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SK25AA 2009

KYMCO Downtown 125i 2009, SK25AA 2009 Service Manual

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Page 1
DOWNTOWN 125i
All rights reserved. Any reproduction or
permission of KWANG YANG Motor Co., Ltd.
By KWANG YANG Motor Co., Ltd.
1st Edition, April 2009
unauthorized use without the written
is expressly prohibited.
T100-LFA7-A2
Page 2
PREFACE
C C
DOWNTOWN 125i
TABLE OF CONTENTS
This Service Manual describes the technical features and servicing procedures for the KYMCO
Downtown 125i.
Section 1 contains the precautions for all operations stated in this manual. Read them carefully before any operation is started.
Section 2 is the removal/installation procedures for the frame covers which are subject to removal/installation frequency during maintenance and servicing operations.
Section 3 describes the inspection/ adjustment procedures, safety rules and service information for each part, starting from periodic maintenance.
Sections 5 to 11 give instructions for disassembly, assembly and adjustment of engine parts. Section 13-14 is the AFI system. Section 15 to 16 is the removal/ installation of chassis. Section 17 to 20 states the testing and measuring methods of electrical equipment.
Most sections start with an assembly or system illustration and troubleshooting for the section. The subsequent pages give detailed procedures for the section.
The information and contents included in this manual may be different from the motorcycle in case specifications are changed.
KWANG YANG MOTOR CO., LTD.
QUALITY TECHNOLOGY DEPT.
EDUCATION SECTION
GENERAL INFORMATION EXHAUST MUFFLER/FRAME
COVERS INSPECTION/ADJUSTMENT LUBRICATION SYSTEM ENGINE REMOVAL/INSTALLATION CYLINDER HEAD/VALVES
ENGINE
CYLINDER/PISTON DRIVE AND DRIVEN PULLEYS FINAL REDUCTION A.C. GENERATOR/STARTER
CLUTCH CRANKCASE/CRANKSHAFT COOLING SYSTEM Fi DIAGNOSTIC TOOL OPERATION FUEL INJECTION SYSTEM
CHASSIS
HANDLEBAR/FRONT WHEEL/FRONT BRAKE/FRONT SHOCK ABSORBER/STEERING STEM
REAR BRAKE/REAR FORK/REAR WHEEL/REAR SHOCK ABSORBER`
ELE
EQUIPMENT
BATTERY/CHARGING SYSTEM
TRI
IGNITION SYSTEM
AL
STARTING SYSTEM LIGHTS/METERS/SWITCHES
1 2
3 4 5 6 7
8 9
10
11 12
13 14
15
16
17 18 19 20
Page 3
1. GENERAL INFORMATION
DOWNTOWN 125i
ENGINE SERIAL NUMBER SPECIFICATIONS SERVICE PRECAUTIONS TORQUE VALUES
SPECIAL TOOLS....................................
ENGINE SERIAL NUMBER
...................................
..................................
................... 1- 1
.....................
LUBRICATION POINTS..........................1-14
1-12
Location of Engine Serial Number
1
-1-
1-1
Page 4
1. GENERAL INFORMATION
SPECIFICATIONS
Name DOWNTOWN125i Model No. SK25AA Overall length 2200mm Overall width 800 mm Overall height 1410 mm Wheel base 1542 mm
Engine type Displacement 124.8cc Fuel Used 92# nonleaded gasoline
Front wheel 68
Net weight (kg) Rear wheel 96
Total 164
Front wheel 70
Gross weight(kg) Rear wheel 104
Total 178
Tires
RR Ground clearance 140 mm Perform- Braking distance (m)
ance
Engine
Min. turning radius 2600mm
Starting system Type Cylinder arrangement Single cylinder
Combustion chamber type Semi-sphere Valve arrangement O.H.C.4V Bore x stroke (mm) 54 x 54.5 Compression ratio 11.7:1
Compression pressure (kg/cm²)
Max .horsepower (ps/rpm) 15/8750~9000
Max. torque (kg m/rpm) 1.17/8500~8750
Port timing
Valve Intake 0.10 mm
Front wheel 120/80-14
Rear wheel 150/70-13
Intake (1mm) Exhaust (1mm)
Open 8 °BTDC Close 31° BTDC Open 32° BTDC Close 6 °BTDC
O.H.C.
7.9m/30km/h
Starting motor
liquid cooled 4 stroke
15
DOWNTOWN 125i
Air cleaner type & No Paper element, wet
Fuel System
Fuel capacity 12.5 L
Throttle type
Ignition System
Electrical Equip.
Battery Capacity 12V10AH
Power Drive System
Clutch Type Dry multi-disc clutch
Transmis-
sion Gear
Reduction
Gear
Front Caster angle 28°
Moving Device
Axle
Tire pressure (kg/cm²)1 person
Turning Left 40? angle
Brake system type
Damping
Device
Suspension type
Frame type PIPE UNDER BONE
Type
Spark plug
Sparkpluggap 0.6～0.7mm
Type Non-stage transmission
Operation
Type Two-stage reduction
Reduction 1st ratio
Trail length 140mm
2nd
Front 2.0 Rear 2.25
Right 40?
Front Disk brake Rear
Front Telescope
Rear DOUBLE SWING
Butterfly type
ECU
NGK CR7E
Automatic centrifugal
type
0.83~2.2
10.41
Disk brake
clearance Exhaust 0.10 mm
Idle speed (rpm) 1850rpm
Lubrication
System
Lubrication type
Oil pump type Inner/outer rotor type Oil filter type Full-flow filtration
Oil capacity 1.2 L
Exchanging capacity 1.0 L
Cooling Type Liquid cooling
Forced pressure &
Wet sump
-2-
Page 5
1. GENERAL INFORMATION
SERVICE PRECAUTIONS
Make sure to install new gasket, O-rings, circlips, cotter pins, etc. When reassembling.
.
When tightening bolts or nuts, begin with larger-diameter to smaller ones at several times, and tighten to specified torque diagonally.
DOWNTOWN 125i
-
Use genuine parts and lubricants.
When servicing the motorcycle, be sure to use special tools for removal and installation.
After diassembly, clean removed parts. Lubricate sliding surfaces with engine oil before reassembly.
-3-
1-3
Page 6
1. GENERAL INFORMATION
Apply or add designated greases and lubricants to the specified lubrication points.
After reassembly, check all parts for proper tightening and operation.
DOWNTOWN 125i
When two person work together, pay attention to the mutual working safety.
Disconnect the battery negative (-) terminal before operation.
When using a spanner or other tools, make sure not to damage the motorcycle surface.
After operation, check all connecting points, fasteners, and lines for proper connection and installation.
When connecting the battery, the positive (+) terminal must be connected first.
After connection, apply grease to the battery terminals.
Terminal caps shall be installed securely.
-4-
Page 7
1. GENERAL INFORMATION
If the fuse is burned out, find the cause and repair it. Replace it with a new one according to the specified capacity.
After operation, terminal caps shall be installed securely.
DOWNTOWN 125i
Confirm Capacity
When taking out the connector, the lock on the connector shall be released before operation.
Hold the connector body when connecting or disconnecting it.
Do not pull the connector wire.
Check if any connector terminal is bending, protruding or loose.
-5-
1-5
Page 8
1. GENERAL INFORMATION
The connector shall be inserted completely.
DOWNTOWN 125i
If the double connector has a lock, lock it at the correct position.
Check if there is any loose wire.
Before connecting a terminal, check for damaged terminal cover or loose negative terminal.
Check the double connector cover for proper coverage and installation.
click
Insert the terminal completely. Check the terminal cover for proper coverage. Do not make the terminal cover opening face up.
Secure wire harnesses to the frame with their respective wire bands at the designated locations. Tighten the bands so that only the insulated surfaces contactthe wireharnesses.
-6-
Page 9
1. GENERAL INFORMATION
After clamping, check each wire to make sure it is secure.
Do not squeeze wires against the weld or its clamp
DOWNTOWN 125i
After clamping, check each harness to make sure that it is not interfering with any moving or sliding parts.
When fixing the wire harnesses, do not make it contact the parts which will generate high heat.
Route wire harnesses to avoid sharp edges or corners. Avoid the projected ends of bolts and screws.
No contact !
Route wire harnesses passing through the side of bolts and screws. Avoid the projected ends of bolts and screws.
-7-
1-7
Page 10
1. GENERAL INFORMATION
Route harnesses so they are neither pulled tight nor have excessive slack.
Protect wires and harnesses with electrical tape or tube if they contact a sharp edge or corner.
DOWNTOWN 125i
Do not pull too tight!
When rubber protecting cover is used to protect the wire harnesses, it shall be installed securely.
Do not break the sheath of wire. If a wire or harness is with a broken sheath,
repair by wrapping it with protective tape or replace it.
