor-
mance may occur.
• Do not use compressed air to clean the throttle body. Foreign materials may ad-
here to the intake air pressure sensor pas-
sage “a” and fuel injector “b” in the
throttle body. 3. Check:
• Starter knob/idle screw passage “c”Obstruction  Blow out with compressed
air.
EAS2GC1354CHECKING THE THROTTLE BODY JOINT
1. Check: • Throttle body joint “1”Crack/damage  Replace.
1
2
3
ba
c
1

IGNITION SYSTEM
9-3
1. Joint connector
2. Joint connector
4. AC magneto
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
22.ECU (engine control unit)
23.Ignition coil
24.Spark plug
30.Joint connector
35.Lean angle sensor
36.Engine stop switch
48.Frame ground
49.Ignition coil sub-lead
50.Negative battery lead