Yamaha YP250D 98 Manual

FOREWORD
This Supplementary Service Manual has been prepared to introduce new service and data for the
YP250D ’98. For complete service information procedures it is necessary to use this Supplementary
Service Manual together with the following manual.
YP250 SERVICE MANUAL: 4UC-AE1
YP250 (J) SUPPLEMENTARY SERVICE MANUAL: 4UC-AE2
YP250D ’98
SUPPLEMENTARY
SERVICE MANUAL
1997 by Yamaha Motor Co., Ltd.
First Edition, December 1997
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.

NOTE:
CAUTION:
EB001000 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
scooter has a basic understanding of the mechanical ideas and the procedures of scooter repair. Re-
pairs attempted by anyone without this knowledge are likely to render the scooter unsafe and unfit for
use.
YamahaMotorCompany,Ltd.iscontinuallystrivingtoimproveallitsmodels.Modificationsandsignifi-
cant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers and
will appear in future editions of this manual where applicable.
Designs and specifications are subject to change without notice.
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!
FailuretofollowWARNINGinstructionscouldresultinsevereinjuryordeathto
thescooter operator, abystander ora personinspectingorrepairingthescoot-
er.
ACAUTION indicatesspecialprecautionsthatmust betakentoavoiddamage
to the scooter.
NOTE: A NOTE provides key information to make procedures easier or clearer.

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YP002000 HOW TO USE THIS MANUAL
MANUAL ORGANIZATION
This manual consists of chapters for the main categories of subjects. (See “Illustrated symbols”)
1st title 1: This is the title of the chapter with its symbol on 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 accompa-
nied by corresponding illustrations.
EXPLODED DIAGRAMS
Tohepsidentifypartsandclarifyproceduresteps,thereareexplodeddiagramsatstartofeachremov-
al and disassembly section.
1. An easy-to-see exploded diagram 4is provided for disassembly and assembly jobs.
2. Numbers 5aregivenintheorderofjobs intheexplodeddiagram.Anumberthatisenclosedbya
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 7accompanies the exploded diagram, providing the order of jobs, names
of parts, notes in jobs, etc.
5. Forjobsrequiring more information,thestep-by-step format supplements 8aregiven inaddition
to the exploded diagram and the job instruction chart.

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3
5
7
9
11
13
15
18
2
4
8
10
12
14
16
6
21
24 25
17
19 20
22 23
EB003000
ILLUSTRATED SYMBOLS
Illustrated symbols 1to 9are designed as
thumb tabs to indicate the chapter’s number
and content.
1General information
2Specifications
3Periodic inspection and adjustment
4Engine
5Cooling system
6Carburetion
7Chassis
8Electrical
9Troubleshooting
Illustrated symbols 10 to 17 are used to identify
the specifications appearing in the text.
10 Possible to maintain with engine mounted
11 Filling fluid
12 Lubricant
13 Special tool
14 Tightening
15 Wear limit, clearance
16 Engine speed
17 Ω, V, A
Illustratedsymbols 18 to 23 in theexplodeddia-
grams indicate the types of lubricants and lu-
brication points.
18 Apply engine oil
19 Apply gear oil
20 Apply molybdenum disulfide oil
21 Apply wheel bearing grease
22 Apply lightweight lithium-soap base grease
23 Apply molybdenum disulfide grease
Illustratedsymbols 24 to 25 in theexplodeddia-
gramsindicatethewheretoapplylockingagent
24 and when to install new parts 25 .
24 Apply locking agent (LOCTITE)
25 Use new one

