Yamaha YZ 2015 Series Application guide

2015
OWNER’S SERVICE MANUAL
YZ250FXF
B29-28199-10LIT-11626-28-51
YZ250FXF 2015
q Read this manual carefully before operating this vehicle.
PRINTED ON RECYCLED PAPER PRINTED IN JAPAN
2014.09––0.8 × 1 !
(E)
B29-28199-10_cover_12mm.indd 1 2014/08/25 10:37:14

For your best ownership experience, think Genuine Yamaha!
Genuine Yamaha Parts – Genuine Yamaha replacement parts are the exact same parts as the ones
originally equipped on your vehicle, providing you with the performance and durability you have come to
expect. Why settle for aftermarket parts that may not provide full confidence and satisfaction?
Genuine Yamaha Accessories – Yamaha only offers accessories that meet our high standards for quality
and performance. Buy with confidence, knowing your Genuine Yamaha Accessories will fit right and
perform right – right out of the box.
Yamalube – Take care of your Yamaha with legendary Yamalube oils, lubricants, and care products.
They're formulated and approved by the toughest judges we know: the Yamaha engineering teams that
know your Yamaha from the inside out.
Genuine Yamaha Service Manuals – Get the same factory manual for your vehicle that the technicians
at your authorized Yamaha dealer use. Service manuals are available through your Yamaha dealer or you
can order them directly through yamahapubs.com.
Genuine Yamaha products are available only from your Yamaha dealer.
Find out more at yamaha-motor.com
postscript3-本文レイアウト準拠-.fm Page 1 Monday, May 23, 2011 1:39 PM
Q Read this manual carefully before operating this vehicle. This manual should stay with this vehicle if it is sold.
B29-28199-10_cover_12mm.indd 2 2014/08/25 10:37:14

EASB291002
YZ250FXF
OWNER’S SERVICE MANUAL
©2014 by Yamaha Motor Corporation, U.S.A.
1st Edition, September 2014
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Corporation, U.S.A.
is expressly prohibited.
Printed in Japan
P/N. LIT-11626-28-51

EASB291003
INTRODUCTION
Congratulations on your purchase of a Yamaha YZ series. This model is the culmination of Yamaha’s
vast experience in the production of pacesetting racing machines. It represents the highest grade of
craftsmanship and reliability that have made Yamaha a leader.
This manual explains operation, inspection, basic maintenance and tuning of your machine. If you
have any questions about this manual or your machine, please contact your Yamaha dealer.
TIP
Yamaha continually seeks advancements in product design and quality. Therefore, while this manual
contains the most current product information available at the time of printing, there may be minor
discrepancies between your machine and this manual. If you have any questions concerning this
manual, please consult your Yamaha dealer.
EWA
WARNING
PLEASE READ THIS MANUAL CAREFULLY AND COMPLETELY BEFORE OPERATING THIS
MACHINE. DO NOT ATTEMPT TO OPERATE THIS MACHINE UNTIL YOU HAVE ATTAINED A
SATISFACTORY KNOWLEDGE OF ITS CONTROLS AND OPERATING FEATURES AND UNTIL
YOU HAVE BEEN TRAINED IN SAFE AND PROPER RIDING TECHNIQUES. REGULAR INSPEC-
TIONS AND CAREFUL MAINTENANCE, ALONG WITH GOOD RIDING SKILLS, WILL ENSURE
THAT YOU SAFETY ENJOY THE CAPABILITIES AND THE RELIABILITY OF THIS MACHINE.
EASB291004
IMPORTANT MANUAL INFORMATION
Particularly important information is distinguished in this manual by the following notations.
This is the safety alert symbol. It is used to alert you to potential personal
injury hazards. Obey all safety messages that follow this symbol to avoid
possible injury or death.
A WARNING indicates a hazardous situation which, if not avoided, could
result in death or serious injury.
A NOTICE indicates special precautions that must be taken to avoid
damage to the vehicle or other property.
A TIP provides key information to make procedures easier or clearer.
WARNING
NOTICE
TIP

