check engine YAMAHA WR 450F 2016 Service Manual

ENGINE REMOVAL
6-10
2. Install:•Clamp
• Exhaust pipe 2 “1”
• Bolt (exhaust pipe 2) “2”
TIP
Install and temporarily tighten the exhaust pipe
2 with its end positioned as shown with respect
to the exhaust pipe 1.
3. Install:
•Clamp
• Silencer “1”
• Bolt (silencer) “2”
TIP
Install and temporarily tighten the silencer so
that its joint is positioned as shown with respect
to the exhaust pipe 2.
4. Tighten:• Bolt (exhaust pipe 2)
•Clamp
TIP
Tighten while checking that their front and rear
joints are inserted in position.
Bolt (silencer) 30 Nm (3.0 m·kgf, 22 ft·lbf)
1
2 2
1
2
2mm (0.08in)
T R..
Bolt (exhaust pipe 2) 20 Nm (2.0 m·kgf, 14 ft·lbf)
Clamp 12 Nm (1.2 m·kgf, 8.7 ft·lbf)
1
22
2mm (0.08in)
T R..
T R..

CAMSHAFT
6-16
EAS2GC1242CHECKING THE DECOMPRESSION SYS-
TEM
1. Check:• Decompression system
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a. Check that the decompressor cam “1”
moves smoothly.
b. Check that the decompressor lever pin “2” projects from the camshaft.
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EAS2GC1243INSTALLING THE CAMSHAFTS
1. Install:• Exhaust camshaft “1”
• Intake camshaft “2”
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a. Turn the crankshaft counterclockwise with a
wrench.
TIP
• Apply molybdenum disulfide oil to the cam-shafts.
• Apply the engine oil on the decompression
system.
b. Align the top dead center (TDC) mark “a” on the rotor with the alignment mark “b” on the
crankcase cover. c. Fit the timing chain “3” onto both camshaft
sprockets and install the camshafts on the
cylinder head.
TIP
Make sure that the alignment mark “c” on the
exhaust camshaft sprocket and the alignment
mark “d” on the intake camshaft sprocket are
aligned with the edge of the cylinder head.
ECA
NOTICE
Do not turn the crankshaft during the cam-
shaft installation. Damage or improper
valve timing will result.
d. Install the clips, the camshaft caps and the bolts (camshaft cap).
TIP
• Before installing the clips, cover the cylinder head with a clean cloth to prevent the clips
from coming off into the cylinder head cavity.
• Apply the engine oil to the threads and con- tact surfaces.
• Tighten the bolts to the specified torque in two or three steps in the proper tightening se-
quence as shown.
ECA
NOTICE
The bolts (camshaft cap) must be tightened
evenly, or damage to the cylinder head,
camshaft caps, and camshaft will result.
1
2
Bolt (camshaft cap)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
ab
c
3
d
T R..

CLUTCH
6-46
EAS2GC1276CHECKING THE PRIMARY DRIVEN GEAR
1. Check:• Primary driven gearDamage/wear  Replace the primary drive
and primary driven gears as a set.
Excessive noise during operation  Re-
place the primary drive and primary driven
gears as a set.
EAS2GC1277INSTALLING THE OIL SEAL
1. Install: • Oil seal “1”
• Washer “2”
• Circlip “3”
TIP
• Apply the lithium-soap-based grease on the
oil seal lip.
• Install the oil seal in parallel with its manufac-
ture's marks or numbers facing inward.
EAS2GC1278INSTALLING THE RIGHT CRANKCASE
COVER
1. Install: • Dowel pin “1”
• O-rings “2”
• Collar “3”
• Gasket “4”
TIP
Apply the lithium-soap-based grease on the O-
ring.
2. Install:
• Right crankcase cover “1” • Right crankcase cover bolt “2”
TIP
• Apply the engine oil on the impeller shaft end.
• When installing the crankcase cover onto the
crankcase, make sure that the impeller shaft
end “3” aligns with the balancer end slot “4”.
• Tighten the right crankcase cover bolts in
stages and in a crisscross pattern.
EAS2GC1279INSTALLING THE CLUTCH
1. Install:
• Push lever shaft “1”
TIP
• Apply the lithium-soap-based grease on the oil seal lip.
• Before installation, apply the engine oil to the
push lever shaft sliding surface.
New
New
3
2
1
LS
New
New
1
1
4
2
New
New
3
LS
Right crankcase cover bolt10 Nm (1.0 m·kgf, 7.2 ft·lbf)
T R..
1 2
1

