Yamaha YP125E 2003 Operating and installation instructions

SERVICE
INFORMATION
YP180E
YP125E
2003
5XL1-SE1

YP125E’03
YP180E’03
SERVICE INFORMATION
© 2002 by Yamaha Motor España, S.A.
1st Edition, November 2002.
All rights reserved. Any reprinting or
unauthorized use without the written
permission of Yamaha Motor España, S.A.
is expressly prohibited.
EB000000

EB001000
NOTICE
This manual was produced by the Yamaha Motor España, S.A., primarily for use by Yamaha/MBK
dealers and their qualified mechanics. It is not possible to include all the knowledge of a mecha-
nic in one manual, so it is assumed that anyone who uses this book to perform maintenance and
repairs on Yamaha/MBK scooter has a basic understanding of the mechanical ideas and the pro-
cedures of scooter repair. Repairs attempted by anyone without this knowledge are likely to render
the scooter unsafe and unfit for use.
Yamaha Motor España, S.A., is continually striving to improve all its models. Modifications and sig-
nificant changes in specifications or procedures will be forwarded to all authorized Yamaha/MBK
dealers and will appear in future editions of this manual where applicable.
NOTE:
Designs and specifications are subject to change without notice.
IMPORTANT INFORMATION
Particularly important information is distinguished in this manual by the following notations.
tThe Safety Alert Symbol means TTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
ssWARNING Failure to follow WARNING instructions could result in severe injury or
death to the scooter operator, a bystander or a person inspecting or
repairing the scooter.
CAUTION: A CAUTION indicates special precautions that must be taken to avoid
damage to the scooter.
NOTE: A NOTE provides key information to make procedures easier or
clearer.

EB003000
ILLUSTRATED SYMBOLS
Illustrated symbols to are designed as
thumb tabs to indicate the chapeter’s number
and content.
 General information
 Specifications
 Periodic checks and adjustments
 Engine
 Cooling system
 Carburetion
 Chassis
 Electrical
 Troubleshooting
Illustrate symbols 10 to 17 are used to iden-
tify 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
Illustrated symbols 18 to 23 in the exploded
diagram indicate the types of lubricants and
lubrication points.
18 Apply engine oil
19 Apply gear oil
20 Aply molybdenium disulfide oil
21 Apply wheel bearing grease
22 Apply lightweight lithium-soap grease
23 Apply molybdenium disulfide grease
Illustrated symbols 24 to 25 in the exploded
diagram indicate the where to apply locking
agent 24 and where to install new parts 25 .
24 Apply locking agent (LOCTITE®)
25 Use new one
INSP
ADJ
COOL
CHAS
SPEC
ENG
CARB
ELEC
GEN
INFO





11
13
18
21




10
12
14
23
19
22
TRBL
SHTG
24 25
15 16 17
20
New

CONTENTS
GENERAL INFORMATION
SCOOTER IDENTIFICATION
FRAME SERIAL NUMBER......................................................................................................1
ENGINE SERIAL NUMBER.....................................................................................................1
MODEL LABEL .......................................................................................................................1
IMPORTANT INFORMATION.....................................................................................................2
PREPARATION FOR REMOVAL PROCEDURES....................................................................2
REPLACEMENT PARTS..........................................................................................................2
GASKETS, OIL SEALS, AND O-RINGS..................................................................................2
LOCK WASHERS/PLATES AND COTTER PINS ....................................................................3
BEARINGS AND OIL SEALS ..................................................................................................3
CIRCLIPS................................................................................................................................3
CHECKING OF CONNECTIONS ............................................................................................4
HOW TO USE THE CONVERSION TABLE.............................................................................5
SPECIAL TOOLS........................................................................................................................6
SPECIFICATIONS
GENERAL SPECIFICATIONS ....................................................................................................9
MAINTENANCE SPECIFICATIONS.........................................................................................12
ENGINE.................................................................................................................................12
LUBRICATION DIAGRAM .....................................................................................................15
TIGHTENING TORQUES (ENGINE) ......................................................................................17
CHASSIS...............................................................................................................................29
TIGHTENING TORQUES (CHASSIS)....................................................................................20
ELECTRICAL.........................................................................................................................21
GENERAL TORQUE SPECIFICATIONS..................................................................................23
CABLE ROUTING.....................................................................................................................24
PERIODIC INSPECTIONS AND ADJUSTMENTS
PERIODIC MAINTENANCE/LUBRICATION INTERVALS ......................................................27
WIRING DIAGRAM..................................................................................................................29