When installing other parts, do not press or squeeze the wires.
Do not press or squeeze the wire.
-8-
Page 11
1. GENERAL INFORMATION
After routing, check that the wire harnesses are not twisted or kinked.
Wire harnesses routed along with handlebar should not be pulled tight, have excessive slack or interfere with adjacent or surrounding parts in all steering positions.
DOWNTOWN 125i
Do you understand the instrument? Is the instrument set correctly?
When a testing device is used, make sure to understand the operating methods thoroughly and operate according to the operating instructions.
Be careful not to drop any parts.
When rust is found on a terminal, remove the rust with sand paper or equivalent before connecting.
Remove Rust !
-9-
1-9
Page 12
1. GENERAL INFORMATION
Symbols :
The following symbols represent the servicing methods and cautions included in this service manual.
DOWNTOWN 125i
Engine Oil
Grease
Gear Oil
Special
:Apply engine oil to the specified points.
(Use designated engine oil for lubrication).
:Apply grease for lubrication.
:Transmission Gear Oil (90#)
:Use special tool.
:Caution
:Warning
.
-10-
Page 13
1. GENERAL INFORMATION
TORQUE VALUES
STANDAR TORQUE VALUES
Item Torque (kg -f m) Item Tor (kg -que f m)
DOWNTOWN 125i
5mm bolt, nut 6mm bolt, nut
8mm bolt, nut 10mm bolt, nut 12mm bolt, nut
Torque specifications listed below are for important fasteners.
ENGINE
Item Qty Thread dia.(mm) Torque (kgf-m) Remarks
Cylinder head bolt A Cylinder head bolt B
Oil filter screen cap O2 sensor
Cylinder head cover Tappet adjusting hole cap Cam chain set plate Engine oil drain bolt Clutch outer nut
Clutch drive plate nut Starter motor mounting bolt
Oil pump bolt Drive face nut Spark plug
A.C. Generator flywheel
Cam chain tensioner pivot
0.45~0.6
0.8~1.2
1.8~2.5
3.0~4.0
5.0~6.0
5mm screw 6mm screw, SH bolt 6mm flange bolt, nut 8mm flange bolt, nut 10mm flange bolt, nut
6 6
30 12
6
30
6 12 12 28
6
6 12 10
12
6
0.45~0.6
0.7~1.1
1.0~1.4
2.4~3.0
3.0~4.5
0.7~1.1
0.7~1.1
2.0~3.0
0.7~1.1
0.8~0.9
1.0~2.0
1.0~1.4
2.0~3.0
5.0~6.0
5.0~6.0
0.8~1.2
0.7~1.1
5.5~6.5
1.0~1.4
5.0~6.0
0.8~1.2
FRAME
Item Qty Thread dia.(mm) Torque (kgf-m) Remarks
Steering stem lock nut Front axle Rear axle nut
Rear shock absorber upper bolt
Rear shock absorber lower bolt Muffler exh. Pipe
-11-
Bc1
14 16 10 10
8
6.0~6.5
1.5~2.5 11~13
3.5~4.5
3.5~4.5
1.8~2.0
U - nut U - nut
Page 14
1. GENERAL INFORMATION
SPECIAL TOOLS
Tool Name Tool No.
Flywheel puller
DOWNTOWN 125i
Illustration
(Note: the special tools may differ
slightly from those shown in the figure of this manual.)
(Refer to the “STARTER CLUTCH” section in the chapter
10.)
Oilsealandbearing installer
Universal holder
(Refer to the “DRIVE PULLEY, DRIVE BELT AND DRIVEN PULLEY” section in the chapter
8.)
Flywheel holder
(Refer to the “STARTER CLUTCH” section in the chapter
10.)
A120E00003
A120E00014
A120E00017
A120E00021
Clutch spring compressor
(Refer to the “DRIVE PULLEY, DRIVE BELT AND DRIVEN PULLEY” section in the chapter
8.)
Valve adjuster
(Refer to the “VA LV E CLEARANCE”sectioninthe
chapter 3.)
A120E00034
A120E00036
(Cont’d)
-12-
Page 15
1. GENERAL INFORMATION
SPECIAL TOOLS
Tool Name Tool No.
Bearing puller A120E00037
Valve spring compressor
DOWNTOWN 125i
Illustration
(Note: the special tools may differ
slightly from those shown in the figure of this manual.)
(Refer to the “CYLINDER
HEAD” section in the chapter 6.)
Lock nut wrench
(Refer to the “STEERING STEM” section in the chapter 15.)
Lock nut wrench
(Refer to the “STEERING STEM” section in the chapter 15.)
Bottom Ball Race
Remove
Cone Race Remove
(Refer to the “STEERING STEM” section in the chapter 15.)
special tool/ Top Ball
special tool
A120E00040
A120F00023
A120F00002
A120F00009
Bottom Ball Race
Install
Top Ball Cone Race
Install
(Refer to the “STEERING STEM” section in the chapter 15.)
-13-
special tool
special tool
A120F00019
1-13
Page 16
1. GENERAL INFORMATION
LUBRICATION POINTS
ENGINE
Lubrication Points Lubricant
DOWNTOWN 125i
Valve guide/valve stem movable part Cam lobes Valve rocker arm friction surface Cam chain Cylinder lock bolt and nut Piston surroundings and piston ring grooves Piston pin surroundings Cylinder inside wall Connecting rod/piston pin hole Connecting rod big end Crankshaft R/L side oil seal Starter reduction gear engaging part Countershaft gear engaging part Final gear engaging part Bearing movable part O-ring face Oil seal lip
Genuine KYMCO Engine Oil (SAE15W-40) API , SJ Engine Oil
Starter idle gear
Friction spring movable part/shaft movable part
Shaft movable grooved part
A.C. generator connector
Transmission case breather tube
High-temperature resistant grease
Adhesive
1-14
-14-
Page 17
2
. EXHAUST MUFFLER/FRAME COVERS
DOWNTOWN 125i
2
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
2
EXHAUST MUFFLER/FRAME COVERS
__________________________________________________________________________________
SERVICE INFORMATION------------------------------------------------ 2- 1 TROUBLESHOOTING----------------------------------------------------- 2- 1 FASTENER REMOVAL AND REINSTALLATION------------------ 2- 2 FRAME COVERS REMOVAL/INSTALLATION--------------------- 2- 3 EXHAUST MUFFLER ----------------------------------------------------- 2-14
2-0
Page 18
2
. EXHAUST MUFFLER/FRAME COVERS
DOWNTOWN 125i
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• When removing frame covers, use care not to pull them by force because the cover joint claws may be damaged.
• Make sure to route cables and harnesses according to the Cable & Harness Routing.
TORQUE VALUES
Exhaust muffler pipe nuts 1.8~2.2 kgf-m Exhaust muffler brake /RR Frok 3.2~3.8 kgf-m
RR/Engine case 3.0~4.0 kgf-m
TROUBLESHOOTING
Noisy exhaust muffler
• Damaged exhaust muffler
• Exhaust muffler joint air leaks
Lack of power
• Caved exhaust muffler
• Clogged exhaust muffler
• Exhaust muffler air leaks
2-1
Page 19
2
. EXHAUST MUFFLER/FRAME COVERS
FASTENER REMOVAL AND REINSTALLATION
REMOVAL
Depress the head of fastener center piece {. Pull out the fastener.
INSTALLATION
Let the center piece stick out toward the head so that the pawls | close.
Insert the fastener into the installation hole.
DOWNTOWN 125i
＊
To prevent the pawl | from damage, insert the fastener all the way into the installation hole
Push in the head of center piece until it becomes flush with the fastener outside face.
2-2
Page 20
2
r
. EXHAUST MUFFLER/FRAME COVERS
FRAME COVERS REMOVAL/ INSTALLATION
SEAT
Unlock the seat with the ignition key. Open the seat.
Remove the two nuts and the seat.
Installation is in the reverse order of removal.
DOWNTOWN 125i
LUGGAGE BOX
Unlock the seat with the ignition key. Open the seat.
Remove four bolts, and the fastener on the right side of luggage box, then lift luggage box.
Disconnect the luggage box light connector, then remove the luggage box.
Installation is in the reverse order of removal.
Luggage Box Light Connecto
2-3
Page 21
2
r
. EXHAUST MUFFLER/FRAME COVERS
DOWNTOWN 125i
CENTER COVER
Remove the luggage box.
Remove the center cover.
＊
During removal, do not pull the joint claws forcedly to avoid damage.
Installation is in the reverse order of removal.
Center Cove
Remove four bolts and , then remove the rear carrier.
2-4
Page 22
2
. EXHAUST MUFFLER/FRAME COVERS
Installation is in the reverse order of removal.
DOWNTOWN 125i
UPPER/LOWER HANDLEBAR COVER
Remove the four screws. then remove upper handlebar cover.
