YFM250BT
SUPPLEMENTARY
SERVICE MANUAL
LIT-11616-18-41 4XE-F8197-13
FOREWORD
This Supplementary Service Manual has been prepared to introduce new service and data for the
YFM250BT. For complete service information procedures it is necessary to use this Supplementary
Service Manual together with the following manual.
YFM250XL(C) SERVICE MANUAL: LIT-11616-12-01 (4XE-F8197-10)
YFM250XN SUPPLEMENTARY SERVICE MANUAL: LIT-11616-14-17 (4XE-F8197-11)
YFM250XP SUPPLEMENTARY SERVICE MANUAL: LIT-11616-15-03 (4XE-F8197-12)
©2004 by Yamaha Motor Corporation, U.S.A.
YFM250BT
SUPPLEMENTARY
SERVICE MANUAL
First edition, July 2004
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Corporation, U.S.A.
is expressly prohibited.
Printed in U.S.A.
LIT-11616-18-41
EBS00002
NOTICE
This manual was produced by the Yamaha Motor Company 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, so it is assumed that anyone who uses this book to perform maintenance and repairs on
Yamaha machine has a basic understanding of the mechanical ideas and the procedures of
machine repair. Repairs attempted by anyone without this knowledge are likely to render the
machine unsafe and unfit for use.
Yamaha Motor Company, Ltd. is continually striving to improve all its models. Modifications 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.
EBS00003
IMPORTANT INFORMATION
Particularly important information is distinguished in this manual by the following notations.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
WARNING
CAUTION:
NOTE:
Failure to follow WARNING instructions could result in severe injury or death
the machine operator, a bystander or a person checking or repairing the
machine.
A CAUTION indicates special precautions that must be taken to avoid damage
to the machine.
A NOTE provides key information to make procedures easier or clearer.
to
EBS00004
HOW TO USE THIS MANUAL
MANUAL ORGANIZATION
This manual consists of chapters for the main categories of subjects. (See “symbols”)
1st title 1: This is the title of the chapter with its symbol in the upper right corner of each page.
2nd title 2: This title indicates the section of the chapter and only appears on the first page of each
section. It is located in the upper left corner of the page.
3rd title 3: This title indicates a sub-section that is followed by step-by-step procedures accompanied by corresponding illustrations.
EXPLODED DIAGRAMS
To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each
removal and disassembly section.
1. An easy-to-see exploded diagram 4 is provided for removal and disassembly jobs.
2. Numbers 5 are given in the order of the jobs in the exploded diagram. A number that is enclosed
by a circle indicates a disassembly step.
3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol marks
6
. The meanings of the symbol marks are given on the next page.
4. A job instruction chart 7 accompanies the exploded diagram, providing the order of jobs, names
of parts, notes in jobs, etc.
5. For jobs requiring more information, the step-by-step format supplements 8 are given in addition
to the exploded diagram and the job instruction chart.
12
GEN
INFO
34
SPEC
CHK
ADJ
56
CARB
78
ENG
DRIV
EBS00005
SYMBOLS
The following symbols are not relevant to
every machine.
Symbols 1 to 9 indicate the subject of each
chapter.
General information
1
Specifications
2
Periodic checks and adjustments
3
Engine
4
Carburetion
5
Drive train
6
Chassis
7
Electrical
8
Troubleshooting
9
CHAS
90
ELEC
–+
TRBL
SHTG
AB
CD
T
.
R
.
EF
GHI
Symbols 0 to F indicate the following.
Filling fluid
0
Lubricant
A
Special tool
B
Torque
C
Wear limit, clearance
D
Engine speed
E
Electrical data (Ω, V, A)
F
Symbols G to M in the exploded diagrams
indicate the types of lubricants and lubrication
points.
LS
G
M
E
J
NO
KLM
B
LT
M
New
Apply engine oil
G
Apply gear oil
H
Apply molybdenum disulfide oil
I
Apply wheel bearing grease
S
J
Apply lithium-soap-based grease
K
Apply molybdenum disulfide grease
L
Apply silicon grease
M
Symbols N to O in the exploded diagrams
indicate where to apply a locking agent N and
when to install a new part O.
