Page 1 of 356
OWNER’S SERVICE MANUALMANUEL D’ATELIER DU PROPRIETAIRE
FA\fRER- UND
WARTUNGS\fANDBUC\f
MANUALE DI SERVI\bIO DEL PROPRIETARIO
YZ250F(
E )
1SM-28199-30PRINTED IN JAPAN
2013.08—2.0 × 1 !(E\f F\f G\f H\b
PRINTED ON RECYCLED PAPER
2014
YZ250F (
E )
2014
q Read this manual carefully before operating this vehicle.
q Il convient de lire attentivement ce manuel avant la première utilisation du véhicule.
q Bitte lesen Sie diese Bedienungsanleitung sorgfältig durch, bevor Sie das Fahrzeug in Betrieb nehmen.
q Leggere attentamente questo manuale prima di utilizzare questo veicolo.
1SM-28199-30_cover.indd 12013/07/23 18:31:44
Page 3 of 356
YZ250F(E)YZ250F(E)
20142014
1SM-28199-30-E01SM-28199-30-E0
OWNER’S SERVICE MANUALOWNER’S SERVICE MANUAL
Read this manual carefully before operating this vehicle.Read this manual carefully before operating this vehicle.
Page 5 of 356
EAS1SM1002
YZ250F(E) 2014
OWNER’S SERVICE MANUAL
©2013 by Yamaha Motor Co., Ltd.
First edition, August 2013
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.
Printed in Japan.
Page 9 of 356
EAS1SM1007
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
Page 13 of 356

1
GENERAL INFORMATION
LOCATION OF IMPORTANT LABELS............................................................ 1-1
DESCRIPTION .................................................................................................. 1-4
IDENTIFICATION ............................................................................................. 1-5
VEHICLE IDENTIFICATION NUMBER ...................................................... 1-5
ENGINE SERIAL NUMBER ....................................................................... 1-5
MODEL LABEL........................................................................................... 1-5
FEATURES ....................................................................................................... 1-6
OUTLINE OF THE FI SYST EM .................................................................. 1-6
FI SYSTEM....................................... .......................................................... 1-7
INCLUDED PARTS .......................................................................................... 1-8
SIDESTAND ............................................................................................... 1-8
SPARK PLUG WRENCH ........................................................................... 1-8
NIPPLE WRENCH...................................................................................... 1-8
HANDLEBAR PROTECTOR .. .................................................................... 1-8
FUEL HOSE JOINT COVER ...................................................................... 1-8
COUPLER FOR CONNECTING OPTIONAL PART................................... 1-8
IMPORTANT INFORMATION ........................................................................ 1-10
PREPARATION FOR REMOVAL A ND DISASSEMBLY.......................... 1-10
REPLACEMENT PARTS.......................................................................... 1-10
GASKETS, OIL SEALS AND O-RINGS ................................................... 1-11
LOCK WASHERS/PLATES AND COTTER PINS .................................... 1-11
BEARINGS AND OIL SEALS ................................................................... 1-11
CIRCLIPS ................................................................................................. 1-11
BASIC SERVICE INFORMATION .................................................................. 1-12
ELECTRICAL SYSTEM.......... .................................................................. 1-12
SPECIAL TOOLS ........................................................................................... 1-15
CONTROL FUNCTIONS ................................................................................ 1-20
ENGINE STOP SWITCH .......................................................................... 1-20
CLUTCH LEVER ................................................................................... ... 1-20
SHIFT PEDAL .......................................................................................... 1-20
KICKSTARTER LEVER.......... .................................................................. 1-20
THROTTLE GRIP ..................................................................................... 1-20
FRONT BRAKE LEVER ........................................................................... 1-20
REAR BRAKE PEDAL.............................................................................. 1-21
STARTER KNOB/IDLE SCREW .............................................................. 1-21
FUEL TANK CAP ..................................................................................... 1-21
Page 26 of 356

BASIC SERVICE INFORMATION
1-12
EAS1SM1029
BASIC SERVICE INFORMATION
EAS1SM1030ELECTRICAL SYSTEM
Electrical parts handling
ECA16620
NOTICE
Handle electrical components with special
care, and do not subject them to strong
shocks.
ECA16630
NOTICE
Electrical components are very sensitive to
and can be damaged by static electricity.
Therefore, never touch the terminals and be
sure to keep the contacts clean.
Checking the electrical system
ECA14371
NOTICE
Never insert the tester probes into the cou-
pler terminal slots. Always insert the probes
from the opposite end “a” of the coupler,
taking care not to loosen or damage the
leads.
ECA16640
NOTICE
For waterproof couplers, never insert the
tester probes directly into the coupler.
When performing any checks using a water-
proof coupler, use the specified test har-
ness or a suitable commercially available
test harness.
Checking the connections
Check leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
• Lead
• Coupler
• Connector
ECA16780
NOTICE
• When disconnecting a coupler, release the
coupler lock, hold both sections of the
coupler, and then disconnect the coupler.
• There are many types of coupler locks;
therefore, be sure to check the type of cou-
pler lock before disconnecting the cou-
pler.
a
Page 27 of 356
BASIC SERVICE INFORMATION
1-13
ECA16790
NOTICE
When disconnecting a connector, do not
pull the leads. Hold both sections of the
connector, and then disconnect the con-
nector.
2. Check:
• Lead
• Coupler
• Connector
Moisture Dry with compressed air.
Rust/stains Connect and disconnect sev-
eral times.
3. Check:
• All connections
Loose connection Connect properly.
TIP
• If the pin “1” on the terminal is flattened, bend
it up.
• After disassembling or assembling a coupler,
pull on the leads to make sure that they are in-
stalled securely.4. Connect:
• Lead
• Coupler
• Connector
TIP
• When connecting a coupler or a connector,
make sure that both terminals are connected
securely.
• Make sure all connections are tight.
1
Page 28 of 356
BASIC SERVICE INFORMATION
1-14
5. Check:
• No continuity
TIP
• If there is no continuity, clean the terminals.
• When checking the wire harness, perform
steps (1) to (4).
• As a quick remedy, use a contact revitalizer
available at most part stores.Pocket tester
90890-03112
Analog pocket tester
YU-03112-C