Remove the four screws, then remove the bottom handlebar cover.
Disconnect the throttle cable refer to the “THROTTLE BODY /TPS” section , then pull the throttle cable out from the lower cover. Remove the lower cover.
Installation is in the reverse order of removal.
2-5
Page 23
2
. EXHAUST MUFFLER/FRAME COVERS
WINDSHIELD/WINDSHIELD GARNISH
Remove five bolts and windshield garnish.
DOWNTOWN 125i
2-6
Page 24
2
. EXHAUST MUFFLER/FRAME COVERS
FRONT CENTER COVER
Remove the windshield Remove four screws, then remove the front
center cover. Remove the front cover.
Installation is in the reverse order of removal.
FRONT COVER
Remove the small front cover(black) screw
DOWNTOWN 125i
Remove the small front cover(black) Remove two nuts.
Remove eight screws from the inner cover. Remove the front cover
2-7
Page 25
2
. EXHAUST MUFFLER/FRAME COVERS
Disconnect the headlight/position light connect and right/left turn signal light connectors.
Installation is in the reverse order of removal.
FRONT FENDER
DOWNTOWN 125i
Remove four screws. screws and front fender. Installation is in the reverse order of removal.
RIGHT/LEFT FOOT SKIRT
Remove the six screws attaching to the right or left skirt.
＊
During removal, do not pull the joint claws forcedly to avoid damage.
Installation is in the reverse order of removal.
2-8
Page 26
2
. EXHAUST MUFFLER/FRAME COVERS
DOWNTOWN 125i
FRONT LOWER COVER
Remove the front cover Remove the foot skirt
Remove seven screws and front lower cover.
Installation is in the reverse order of removal.
REAR FENDER
Remove the body cover and then the rear fender .
Installation is in the reverse order of removal.
BODY COVER
Remove the rear center cover. Remove the right and left foot skirts
Remove the rear carrier.
Remove six screws and two nuts then remove the body cover.
2-9
Page 27
2
r
. EXHAUST MUFFLER/FRAME COVERS
DOWNTOWN 125i
Disconnect the taillight connector.
Installation is in the reverse order of removal.
TIRE FENDER
Remove the body cover .
Remove four bolts attaching to the tire fender
Taillight Connecto
Installation is in the reverse order of removal.
FLOORBOARD
Remove the body cover Remove the right /left skirt
Remove two screws.
2-10
Page 28
2
. EXHAUST MUFFLER/FRAME COVERS
Remove eight bolts, then remove the floorboard.
DOWNTOWN 125i
UNDER COVER
Remove four bolts Remove the under cover.
2-11
Page 29
2
. EXHAUST MUFFLER/FRAME COVERS
Remove the fuel tank cap cover.
Installation is in the reverse order of removal.
Speedometer Wires
METER PANEL
DOWNTOWN 125i
Disconnect the speedometer wires. Disconnect the DC power connectors.
Remove one screws Remove the ignition key garnish Remove three screws from the inner cover,
then remove the handler panel.
Installation is in the reverse order of removal.
DC power Connectors
2-12
Page 30
2
. EXHAUST MUFFLER/FRAME COVERS
INNER COVER
Remove the front cover . Remove the front lower cover . Remove the floorboard
Remove four bolts and front glove box one screw.
DOWNTOWN 125i
(1)
Remove two fastener bolts then remove the fuel tank fill cap. Remove the inner cover
(3)
(4)
(2)
(2)
(5)
2-13
(6)
Page 31
2
. EXHAUST MUFFLER/FRAME COVERS
EXHAUST MUFFLER
REMOVAL
Disconnect the O2 heater/O2 sensor connector .
Remove the two exhaust pipe joint nuts
DOWNTOWN 125i
Remove three muffler mount bolts and muffler and gasket.
2-14
Page 32
2
t
. EXHAUST MUFFLER/FRAME COVERS
INSTALLATION
Replace the gasket with a new one. Install the exhaust muffler and three
mounting bolt.
Install and tighten the two exhaust pipe joint nuts to the specified torque
Torque: 20 N•m (2 kgf•m,)
Tighten the three mounting bolts
DOWNTOWN 125i
Torque: 35 N•m (3.5 kgf•m,)
Remove the coolant tank cover.
Gaske
2-15
Page 33
3
. INSPECTION/ADJUSTMENT
DOWNTOWN 125i
3
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
INSPECTION/ADJUSTMENT
3
__________________________________________________________________________________
SERVICE INFORMATION------------------------------------------------ 3- 1 MAINTENANCE SCHEDULE-------------------------------------------- 3- 2 FUEL LINE------------------------------------------------------------------- 3- 4 THROTTLE OPERATION------------------------------------------------- 3- 4 ENGINE OIL ----------------------------------------------------------------- 3- 5 TRANSMISSION OIL ------------------------------------------------------ 3-11 AIR CLEANER -------------------------------------------------------------- 3-12 SPARK PLUG---------------------------------------------------------------- 3-13 VALVE CLEARANCE ----------------------------------------------------- 3-14 IDLE SPEED ----------------------------------------------------------------- 3-15 CYLINDER COMPRESSION --------------------------------------------- 3-16 DRIVE BELT ---------------------------------------------------------------- 3-16 CLUTCH SHOE WEAR---------------------------------------------------- 3-17 HEADLIGHT AIM ---------------------------------------------------------- 3-17 COOLANT ------------------------------------------------------------------- 3-18 BRAKE FLUID -------------------------------------------------------------- 3-19 BRAKE PAD WEAR ------------------------------------------------------- 3-19 NUTS/BOLTS/FASTENERS ---------------------------------------------- 3-20 WHEELS/TIRES ------------------------------------------------------------ 3-20 SUSPENSION---------------------------------------------------------------- 3-21 SIDE STAND ---------------------------------------------------------------- 3-22
3-0
Page 34
3
g
y
. INSPECTION/ADJUSTMENT
DOWNTOWN 125i
SERVICE INFORMATION
GENERAL
！ WARNING
•Before running the engine, make sure that the working area is well-ventilated. Never run the en
ine in a closed area. The exhaust contains poisonous carbon
monoxide gas which may cause death to people.
•Gasoline is extremel
flammable and is explosive under some conditions. The working area must be well-ventilated and do not smoke or allow flames or sparks near the working area or fuel storage area.
SPECIFICATIONS
Throttle grip free play : 2～6 mm Spark plug : DINK 125: NGK: DPR7EA9
: DOWNTOWN125 i: NGK CR7E Spark plug gap : 0.6~0.7 mm Valve clearance : IN: 0.1 mm EX: 0.1 mm
Idle speed : 1850 rpm Cylinder compression : 15 kg/cm²
Engine oil capacity: At disassembly : 1.2L At change : 1.0L
Gear oil capacity : At disassembly : 0.13L At change : 0.12L Coolant capacity : Reserve tank capacity: 0.49 liter Radiator capacity : 0.87 liter Ignition timing : ECU control
TIRE
1 Rider (75 kg) 2 Riders (150 kg)
Front 2.0 kgf/cm² 2.00 kgf/cm²
Rear 2.25 kgf/cm² 2.25 kgf/cm²
TIRE SPECIFICATION: Front :120/80-14
Rear : 150/70-13
3-1
Page 35
3
. INSPECTION/ADJUSTMENT
TORQUE VALUES
Front axle : 2.0 kgf-m Rear axle nut : 12 kgf-m
DOWNTOWN 125i
MAINTENANCE SCHEDULE
Perform the pre-ride inspection at each scheduled maintenance period. This interval should be judged by odometer reading or months, whichever comes first. I: INSPECT AND CLEAN, ADJUST, LUBRICATE OR REPLACE IF NECESSARY C: CLEAN R: REPLACE A: ADJUST L: LUBRICATE The following maintenance schedule specifies all maintenance required to keep your scooter in
peak operating condition. Maintenance work should be performed in accordance with standards and specifications of KYMCO by properly trained and equipped technicians. Your KYMCO dealer meets all of these requirements.
＊Should be serviced by your KYMCO dealer, unless the owner has the proper tools and service
data and is mechanically qualified.
＊＊In the interest of safety, we recommend these items be serviced only by your KYMCO dealer.
KYMCO recommends that your KYMCO dealer should road test your scooter after each periodic maintenance is carried out.