®
Apply the locking agent (LOCTITE
N
Replace
O
)
CONTENTS
SPECIFICATIONS
GENERAL SPECIFICATIONS ....................................................................1
MAINTENANCE SPECIFICATIONS ...........................................................2
ENGINE ................................................................................................2
CHASSIS ..............................................................................................3
ELECTRICAL ........................................................................................4
CABLE ROUTING .......................................................................................5
PERIODIC CHECKS AND ADJUSTMENTS
INTRODUCTION .......................................................................................14
PERIODIC MAINTENANCE/LUBRICATION .............................................14
SEAT, CARRIERS, FENDERS AND FUEL TANK ....................................16
SEAT, FRONT CARRIER, FRONT BUMPER
AND FRONT FENDER ......................................................................16
REAR CARRIER AND REAR FENDER ..............................................18
FUEL TANK ........................................................................................20
FOOTREST BOARDS ...............................................................................21
ENGINE .....................................................................................................22
ADJUSTING THE STARTER CABLE .................................................22
CHASSIS ...................................................................................................23
ADJUSTING THE REAR BRAKE .......................................................23
ADJUSTING THE SELECT LEVER CONTROL CABLE
AND SHIFT ROD ...............................................................................25
ADJUSTING THE HEADLIGHT BEAM ...............................................26
REPLACING A HEADLIGHT BULB ....................................................26
.............................................................................................1
...................................................14
ENGINE
CARBURETION
CHASSIS
...........................................................................................................28
ENGINE REMOVAL ..................................................................................28
SELECT LEVER ASSEMBLY .............................................................28
...............................................................................................29
CARBURETOR .........................................................................................29
.........................................................................................................32
REAR BRAKE ...........................................................................................32
STEERING SYSTEM ................................................................................34
STEERING STEM ...............................................................................34
REMOVING THE REAR BRAKE SWITCH .........................................36
INSTALLING THE HANDLEBAR ........................................................36
ELECTRICAL ..................................................................................................37
ELECTRICAL COMPONENTS ..................................................................37
YFM250BT WIRING DIAGRAM
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Item Standard
Model code: 1P01
Dimensions:
Overall length 1,916 mm (75.4 in)
Overall width 1,038 mm (40.9 in)
Overall height 1,118 mm (44.0 in)
Seat height 772 mm (30.4 in)
Wheelbase 1,170 mm (46.1 in)
Minimum ground clearance 150 mm (5.9 in)
Minimum turning radius 2,900 mm (114 in)
Basic weight:
With oil and full fuel tank 216 kg (476 lb)
Carburetor:
Type/quantity BSR33/1