CONTENTS
SPECIFICATIONS 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL SPECIFICATIONS 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE SPECIFICATIONS 2. . . . . . . . . . . . . . . . . . . . . . . . . . .
ENGINE 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHASSIS 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ELECTRICAL 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CABLE ROUTING 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PERIODIC INSPECTION AND ADJUSTMENTS 10. . . . . . . . . . . . . . . . . . .
INTRODUCTION 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PERIODIC MAINTENANCE/LUBRICATION INTERVALS 10. . . . . . . . .
COVER AND PANEL 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SIDE PANEL AND SEAT 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADJUSTING THE REAR BRAKE 13. . . . . . . . . . . . . . . . . . . . . . . . . . .
CHECKING THE REAR BRAKE FLUID 13. . . . . . . . . . . . . . . . . . . . . .
CHECKING THE REAR BRAKE PADS 14. . . . . . . . . . . . . . . . . . . . . .
BLEEDING THE HYDRAULIC BRAKE SYSTEM 14. . . . . . . . . . . . . .
ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLIES 16. .
CHASSIS 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REAR WHEEL AND BRAKE DISC 17. . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHECKING THE BRAKE DISC 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REAR BRAKE 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BRAKE PAD 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REPLACING THE BRAKE PADS 20. . . . . . . . . . . . . . . . . . . . . . . . . . .
CALIPER 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CALIPER DISASSEMBLY 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLING THE REAR BRAKE CALIPER 23. . . . . . . . . . . . . . . . . .
MASTER CYLINDER 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MASTER CYLINDER DISASSEMBLY 25. . . . . . . . . . . . . . . . . . . . . . .
REAR SHOCK ABSORBER AND SWINGARM 26. . . . . . . . . . . . . . . . .

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GENERAL SPECIFICATIONS SPEC
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model YP250D
Model code: 5DF1 (except for CH, A, AUS)
5DF2 (for CH, A)
Basic weight:
With oil and full fuel tank 164 kg
Transmission:
Primary reduction system
Primary reduction ratio
Secondary reduction system
Secondary reduction ratio
Transmission type
Operation
Single speed automatic
Helical gear
38/15 (2.533)
Sper gear
37/16 (2.312)
Single speed automatic (V-belt type)
Centrifugal automatic type
2.34 0.82 : 1
Tire pressure (cold tire):
Maximum load-except motorcycle
Loading condition A*
front
rear
Loading condition B*
front
rear
High-speed riding
front
rear
191 kg
0 90 kg
175 kPa (1.75 kg/cm2, 1.75 bar)
200 kPa (2.0 kg/cm2, 2.0 bar)
90 191 kg
200 kPa (2.0 kg/cm2, 2.0 bar)
225 kPa (2.25 kg/cm2, 2.25 bar)
200 kPa (2.0 kg/cm2, 2.0 bar)
250 kPa (2.5 kg/cm2, 2.5 bar)
Brake:
Front brake type
operation
Rear brake type
operation
Single disc brake
Right hand operation
Single disc brake
Left hand operation
Wheel travel:
Front wheel travel
Rear wheel travel 85 mm
90 mm
Electrical:
Ignition system
Generator system
Battery type
Battery capacity
T.C.I. (Digital)
A.C. magneto
GT7B-4
12 V 6.5 AH
*Load is the total weight of cargo, rider, passenger, and accessories.

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MAINTENANCE SPECIFICATIONS SPEC
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
Automatic centrifugal clutch:
Clutch shoe thickness
Clutch housing inside diameter
Clutch shoe spring free length
Weight outside diameter
Clutch - in revolution
Clutch - stall revolution
3.0 mm
135 mm
28.1 mm
20 mm
2,250 2,850 r/min
3,700 4,700 r/min
2.0 mm
135.5 mm
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19.5 mm
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Carburetor:
Type
I.D. mark
Ventuly outside diameter
Main jet (M.J)
Main air jet (M.A.J)
Jet needle (J.N)
Throttle valve size (Th.V)
Pilot air jet (P.A.J.1)
Needle jet (N.J)
Pilot outlet (P.O)
Pilot jet (P.J)
Bypass (B.P)
Pilot screw (P.S)
Valve seat size (V.S)
Starter jet 1 (G.S.1)
Starter jet 2 (G.S.2)
Float height (F.H)
Engine idle speed
Intake vacuum
Oil temperature
Cooling water temperature
Y28V-1A
4UC 02 [4UD 00 (CH)]
ø28
#130
ø0.9
5D32-3/5
11
ø1.2
#85
ø0.8
#44
0.7 3
1 7/8 [1 5/8 (CH)]
1.4
ø0.45 [ø0.47 (CH)]
ø0.5
27 mm
1,350 1,450 r/min
220 260 mmHg
65 75C
80C
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CHASSIS
Item Standard Limit
Front suspension:
Front fork travel
Fork spring free length
Spring rate (K1)
Stroke (K1)
Oil capacity
Oil level
Oil grade
Inner tube vend limit
100 mm
268.5 mm
5.7 N/mm (0.57 kg/mm)
0 100 mm
0.142 L (142 cm3)
80 mm
Fork oil 15 WT or equivalent
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263.5 mm
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0.2 mm