3-2
Page 36
3
. INSPECTION/ADJUSTMENT
MAINTENANCE SCHEDULE
DOWNTOWN 125i
FREQUENCY
ITEM MONTH
AIR CLEANER
THROTTLE OPERATION VALVE CLEARANCE FUEL LINE CRANKCASE BREATHER ENGINE OIL
ENGINE OIL FILTER ENGINE IDLE SPEED
TRANSMISSION OIL DRIVE BELT
OIL STRAINER SCREEN
WHICHEVER COMES FIRST
X 1000 km X 1000 mi
ODOMET E R READING
5
1
0.6 1
C
RRRR
10 15 20 25 30
36
I I
I I
RRR
RRR
I
912
126
R
I
I
IIII
AAA
I
CCCCCC
CC
RRR
III
I
I
R R
II
I
15 18 302418
36
RR
RRR
RRRSPARK PLUGS
RI
I
RRRR
I
II
REFER
TO
PAGE
FREQUENCY
ITEM
CLUTCH SHOE WEAR BRAKE FLUID BRAKE PAD WEAR BRAKE SYS T EM BRAKE LIG HT SW ITCH
STEERING BEARINGS HEADLIGHT AIM NUTS, BOLTS, FASTENERS WHEELS/TIRES
WHICHEVER COMES FIRST
X 1000 km X 1000 mi
NOTE MONTH
ODOMETER READING [NOTE (1)]
5
1
0.6 3 6 9 12 15 18 1
10 15 20 25 30
126
I
I
III
I
R
IIII II IIIIII
IIIIII IIIIII
IIIIII III
302418
36
II
R
I
R
II I
III
REFER
TO
PAGE
3-3
Page 37
3
. INSPECTION/ADJUSTMENT
FUEL LINE
Check the fuel lines and replace any parts which show signs of deterioration, damage or leakage.
THROTTLE OPERATION
DOWNTOWN 125i
Check the throttle grip for smooth movement. Measure the throttle grip free play.
Free Play: 2～6 mm
Major adjustment of the throttle grip free play is made with the adjusting nut at the throttle body side. Adjust by loosening the lock nut and turning the adjusting nut.
3-4
Page 38
3
S
. INSPECTION/ADJUSTMENT
Minor adjustment is made with the adjusting nut at the throttle grip side. Slide the rubber cover (1) out and adjust by loosening the lock nut (3) and turning the adjusting nut (2).
(Chart)
ENGINE OIL VIS C OSITIE
20W-40 , 20W-50
20W-40, 20W-50
15W-40 , 15W-50
15W-40, 15W-50
10W-40
10W-40
10W-30
10W-30
20W-40 , 20W-50
5W-50
-10 0 10 20 30 40 C
0 20 40 60 80 100 F
0
0
ENGINE OIL
DOWNTOWN 125i
Engine oil recommendation
Use a premium quality 4-stroke motor oil to ensure longer service life of your scooter. Use only oils which are rated, SJ under the API service classification. The recommended viscosity is SAE 15W-40. If a SAE 15W-40 motor oil is not available, select an alternative according to the chart.
Engine oil capacity:
At disassembly:
1.2 L (0.968 lmp qt, 1.166 US qt)
At change:
1.0 L
Engine oil level check
2. Stop the engine and put the scooter on its center stand on level ground.
3. After a few minutes, remove the oil filler cap/dipstick, wipe it clean, and reinsert the oil filler cap/dipstick without screwing it in. Remove the oil filler cap/dipstick. The oil level should be between the upper and lower marks on the oil filler cap/dipstick.
4. If required, add the specified oil up to the upper level mark. Do not overfill.
5. Reinstall the oil filler cap/dipstick. Check for oil leaks.
＊
Let the engine and exhaust system cool before working in those areas.
Check the engine oil level each day before riding the scooter.
The level must be maintained between the upper and lower level marks on the oil filler cap/dipstick.
1. Start the engine and let it idle for a few minutes.
3-5
Page 39
3
. INSPECTION/ADJUSTMENT
Engine oil replacement
Engine oil quality is the chief factor affecting engine service life. Change the engine oil as specified in the maintenance schedule.
When running in very dusty conditions, oil changes should be performed more frequently than specified in the maintenance schedule.
Please dispose of used engine oil in a manner that is compatible with the environment. We suggest you take it in a sealed container to your local recycling center or service station for reclamation. Do not throw it in the trash or pour it on the ground or down a drain.
Used engine oil may cause skin cancer if repeatedly left in contact with the skin for prolonged periods. Although this is unlikely unless you handle used oil on a daily basis, it is still advisable to thoroughly wash your hands with soap and water as soon as possible after handling used oil.
DOWNTOWN 125i
Change the engine oil with the engine at normal operating temperature and the scooter on its center stand to assure complete and rapid draining.
3-6
Page 40
3
. INSPECTION/ADJUSTMENT
1. Remove the oil filler cap/dipstick(1) from the right crankcase cover.
2. Place a container under the left crankcase.
3. Remove the oil drain plug (2) to drain the oil.
4. Reinstall the drain plug and tighten the drain plug to specification.
Oil drain plug torque:
25 N-m (2.5 kgf-m,)
5. Fill the crankcase with the recommended grade oil and install the oil filler cap.
Oil capacity (after draining):
1.0 L(0.95 US qt, 0.8 lmp qt)
6. Start the engine and let it idle for 2－3 minutes.
7. Stop the engine and check that the oil level is at the upper level mark on the oil filler cap/dipstick with the scooter upright on firm, level ground. Make sure there are no oil leaks.
DOWNTOWN 125i
(1)
＊
Let the engine and exhaust system cool before working in those areas.
(2)
3-7
Page 41
3
. INSPECTION/ADJUSTMENT
Oil strainer screen clean
Change the engine oil with the engine at normal operating temperature and the scooter on its center stand to assure complete and rapid draining.
＊
Let the engine and exhaust system cool before working in those areas.
1. Remove the oil filler cap/dipstick (1) from the right crankcase cover.
2. Place a drain pan under the crankcase and remove the oil strainer screen cap (2). The spring (3) and oil strainer screen (4) will come out when the drain plug is removed. Let the engine oil drain out.
3. Clean the oil strainer screen.
4. Check that the oil strainer screen, sealing rubber and drain plug O-ring are in good condition.
5. Install the oil strainer screen, spring and oil strainer screen cap.
DOWNTOWN 125i
(1)
Oil strainer screen cap torque:
15N-m (1.5 kgf-m)
6. Fill the crankcase with the recommended grade oil and install the oil strainer screen cap.
Oil capacity (after draining):
1.0 L
7. Start the engine and let it idle for 2－3 minutes.
8. Stop the engine and check that the oil level is at the upper level mark on the oil filler cap/dipstick with the scooter upright on firm, level ground. Make sure there are no oil leaks.
3-8
Page 42
3
. INSPECTION/ADJUSTMENT
Oil filter replacement
Change the engine oil with the engine at normal operating temperature and the scooter on its center stand to assure complete and rapid draining.
＊
Let the engine and exhaust system cool before working in those areas.
1. Remove the oil filler cap/dipstick (1) from the right crankcase cover.
2. Place a drain pan under the crankcase. Remove three bolts and then remove the oil filter cap (2) and O-ring (3). The spring (4) will come out when the filter cap is removed. Let the engine oil drain out.
DOWNTOWN 125i
(1)
3. Remove and discard the oil filter (5).
＊
Do not remain the rubber seal on the oil filter in the oil filter housing.
4. Check that the O-ring is in good condition.
(2)
3-9
Page 43
3
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. INSPECTION/ADJUSTMENT
5. Install the new oil filter.
＊
Make sure the rubber seal on the oil filte facing the left crankcase.
6. Install the spring, O-ring and cap.
Torque:
12 N-m (1.2 kgf-m)
DOWNTOWN 125i
Rubber Seal
7. Fill the crankcase with the recommended grade oil and install the oil filler cap.
Oil capacity (after draining):
1.0 L
8. Start the engine and let it idle for 2－3 minutes.
9. Stop the engine and check that the oil level is at the upper level mark on the oil filler cap/dipstick with the scooter upright on firm, level ground. Make sure there are no oil leaks.
3-10
Page 44
3
. INSPECTION/ADJUSTMENT
TRANSMISSION OIL
Oil change
1. Place the scooter in its center stand.
2. Place a drain pan under the drain bolt (1).
3. Remove the transmission oil drain bolt.
4. Remove the transmission oil filler bolt (2), slowly turn the rear wheel and drain the oil. After draining the oil completely, install the oil drain bolt with a new sealing washer and tighten it.
Torque: 13 N-m (1.3 kgf-m)
DOWNTOWN 125i
(1)
5. Fill the transmission case with recommended oil.
Recommended transmission oil: SAE 90
Oil capacity (at draining):
0.12 L
6. Install the transmission oil filler bolt with a new sealing washer and tighten it.
Torque: 13 N-m (1.3 kgf-m)
(2)
3-11
Page 45
3
. INSPECTION/ADJUSTMENT
AIR CLEANER
The air cleaner should be serviced at regular intervals. Service more frequently when riding in unusually wet or dusty areas.