Manufacturer MIKUNI
Tire:
Type Tubeless
Size front AT22 × 7-10
rear AT22 × 10-10
Manufacturer front MAXXIS
rear MAXXIS
Type front M905
rear M906
Electrical:
Ignition system DC C.D.I.
Generator system A.C. magneto
Battery type CB14A-A2
Battery capacity 12 V 14 AH
Bulb wattage × quantity:
Headlight 12 V 30 W/30 W × 2
Tail/brake light 12 V 5 W/21 W × 1
Indicator lights:
Neutral 12 V 1.7 W × 1
Reverse 12 V 1.7 W × 1
SPEC
– 1 –
MAINTENANCE SPECIFICATIONS
SPEC
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
Carburetor:
I. D. mark 1P01 00 ---Main jet (M.J) #93.8 ---Main air jet (M.A.J) #70 ---Jet needle (J.N) 5EP17-2 ---Needle jet (N.J) P-2M (826) ---Pilot air jet (P.A.J.1) #80 ---Pilot air jet (P.A.J.2) 1.3 ---Pilot outlet (P.O) 0.8 ---Pilot jet (P.J) #20 ---Bypass 1 (B.P.1) 0.8 ---Bypass 2 (B.P.2) 0.8 ---Bypass 3 (B.P.3) 0.8 ---Valve seat size (V.S) 2.0 ---Starter jet (G.S.1) #62.5 ---Starter jet (G.S.2) 0.9 ---Throttle valve size (Th.V) #100 ---Float height (F.H) 12.0 ~ 14.0 mm (0.47 ~ 0.55 in) ---Fuel level (F.L) 4.0 ~ 5.0 mm (0.16 ~ 0.20 in) ----
Engine idle speed 1,400 ~ 1,500 r/min ---Intake vacuum 30.7 kPa (230 mmHg, 9.06 inHg) ----
Tightening torques
Part to be tightened
Starter motor holding bracket Screw M6 2 7 0.7 5.1
Bearing retainer 1
(bearing housing)
Drive select lever unit and frame Bolt M8 2 23 2.3 17
Drive select lever component:
Lever component Bolt M6 1 14 1.4 10
Middle drive pinion gear Nut M16 1 90 9.0 65 Stake
Shift guide stopper bolt Bolt M8 1 20 2.0 14
Part
name
Nut M50 1 80 8.0 58
Thread
size
Q’ty
Tightening torque
Remarks
Nm m · kg ft · lb
LT
– 2 –
MAINTENANCE SPECIFICATIONS
CHASSIS
Item Standard Limit
Brake lever and brake pedal:
Front brake lever free play (at lever pivot) 0 mm (0 in) ---Rear brake lever free play (at lever pivot) 5 ~ 7 mm (0.20 ~ 0.28 in) ---Brake pedal free play 20 ~ 30 mm (0.79 ~ 1.18 in) ---Throttle lever free play 3 ~ 5 mm (0.12 ~ 0.20 in) ----
Tightening torques
SPEC
Part to be tightened
Steering knuckle and tie-rod end Nut M12 × 1.25 2 30 3.0 22
Tie-rod and locknut Nut M12 × 1.25 4 40 4.0 29
Steering shaft and tie-rod end Nut M12 × 1.25 2 30 3.0 22
Front carrier and frame Bolt M8 × 1.25 4 34 3.4 24
Front carrier and front fender Bolt M6 × 1.0 2 7 0.7 5.1
Front carrier and front bumper Bolt M8 × 1.25 2 34 3.4 24
Front bumper and frame Bolt M8 × 1.25 4 34 3.4 24
Front bumper, front fender and
front grill
Front fender and front grill Bolt M6 × 1.0 2 7 0.7 5.1
Rear carrier and frame Bolt M8 × 1.25 4 34 3.4 24
Rear carrier and rear fender Bolt M6 × 1.0 2 7 0.7 5.1
Rear fender, air filter case and
frame
Rear fender and frame Bolt M6 × 1.0 1 7 0.7 5.1
Battery holding bracket Bolt M6 × 1.0 2 7 0.7 5.1
Footrest bracket and frame
(left and right)
Footrest, footrest board and footrest bracket (left and right)
Part
name
Bolt M6 × 1.0 2 7 0.7 5.1
Bolt M6 × 1.0 2 7 0.7 5.1
Bolt M10 × 1.25 4 65 6.5 47
Bolt M8 × 1.25 4 34 3.4 24
Bolt M6 × 1.0 4 7 0.7 5.1
Thread size Q’ty
Tightening torque
Nm m · kg ft · lb
Remarks
– 3 –
MAINTENANCE SPECIFICATIONS
ELECTRICAL
Item Standard Limit
C.D.I.:
Magneto model/manufacturer F4T259/MITSUBISHI ---Pickup coil resistance/color 189 ~ 231 Ω at 20 °C (68 °F)/
White/Green – White/Red
Rotor rotation direction detection coil resistance/color
C.D.I. unit model/manufacturer F8T38683/MITSUBISHI ----
Electric starter system:
Type Constant mesh type ---Starter motor:
Model/manufacturer 5XG/MORIC TAIWAN ---Output 0.4 kW ---Armature coil resistance 0.0144 ~ 0.0176 Ω at 20 °C
Brush overall length 10 mm (0.4 in) 3.5 mm
Spring force 563 ~ 844 g (5.52 ~ 8.28 N) ---Commutator diameter 22 mm (0.87 in) 21 mm
Mica undercut 1.5 mm (0.059 in) ----
Starter relay:
Model/manufacturer MS5F-721/JIDECO ---Amperage rating 180 A ---Coil winding resistance/color 4.2 ~ 4.6 Ω at 20 °C (68 °F)/
0.065 ~ 0.080 Ω at 20 °C (68 °F)/
Red – White/Blue
(68 °F)
Blue/Black – Blue/White
SPEC
----
----
----
(0.14 in)
(0.83 in)
----
– 4 –
Loading...