OIL PUMP AND BALANCER GEAR
6-60
3. Check:• Oil pump operationRough movement  Repeat steps (1) and
(2) or replace the defective part(s).
EAS2GC1303ASSEMBLING THE OIL PUMP
1. Install: • Oil pump drive shaft “1”
• Inner rotor “2”
• Dowel pin “3”
TIP
• Apply the engine oil on the oil pump drive shaft and inner rotor.
• Fit the dowel pin into the groove in the inner
rotor.
2. Install: • Outer rotor “1”
TIP
Apply the engine oil on the outer rotor.
3. Install:• Oil pump cover “1”
• Oil pump cover screw “2”
Inner-rotor-to-outer-rotor-tip
clearance
0.000–0.150 mm (0.0000–0.0059
in)
Limit 0.20 mm (0.0079 in)
Outer-rotor-to-oil-pump-housing
clearance 0.13–0.18 mm (0.0051–0.0071 in)
Limit 0.24 mm (0.0094 in)
Oil-pump-housing-to-inner-and-
outer-rotor clearance 0.06–0.11 mm (0.0024–0.0043 in)
Limit 0.17 mm (0.0067 in)
1. Inner rotor
2. Outer rotor
3. Oil pump housing
b
a
1
2
3
c
Oil pump cover screw
2.0 Nm (0.20 m·kgf, 1.4 ft·lbf)
21
3
1
E
T R..
2
1

CRANKCASE
6-72
EAS2GC1311DISASSEMBLING THE CRANKCASE
1. Separate:• Right crankcase
• Left crankcase
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a. Remove the crankcase bolts.
TIP
Loosen each bolt 1/4 of a turn at a time and af-
ter all the bolts are loosened, remove them.
b. Remove the right crankcase “1”.
TIP
• Place the crankcase with its left side down-ward and split it by inserting a screwdriver tip
into the splitting slit “a” in the crankcase.
• Lift the right crankcase horizontally while light-
ly patting the crankcase splitting slit and the
engine mounting boss using a soft hammer,
and leave the crankshaft and the transmission
with the left crankcase.
ECA33DD041
NOTICE
Use soft hammer to tap on the case half.
Tap only on reinforced portions of case. Do
not tap on gasket mating surface. Work
slowly and carefully. Make sure the case
halves separate evenly. If the cases do not
separate, check for a remaining case bolt or
fitting. Do not force. c. Remove the dowel pins and O-ring.
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EAS2GC1312REMOVING THE CRANKCASE BEARING
1. Remove:
• Bearing “1”
TIP
• Remove the bearing from the crankcase by pressing its inner race.
• Do not use the removed bearing.
EAS2GC1313CHECKING THE TIMING CHAIN, TIMING
CHAIN GUIDE, OIL STRAINER
1. Check:• Timing chainStiffness  Replace the camshaft sprocket,
timing chain and crankshaft sprocket as a
set.
2. Check: • Timing chain guide
Damage/wear  Replace
EAS2GC1314CHECKING THE CRANKCASE
1. Wash:
• Crankcase
TIP
• Wash the crankcase in a mild solvent.
• Remove any remaining gasket from the
crankcase mating surface.
2. Check: • CrankcaseCrack/damage  Replace.
1
a