Air cleaner element replacement
1. Remove the screws from the air cleaner cover , then remove air cleaner cover.
2. Remove screws from the air cleaner element , then remove and discard this air cleaner element.
4. The new air cleaner element installation is in the reverse order of removal.
DOWNTOWN 125i
Use the KYMCO genuine air cleaner element or an equivalent air cleaner element specified for your model. Using the wrong KYMCO air cleaner element or a non-KYMCO air cleaner element which is not of equivalent quality may cause premature engine wear or performance problems.
1. Remove the band (1).
3-12
Page 46
3
k
. INSPECTION/ADJUSTMENT
SPARK PLUG
Remove the spark plug cap and spark plug Check the spark plug for wear and fouling deposits. Clean any fouling deposits with a spark plug cleaner or a wire brush.
Specified Spark Plug:
NGK CR7E
Measure the spark plug gap.
Spark Plug Gap: 0.6~0.7 mm
DOWNTOWN 125i
Cracks Damage
Deformation
＊
When installing, first screw in the spar plug by hand and then tighten it with a spark plug wrench.
Torque: 0.9 kgf-m (9 N-m)
Gap Wear Fouling Deposits
｝
0.6~0.7mm
3-13
Page 47
3
. INSPECTION/ADJUSTMENT
VALVE CLEARANCE
＊
• Inspect and adjust valve clearance
while the engine is cold (below 35℃).
Remove the four bolts , then remove cylinder head cover.
Remove the timing hole cap and O-ring Remove the crankshaft hole cap and O-ring .
DOWNTOWN 125i
Timing hole cap
Turn the A.C. generator flywheel to the top dead center (TDC) on the compression stroke so that the “T” mark on the flywheel aligns with the index mark on the left crankcase cover.
The punch mark on the camshaft should face upward as shown.
If the punch mark on the camshaft are facing downward, turn the crankshaft one full turn (180°) and the punch mark are facing upward.
Crankshaft hole cap
Punch Mark
3-14
Page 48
3
. INSPECTION/ADJUSTMENT
Adjust by loosening the valve adjusting screw lock-nut and turning the adjusting screw until there is a slight drag on the thickness gauge .
Valve Clearance: IN: 0.1 mm
EX:0.1 mm
Apply oil to the valve adjusting screw lock­nut threads and seating surface.
Hold the adjusting screw and tighten the lock nut to the specified torque.
Torque: 0.9 kgf-m (9 N-m)
Special tool:
Valve adjuster A120E00036
DOWNTOWN 125i
After tightening the lock-nut, recheck the valve clearance.
Install the removed parts in the reverse order of removal.
IDLE SPEED
＊
● It is not necessary to adjust idle speed
for DOWNTOWN125i. The throttle
body is factory preset originally, do not loosen or tighten the painted bolts and screws of throttle body. Loosening or tightening them can cause throttle a idle and valve with failure.
Warm up the engine before this operation. Start the engine and connect a tachometer.
Turn the throttle stop screw (1) to obtain the specified idle speed.
Idle Speed:
DINK 125: 1700 rpm
DOWNTOWN125i: 1850 rpm
When the engine misses or run erratic, adjust the pilot screw (2).
3-15
Page 49
3
. INSPECTION/ADJUSTMENT
CYLINDER COMPRESSION
Warm up the engine before compression test. Remove the center cover and spark plug cap. Remove the spark plug . Insert a compression gauge. Open the throttle valve fully and push the starter button to test the compression.
Compression: Downtown125i:15 kg/cm²
If the compression is low, check for the following:
‧Leaky valves ‧Valve clearance too small ‧Leaking cylinder head gasket ‧Worn pistons ‧Worn piston/cylinder
If the compression is high, it indicates that carbon deposits have accumulated on the combustion chamber and the piston head.
DOWNTOWN 125i
DRIVE BELT
Remove the left crankcase cover. Inspect the drive belt for cracks or excessive wear. Replace the drive belt with a new
one if necessary and in accordance with the Maintenance Schedule.
3-16
Page 50
3
. INSPECTION/ADJUSTMENT
CLUTCH SHOE WEAR
Start the engine and check the clutch operation by increasing the engine speed gradually. If the scooter tends to creep, or the engine stalls, check the clutch shoes for wear and
replace if necessary (refer to the “DRIVE
PULLEY, DRIVE BELT AND DRIVEN PULLEY” section in the chapter 8).
DOWNTOWN 125i
HEADLIGHT AIM
Remove the front cover Place the scooter on a level surface Adjust the headlight beam adjuster. A clockwise rotation moves the beam up
and counterclockwise rotation moves the beam down.
Adjust the headlight beam horizontally by turning the horizontal beam adjuster.
A clockwise rotation moves the beam toward the right side of the rider.
Horizontally Adjusting Screw
Vertically Adjusting Screw
3-17
Page 51
3
. INSPECTION/ADJUSTMENT
COOLANT
Inspection
The reserve tank is under left foot board. Check the coolant level through the inspection window (1) at the front lower cover while the engine is at the normal operating temperature with the scooter in an upright position. If the coolant level is below the LOWER level mark (3), remove screw (4) and reserve tank lid (5) and reserve tank cap (6) and add coolant mixture until it reaches the upper level mark (2). Always add coolant to the reserve tank. Do not attempt to add coolant by removing the radiator cap. If the reserve tank is empty, or if coolant loss is excessive, check for leaks and see your KYMCO dealer for repair.
DOWNTOWN 125i
3-18
Page 52
3
. INSPECTION/ADJUSTMENT
BRAKE FLUID
Brake fluid level
With the scooter in an upright position, check the front and rear fluid level. It should be above the lower level mark. If the level is at or below the lower level mark "L", check the brake pads for wear. Worn pads should be replaced. If the pads are not worn, have your brake system inspected for leaks.
The recommended brake fluid is DOT 4
brake fluid from a sealed container, or an equivalent.
Other checks
Make sure there are no fluid leaks. Check for deterioration or cracks in the hoses and fittings.
DOWNTOWN 125i
Front brake
BRAKE PAD WEAR
Brake pad wear depends upon the severity of usage, the type of riding, and road conditions. (Generally, the pads will wear faster on wet and dirty roads.) Inspect the pads at each regular maintenance interval.
Front brake /Rear brake
Check the cutout in each pad. If either pad is worn to the cutout, replace
both pads as a set. See your KYMCO dealer for this service.
Rear brake
3-19
Page 53
3
. INSPECTION/ADJUSTMENT
NUTS/BOLTS/FASTENERS
Check all important chassis nuts and bolts for looseness. Tighten them to their specified torque values if any looseness is found.
WHEELS/TIRES
Tire pressure
Insufficient air pressure in the tires not only hastens tire wear but also seriously affects the stability of the scooter. Under inflated tires make smooth cornering difficult and overinflated tires decrease the amount of tire in contact with the ground which can lead to skids and loss of control. Be sure that the tire pressure is within the specified limits at all times. Tire pressure should only be adjusted when the tires are cold.
DOWNTOWN 125i
Cold inflation tire pressure
1 Rider (75 kg) 2 Riders (150 kg)
2.0kg/cm² 2.25 kg/cm²
Front
2.0kg/cm² 2.25 kg/cm²
Rear
3-20
Page 54
3
. INSPECTION/ADJUSTMENT
SUSPENSION
Check the action of the front/rear shock absorbers by compressing them several times. Check the entire shock absorber assembly for oil leaks, looseness or damage. Jack the rear wheel off the ground and move the rear wheel sideways with force to see if the engine hanger bushings are worn. Replace the engine hanger bushings if there is any looseness.
DOWNTOWN 125i
Rear suspension adjustment
3-21
Page 55
3
. INSPECTION/ADJUSTMENT
SIDE STAND
Perform the following maintenance in accordance with the maintenance schedule.
Functional check
Check the spring for damage or loss of tension and the side stand assembly for freedom of movement.
Check the side stand ignition cut-off system:
DOWNTOWN 125i
1. Place the scooter on its center stand.
2. Put the side stand up and start the engine.
3. Lower the side stand. The engine should stop as you put the side stand down.
If the side stand system does not operate as described, see your KYMCO dealer for service.
Side stand up
Side stand down
3-22
Page 56
4
. LUBRICATION SYSTEM
DOWNTOWN 125i
4
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
4
LUBRICATION SYSTEM
__________________________________________________________________________________
LUBRICATION SYSTEM DIAGRAM---------------------------------- 4-1 SERVICE INFORMATION------------------------------------------------ 4-2 TROUBLESHOOTING----------------------------------------------------- 4-2 OIL PUMP ------------------------------------------------------------------- 4-3
4-0
Page 57
4
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. LUBRICATION SYSTEM
LUBRICATION SYSTEM DIAGRAM
Rocker Arm Shaft
DOWNTOWN 125i
4-1
Crankshaft
Oil Straine Screen
Oil Pump
Oil Filter Screen
Page 58
4
. LUBRICATION SYSTEM
DOWNTOWN 125i
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• The maintenance of lubrication system can be performed with the engine installed in the frame.