EASB291005
SAFETY INFORMATION
THIS MACHINE IS DESIGNED STRICTLY FOR COMPETITION USE, ONLY ON A CLOSED
COURSE. It is illegal for this machine to be operated on any public street, road, or highway. Off-road
use on public lands may also be illegal. Please check local regulations before riding.
• THIS MACHINE IS TO BE OPERATED BY AN EXPERIENCED RIDER ONLY.
Do not attempt to operate this machine at maximum power until you are totally familiar with its char-
acteristics.
• THIS MACHINE IS DESIGNED TO BE RIDDEN BY THE OPERATOR ONLY.
Do not carry passengers on this machine.
• ALWAYS WEAR PROTECTIVE APPAREL.
When operating this machine, always wear an approved helmet with goggles or a face shield. Also
wear heavy boots, gloves, and protective clothing. Always wear proper fitting clothing that will not
be caught in any of the moving parts or controls of the machine.
• ALWAYS MAINTAIN YOUR MACHINE IN PROPER WORKING ORDER.
For safety and reliability, the machine must be properly maintained. Always perform the pre-oper-
ation checks indicated in this manual.
Correcting a mechanical problem before you ride may prevent an accident.
• GASOLINE IS HIGHLY FLAMMABLE.
Always turn off the engine while refueling. Take care to not spill any gasoline on the engine or ex-
haust system. Never refuel in the vicinity of an open flame, or while smoking.
• GASOLINE CAN CAUSE INJURY.
If you should swallow some gasoline, inhale excess gasoline vapors, or allow any gasoline to get
into your eyes, contact a doctor immediately. If any gasoline spills onto your skin or clothing, imme-
diately wash skin areas with soap and water, and change your clothes.
• ONLY OPERATE THE MACHINE IN AN AREA WITH ADEQUATE VENTILATION.
Never start the engine or let it run for any length of time in an enclosed area. Exhaust fumes are
poisonous. These fumes contain carbon monoxide, which by itself is odorless and colorless. Car-
bon monoxide is a dangerous gas which can cause unconsciousness or can be lethal.
• PARK THE MACHINE CAREFULLY; TURN OFF THE ENGINE.
Always turn off the engine if you are going to leave the machine. Do not park the machine on a slope
or soft ground as it may fall over.
• THE ENGINE, EXHAUST PIPE AND MUFFLER WILL BE VERY HOT AFTER THE ENGINE HAS
BEEN RUN.
Be careful not to touch them or to allow any clothing item to contact them during inspection or repair.
• PROPERLY SECURE THE MACHINE BEFORE TRANSPORTING IT.
For safety, drain the gasoline from the fuel tank before transporting the vehicle.

EASB291006 YAMAHA MOTOR CORPORATION, U.S.A.
YZ MOTORCYCLE LIMITED WARRANTY

EASB291007
HOW TO USE THIS MANUAL
In this manual, descriptions of installation, removal, disassembly, assembly, check, and adjustment
procedures are laid out with the individual steps in sequential order.
• The manual is divided into chapters and each chapter is divided into sections. The current section
title “1” is shown at the top of each page.
• Sub-section titles “2” appear in smaller print than the section title.
• To help identify parts and clarify procedure steps, there are exploded diagrams “3” at the start of
each removal and disassembly section.
• Numbers “4” are given in the order of the jobs in the exploded diagram. A number indicates a re-
moval or a disassembly step.
• Symbols “5” indicate parts to be lubricated or replaced.
Refer to “SYMBOLS”.
• A job instruction chart “6” accompanies the exploded diagram, providing the order of jobs, the
names of parts, the notes in jobs, etc.
• Jobs “7” requiring more information (such as special tools and technical data) are described se-
quentially.
1
7
3
4
6
2
5

EASB291008
SYMBOLS
The following symbols are used in this manual for easier understanding.
TIP
The following symbols are not relevant to every vehicle.
SYMBOL DEFINITION SYMBOL DEFINITION
Serviceable with engine mounted Gear oil
Filling fluid Molybdenum disulfide oil
Lubricant Brake fluid
Special tool Wheel bearing grease
Tightening torque Lithium-soap-based grease
Wear limit, clearance Molybdenum disulfide grease
Engine speed Silicone grease
Electrical data Locking agent (LOCTITE®)
Engine oil Replace the part with a new one.
G
M
BF
B
T
R
.
.
LS
M
S
LT
E
New

