Yamaha YBR250 2007 User manual

YBR250
SERVICE MANUAL
5D1-F8197-E0
2007

YBR250
SERVICE MANUAL
©2007 Yamaha Motor da Amazônia Ltda.
First edition, February 2007
All rights reserved.
Any reproduction or unauthorized use without
the written permission of Yamaha Motor da
Amazônia Ltda is expressly prohibited.

NOTICE
This manual was produced by the YAMAHA MOTOR DA AMAZÔNIA LTDA., primarily for use by
Yamaha dealers and their qualified mechanics. It is not possible to include all the knowledge of a
mechanic in one manual. Therefore, anyone who uses this book to perform maintenance and repairs
on Yamaha vehicles should have a basic understanding of mechanics and the techniques to repair
these types of vehicles. Repair and maintenance work attempted by anyone without this knowledge
is likely to render the vehicle unsafe and unfit for use.
YAMAHA MOTOR DA AMAZÔNIA LTDA. is continually striving to improve all of its models. Modifi-
cations and significant changes in specifications or procedures will be forwarded to all authorized
Yamaha dealers and will appear in future editions of this manual where applicable.
NOTE:
Designs and specifications are subject to change without notice.
IMPORTANT MANUAL INFORMATION
Particularly important information is distinguished in this manual by the following.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
Failure to follow WARNING instructions could result in severe injury or death to
the vehicle operator, a bystander or a person checking or repairing the vehicle.
A CAUTION indicates special precautions that must be taken to avoid damage
to the vehicle.
A NOTE provides key information to make procedures easier or clearer.
VV
VV
V
CAUTION:
VV
VV
VWARNING
NOTE:

HOW TO USE THIS MANUAL
This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive
explanations of all installation, removal, disassembly, assembly, repair and check procedures are
laid out with the individual steps in sequential order.
1 The manual is divided into chapters. An abbreviation and symbol in the upper right corner of each
page indicate the current chapter.
2 Each chapter is divided into sections. The current section title is shown at the top of each page,
except in Chapter 3 (“PERIODIC CHECKS AND ADJUSTMENTS”), where the sub-section title(s)
appears.
3 Sub-section titles appear in smaller print than the section title.
4 To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each
removal and disassembly section.
5 Numbers are given in the order of the jobs in the exploded diagram. A circled number indicates a
disassembly step.
6 Symbols indicate parts to be lubricated or replaced.
Refer to “SYMBOLS”.
7 A job instruction chart accompanies the exploded diagram, providing the order of jobs, names of
parts, notes in jobs, etc.
8 Jobsrequiringmoreinformation(suchasspecialtoolsandtechnicaldata)aredescribedsequentially.
8
1
23
4
5
6
7

SYMBOLS
The following symbols are not common to all
vehicles
Symbols 1- 8indicate the subject of each
chapter.
1Generalinformation
2Specifications
3Periodic checks and adjustments
4Chassis
5Engine
6Fuel Injection system
7Electrical system
8Troubleshooting
Symbols 9- Findicate the following:
9Serviceable with engine mounted
0Fillingfluid
ALubricant
BSpecial tool
CTighteningtorque
DClearance, wear limit
EEngine speed
FElectrical data
SymbolsG-Nin theexploded diagrams indi-
cate the types of lubricants and lubrication
points.
GEngineoil
HGear oil
IMolybdenum-disulphideoil
JBrake fluid
KWheel-bearinggrease
LLithium-soap-based grease
MMolybdenum-disulphidegrease
NSilicone grease
SymbolsO- Pinthe explodeddiagrams indi-
cate the following.
OApply locking agent (LOCTITE®)
PReplace the part.
12
34
56
78
F
KM
OP
GI
L
H
New
GEN
INFO SPEC
CHK
ADJ
ENG
CHAS
ELEC ?
TRBL
SHTG
E
DC
B
A
FI
90
J
N

TABLE OF CONTENTS
?8
7
6
5
4
3
GEN
INFO 1
2
PERIODIC CHECKS
AND ADJUSTMENTS
GENERALINFORMATION
SPECIFICATIONS
CHASSIS
ELECTRICAL SYSTEM
TROUBLESHOOTING
ENGINE
FUEL INJECTION SYSTEM
SPEC
CHK
ADJ
CHAS
ENG
FI
ELEC
TRBL
SHTG