• Drain the coolant before starting any operations.
• Be careful when removing and installing the oil pump not to allow dust and foreign matters to
enter the engine and oil line.
• Do not attempt to disassemble the oil pump. The oil pump must be replaced as a set when it
reaches its service limit.
• After the oil pump is installed, check each part for oil leaks.
SPECIFICATIONS Unit: mm
Standard Inner rotor-to-outer rotor clearance 0.15 Outer rotor-to-pump body clearance 0.15～0.2 Rotor end-to-pump body clearance 0.04～0.09
ENGINE OIL
Engine Oil Capacity
Recommended Oil SAE15W40 API: SJ
At disassembly: 1.2 liter At change: 1.0 liter
TROUBLESHOOTING
Oil level too low Poor lubrication pressure
• Natural oil consumption • Oil level too low
• Oil leaks • Clogged oil filter or oil passage
• Worn piston rings • Faulty oil pump
• Worn valve guide
• Worn valve guide seal
Oil contamination
• Oil not changed often enough
• Faulty cylinder head gasket
• Loose cylinder head bolts
4-2
Page 59
4
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. LUBRICATION SYSTEM
OIL PUMP
DOWNTOWN 125i
REMOVAL
Remove the flywheel and driven gear (refer to the “STARTER CLUTCH” section in the chapter 10).
Remove the bolt and then oil separator cover.
＊
When removing and installing the oil pump, be careful not to allow dust or dirt to enter the engine.
Pry the snap ring off and remove the oil pump driven gear, then remove the oil pump drive chain.
Bolts
Oil Separator Cove
Remove the two oil separator bolts to remove the oil pump.
4-3
Snap Ring
Oil Separator Bol
Oil Pump Driven Gea
Oil Pump
Page 60
4
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. LUBRICATION SYSTEM
DOWNTOWN 125i
INSTALLATION
Install the oil pump and oil separator and tighten the two bolts. The arrow mark must be keep upward.
＊
Make sure the pump shaft rotates freely and arrow on the oil pump is upside.
Install the pump drive chain and driven gear, then set the snap ring securely on the pump shaft.
Arrow Mark
Oil Separato
Pump Drive Chain Snap Ring
Bolts
Snap Ring
Install the oil separator cover properly.
＊
Fit the tab of the separator cover into the slit in the separator.
Pump Driven Gea
Oil Se
arator Cove
Bol
4-4
Page 61
4
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. LUBRICATION SYSTEM
DISASSEMBLY
Remove the screw and disassemble the oil pump as shown.
Pump Cove
DOWNTOWN 125i
Outer Roto
Screw
ASSEMBLY
Inner Roto
Pump Body
Dowel Pin
Pump Shaf
Install the outer rotor, inner rotor and pump shaft into the pump body.
＊
Insert the pump shaft by aligning the flat on the shaft with the flat in the inner rotor. Install the dowel pin.
There is one punch mark on the surface of the inner rotor and outer rotor.
The mark is upside.
4-5
Dowel Pin
Outer Roto
Inner Roto
Pump Body
Pump Shaf
Page 62
5
. ENGINE REMOVAL/INSTALLATION
DOWNTOWN 125i
5
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
5
ENGINE REMOVAL/INSTALLATION
__________________________________________________________________________________
SERVICE INFORMATION------------------------------------------------ 5-1 ENGINE REMOVAL/INSTALLATION--------------------------------- 5-2 ENGINE HANGER --------------------------------------------------------- 5-8
5-0
Page 63
5. ENGINE REMOVAL/INSTALLATION
DOWNTOWN 125i
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• A floor jack or other adjustable support is required to support and maneuver the engine. Be careful not to damage the scooter body, cables and wires during engine removal.
• Use shop towels to protect the scooter body during engine removal.
• Drain the coolant before removing the engine.
• After the engine is installed, fill the cooling system with coolant and be sure to bleed air from the
water jacket. Start the engine to check for coolant leaks.
• Before removing the engine, the rear brake caliper must be removed first. Be careful not to bend or twist the brake fluid tube.
SPECIFICATIONS
Engine oil capacity: at disassembly: 1.2 L ( 1.27 US qt)
: at change: 1.0 L ( 1.06 US qt)
Coolant capacity:
Radiator capacity : 0.87 liter Reserve tank capacity : 0.49 liter
TORQUE VALUES
Engine hanger (Engine side) 5 kgf-m (50 N-m) Engine hanger (Frame side) 6.5 kgf-m (65 N-m)
5-1
Page 64
5
. ENGINE REMOVAL/INSTALLATION
ENGINE REMOVAL/INSTALLATION
REMOVAL
Remove the air cleaner
Disconnect the ECU connector (A)
Disconnect the O2 heater/O2 sensor connector
Disconnect the throttle cable(B)
DOWNTOWN 125i
(A)
＊
Remove a bolt from fuel hose guide (C). Disconnect the fuel hose (D) from fuel injector. Disconnect the WTS connector (E) from WTS. Disconnect the coolant temperature sensor connector (F) from coolant temperature sensor. Disconnect the fuel injector connector(G) Disconnect the output water hose(H) Disconnect the air bleed hose(I)
(B)
(G)
(C) (D) (E) (F)
(I)
(H)
5-2
Page 65
5. ENGINE REMOVAL/INSTALLATION
Loosen the rear axle nut. Support the scooter securely on its main stand.
Remove three bolts (1) attaching to rear brake hose clamps. Remove the two bolts (2), then remove the rear brake caliper.
DOWNTOWN 125i
(1)(2)
Disconnect the alternator connector (3). Disconnect the ignition pulse generator
connector (4).
Release the rubber cap and remove the terminal screw (5) to disconnect the start motor cable from the start motor.
(4) (3)
(5)
5-3
Page 66
5
. ENGINE REMOVAL/INSTALLATION
Remove the bolts and engine ground cable.
DOWNTOWN 125i
Remove the two nuts (7), then remove the intake manifold from cylinder head.
Remove the bolt (8), then remove the thermostat from cylinder head.
Remove the spark plug cap .
5-4
Page 67
5. ENGINE REMOVAL/INSTALLATION
Disconnect the lower radiator hose from lower radiator pipe.
DOWNTOWN 125i
Remove the right and left rear shock absorber lower mount bolts .
5-5
Page 68
5
. ENGINE REMOVAL/INSTALLATION
Remove the engine mount nut Pull out the engine mount bolt.
Remove the engine from the frame.
DOWNTOWN 125i
＊
At removing the engine, be careful not to catch your hand or finger between the engine hanger and crankcase.
5-6
Page 69
5. ENGINE REMOVAL/INSTALLATION
INSTALLATION
Installation is in the reverse order of removal.
Tighten the engine mounting bolt/nut to the specified torque.
Torque: 5 kgf-m (50 N-m)
Tighten the right and left rear shock absorber lower mount bolts to the specified torque.
Torque: 4.0kgf-m (40N-m)
Install the rear brake caliper and tighten the mount bolts to the specified torque.
Torque: 3.2 kgf-m (32 N-m, 23 lbf-ft)
DOWNTOWN 125i
After installation, inspect and adjust the following:
• Throttle grip free play
• Fill the cooling system with coolant and
start the engine to bleed air from the system.
API/ABV Reset(Refer to chapter14 page 17)
5-7
Page 70
5
. ENGINE REMOVAL/INSTALLATION
ENGINE HANGER
REMOVAL
Remove the engine mount nut . Pull the engine mount bolt out.
＊
Be careful to put the engine down.
Remove the left engine hanger mount bolt . Remove the right engine hanger mount bolt
and collar . Remove the engine from frame.
INSTALLATION
Installation is in the reverse order of removal.
DOWNTOWN 125i
Tighten the engine hanger mount bolts to the specified torque.(engine side)
Torque: 5 kgf-m (50 N-m)
Tighten the engine mount bolt/nut to the specified torque. (frame side)
Torque: 5 kgf-m (50 N-m, 36 lbf-ft)
5-8
Page 71
6
. CYLINDER HEAD/VALVES
DOWNTOWN 125i
6 .
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
CYLINDER HEAD/VALVES
__________________________________________________________________________________
SCHEMATIC DRAWING ------------------------------------------------- 6- 1 SERVICE INFORMATION------------------------------------------------ 6- 2 TROUBLESHOOTING----------------------------------------------------- 6- 3 CYLINDER HEAD COVER----------------------------------------------- 6- 4 CAMSHAFT HOLDER----------------------------------------------------- 6- 5 CAMSHAFT ----------------------------------------------------------------- 6- 8 CYLINDER HEAD---------------------------------------------------------- 6- 13
6
6-0
Page 72
6
. CYLINDER HEAD/VALVES
SCHEMATIC DRAWING
DOWNTOWN 125i
6-1
Page 73
6
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. CYLINDER HEAD/VALVES
DOWNTOWN 125i
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• The cylinder head can be serviced with the engine installed in the frame. Coolant in the radiator and water jacket must be drained first.