1
2
3
4
5
6
7
8
9
10
TOC
TABLE OF CONTENTS
GENERAL INFORMATION
SPECIFICATIONS
PERIODIC CHECKS AND ADJUST-
MENTS
CHASSIS
ENGINE
COOLING SYSTEM
FUEL SYSTEM
ELECTRICAL SYSTEM
TROUBLESHOOTING
TUNING

1
GENERAL INFORMATION
LOCATION OF IMPORTANT LABELS............................................................1-1
DESCRIPTION..................................................................................................1-2
IDENTIFICATION..............................................................................................1-3
VEHICLE IDENTIFICATION NUMBER ......................................................1-3
ENGINE SERIAL NUMBER........................................................................1-3
FEATURES.......................................................................................................1-4
OUTLINE OF THE FI SYSTEM ..................................................................1-4
FI SYSTEM.................................................................................................1-5
INCLUDED PARTS...........................................................................................1-6
SPARK PLUG WRENCH............................................................................1-6
NIPPLE WRENCH......................................................................................1-6
HANDLEBAR PROTECTOR ......................................................................1-6
FUEL HOSE JOINT COVER ......................................................................1-6
COUPLER FOR CONNECTING OPTIONAL PART...................................1-6
IMPORTANT INFORMATION...........................................................................1-7
PREPARATION FOR REMOVAL AND DISASSEMBLY............................1-7
REPLACEMENT PARTS............................................................................1-7
GASKETS, OIL SEALS AND O-RINGS .....................................................1-8
LOCK WASHERS/PLATES AND COTTER PINS ......................................1-8
BEARINGS AND OIL SEALS .....................................................................1-8
CIRCLIPS ...................................................................................................1-8
BASIC SERVICE INFORMATION ....................................................................1-9
ELECTRICAL SYSTEM..............................................................................1-9
SPECIAL TOOLS ...........................................................................................1-13
CONTROL FUNCTIONS.................................................................................1-19
ENGINE STOP SWITCH ..........................................................................1-19
START SWITCH.......................................................................................1-19
CLUTCH LEVER ......................................................................................1-19
SHIFT PEDAL...........................................................................................1-19
KICKSTARTER LEVER............................................................................1-19
THROTTLE GRIP .....................................................................................1-19
FRONT BRAKE LEVER ...........................................................................1-20
REAR BRAKE PEDAL..............................................................................1-20
SIDESTAND .............................................................................................1-20
STARTER KNOB/IDLE ADJUSTING SCREW .........................................1-20
FUEL TANK CAP......................................................................................1-20

STARTING AND BREAK-IN...........................................................................1-22
FUEL.........................................................................................................1-22
HANDLING NOTE ....................................................................................1-22
AIR FILTER MAINTENANCE ...................................................................1-22
STARTING A COLD ENGINE ..................................................................1-22
STARTING A WARM ENGINE .................................................................1-23
BREAK-IN PROCEDURES ......................................................................1-24
MAINTENANCE AFTER BREAK-IN ..............................................................1-25
MAJOR MAINTENANCE ..........................................................................1-25
TORQUE-CHECK POINTS.............................................................................1-26
MOTORCYCLE CARE AND STORAGE ........................................................1-28
CARE........................................................................................................1-28
STORAGE ................................................................................................1-29

LOCATION OF IMPORTANT LABELS
1-1
EASB291009
LOCATION OF IMPORTANT LABELS
Please read the following important labels carefully before operating this vehicle.
3,42
5
1
Premium unleaded
gasoline only.
3FB-2415E-02
4AA-22259-80
WARNING
This unit contains high pressure nitrogen gas.
Mishandling can cause explosion.
Read owner’s manual for instructions.
Do not incinerate, puncture or open.
17D-2812P-00
For use only on a closed course
in sanctioned competition.
This motorcycle does not meet
EPA noise and emissions
standards and is not for general
off-road recreational riding.