1
YP100000
GENERAL INFORMATION
SCOOTER IDENTIFICATION
YP100010
FRAME SERIAL NUMBER
The identification number is stamped onto the
frame.
YP100020
ENGINE SERIAL NUMBER
The engine serial number is stamped onto the
right side of the crankcase.
NOTE:
Design and specifications may change without
notice.
MODEL LABEL
The model reference label is affixed under the
seat. This information will be needed to order
sparre parts.
SCOOTER IDENTIFICATION
2
1
GEN
INFO


2
EB101000
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL
PROCEDURES
1. Remove all dirt, mud, dust and foreign mate-
rial before removal and disassembly.
2. Use proper tools and cleaning equipment.
3. Refer to the “SPECIAL TOOLS” section.
4. When disassembling the machine, 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 repla-
ced as an assembly.
5. During machine disassembly, clean all parts
and place them in trays in the order o disas-
sembly. This will speed up assembly and
allow for the correct installation of all parts.
6. Keep all parts away from any source of fire.
EB101010
REPLACEMENT PARTS
1. Use only genuine Yamaha parts for all repla-
cements. Use oil and grease recommended
by Yamaha for all lubrication jobs. Other
brands may be similar in function and appea-
rance, but inferior in quality.
EB101020
GASKETS, OIL SEALS AND O-RINGS
1. Replace all gaskets, seals and O-rings when
overhauling the engine. All gasket surfaces, oil
seal lips and O-rings must be cleaned.
2. Properly oil all mating parts and bearings
during reassembly. Apply grease to the oil
seal lips.
IMPORTANT INFORMATION GEN
INFO

3
EB101030
LOCK WASHERS/PLATES AND COTTER PINS
1. Replace all lock washers/plates and cotter
pins after removal. Bend lock tabs along the
bolt or nut flats after the bolt or nut has been
tightened to specification.
EB101040
BEARINGS AND OIL SEALS
Install bearings and oil seals so that the manu-
facturer’s marks or numbers are visible. When
installing oil seals, apply a light coating of light-
weight lithium base grease to the seal lips. Oil
bearings liberally when installing, if appropriate.
Oil seal
CAUTION:
Do not use compressed air to spin the bea-
rings dry. This will damage the bearing surfa-
ces.
Bearing
EB101050
CIRCLIPS
1. Check all circlips carefully before reassembly.
Always replace piston pin clips after one use.
Replace distorted circlips. When installing a
circlip , make sure that the sharp-edged
corner is positioned opposite the thurst 
it receives. See sectional view.
Shaft
IMPORTANT INFORMATION GEN
INFO

4
EB801000
CHECKING OF CONNECTIONS
Dealing with stains, rust, moisture, etc. on the
connector.
1. Disconnect:
• Connector
2. Dry each terminal with an air blower.
3. Connect and disconnect the connector two or
three times.
4. Pull the lead to check that it will not come off.
5. If the terminal comes off, bend up the pin 
and reinsert the terminal into the connector.
6. Connect:
• Connector
NOTE:
The two connectors “click” together.
7. Check for continuity with a tester.
NOTE:
• If there is no continuity, clean the terminals.
• Be sure to perform the steps 1 to 7 listed
above when checking the wireharness.
• For a field remedy, use a contact revitalizer
available on the market.
• Use the tester on the connector as shown.
IMPORTANT INFORMATION GEN
INFO

5
EB201000
HOW TO USE THE CONVERSION TABLE
All specification data in this manual are listed in SI and METRIC UNITS.
Use this table to convert METRIC unit data to IMPERIAL unit data.
EX.
METRIC MULTIPLIER IMP
** mm x 0,03937 = **in
2 mm x 0,03937 = 0,08 in
TABLA DE CONVERSIÓN
METRIQUES EN ANGLAISES
Connu Multiplicateur Résultat
m•kg 7,233 ft•lb
Torque m•kg 86,794 in•lb
cm•kg 0,0723 ft•lb
cm•kg 0,8679 in•lb
Weight kg 2,205 lb
g 0,03527 oz
km/h 0,6214 mph
km 0,6214 mi
Distance m 3,281 ft
m 1,094 yd
cm 0,3937 in
mm 0,03937 in
cc (cm3) 0,03527 oz (IMP liq.)
Volume/ cc (cm3) 0,06102 cu•in
Capacity lit (litre) 0,08799 qt (IMP liq.)
lit (litre) 0,2199 gal (IMP liq.)
kg/mm 55,997 lb/in
Micescellaneous kg/cm214,2234 psi (lb/in2)
Centígrade 9/5 (°C) + 32 Fahrenheit (ºF)
IMPORTANT INFORMATION GEN
INFO