• When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable parts and valve arm sliding surfaces for initial lubrication.
• The valve rocker arms are lubricated by engine oil through the cylinder head engine oil passages. Clean and unclog the oil passages before assembling the cylinder head.
• After disassembly, clean the removed parts and dry them with compressed air before inspection.
• After removal, mark and arrange the removed parts in order. When assembling, install them in
the reverse order of removal.
SPECIFICATIONS
Ite
Valve clearance (cold)
Cylinder head compression pressure
Cylinder head warpage ⎯
Camshaft cam height EX 25.810 Valve rocker arm I.D.
Valve rocker arm shaft IN 9.972~9.987 O.D. EX 9.972~9.987
Valve stem O.D. Valve guide I.D.
Valve stem-to-guide IN 0.010~0.037 clearance EX 0.030~0.057
IN 0.1
EX 0.1
15kg/cm²
IN 25.965 IN 10.0~10.015
EX 10.0~10.015
IN 4.975~4.970
EX 4.975~4.970
IN 5.0~5.012
EX 5.0~5.012
Standar
Unit: mm
TORQUE VALUES
Cylinder head cover bolt 0.8~0.9 kgf-m Tensioner mounting bolt 0.9 kgf-m Tensioner sealing bolt 0.9 kgf-m
Cylinder head cap nut 2 kgf-m
Cylinder head bolt 0.7~1.1 kgf-m
Apply engine oil to threads
6-2
Page 74
6
. CYLINDER HEAD/VALVES
SPECIAL TOOLS
Valve spring compressor A120E00040
DOWNTOWN 125i
TROUBLESHOOTING
• The poor cylinder head operation can be diagnosed by a compression test or by tracing engine
Poor performance at idle speed White smoke from exhaust muffler
• Compression too low • Worn valve stem or valve guide
• Damaged valve stem oil seal
Compression too low
• Incorrect valve clearance adjustment Abnormal noise
• Burned or bend valves • Incorrect valve clearance adjustment
• Incorrect valve timing • Sticking valve or broken valve spring
• Broken valve spring • Damaged or worn camshaft
• Poor valve and seat contact • Worn cam chain tensioner
• Leaking cylinder head gasket • Worn camshaft and rocker arm
• Warped or cracked cylinder head
• Poorly installed spark plug
Compression too high
• Excessive carbon build-up in combustion chamber
6-3
Page 75
6
. CYLINDER HEAD/VALVES
CYLINDER HEAD COVER
REMOVAL
Remove four bolts then remove the cylinder head cover.
DOWNTOWN 125i
INSTALLATION
Install a new cylinder head cover O-ring and install the cylinder head cover.
＊
Be sure to install the O-ring into the groove properly.
Install and tighten the cylinder head cover bolts to the specified torque in a crisscross pattern.
Torque: 0.8~0.9kgf-m
6-4
Page 76
6
. CYLINDER HEAD/VALVES
CAMSHAFT HOLDER
REMOVAL
Turn the A.C. generator flywheel so that the T mark on the flywheel aligns with the index mark on the crankcase.
Hold the round hole on the camshaft gear facing up and location is the top dead center
on the compression stroke. Remove two bolts attaching cam chain
tensioner. Remove four nuts of camshaft holder and
remove the sprocket fixed nut then remove the sprocket.
DOWNTOWN 125i
Remove the camshaft gear bolt.
INSTALLATION
Install the camshaft gear bolt and holder washers and nuts. Tighten four cylinder head nuts to the specified torque.
Torque:
0.7~1.1 kgf-m (Holder nuts)
1.0~1.4 kgf-m (Cam shaft set plate)
1.8~2.2 kgf-m (Cylinder head M8X1.25)
＊
• Install the camshaft holder with the “EX” mark face exhaust valve side.
• Apply engine oil to the threads of the cylinder head cap nuts.
• Diagonally tighten the cylinder head nuts in 2～3 times.
6-5
Page 77
6
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. CYLINDER HEAD/VALVES
DISASSEMBLY
Take out the valve rocker arm shafts Remove the valve rocker arms.
INSPECTION
DOWNTOWN 125i
Rocker Arm Shafts
Camshaft Holde
Inspect the camshaft holder, valve rocker arms and rocker arm shafts for wear or damage.
＊
If the valve rocker arm contact surface is worn, check each cam lobe for wear or damage.
Inspect the rocker arm bore, cam lobe contact surface and adjuster surface for wear/pitting/scratches/blue discoloration.
Rocker Arm Shafts
Rocker Arm Bore
If any defects are found, replace the rocker arm shaft with a new one, then inspect lubrication system.
Contact SurfaceAdjuster Surface
6-6
Page 78
6
m
. CYLINDER HEAD/VALVES
ASSEMBLY
Apply engine oil to the rocker arms and rocker arm shafts.
Install the rocker arms and shafts into the camshaft holder.
• Install the exhaust valve rocker ar shaft on the “EX” side of the camshaft holder
• Clean the intake valve rocker arm shaft off any grease before installation.
DOWNTOWN 125i
Rocker Arm Shafts
6-7
Page 79
6
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. CYLINDER HEAD/VALVES
CAMSHAFT
REMOVAL
Turn the A.C. generator flywheel so that the “T” mark on the flywheel aligns with the index mark on the crankcase. Hold the round hole on the camshaft gear facing up and the location is the top dead center on the compression stroke.
Remove the tensioner sealing bolt and spring. Remove the two bolts from cam chain tensioner and then remove the tensioner and gasket.
DOWNTOWN 125i
Tensioner Sealing Bol
Round Hole
Remove the camshaft gear and bolt.
Remove the camshaft from the cylinder head
Camshaf
6-8
Page 80
6
. CYLINDER HEAD/VALVES
INSPECTION
Camshaft
Inspect camshaft lobes for pitting/scratches/blue discoloration.
If any defects are found, replace the camshaft with a new one, then inspect lubrication system.
DOWNTOWN 125i
Camshaft Bearings
Check each camshaft bearing for play or damage. Replace the camshaft assembly with a new one if the bearings are noisy or have excessive play.
6-9
Page 81
6
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. CYLINDER HEAD/VALVES
DOWNTOWN 125i
INSTALLATION
Turn the A.C. generator flywheel so that the “T” mark on the flywheel aligns with the index mark on the crankcase. Keep the round hole on the camshaft gear facing up and align the punch marks on the camshaft gear with the cylinder head surface (Position the intake and exhaust cam lobes down.) and install the cam chain onto the camshaft gear.
Install the rocker arms shafts fixed bolt .
Punch Marks
Round Hole
Cam shaf
Install the camshaft gear
Bol
Camshaft Gea
6-10
Page 82
6
r
. CYLINDER HEAD/VALVES
DOWNTOWN 125i
DISASSEMBLY
Remove the valve spring cotters, retainers, springs, spring seats, oil seals and valves using a valve spring compressor.
＊
• Be sure to compress the valve springs with a valve spring compressor.
• Mark all disassembled parts to ensure correct reassembly.
Special tool:
Valve Spring Compressor A120E00040
Valve Spring Compresso
Valves
6-11
Page 83
6
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. CYLINDER HEAD/VALVES
INSPECTION
DOWNTOWN 125i
Remove carbon deposits from the exhaust port and combustion chamber.
＊
Be careful not to damage the cylinde head mating surface.
Valve /Valve guide
Inspect each valve for bending, burning, scratches or abnormal stem wear. If any defects are found, replace the valve with a new one.
Service limits:
IN: 0.08 mm
EX: 0.1 mm
Combustion Chambe
Exhaust Por
＊
If the stem-to-guide clearance exceeds the service limits, replace the cylinder head is necessary.
Valve spring
Measure the free length of the inner and outer valve springs.
6-12
Page 84
6
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. CYLINDER HEAD/VALVES
Cylinder head
Check the spark plug hole and valve areas for cracks.
Check the cylinder head for warpage with a straight edge and feeler gauge.
Service Limit: 0.05 mm
ASSEMBLY
Install the valve spring seats and oil seal.
＊
Be sure to install the new oil seals.
DOWNTOWN 125i
Valve Spring Compresso
Lubricate each valve with engine oil and insert the valves into the valve guides.
Install the valve springs and retainers. Compress the valve springs using the valve spring compressor, then install the valve cotters.
• When assembling, a valve spring compressor must be used.
Special tool:
Valve Spring Compressor A120E00040
Tap the valve stems gently with a plastic hammer for 2～3 times to firmly seat the cotters.
＊
Be careful not to damage the valves.