DESCRIPTION
1-2
EASB291010
DESCRIPTION
TIP
Designs and specifications of the vehicle are subject to change without notice. Therefore, please
note that the descriptions in this manual may be different from those for the vehicle you have pur-
chased.
1. Clutch lever 10. Radiator
2. Front brake lever 11. Coolant drain bolt
3. Throttle grip 12. Rear brake pedal
4. Start switch 13. Air filter
5. Radiator cap 14. Drive chain
6. Fuel tank cap 15. Shift pedal
7. Engine stop switch 16. Oil level check window
8. Fuel tank 17. Starter knob/idle screw
9. Kickstarter lever 18. Front fork
21
7
89 10
65 43
12 11 18 17 16 15 14
13

IDENTIFICATION
1-3
EASB291011
IDENTIFICATION
There are two significant reasons for knowing
the serial number of your vehicle:
1. When ordering parts, you can give the num-
ber to your Yamaha dealer for positive iden-
tification of the model you own.
2. If your vehicle is stolen, the authorities will
need the number to search for and identify
your vehicle.
EASB291012
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number “1” is
stamped into the right side of the frame.
EASB291013
ENGINE SERIAL NUMBER
The engine serial number “1” is stamped into
the elevated part of the right-side of the engine.
1
1

FEATURES
1-4
EAS20170
FEATURES
EASB291014
OUTLINE OF THE FI SYSTEM
The main function of a fuel supply system is to provide fuel to the combustion chamber at the opti-
mum air-fuel ratio in accordance with the engine operating conditions and the atmospheric tempera-
ture. In the conventional carburetor system, the air-fuel ratio of the mixture to be supplied to the
combustion chamber is determined by the amount of intake air and fuel that is measured on the basis
of the jets to be used in the carburetor.
Despite the same amount of intake air, the fuel amount requirement varies with the engine operating
conditions (acceleration, deceleration, and operation under a heavy load). The carburetor that mea-
sures fuel through the use of jets are provided with various auxiliary devices, so that the optimum air
fuel ratio can be obtained to accommodate frequent changes in the operating conditions of the en-
gine. This model has adopted an electronically controlled fuel injection (FI) system, in place of the
conventional carburetor system. This system can obtain the optimum air-fuel ratio required by the
engine at all times by using a microprocessor that regulates the fuel injection amount according to
the engine operating conditions detected by various sensors.
1. Fuel injector
2. Throttle position sensor
3. Intake air pressure sensor
4. Intake air temperature sensor
5. ECU
6. Fuel pump
7. Battery
8. Lean angle sensor
9. Crankshaft position sensor
10.Coolant temperature sensor
11.Ignition coil
6 7
8910
54123
11

FEATURES
1-5
EASB291015
FI SYSTEM
The fuel pump delivers fuel to the fuel injector via the fuel filter. The pressure regulator maintains the
fuel pressure that is applied to the fuel injector at only 324 kPa (3.24 kgf/cm2, 47.0 psi). Accordingly,
when the energizing signal from the ECU energizes the fuel injector, the fuel passage opens, causing
the fuel to be injected into the intake manifold only during the time the passage remains open. There-
fore, the longer the length of time the fuel injector is energized (injection duration), the greater the
volume of fuel that is supplied. Conversely, the shorter the length of time the fuel injector is energized
(injection duration), the lesser the volume of fuel that is supplied.
The injection duration and the injection timing are controlled by the ECU. Signals input from the throt-
tle position sensor, the coolant temperature sensor, the crankshaft position sensor, the intake air
pressure sensor, and the intake air temperature sensor enable the ECU to determine the injection
duration. The injection timing is determined through the signals from the crankshaft position sensor.
As a result, the volume of fuel that is required by the engine can be supplied at all times in accordance
with the driving conditions.
1. Fuel pump
2. Fuel injector
3. ECU
4. Throttle position sensor
5. Coolant temperature sensor
6. Crankshaft position sensor
7. Intake air pressure sensor
8. Throttle body
9. Intake air temperature sensor
10.Air filter case
A. Fuel system
B. Intake system
C. Control system
1
2
3
5
6
7
8
9
10
A
B
C
4