CHAPTER 1
GENERALINFORMATION
VEHICLE IDENTIFICATION......................................................................... 1-1
VEHICLE IDENTIFICATION NUMBER................................................... 1-1
MODEL LABEL ........................................................................................ 1-1
FEATURES .................................................................................................... 1-2
FEATURES .............................................................................................. 1-2
FI SYSTEM .............................................................................................. 1-3
IMPORTANT INFORMATION ....................................................................... 1-4
PREPARATION FOR REMOVAL AND DISASSEMBLY........................ 1-4
REPLACEMENT PARTS......................................................................... 1-4
GASKETS, OIL SEALS AND O-RINGS.................................................. 1-4
LOCK WASHERS, PLATES AND COTTER PINS ................................ 1-5
BEARINGS AND OIL SEALS .................................................................. 1-5
CIRCLIPS................................................................................................. 1-5
CHECKING THE CONNECTIONS ............................................................... 1-6
SPECIAL TOOLS .......................................................................................... 1-7

GEN
INFO
VEHICLE IDENTIFICATION
VEHICLE IDENTIFICATION NUMBER
Chassis serial number 1is stamped into the right
side of the steering head pipe.
VEHICLE IDENTIFICATION
MODEL LABEL
The model label (1) is affixed to the frame.
Thisinformation will beneeded to orderspare parts.
1-1
1
1

GEN
INFO
FEATURES
Themain functionof afuel supplysystem isto providefuel tothe combustionchamber atthe optimum
air-fuel ratio in accordance with the engine operating conditions and the atmospheric temperature. In
the conventional carburetor system, the air-fuel ratio of the mixture that is supplied to the combustion
chamber is created by the volume of the intake air and the fuel that is metered by the jet that is used
in the respective chamber.
Despite the same volume of intake air, the fuel volume requirement varies by the engine operating
conditions, such as acceleration, deceleration, or operating under a heavy load. Carburetors that
meter the fuel through the use of jets have been provided with various auxiliary devices, so that an
optimum air-fuel ratio can be achieved to accommodate the constant changes in the operating
conditions of the engine.
As the requirements for the engine to deliver more performance and cleaner exhaust gases increase,
it becomes necessary to control the air-fuel ratio in a more precise and finely tuned manner. To
accommodatethis need, this model has adopted anelectronically controlledfuel injection (FI) system,
in place of the conventional carburetor system. This system can achieve an optimum air-fuel ratio
required by the engine at all times by using a microprocessor that regulates the fuel injection volume
according to the engine operating conditions detected by various sensors.
The adoption of the FI system has resulted in a highly precise fuel supply, improved engine response,
better fuel economy, and reduced exhaust emissions.
FEATURES
1ECU (engine control
unit)
2Engine trouble
warning light
3Lean angle sensor
4Fuel delivery hose
5Ignition coil
6Fuel injector
7FID (fast idle
solenoid)
8Throttle body sensor
assembly
9Battery
0Air filter case
ACatalytic converter
BCrankshaft position
sensor
CEngine temperature
sensor
DSpark plug
EFuel tank
FFuel pump
GAir induction system
(A.I.System)
HO2 sensor
1-2
2E
57F
4931
BC8 0
6
DA
GH

GEN
INFO
FEATURES
FI SYSTEM
The fuel pump delivers fuel to the injector via the fuel filter. The pressure regulator maintains the fuel
pressure that is applied to the injector at 36,3psi (250 kpa). Accordingly, when the energizing signal
from the ECU energizes the injector, the fuel passage opens, causing the fuel to be injected into the
intake manifold only during the time the passage remains open. Therefore, the longer the length of
time the injector is energized (injection duration), the greater the volume of fuel that is supplied.
Conversely, the shorter the length of time the 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 that are input from
the throttle position sensor, crankshaft position sensor, intake air pressure sensor, atmospheric
pressure sensor, intake temperature sensor, coolant temperature sensor, and O2sensor 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.
Drawing for reference only
1-3
1Fuel pump
2Fuel injector
3Ignition coil
4ECU (Engine control unit)
5Catalytic converter
6Engine temperature sensor
7Crankshaft position sensor
8Intake air pressure sensor
9Throttle body
0Intake air temperature
sensor
AAir filter case
BFID (fast idle solenoid)
CTPS (throttle position
sensor)
AFuel system
BAir system
CControl system
E O2 sensor
DThrottle body sensor
assembly =
8 +0 +C

GEN
INFO
IMPORTANTINFORMATION
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL AND
DISASSEMBLY
1. Beforeremovalanddisassembly,removealldirt,
mud, dust and foreign material.
2. Use only the proper tools and cleaning
equipment.
Refer to the "SPECIAL TOOLS".
3. When disassembling, always keep mated parts
together.This includes gears, cylinders, pistons
and other parts that have been "mated" through
normal wear. Mated parts must always be
reused or replaced as an assembly.
4. During disassembly, clean all of the parts and
place them in trays in the order of disassembly.
This will speed up assembly and allow for the
correct installation of all parts.
5. Keep all parts away from any source of fire.
REPLACEMENT PARTS
UseonlygenuineYamahapartsforall replacements.
Use oil and grease recommended by Yamaha for
all lubrication jobs. Other brands may be similar in
function and appearance, but inferior in quality.
GASKETS, OIL SEALS AND
O-RINGS
1. When overhauling the engine, replace all
gaskets, seals and O-rings.All gasket surfaces,
oil seal lips and O-rings must be cleaned.
2. During reassembly, properly oil all mating parts
and bearings and lubricate the oil seal lips with
grease.
1-4