Plastic Hamme
6-13
Cylinder Head
Page 85
7
. CYLINDER/PISTON
DOWNTOWN 125i
7
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
CYLINDER/PISTON
__________________________________________________________________________________
SCHEMATIC DRAWING ------------------------------------------------- 7-1
SERVICE INFORMATION------------------------------------------------ 7-2
TROUBLESHOOTING----------------------------------------------------- 7-3
CYLINDER AND PISTON ------------------------------------------------ 7-4
7
7-0
Page 86
7
. CYLINDER/PISTON
SCHEMATIC DRAWING
DOWNTOWN 125i
7-1
Page 87
7
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. CYLINDER/PISTON
DOWNTOWN 125i
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• When installing the cylinder, use a new cylinder gasket and make sure that the dowel pins are correctly installed.
• After disassembly, clean the removed parts and dry them with compressed air before inspection.
SPECIFICATIONS
Ite
I.D.
Cylinder
Piston, piston ring
Piston pin O.D
Piston-to-piston pin clearance
Connecting rod small end I.D. bore
Warpage
Cylindricity
True roundness
Ring-to-groove Top clearance
Ring end gap Second
Piston O.D.
Piston O.D. measuring position
Piston-to-cylinder clearance
Piston pin hole I.D.
Second
Top
Oil side rail
Unit: mm
Standar
52.4～52.41
⎯
⎯
⎯
0.015～0.055
0.015～0.055
0.10～0..25
0.10～0..25
0.2～0.7
52.37～52.39
9 mm from bottom of skirt
0.01～0.04
15.002～15.008
14.994～15
0.002～0.014
15.016～15.034
7-2
Page 88
7
. CYLINDER/PISTON
DOWNTOWN 125i
TROUBLESHOOTING
• When hard starting or poor performance at low speed occurs, check the crankcase breather for white smoke. If white smoke is found, it means that the piston rings are worn, stuck or broken.
Compression too low or uneven compression Excessive smoke from exhaust muffler
• Worn or damaged cylinder and piston rings • Worn or damaged piston rings
• Worn, stuck or broken piston rings • Worn or damaged cylinder and piston
Compression too high Abnormal noisy piston
• Excessive carbon build-up in combustion • Worn cylinder, piston and piston rings chamber or on piston head • Worn piston pin hole and piston pin
• Incorrectly installed piston
7-3
Page 89
7
. CYLINDER/PISTON
CYLINDER AND PISTON
REMOVAL
Remove the cylinder head (refer to
“CYLINDER HEAD” section in the chapter
6).
Remove the water hose attached the cylinder.
Remove the two cylinder bolts/washers (2).
Remove the cylinder.
DOWNTOWN 125i
(4)
Remove the cylinder gasket (4) and dowel pins (3). Clean any gasket material onto the cylinder surface.
Remove the piston pin clip
＊
Place a clean shop towel in the crankcase to keep the piston pin clip from falling into the crankcase.
(3)
Press the piston pin out of the piston and remove the piston .
7-4
Page 90
7
. CYLINDER/PISTON
Spread each piston ring and remove it by lifting up at a point opposite the gap
＊
Do not damage the piston ring by spreading the ends too far.
Clean carbon deposits from the piston ring grooves.
INSPECTION
DOWNTOWN 125i
Piston ring
Inspect the piston rings for movement by rotating the rings. The rings should be able to move in their grooves without catching.
Push the ring until the outer surface of the piston ring is nearly flush with the piston and measure the ring-to-groove clearance.
Insert each piston ring into the bottom of the cylinder squarely.
＊
Use the piston head to push each piston ring into the cylinder.
Measure the piston ring end gap.
7-5
Page 91
7
m
. CYLINDER/PISTON
Piston/Piston pin
Measure the piston O.D. at the point (A) from the bottom and 90° to the piston pin hole.
10 m
(A)
DOWNTOWN 125i
Service Limit: 15.04 mm (0.6016 in)
Service Limit: 0.02 mm (0.0008 in)
7-6
Page 92
7
. CYLINDER/PISTON
Cylinder
Check the cylinder for warpage with a straight edge and feeler gauge in the directions shown.
Se
Check the cylinder wall for wear or damage. Measure and record the cylinder I.D. at three
levels in an X and Y axis. Take the maximum reading to determine the cylinder wear.
DOWNTOWN 125i
TOP
Measure the piston-to-cylinder clearance. Take a maximum reading to determine the
clearance.
Measure the taper and out-of-round at three levels in an X and Y axis. Take the maximum reading to determine them.
Measure the connecting rod small end I.D.
vi
Measure the connecting rod-to-piston pin clearance.
MIDDLE
BOTTOM
7-7
Page 93
7
d
. CYLINDER/PISTON
Inspect the exhaust side and intake side chain guides.
Wear/Damage → Replace.
DOWNTOWN 125i
Intake Side Guide
Exhaust Side Guide
INSTALLATION
Piston ring
Carefully install the piston rings into the piston ring grooves with the markings facing up.
＊
Be careful not to damage the piston an rings.
Do not confuse the top and second rings.To install the oil ring, install the oil ring,
then install the side rails.
Stagger the piston ring end gaps 120° degrees apart from each other. Stagger the side rail end gaps as shown.
7-8
Page 94
7
. CYLINDER/PISTON
Cylinder/Piston
Clean any gasket material attached the cylinder mating surfaces of the crankcase and oil passage.
Apply engine oil to the piston pin. Apply engine oil to the connecting rod small
end and piston pin hole.
Install the piston with the “IN” mark face intake side and piston pin.
DOWNTOWN 125i
Place a clean shop towel over the crankcase prevent the clip from falling into the crankcase.
Install the new pin clip.
＊
Make sure that the piston pin clips are
seated securely.
Do not align the piston pin clip end gap
with the piston cut-out
Install the dowel pins and gasket.
Gasket
7-9
Dowel pins
Page 95
7
. CYLINDER/PISTON
Apply engine oil to the cylinder wall, piston and piston ring outer surfaces.
Pass the cam chain through the cylinder and install the cylinder over the piston.
＊
Be careful not to damage the piston rings and cylinder walls.
Install the cylinder head and camshaft holder
has installed (refer to the “CYLINDER HEAD” section in the chapter 6),
Connect the water hose .
DOWNTOWN 125i
7-10
Page 96
8
. DRIVE AND DRIVEN PULLEYS
DOWNTOWN 125i
8
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
DRIVE AND DRIVEN PULLEYS
__________________________________________________________________________________
SCHEMATIC DRAWING ------------------------------------------------- 8- 1
SERVICE INFORMATION------------------------------------------------ 8- 2
TROUBLESHOOTING----------------------------------------------------- 8- 3
LEFT CRANKCASE COVER --------------------------------------------- 8- 4
DRIVE PULLEY, DRIVE BELT AND DRIVEN PULLEY ---------- 8- 5
8
8-0
Page 97
8
. DRIVE AND DRIVEN PULLEYS
SCHEMATIC DRAWING
DOWNTOWN 125i
8-1
Page 98
8
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. DRIVE AND DRIVEN PULLEYS
DOWNTOWN 125i
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• The drive pulley, clutch and driven pulley can be serviced with the engine installed.
• Avoid getting grease and oil on the drive belt and pulley faces. Remove any oil or grease from
them to minimize the slipping of drive belt and drive pulley.
SPECIFICATIONS Unit: mm
Ite Movable drive face bushing I.D.
Drive face collar O.D.
Clutch outer I.D.
Driven face O.D.
Movable driven face I.D.
Weight roller O.D.
TORQUE VALUES
Drive face nut ( 5.5~6.5 kgf-m Clutch outer nut 5.0~6.0 kgf-m Clutch plate comp 5.0~6.0 kgf-m
SPECIAL TOOLS
Standar
24.011~24.052
23.960~23.974
130～130.2
33.965～33.985 34～34.025
17.920~18.080
Bearing installer A120E00014
Universal holder A120E00017
Clutch spring compressor A120E00034
8-2
Page 99
8
. DRIVE AND DRIVEN PULLEYS
TROUBLESHOOTING
Engine starts but motorcycle fail to move Lack of power
• Worn drive belt • Worn drive belt
• Broken ramp plate • Weak driven face spring
• Worn or damaged clutch lining • Worn weight roller
• Broken driven face spring • Faulty driven face
Engine stalls or motorcycle creeps
• Broken clutch weight spring
DOWNTOWN 125i
8-3
Page 100
8
. DRIVE AND DRIVEN PULLEYS
LEFT CRANKCASE COVER
REMOVAL
Remove ten left crankcase cover bolts and then remove the left crankcase cover. Remove the gasket and dowel pins.
DOWNTOWN 125i
INSTALLATION
Install the dowel pins and gasket.
Install the left crankcase cover.
Dowel Pins
Install and tighten ten bolts diagonally to specified torque.
8-4
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