6
EB102000
SPECIAL TOOLS
The following special tools are necessary for complete and accurate tune-up and assembly.
Use only the appropriate special tools; this will help prevent damage caused by the use of inap-
propriate tools or improvised techniques.
When placing an order, refer to the list provided below to avoid any mistakes.
Tool No. Tool name/Usage Illustration
90793-80009 Engine tachometer
This tools is needed for detecting
engine rpm.
90890-01083 Weight
-01084 Rocker arm shaft puller bolt
These tools are used when removing
or installing the rocker arm shafts.
90890-01189 Rotor holding tool
This tools is used to remove the
flywheel magneto.
90890-01235 Flywheel puller
This tools is used for removing the
rotor
90890-01268 Ringnut wrench
This tool is used to loosen and tighten
the exhaust pipe.
90890-01311 Valve adjusting tool
This tools is necessary for adjusting
valve clearance.
90890-01312 Fuel level gauge
This gauge is used to measure the fuel
level in the float chamber.
90890-01325 Radiator cap tester
-01352 Adaptor
These tools are used for checking
the cooling system.
90890-01326 T-handle
-01294 Damper rod holder
These tool are used for holding the
damper rod holder when removing or
installing the damper rod holder.
SPECIAL TOOLS GEN
INFO

7
Tool No. Tool name/Usage Illustration
90890-01337 Clutch spring compressor
-01464
These tools are used for removing the
nut with holding the compression spring
90890-01348 Locknut wrench
This tool is used when removing or
installing the secondary sheave nut.
90890-01367 Fork seal driver weight
-01368 Fork seal driver attachment (ø 33)
This tool is used when installing the
fork seal
90890-01403 Ring nut wrench
This tools is used to loosen and tighten
the steering ring nut.
90890-01701 Sheave holder
This tool is used for holding the
secondary sheave.
90890-03079 Thickness gauge
This tool is used to measure the valve
clearance.
90890-03081 Compression gauge
These tools are used to measure the
engine compression.
90890-03112 Pocket tester
These instruments are invaluable for
checking the electrical system.
SPECIAL TOOLS GEN
INFO

8
Tool No. Tool name/Usage Illustration
90890-03141 Timing light
This tools is needed for detecting
ignition timing.
90890-04101 Valve lapper
This tools is used for removing and
installing the lifter and for lapping
the valve.
90890-04019 Valve spring compressor
-04108 Attachment
These tools are used for removing
or installing the valve and the valve
spring.
90890-04116 Valve guide puller
90890-04117 Valve guide installer
90890-04118 Valve guide reamer
90890-06754 Ignition checker
This instrument is necessary for checking
the ignition system components.
90890-85505 Yamaha bond No. 1215
This sealant (bond) is used for
crankcase mating surface, etc.
SPECIAL TOOLS GEN
INFO

9
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model YP125E YP180E
Model code 5XL 5XM
Dimensions:
Overall lenght 2,030 mm
Overall width 745 mm
Overall height 1,285 mm
Seatheight 774 mm
Wheelbase 1,480 mm
Minimum ground clearance 102 mm
Basic weight:
With oil and full fuel tank 141 kg
Engine:
Engine type Liquid cooled-4-stroke, SOHC
Cylinder arrangement Forward-inclined single cylinder
Displacement 124,11 cm3175,6 cm3
Bore x stroke 53,7 x 54,8 mm 62,2 x 57,8 mm
Compression ratio 11:1
Starting system Electrical starter
Lubrication system: Wet sump
Oil type or grade:
Engine oil API STANDARD: SE or higher grade
Standard type: SAE 10W-30 or 10W-40
Periodic oil change 1,3 L
Total amount 1,4 L
Transmission oil
Standard type: SAE 10W-30
Total amount 0,15 l
Radiator capacity:
Total amount (including all routes) 1,1 L
Air filter:
Carburetor side Dry tpe element
Crankcase side Wet type element
Fuel:
Type Regular unleaded gasoline
Fuel tank capacity 10,5 L
GENERAL SPECIFICATIONS SPEC
-10º 0º 10º 20º 30º 40ºC
SAE 10W/30
SAE 10W/40
SAE 20W/40
SAE 20W/50