TRANSMISSION
6-81
6. Install:• Shift fork 1 (L) “1”
• Shift fork 2 (C) “2”
• Shift fork 3 (R) “3”
• Shift cam “4”(to the main axle and the drive axle)
TIP
• Apply engine oil to the shift fork grooves.
• Apply engine oil to the shift cam groove and
the bearing contact surface.
• Mesh the shift fork 1 (L) with the 4th wheel gear “5” and shift fork 3 (R) with the 5th wheel
gear “7” on the drive axle.
• Mesh the shift fork 2 (C) with the 3rd pinion
gear “6” on the main axle. 7. Install:
• Long shift fork guide bar “1”
• Short shift fork guide bar “2”
• Spring “3”
TIP
• Screw the spring into the shift fork guide bar lightly beforehand.
• Apply the engine oil on the shift fork guide
bars.
8. Check: • Operation of shift cam and shift fork
• Transmission operationUnsmooth operation  Repair.
3
12
EE
E
2
1 3
E

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

FUEL TANK
8-5
TIP
• Insert the fuel hose into the fuel pipe securely until you hear a “click”.
• Slide the fuel hose connector cover “1” at the hose end in the direction of the arrow.
• Install the fuel hose connector holder “a”.
• Check that the fuel hose and the fuel pump
lead are routed through the guide on the cov-
er.
3. Connect: • Fuel pump coupler
4. Install: • Air scoop (left/right)
• Seat
• Side cover (left/right)Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GC1348CHECKING THE FUEL PRESSURE
1. Check:• Fuel pressure
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a. Remove the side cover (left/right), the seat and the air scoop (left/right).
Refer to “GENERAL CHASSIS” on page 5-
1.
b. Remove the fuel tank bolt and lift the fuel
tank.
c. Disconnect the fuel hose from the fuel pump.
Refer to “REMOVING THE FUEL TANK” on
page 8-3.
EWA
WARNING
Cover the fuel hose connection with a cloth
when disconnecting it. This is because re-
sidual pressure in the fuel hose could cause
fuel to spurt out when the hose is removed.
ECA
NOTICE
Make sure that the fuel hose is disconnect-
ed by hand. Do not forcibly disconnect the
hose with tools.
d. Connect the pressure gauge “1” and the fuel pressure adapter “2” to the fuel hose.
e. Start the engine.
f. Measure the fuel pressure. Out of specification  Replace the fuel
pump.
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EAS2GC1349CHECKING THE DAMPER
1. Check:
• Damper 1 “1”
• Damper 2 “2”
• Damper 3 “3”Wear/damage  Replace.
TIP
• Affix dampers 1 and 3 with the arrow on each
damper pointing outward.
• Affix the damper 2 with its projection “a” facing
the rear of the vehicle.
1
a
Pressure gauge 90890-03153
Pressure gauge YU-03153
Fuel pressure adapter 90890-03186
Fuel pressure adapter YM-03186
Fuel line pressure (at idle) 300.0–390.0 kPa (3.00–3.90 kgf/
cm
2, 43.5–56.6 psi)
1
2

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
9-4
EAS2GC1360TROUBLESHOOTING
The ignition system fails to operate (no spark or intermittent spark).
TIP
Before troubleshooting, remove the following part (s):
1. Seat
2. Side cover (left/right)
3. Air scoop (left/right)
4. Fuel tank
5. Air filter case cover1. Check the fuse. Refer to “CHECKING THE FUSES”
on page 9-68. NG

Replace the fuse(s).
OK 
2. Check the battery. Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 9-69. NG

• Clean the battery terminals.
• Recharge or replace the battery.
OK 
3. Check the spark plug. Refer to “CHECKING THE SPARK
PLUG” on page 3-40. NG

Re-gap or replace the spark plug.
OK 
4. Check the ignition spark gap. Refer to “CHECKING THE IGNI-
TION SPARK GAP” on page 9-73. OK

The ignition system is normal.
NG 
5. Check the ignition coil. Refer to “CHECKING THE IGNI-
TION COIL” on page 9-74. NG

Replace the ignition coil.
OK 
6. Check the crankshaft position sen- sor.
Refer to “CHECKING THE CRANK-
SHAFT POSITION SENSOR” on
page 9-74. NG

Replace the stator assembly.
OK 
7. Check the engine stop switch. Refer to “CHECKING THE
SWITCHES” on page 9-64. NG

Replace the engine stop switch.
OK 