2015 YAMAHA WR 250F fuel pump

PERIODIC MAINTENANCE
3-6
COOLING SYSTEM
Check coolant lev-
el and leakage
Check radiator cap
operation
Replace coolant Every two years
Inspect hoses
OUTSIDE NUTS
AND BOLTS
RetightenRefer to “STARTING AND
BREAK-IN” on page 1-32.
AIR FILTER
Clean and lubri-
cateUse foam air-filter oil or equiv-
alent oil.
Replace
OIL FILTER
Replace
ENGINE GUARD
Replace Breakage
FRAME
Clean and inspect
FUEL TANK, FUEL
PUMP
Clean and inspect
FUEL HOSE
Inspect
Replace Every four yearsITEMAfter
break-
inEvery
raceEvery
third
(or
500
km)Every
fifth
(or
1,000
km)As re-
quiredRemarks

ENGINE
3-18
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
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
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.
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.
b. If no engine oil seeps out, check the engine
oil for leaks, and the engine oil passage and
the oil pump for damage.
c. Check the oil pressure again.
d. Tighten the oil pressure check bolt.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GB2100
ADJUSTING 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.
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.
Oil pressure check bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
T R..
Oil temperature
70.0–80.0 °C (158.00–176.00 °F)
Digital tachometer
90890-06760
Digital tachometer
YU-39951-B
1
1 1
a 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

FUEL TANK
8-1
EAS2GB2340
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.
EAS2GB2341
FUEL TANK
Removing the fuel tank
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right)
Air scoop (left/right)
1 Fuel pump coupler 1 Disconnect.
2 Fuel hose 1 Disconnect.
3Fuel tank 1
4 Fuel pump bracket 1
5 Fuel pump 1
6 Fuel pump gasket 1
7 Fuel sender 1
4(6) (2)
(2) (2)(2)2
5
6
3
1
New
4.0 Nm (0.40 m kgf, 2.9 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
9 Nm (0.9 m kgf, 6.5 ft Ibf)T.R.
4.0 Nm (0.40 m kgf, 2.9 ft Ibf)T.R.
4.0 Nm (0.40 m kgf, 2.9 ft Ibf)T.R.
7

FUEL TANK
8-3
EAS2GB2342REMOVING 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.
EAS2GB2343REMOVING THE FUEL PUMP
1. Remove:
• Fuel pump
ECA
NOTICE
Do not drop the fuel pump or give it a strong
shock.
EAS2GB2344CHECKING THE FUEL PUMP BODY
1. Check:
• Fuel pump body
Obstructions  Clean.
Cracks/damage  Replace the fuel pump
assembly.
EAS2GB2345INSTALLING 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
8-4
EAS2GB2346REMOVING THE FUEL SENDER
1. Remove:
• Fuel sender
ECA
NOTICE
Do not drop the fuel sender or give it a
strong shock.
EAS2GB2347CHECKING THE FUEL SENDER
1. Disconnect:
• Fuel pump coupler
• Fuel sender coupler
(from the wire harness)
2. Disconnect:
• Starter motor lead
(from starter relay)
3. Remove:
• Fuel tank
4. Remove:
• Fuel sender
(from the fuel tank)
5. Connect:
• Fuel sender coupler
6. Push the start switch.
7. Check:
• Fuel level warning light
Out of specification  Replace the fuel
sender.
EAS2GB2348INSTALLING THE FUEL SENDER
1. Install:
• Fuel sender gasket
• Fuel sender
TIP
• Do not damage the installation surfaces of the
fuel tank when installing the fuel sender.
• Always use a new fuel sender gasket.
• Install the fuel sender as shown in the illustra-
tion.
• When install the fuel sender, make sure that
the projection “a” faces the rear of the vehicle.
EAS2GB2349INSTALLING THE FUEL TANK
1. Install:
• Fuel tank
2. Connect:
• Fuel hose
ECA
NOTICE
• Connect the fuel hose securely, and check
that the orientation of the installed fuel
hose holder is correct.
• Take care not to kink or pinch the fuel
hose.
Fuel pump is atmosphere “A”
 Fuel level warning light is come on
Fuel pump is soaked in fuel “B”
Fuel level warning light is goes off
a
b
4 1
2
6
53
Fuel sender bolts
4.0 Nm (0.40 m·kgf, 2.9 ft·lbf)
AB
New
T R..
a

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.
EAS2GB2350CHECKING 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.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GB2351CHECKING 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 idling
324.0 kPa (3.24 kgf/cm
2, 47.0
psi)
1
2

THROTTLE BODY
8-10
EAS2GB2354CHECKING THE INJECTOR
1. Check:
• Injectors
Obstruction  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 resistance
Refer to “CHECKING THE FUEL INJEC-
TOR” on page 9-81.
EAS2GB2355CHECKING THE THROTTLE BODY
1. Check:
• Throttle body
Cracks/damage  Replace.
2. Check:
• Fuel passages
Obstructions  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.
EAS2GB2356CHECKING THE THROTTLE BODY JOINT
1. Check:
• Throttle body joint “1”
Crack/damage  Replace.
1 2
3
ba
c
1