10
Model YP125E YP180E
Carburetor:
Type/quantity Y28V-1K/1 Y28V-1L/1
Manufacturer TEIKEI
Spark plug:
Type CR8E
Manufacturer NGK
Spark plug gap 0,7 ~ 0,8 mm
Clutch type: Dry, centrigual automatic
Transmission:
Primary reduction system Helical gear
Primary reduction ratio 40/15(2.666)
Secondary reduction system Sper gear
Secondary reduction ratio 44/12 (3.666) 42/14 (3.000)
Transmission type Single speed automatic (V-belt type)
Operation Centrifugal automatic type
Chassis:
Chassis type Steel tube under-bone
Caster angle 28°
Trail 104 mm
Tyre:
Type Tubeless
Size front 120/70-12 51 L
rear 130/70-12 56 L
Tyre pressure (cold tire):
Maximum load (excluding motorcycle) 183kg
Loading condition A* 0 ~ 90kg
front 190 kPa (1,9 kg/cm2, 1,9 bar)
rear 220 kPa (2,2 kg/cm2, 2,2 bar)
Loading condition B* 90 ~ kg
front 190 kPa (1,9 kg/cm2, 1,9 bar)
rear 240 kPa (2,4 kg/cm2, 2,4 bar)
*Load is the total weigh of cargo, rider, passenger, and accessories.
GENERAL SPECIFICATIONS SPEC

11
Model YP125E YP180E
Brake:
Front brake
type Single disc brake
operation Right hand operation
Rear brake
type Single disc brake
operation Left hand operation
Suspension:
Front suspension Telescopic fork
Rear suspension Unit swing
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/oil damper
Wheel travel:
Front wheel travel 90 mm
Rear wheel travel 90 mm
Electrical:
Igntion system CDI
Generator A.C. magneto
Batter y type CB7L-B2
Batter y capacity 12V 8 AH
Bullbs, wattage x quantity:
Headlight 12V 35 W/35 W x 2
Marker light 12 V 5W x 2
Tail/brake light 12 V 5 W/21 W x 2
Front flasher light 12V 21 W x 2
Rear flasher light 12 V 10 W x 2
Meter light 12V LED x 3
Hight beam indicator light 12 V 3,4 W x 1
Turn indiactor light 12V 3,4 W x 2
Coolant temperature warning light 12V LED x 1
License light 12V 5W x1
GENERAL SPECIFICATIONS SPEC

12
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
YP125E YP180E
Cylinder head:
Warp limit ••• 0,03 mm
Cylinder:
Bore size 53,700 ~ 53,715 62,200 ~ 62,215 •••
Out of round limit ••• 0,03 mm
Camshaft:
Cam dimensions
Intake “A” 30,811 ~ 30,911 mm 30,711 mm
“B” 25,145 ~ 25,245 mm 25,045 mm
“C” 5,666 mm •••
Exhaust “A” 30,811 ~ 30,911 mm 30,711 mm
“B” 25,152 ~ 25,252 mm 25,052 mm
“C” 5,659 mm •••
Camshaft runout limit ••• 0,03 mm
Cam chain:
Cam chain type/No. of links 82 RH2005 / 94 •••
Rocker arm/rocker arm shaft:
Rocker arm inside diameter 11,990 ~ 12,028 mm •••
Shaft outside diameter 11,981 ~ 11,991 mm •••
Arm-to-shaft clearance 0,009 ~ 0,037 mm •••
Valve, valve seat, valve guide:
Valve clearance (cold) IN 0,10 ~ 0,14 mm •••
EX 0,16 ~ 0,20 mm •••
Valve dimensions
“A” Head diameter IN 26,9 ~ 27,1 mm 28,9 ~ 29,1 mm •••
EX 22,9 ~ 23,1 mm 23,9 ~ 24,1 mm •••
“B” Face width IN 1,402 ~ 2,568 mm •••
EX 1,402 ~ 2,568 mm •••
Stem outside diameter IN 4,475 ~ 4,490 mm •••
EX 4,460 ~ 4,475 mm •••
Stem inside dimater IN 4,500 ~ 4,512 mm •••
EX 4,500 ~ 4,512 mm •••
MAINTENANCE SPECIFICATIONS SPEC
Head diameter Face Width