INCLUDED PARTS
1-6
EASB291016
INCLUDED PARTS
EASB291017
SPARK PLUG WRENCH
The spark plug wrench “1” is used to remove or
install the spark plug.
EASB291018
NIPPLE WRENCH
The nipple wrench “1” is used to tighten the
spoke.
EASB291019
HANDLEBAR PROTECTOR
Install the handlebar protector “1” with the mark
“a” facing forward.
EASB291020
FUEL HOSE JOINT COVER
The fuel hose joint covers “1” are used to pre-
vent mud, dust, and other foreign materials
from entering the inside when the fuel hose is
disconnected.
EASB291021
COUPLER FOR CONNECTING OPTIONAL
PART
The coupler “1” is used for connecting the op-
tional Power Tuner and so on.
ECA
NOTICE
When no optional parts, etc. are connected,
connect the connection terminal to the orig-
inal coupler.
Before disconnecting the coupler, thor-
oughly wipe off any mud or water stuck to it.
The Power Tuner is an optional part.
1
1
a
1
Part name Part number
GYTR Power Tuner
(For USA)
33D-H59C0-V0-00
YZ Power Tuner
(Except for USA)
33D-859C0-10
1
1

IMPORTANT INFORMATION
1-7
EAS20180
IMPORTANT INFORMATION
EASB291022
PREPARATION FOR REMOVAL AND DIS-
ASSEMBLY
1. Before the jobs, completely remove mud,
dust, and the like in order to prevent the en-
try of them into the inside during the jobs.
• Before cleaning with high-pressure water of
washers, cover the following parts.
Air duct
Silencer exhaust port
Drain hole on the cylinder head (right side)
Hole under the water pump housing
2. Use proper special tools and equipment.
See “SPECIAL TOOLS”.
3. During disassembly, check and measure the
required parts, and make a record of them
so that you may refer to the record when in-
stalling them. Moreover, arrange gears, cyl-
inders, pistons, and other parts for each
section so as not to confuse or lose them.
4. During disassembly, clean each of the parts,
and store them in trays for each section.
5. Flammable. Keep servicing areas away
from any source of fire.
6. During servicing, take special care not to re-
ceive an injury or a burn on the engine, the
exhaust pipe, the silencer, or the like.
7. If coolant is left adhered to the chassis, paint
and plating will be damaged. Therefore,
rinse it out with water in good time.
EWA
WARNING
Coolant is potentially harmful and should
be handled with special care.
• If it enters your eyes, wash it away with wa-
ter enough and then get medical attention
• If it splashes on your skin or clothes,
quickly wash it away with water and then
with soapy water.
• If it is swallowed, immediately induce vom-
iting and get medical attention.
EASB291023
REPLACEMENT PARTS
Make sure that the parts and grease or oil to be
used for repair of the vehicle, including periodic
replacement parts, are new YAMAHA genuine
parts and recommended parts.
Do not use any used parts, because these may
not be genuine though they have similar ap-
pearances or because the quality may be
changed by aging.

IMPORTANT INFORMATION
1-8
EASB291024
GASKETS, OIL SEALS AND O-RINGS
1. When overhauling the engine, replace all
gaskets and O-rings. All gasket surfaces, oil
seal lips, and O-rings must be cleaned so
that there may be no dust on them.
2. During assembly, always apply proper oil to
bearings and proper grease to oil seal lips
before installation.
EASB291025
LOCK WASHERS/PLATES AND COTTER
PINS
After removal, replace lock washers/plates “1”
and cotter pins with new ones. After the bolt or
nut has been tightened to specification, firmly
bend the lock tabs along a flat of the bolt or nut.
EASB291026
BEARINGS AND OIL SEALS
Install bearings “1” and oil seals “2” with their
manufacturer’s marks or size symbols facing
outward. During installation of an oil seal, make
sure that its main lip faces the oil chamber (the
target to be sealed). Before installation, always
apply a light coat of grease to the oil seal lip.
ECA
NOTICE
Do not spin the bearing with compressed air
because this will damage the bearing sur-
faces.
EASB291027
CIRCLIPS
When assembling parts, always use new cir-
clips. During installation of a circlip, make sure
that the edge “2” of the circlip “1” is positioned
opposite to the force “3” that the circlip re-
ceives. Install the circlip with its end aligned
with the center of the spline, without opening
the circlip more than necessary.
1. Oil
2. Lip
3. Spring
4. Grease