GEN
INFO
BEARINGS AND OIL SEALS
Install bearings and oil seals so that the
manufacturer'smarks or numbers are visible.When
installing oil seals, lubricate the oil seal lips with a
lightcoatof lithium-soap-based grease.Oil bearings
liberally when installing, if appropriate.
1Oil Seal
1Bearing
IMPORTANTINFORMATION
LOCK WASHERS / PLATES
AND COTTER PINS
Afterremoval,replaceall lock washers/plates1and
cotter pins.After the bolt or nut has been tightened
to specification, bend the lock tabs along a flat of
the bolt or nut.
CIRCLIPS
Before reassembly, check all circlips carefully and
replacedamagedordistortedcirclips.Alwaysreplace
pistonpinclipsafteroneuse.Wheninstallingacirclip
1, make sure the sharp-edged corner 2is
positioned opposite the thrust 3that the circlip
receives.
4Shaft
1-5
CAUTION:
Donotspinthebearingwithcompressedairbecause
this will damage the bearing surfaces.

GEN
INFO
CHECKING THE CONNECTIONS
Check the leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
•lead
• coupler
• connector
2. Check
•lead
• coupler
• connector
Moisture -->Dry with an air blower.
Rust/stains --> Connect and disconnect
several times.
3. Check:
• all connections
Loosen connection --> Connect properly
4. Connect:
•lead
• coupler
• connector
CHECKING THE CONNECTIONS
5. Check
• continuity
(with the pocket tester)
If the pin 1on the terminal is flattened, bend it up.
Pocket tester
90890-03174
1-6
NOTE:
Make sure that all connections are tight.
NOTE:
• If there is no continuity, clean the terminals.
• When checking the wire harness, perform
steps (1) to (3).
• As a quick remedy, use a contact revitalizer
available at most part stores.
NOTE:

GEN
INFO
SPECIAL TOOLS
SPECIAL TOOLS
The following special tools are necessary for complete and accurate tune-up and assembly. Use only
theappropriate specialtools asthis willhelp preventdamage causedby theuse ofinappropriate tools
or improvised techniques. Special tools, part numbers or both may differ depending on the country.
When placing an order, refer to the list provided below to avoid any mistakes.
Tool No. IllustrationTool name / Function
90890-01084
90890-01083
90890-04019
90890-01243
90890-01268
1
2
90890-01135 Crankshaft puller
Use to remove crankshaft
Sliding hammer 1
Shaft 2
Use to install or remove shafts
of rocker arm.
Valve spring compressor 1
Adapter 2
Use to install or remove valves.
Ringnutwrench
Usetoloosenor tighten ringnutstosteering,
exhaust and shock absorber.
90890-01311
Use to adjust valves clearance.
Adjustmentscrewwrench
90890-01326
90890-01294
Use to fix or extract bolt from the
frontsuspensionrod
T-handle 1
Adapter2
90890-01362
Use to extract magneto flywheel
Magnetoflywheelpuller
1
2
90890-01367
90890-01371
Usetoinstalloilseal,outerbushingfromstaffs
of the front fork and dust seal
Staff oil seal installer 1
Adapter 2
1-7
90890-01274
90890-01275
90890-01383
Use to install crankshaft.
Crankshaftinstaller1
Traction fuse 2
Adapter(10mm)3

GEN
INFO
SPECIAL TOOLS
Tool No. IllustrationTool name / Function
90890-01701
90890-01403 Steering nut wrench
Use to fix or extract ring nuts
fromsteering
Sheaveholder
Feelergauge
Use to check valve clearance.
90890-03081 Compressiongauge
Usetomeasureenginecompression.
90890-03141
Use to check ignition timing.
Timing light
90890-03153
90890-03176
Use to measure fuel pump pressure.
Fuelpressuregauge
Fuelpressureadapter
90890-03174
Use to check electrical system
Pocket tester
Use to fix the flywheel magneto rotor.
90890-03079
90890-01519
90890-01520 Rearshockabsorberwrench Handlespanner
Use together with the socket extensor,
for adjusting preload of the shock
absorberspring.
90890-06754 Spark dynamic tester
Use to check the length of spark at
the spark plug.
90890-85505 Yamaha Bond # 1215
Use to seal surfaces (e.g.: engine cases).
1-8

