2016 YAMAHA WR 450F engine

ENGINE
3-14
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EAS2GC1090LUBRICATING THE THROTTLE CABLE
1. Remove:• Cover (throttle cable cap) “1”
• Cover (grip cap) “2”
• Throttle grip cap “3”
2. Lubricate: • Throttle cable end “a”
3. Install: • Throttle grip cap
• Screw (throttle grip cap) 4. Install:
• Cover (grip cap)
• Cover (throttle cable cap)
EWA
WARNING
Check that the throttle grip moves smooth-
ly. If this does not move smoothly, correct
the installed positions.
EAS2GC1091CLEANING THE AIR FILTER ELEMENT
1. Remove:• Fuel tank cap cover “1”Refer to “FUEL TANK CAP” on page 1-20.
• Air filter case cover “2”
TIP
Loosen the quick fastener screw “3” and re-
move the air filter case cover.
2. Remove:
• Air filter mounting bolt “1”
• Air filter element “2”
• Air filter guide “3” (from the air filter element)
3. Wash: • Air filter element
EWA
WARNING
Do not use gasoline or organic (acid/alka-
line) volatile oil for washing.
TIP
After washing the element with air filter cleaner
or kerosene, squeeze and dry it completely.
ECA
Recommended lubricantLithium-soap-based grease
Screw (throttle grip cap) 3.8 Nm (0.38 m·kgf, 2.8 ft·lbf)
1
2
b
a
T R..
1
2
3
3
3
13
2

ENGINE
3-15
NOTICE
Do not twist the element when squeezing
the element.
4. Check:• Air filter element
Damage  Replace.
5. Yamaha foam air filter oil or other quality foam air filter oil.
TIP
Squeeze out the excess oil. Element should be
wet but not dripping.
6. Install:• Air filter guide “1” (to the air filter element)
• Air filter element “2”
• Air filter mounting bolt “3”
7. Install: • Air filter case cover “1”
TIP
Align the air filter case cover groove “a” with the
air filter case edge “b”. 8. Install:
• Fuel tank cap cover
EAS2GC1092CHECKING THE THROTTLE BODY JOINT
1. Check:
• Throttle body jointRefer to “CHECKING THE THROTTLE
BODY JOINT” on page 8-10.
EAS2GC1093CHECKING THE BREATHER HOSES
1. Check:• Breather hose “1”
Crack/damage  Replace.
Loose connection  Connect properly.
ECA
NOTICE
Make sure the cylinder head breather hose
is routed correctly.
EAS2GC1094CHECKING THE EXHAUST SYSTEM
1. Remove:
• Exhaust pipe protector
2. Check: • Exhaust pipe 1
• Exhaust pipe 2
• SilencerCrack/damage  Replace.
Refer to “ENGINE REMOVAL” on page 6-1.
• Exhaust gas Leaks  Replace the gasket.
Refer to “ENGINE REMOVAL” on page 6-1.
Oil application quantify
50 g
Air filter mounting bolt 2.0 Nm (0.20 m·kgf, 1.4 ft·lbf)
T R..
31
2
a
b
1
1

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
3-18
c. Replace the O-ring “2”.
d. Install the oil strainer.
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6. Install:•Gasket
• Drain bolt
7. Pour the specified amount of engine oil into the oil filler cap hole.
8. Install: • Oil filler cap
9. Check: • Oil level
Refer to “CHECKING THE ENGINE OIL
LEVEL” on page 3-16. 10.Check:
• Engine oil pressure
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a. Slightly loosen the oil pressure check bolt “1”.
EWA
WARNING
When the engine is started with the check
bolt removed, oil will spout; therefore, al-
ways loosen it before the checkup.
b. Start the engine and keep it idling until oil starts to seep from the oil pressure check
bolt.
EWA
WARNING
Always keep the engine idling speed during
the checkup without increasing the engine
speed.
ECA
NOTICE
If no engine oil seeps out after one minute,
immediately turn the engine off so it will not
seize.
c. If no engine oil seeps out, check the engine oil for leaks, and t he engine oil passage and
the oil pump for damage.
d. Check the oil pressure again.
e. Tighten the oil pressure check bolt.
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Oil strainer bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Drain bolt 20 Nm (2.0 m·kgf, 14 ft·lbf)
Engine oil quantity Oil change 0.67 L (0.71 US qt, 0.59 Imp.qt)
With oil filter removal 0.69 L (0.73 US qt, 0.61 Imp.qt)
Quantity (disassembled) 0.95 L (1.00 US qt, 0.84 Imp.qt)
1
2New
T R..
New
T R..
Oil pressure check bolt10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
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

ENGINE
3-20
EAS2GC1099ADJUSTING THE VALVE CLEARANCE
TIP
• This section is intended for those who have basic knowledge and skill concerning the ser-
vicing of Yamaha motorcycles (e.g., Yamaha
dealers, service engineers, etc.). Those who
have little knowledge and skill concerning ser-
vicing are requested not to undertake inspec-
tion, adjustment, disassembly, or reassembly
only by reference to this manual. It may lead
to servicing trouble and mechanical damage.
• Make sure that the valve clearance is checked or adjusted while the engine is cold
(at room temperature).
• While the valve clearance is checked or ad- justed, make sure that the piston is positioned
in the top dead center (TDC).
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.
•ECU
2. Remove:
• Spark plug
• Cylinder head coverRefer to “CAMSHAFT” on page 6-11.
3. Remove: • Timing mark accessing screw “1”
• Crankshaft end accessing screw “2”
• O-ring 4. Check:
• Valve clearanceOut of specification  Regulate.
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a. Turn the crankshaft counterclockwise with a
wrench.
b. Align the top dead center (TDC) mark “a” on the rotor with the alignment mark “b” on the
crankcase cover.
TIP
Check that the alignment mark “c” on the cam-
shaft sprocket and the alignment mark “d” on
the intake camshaft sprocket are aligned with
the edge of the cylinder head.
c. Measure the valve clearance “e” using a
thickness gauge “1”.
TIP
Record the measured reading if the clearance
is incorrect.
12
Valve clearance (cold)Intake 0.13–0.20 mm (0.0051–0.0079 in)
Exhaust 0.18–0.25 mm (0.0071–0.0098 in)
ab
d
c

ENGINE
3-21
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5. Adjust:• Valve clearance
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a. Remove the camshaft (intake and exhaust). Refer to “CAMSHAFT” on page 6-11.
b. Remove the valve lifter “2” and the adjusting
pad “3” with a valve lapper “1”.
TIP
• Place a cloth in the timing chain space to pre-vent adjusting pads from falling into the crank-
case.
• Identity each valve lifter and adjusting pad po-
sition very carefully so that they can be rein-
stalled in their original place. c. Check the number on the originally installed
adjusting pad.
TIP
• The adjusting pad number “a” is indicated on the top of the adjusting pad.
• For the number on the originally installed ad- justing pad, convert the last digit of adjusting
pad number as per the below table.
d. Select an adjusting pad with a proper valve clearance from the adjusting pad selection
table.
TIP
• There are 25 types of adjusting pads, ranging from 1.20 mm (0.0472 in) to 2.40 mm (0.0945
in), in increments of 0.05 mm (0.0020 in).
• The field where the number on the originally installed adjusting pad and the measured
valve clearance intersect shows the adjusting
pad number to replace.
Example:
Pad number = 148
Rounded value = 150
Valve lapper
90890-04101
Valve lapping tool YM-A8998
e e
1
1
3 2Last digit of pad
number Rounded valve
0, 1 or 2 0
4, 5 or 6 5 8 or 9 10