2016 YAMAHA YZ250F fuel

ENGINE REMOVAL
5-4
Removing the engine
Order Part name Q’ty Remarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 4-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 4-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to “FUEL TANK” on page 7-1.
Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 5-1.
Air filter case Refer to “THROTTLE BODY” on page 7-5.
Throttle body Refer to “THROTTLE BODY” on page 7-5.
Clutch cable Refer to “CLUTCH” on page 5-35.
Shift pedal Refer to “SHIFT SHAFT” on page 5-47.
1 Engine guard 1
2 Brake pedal 1
3Spring 1
4 Cylinder head breather hose 1
5 Drive sprocket cover 1
New
New
LS
M
8
8
7
6
13
45
New
1 12
3
2
1110 9
55 Nm (5.5 mkgf, 40 ftIbf)T.R.

CAMSHAFT
5-11
EAS1SM9205
CAMSHAFT
Removing the cylinder head cover
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 4-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 4-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to “FUEL TANK” on page 7-1.
1 Spark plug 1
2 Cylinder head breather hose 1
3 Bolt (cylinder head cover) 3
4 Cylinder head cover 1
5 Cylinder head cover gasket 1
6 Timing chain guide (top side) 1
7 Cylinder head cover gasket 1
For installation, reverse the removal proce-
dure.
1
4
6 7
5 2
3
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R
.
13 Nm (1.3 mkgf, 9.4 ftIbf)T.R.
3

CYLINDER HEAD
5-18
EAS1SM9212
CYLINDER HEAD
Removing the cylinder head
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 4-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 4-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to “FUEL TANK” on page 7-1.
Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 5-1.
Radiator hose Disconnect.
Coolant temperature sensor coupler Disconnect.
Throttle body Refer to “THROTTLE BODY” on page 7-5.
Camshaft Refer to “CAMSHAFT” on page 5-11.
Upper engine bracket Refer to “ENGINE REMOVAL” on page 5-1.
1 Nut (cylinder head) 2
2 Bolt (cylinder head) 4
3 Cylinder head 1
4 Cylinder head gasket 1
6
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
33 Nm (3.3 m kgf, 24 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

RADIATOR
6-1
EAS1SM9293
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.
EAS1SM9294
RADIATOR
Removing the radiator
Order Part name Q’ty Remarks
CoolantDrain.
Refer to “CHANGING THE COOLANT” on
page 3-8.
Seat Refer to “GENERAL CHASSIS” on page 4-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 4-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to “FUEL TANK” on page 7-1.
Air filter case Refer to “THROTTLE BODY” on page 7-5.
1 Radiator guard 2
2 Radiator hose clamp 8 Loosen.
11
12
New
New
New
LS
LS

7
FUEL SYSTEM
FUEL TANK...................................................................................................... 7-1
REMOVING THE FUEL TANK ................................................................... 7-2
REMOVING THE FUEL PUMP .................................................................. 7-2
CHECKING THE FUEL PUMP BODY........................................................ 7-2
INSTALLING THE FUEL PUMP ................................................................. 7-2
INSTALLING THE FUEL TANK.................................................................. 7-3
CHECKING THE FUEL PRESSURE ......................................................... 7-3
CHECKING THE DAMPER ........................................................................ 7-4
CHECKING AND REPLACING THE PROTECTOR .................................. 7-4
THROTTLE BODY............................................................................................ 7-5
CHECKING THE INJECTOR ..................................................................... 7-8
CHECKING THE THROTTLE BODY ......................................................... 7-8
CHECKING THE THROTTLE BODY JOINT .............................................. 7-8
ADJUSTING THE THROTTLE POSITION SENSOR................................. 7-9

FUEL TANK
7-1
EAS1SM9303
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.
EAS1SM9304
FUEL TANK
Removing the fuel tank
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 4-1.
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
For installation, reverse the removal proce-
dure.
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
7-2
EAS1SM9305REMOVING 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.
EAS1SM9306REMOVING THE FUEL PUMP
1. Remove:
• Fuel pump
ECANOTICE
Do not drop the fuel pump or give it a strong
shock.
EAS1SM9307CHECKING THE FUEL PUMP BODY
1. Check:
• Fuel pump body
Obstructions  Clean.
Cracks/damage  Replace the fuel pump
assembly.
EAS1SM9308INSTALLING 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
7-3
EAS1SM9309INSTALLING 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.
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 4-
1.
EAS1SM9310CHECKING 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 4-
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 7-2.
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.
a
b
4 1
2
6
53
1
Pressure gauge
90890-03153
YU-03153
Fuel pressure adapter
90890-03186
YM-03186
a