13
Item Standard Limit
YP125E YP180E
Valve spring:
Free length IN/EX 41,94 mm 39,8 mm
Set length (valve closed) IN/EX 37,5 mm •••
Compressed pressure IN/EX 45,1 - 50,9 kg •••
Tilt IN/EX ••• 2,5 º / 1,9 mm
Piston:
Piston to cylinder clearance 0,013 ~ 0,045 mm 0,15 mm
Piston size “D” 53,670~53,687 mm 62,170~62,187 mm •••
Measuring point “H” 5 mm •••
Piston pin bore 15,002 ~ 15,013 mm •••
in side diameter
Piston pin outside diameter 14,991 ~ 15,000 mm •••
Piston rings:
Top ring:
Type Barrel •••
End gap (installed) 0,15 ~ 0,25 mm 0,15 ~ 0,30 mm 0,45 mm
Side clearance (installed) 0,03 ~ 0,07 mm 0,12 mm
2nd ring:
Type Taper •••
End gap (installed) 0,15 ~ 0,30 mm 0,30 ~ 0,45 mm 0,45/0,70 mm
Side clearance (installed) 0,02 ~ 0,06 mm 0,12 mm
Oil ring:
End gap (installed) 0,2 ~ 0,7 mm •••
Crankshaft:
Crank width “A” 47,95 ~ 48,00 mm 48,95 ~ 49,00 mm •••
Runout limit “C” 0,03 mm •••
Big end side clearance “D” 0,15 ~ 0,45 mm •••
MAINTENANCE SPECIFICATIONS SPEC

14
Item Standard Limit
YP125E YP180E
Automatic centrigual clutch:
Clutch shoe tickness 2,0 mm 2,75 mm 1/1,75 mm
Clutch shoe spring free length 28,5 mm 32 mm •••
Clutch - in revolution 3800±250 r/min 3400±250 r/min •••
Cluth - stall revolution 5800±500 r/min 5300±500 r/min •••
V-belt:
V-belt width 21 mm •••
Carburetor:
Type Y28V-1K Y28V-1L
I.D. mark 5XL 5XM •••
Main jet (M.J.) # 112 # 112 •••
Main air jet (M.A.J.) ø 0,9 ø 0,9 •••
Jet needle (J.N.) 5D34-3/5 5D35-3/5 •••
Pilot air jet (P.A.J.1) ø 1,2 ø 1,1 •••
Needle Jet (N.J.) ø 2,585 ø 2,585 •••
Pilot jet (P.J.) # 38 # 44 •••
Pilot screw (P.S.) 3 3/4 ± 1/2 1 3/4 ± 1/2 •••
Valve seat size (V.S.) 2,5 mm 2,5 mm •••
Starter jet 1 (G.S.1) # 45 # 45 •••
Engine idle speed 1700 ~ 1900 rpm 1600 ~ 1800 rpm •••
Intake vacuum 200 ~ 260 mmHg 280 ~ 340 mmHg •••
Oil temperature 65 ~ 75 ºC •••
Coolant temperature 75 º ~ 85 º C •••
CO% 2 ~ 4 % 2,5 ~ 4,5% •••
Oil pump
Type Trochoid type •••
Tip clearance ••• 0,15 mm
Side clearance ••• 0,17 mm
Housing and rotor clearance ••• 0,07 mm
Radiator:
Type Cooling fin with electric fan •••
Width/height/thickness 166,4/220/23 •••
Radiator cap opening pressure 110 kPa (1,1 kg/cm2,1,1 bar) •••
Reservoir tank capacity 1,2 L •••
MAINTENANCE SPECIFICATIONS SPEC

15
LUBRICATION DIAGRAM
1) Cylinder head lubrication
2) Crankshaft lubrication
MAINTENANCE SPECIFICATIONS SPEC
12