2016 YAMAHA WR 450F fuel pressure

PRE-OPERATION INSPECTION AND MAINTENANCE
3-9
EAS2GC1079
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EAS2GC1080GENERAL INSPECTION AND MAINTENANCE
TIP
Perform usual maintenance enough so that, in the race course, a confirmation of that and simple set-
ting adjustments may only be left, in order to get enough time to use effectively.ITEM inspect Page
Coolant Check that coolant is filled up to the radiator cap.
Check the cooling system for leakage. 3-10 – 12
Fuel Check that a fresh gasoline is filled in the fuel tank.
Check the fuel line for leakage. 1-28
Engine oil Check that the oil level is correct. Check the crank-
case and oil line for leakage. 3-16 – 18
Gear shifter and clutch Check that gears can be shifted correctly in order and
that the clutch operates smoothly. 3-12 – 13
Throttle grip/Housing Check that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and
housing, if necessary. 3-13 – 14
Brakes Check the play of front brake and effect of front and
rear brake. 3-25 – 31
Drive chain Check drive chain slack and alignment. Check that
the drive chain is lubricated properly. 3-31
5-69 – 70
Wheels Check for excessive wear and tire pressure. Check
for loose spokes and have no excessive play. 3-36 – 37
Steering Check that the handlebar can be turned smoothly and
have no excessive play. 3-37 – 38
Front forks and rear
shock absorber Check that they operate smoothly and there is no oil
leakage.
3-31 – 36
Cables (wires) Check that the clutch and throttle cables move
smoothly. Check that they are not caught when the
handlebars are turned or when the front forks travel
up and down.
—
Exhaust pipe Check that the exhaust pipe is tightly mounted and
has no cracks. 3-15 – 16
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is
not loose. 5-10 – 11
Lubrication Check for smooth operation. Lubricate if necessary. 3-14
3-38 – 39
Bolts and nuts Check the chassis and engine for loose bolts and
nuts. 1-32 – 33
Lead connectors Check that the AC magneto, ECU and ignition coil are
connected tightly. 1-9 – 12
Settings Is the machine set suitably for the condition of the rac-
ing course and weather or by taking into account the
results of test runs before racing? Are inspection and
maintenance completely done?
4-1 – 8

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
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Turn the starter knob/idle screw “1” in the di- rection of “a” or “b” to make an adjustment.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
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

8
FUEL SYSTEM
FUEL TANK...................................................................................................... 8-1
REMOVING THE FUEL TANK ................................................................... 8-3
REMOVING THE FUEL PUMP .................................................................. 8-3
CHECKING THE FUEL PUMP BODY........................................................ 8-3
INSTALLING THE FUEL PUMP ................................................................. 8-3
REMOVING THE FUEL SENDER.............................................................. 8-4
CHECKING THE FUEL SENDER .............................................................. 8-4
INSTALLING THE FUEL SENDER ............................................................ 8-4
INSTALLING THE FUEL TANK.................................................................. 8-4
CHECKING THE FUEL PRESSURE ......................................................... 8-5
CHECKING THE DAMPER ........................................................................ 8-5
CHECKING AND REPLACING THE PROTECTOR .................................. 8-6
THROTTLE BODY ............................................................................................ 8-7
CHECKING THE INJECTOR ................................................................... 8-10
CHECKING THE THROTTLE BODY ....................................................... 8-10
CHECKING THE THROTTLE BODY JOINT ............................................ 8-10
ADJUSTING THE THROTTLE POSITION SENSOR............................... 8-11
INSTALLING THE INJECTOR ................................................................. 8-11

FUEL TANK
8-3
EAS2GC1340REMOVING THE FUEL TANK
1. Extract the fuel in the fuel tank through the fuel tank cap with a pump.
2. Remove:
• Fuel hose coupler
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 forcefully disconnect the
hose with tools.
TIP
• To disconnect the fuel hose from the fuel tank, remove the fuel hose connector holder “a”,
and then slide the fuel hose connector cover.
• To remove the fuel hose from the fuel rail,
slide the fuel hose connector cover “1” on the
end of the hose in the direction of the arrow
shown, press the two buttons “2” on the sides
of the connector, and then remove the hose.
• Before removing the hose, place a few cloths in the area under where it will be removed.
• To prevent sand, dust, and other foreign ma- terials from entering the fuel pump, install the
included fuel hose joint cover 1 “3” and the
fuel hose joint cover 2 “4” onto the disconnect-
ed fuel hose and the fuel pump. 3. Remove:
• Side cover (left/right)
• Seat
• Air scoop (left/right)
• Fuel tank
TIP
Do not set the fuel tank down on the installation
surface of the fuel pump. Be sure to lean the
fuel tank against a wall or the like.
EAS2GC1341REMOVING THE FUEL PUMP
1. Remove:
• Fuel pump
ECA
NOTICE
Do not drop the fuel pump or give it a strong
shock.
EAS2GC1342CHECKING THE FUEL PUMP BODY
1. Check:• Fuel pump bodyObstructions  Clean.
Cracks/damage  Replace the fuel pump
assembly.
EAS2GC1343INSTALLING THE FUEL PUMP
1. Install: • Fuel pump gasket
• Fuel pump
• Fuel pump bracket
TIP
• Take care not to damage the installation sur-faces of the fuel tank.
• Always use a new fuel pump gasket.
• Install the lip on the fuel pump gasket upward.
• Install the fuel pump as shown in the figure.
• Align the projection “a” on the fuel pump with
the slot “b” in the fuel pump bracket.
• Tighten the fuel pump bolts in the proper tight-
ening sequence as shown.
a
1
2
Fuel pump bolts 4.0 Nm (0.40 m·kgf, 2.9 ft·lbf)
3
4
New
T R..

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
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
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.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
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
8-7
EAS2GC1351
THROTTLE BODY
Removing the throttle body
OrderPart name Q’tyRemarks
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.
ECU Refer to “ENGINE REMOVAL” on page 6-1.
Ignition coil Refer to “ENGINE REMOVAL” on page 6-1.
1 Intake air temperature sensor coupler 1 Disconnect.
2 Breather hose 3 1
3 Air filter case 1
4 Fuel injector coupler 1 Disconnect.
5 Intake air pressure sensor coupler 1 Disconnect.
6 Throttle position sensor coupler 1 Disconnect.
7 Throttle cable cover 1
8 Throttle cable 2
3
1
2
7
11
12
10
9
4
8
6
5
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
3.0 Nm (0.30 m kgf, 2.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

THROTTLE BODY
8-9
Removing the injector
OrderPart name Q’tyRemarks
1 Fuel inlet pipe 1
2Injector 1
3 Gaskets 1
4 Throttle position sensor 1
5 Intake air pressure sensor 1
For installation, reverse the removal proce-
dure.
1
2
(2)
(2) 5
4 3
T.R.3.4 Nm (0.34 mlbf)
kgf, 2.5 ft
T.R.5 Nm (0.5 mlbf)
kgf, 3.6 ft
T.R.3.4 Nm (0.34 mlbf)
kgf, 2.5 ft

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