GEN
INFO
SPECIAL TOOLS
Tool Nº IllustrationTool name / Function
90890-04064
90890-06760 Inductivetachometer
Use to check engine rotation.
Valve guide extractor
Valveguideinstaller
Use to install valve guides.
90890-04066 Valve guidereamer
Use to rebore the hole on the new valve
guides.
90890-04086
Use to fix the clutch holder.
Clutchhubholder
90890-04101
Use to spin and polish valves.
Valvepolisher
Use to extract and install valve guides.
90890-04065
FI electronic injection diagnosis90890-03182
Use to adjust the exhaust gas.
1-9

CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS ...................................................................... 2-1
ENGINE SPECIFICATIONS.......................................................................... 2-2
CHASSIS SPECIFICATIONS...................................................................... 2-10
ELECTRICAL SPECIFICATIONS ............................................................... 2-14
CONVERSION TABLE ................................................................................ 2-16
GENERAL TIGHTENING TORQUE SPECIFICATION............................... 2-16
TIGHTENING TORQUES ............................................................................ 2-17
ENGINE TIGHTENING TORQUES....................................................... 2-17
CHASSIS TIGHTENING TORQUES..................................................... 2-19
LUBRICATION POINTS AND LUBRICANT TYPES.................................. 2-21
ENGINE ................................................................................................. 2-21
CHASSIS ............................................................................................... 2-22
OIL COOLING SYSTEM DIAGRAM ........................................................... 2-23
LUBRICATION FLOW ................................................................................. 2-24
LUBRICATION SYSTEM DIAGRAMS ........................................................ 2-25
CABLE ROUTING ....................................................................................... 2-29

SPEC
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model YBR250
Dimensions
Overalllength
Overallwidth
Overallheight
Seatheight
Wheelbase
Groundclearance
Minimumturningradius
2,025mm(79,724in)
745mm(29,33in)
1,065mm(41,93in)
805mm(31,69in)
1,360mm(53,54in)
190mm(7,48in)
2,395mm(94,29in)
Weight
Dry
With oil and fuel
Maximum load (total of cargo,
conductor,passengerand
accessories)
138.0kg(304lb)
----
----
----
----
----
----
----
----
167.0kg(368lb)
154.0kg(339lb)
2-1
Model code 5D11
----
----
----
Item Standard Limit

SPEC
ENGINE SPECIFICATIONS
ENGINE SPECIFICATIONS
Item Standard Limit
Engine oil
Lubricationsystem
Recommendedoil
Quantity
Total amount
Periodicoilchange
Withoilfilterreplacement
Oil filter
Oil filter type
Place for pressure checking
Wetsump
SAE20W40ORSAE20W50
API service SG type or higher
JASO standard MA
1.55 L (1.4 Imp.gal, 1.6 US.gal)
1.35 L (1.2 Imp.gal, 1.4 US.gal)
1.45 L (1.3 Imp.gal, 1.5 US.gal)
Wiremesh
Drainscrewoncylinder head ----
----
----
----
Engine
Enginetype
Cylinderarrangement
Displacement
Cylinder - bore x stroke
Compressionratio
Idlespeed
Oiltemperature
Air-cooled,4-strokes,SOHC
249.0cm³(15cu.in)
Forward-inclined1-cylinder
74.0 x 58.0 mm (2.91 x 2.28 in)
9,8 : 1
1,300 ~ 1,500 r/min
70.0~90.0°C
----
----
----
----
----
Fuel
Recommendedfuel
Full tank capacity
Total (including reserve tank)
Reserve
RegularUnleaded Gasoline
19.2 L (17.4 Imp.gal, 20.3 US.gal)
4.5 L (4.0 Imp.gal, 4.7 US.gal) ----
----
Oil pump
Oil pump type
Inner-rotorto-outerrotor-tipclearance
Outer-rotor-to-oil-pump-housing
clearance
Oil-pump-housing-to-inner-rotor-and-
outer-rotorclearance
Trochoidal
0.15mm(0.006in)
0.10 ~ 0,151 mm (0.004 ~ 0.006 in)
0.04 ~ 0,09 mm (0.0016 ~ 0.0035 in)
0.20mm
(0.008in)
0.20mm
(0.008in)
0.15mm
(0.006in)
Cooling system
Radiatorcore
Width
Height
Depth
Spark plug
Model / manufacturer x quantity
Gapbetweenelectrodes
187.0mm(7.36in)
35.2 mm (1.38 in)
32.0 mm (1.26 in)
----
----
----
----
----
Starting system type Electric starter
DR8EA/NGK x 1
0.6~0.7 mm (0.224 ~ 0.028 in)
----
2-2