Yingang YG48Q-5A User manual

YG48Q-5AMaintenance ManualForeword
1
Foreword
With the ever increasing varieties of motorcycles, new structures and new techniques have increasingly been applied.
To help YINGANG TECHNOLOGY Co., Ltd users and maintenance personnel better understand the maintenance,
adjustment and repair techniques of YG48Q-5A motorcycle, we prepared this maintenance manual. This manual is
expected to facilitate the YINGANG TECHNOLOGY Co., Ltd users and maintenance personnel and provide technical
guidance for them.
The masterstroke of the manual is the YG48Q-5Amotorcycle , and the contents in Chapter 1-Chapter 3 are applicable
to the adjustment of various parts of the motorcycle. Chapter 4-18 describes various constituting parts of the motorcycle
respectively. Chapter 19 contains the electrical system diagram.
The standard maintenance procedures, maintenance precautions and general maintenance knowledge are not
covered in this manual. Any user or maintenance personnel who needs the above information may refer to the related
materials
All materials, charts and various data, as well as performance indices referenced herein, are for the latest model in our
product family at the date this manual is printed. YINGANG TECHNOLOGY Co., Ltd. shall have the right to, at any time,
amend this manual without prior notice. The copyright of all parts of this manual belongs to China YINGANG
TECHNOLOGY Co., Ltd. and no units or individuals are allowed to reprint it the without consent of our company.
We hope you will enjoy the comfort and pleasure it brings to you during your driving!

YG48Q-5A Maintenance ManualContents
2
Contents
1. Overview
1-12
2. Lubrication system
13-23
3. Inspection and adjustment
24-39
4. Fuel system
40-45
5. Removal and installation of engine
46-50
6. Cylinder head, cylinder and piston
51-67
7. Clutch and Right crankcase cover
68-78
8. Magneto and starting system
79-87
9. Crankcase, crankshaft and Shift mechanism
88-104
10. Frame and exhaust system
105-109
11. Front wheel, front overhang and steering stem
110-121
12. Rear wheel and rear overhang
122-127
13. General remarks of electrical system
128
14. Power supply system
129-131
15. Starting system
132-134
16. Illumination signal system
135-140
17. Electrical starting control system
141-144
18. Engine management system
145-156
19. Electrical System Diagram
157
Engine
Vehicle body
Electrical system
Overview

YG48Q-5AMaintenanceManualOverview
1
1、Overview
Engine Number Position
Bar Tool
About Motorcycle Maintenance
Maintenance Period Table
Technical Data of Main Performance
Symbol Descriptions
Standard Torque Values
Engine Number Position
Photo of Complete Vehicle:
Frame Number Position:
Engine Number Position:
Engine Number
Frame Number

YG48Q-5AMaintenanceManualOverview
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Maintenance Precautions
1. Whenever reassembling after being disassembled,
replace new washers, sealing members, etc.
2. While fastening bolts or nuts, proceed in diagonal
crossing sequence to gradually screw down to the
required torque for 2 to 3 tries.
3. After being disassembled, the parts and
components should be cleaned before being
inspected and measured
To clean the spare parts, use only the cleaning
fluid that is incombustible or has high ignition point.
Before reassembling, apply the specified
lubricating oil to the sliding surface of the parts and
components.
After reassembling, check whether all the spare
parts are mounted properly by means of turning,
moving and operating them.
4. To disassemble and assemble a motorcycle,
special service tools (SST) and general-purpose
tools must be used in accordance with relevant
regulations.
5. The specified or equivalent lubricating grease (oil)
must be applied to or refilled into the specified
locations.
6. When 2 or more persons are carrying out the
operation, they shall work with each other and pay
attention to safety.
7. Before operating, always remove the negative (-)
end of the battery first and take care to prevent the
wrench or the like from touching the frame. After
operating, reconfirm all the connections, fixings
and junctions. If the battery is already removed,
connect the positive (+) end first.

YG48Q-5AMaintenanceManualOverview
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8. In case the fuse is blown, check for the causes and,
after being repaired, replace corresponding fuse
as per the specified capacity.
9. The caps must be securely put on the terminals
after the operation is complete
10. While disassembling a connector joints with lock,
release the lock before proceeding with operation.
While disassembling a connector joints, hold the
connector body without pulling the wire harness.
Before connecting the connector, the terminals shall be
free from breaking or bending. Make sure the terminals
are not too long or are falling off.
The connector shall be fully inserted in place.
For a connector with lock, confirm whether the lock is
completely fixed.
Make sure the harness is not falling off
Make sure the plastic jacket of the connector is securely
covering the connector without scaling off.
11. Before connecting a connector, make sure the
sleeve is not broken and the opening of the
intermediate terminal is not too large
The joint shall be fully inserted in place.
Make sure the plastic jacket is housing the terminal
completely. The opening of the plastic jacket shall not
face up.
12. The harness fixing strap shall firmly button the
specified position on the frame.
13. The clamp shall reliably bite the wire harness
Crackle

YG48Q-5AMaintenanceManualOverview
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In case of a welded clamp, it shall not bite the wire
harness towards the weld mark
The wire harness shall be clamped at the position
without contacting a rotating part or a removing element.
The wire harness shall be clamped at the position
without contacting a part that generates high
temperature.
The wire harness shall be clamped at the position
without contacting the edge or sharp corners of the
vehicle body.
The wire harness shall be incapable of passing through
the position contacting a bolt, a screw head or any front
part.
The wire harness shall not be slackened or be forcibly
pulled.
If the wire harness has to contact the edge or sharp
corner parts, the contacting part shall be protected with
hose or adhesive tape.
In case of a wire harness with garland, it shall be reliably
harnessed.
Do not damage the garnish of the wire harness.
Once the wire harness is damaged, repair it by coiling
with plastic adhesive tape.
While mounting parts and components, do not press the
wire harness.
Do not mount wire harness with it twisted.
14. When wiring, note when turning it leftwards or
rightwards to the limit position, the wire harness
shall not be tightened up or slackened, and make
sure there is no significant bending, pressing,
intervening of marginal parts.
Do not touch!
Do notpull!
Pay attention not to press it.

YG48Q-5AMaintenanceManualOverview
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15. While using the test table, operate according to the
maintenance manual after understanding the
explanations in the instruction manual.
16. Do not drop or throw the parts and components.
17. In case of rust on the terminals, carry out
connection operation after disposing it with
abrasive paper, etc.
18. Do not forcibly twist or forcefully bend the cable.
Because a deformed or damaged cable is the
cause of bad operation and damage.
Rust must be
eliminated!
Have you learned by heart the method
of application? Are the measurement
range and polarity in accordance with
the instruction manual?

YG48Q-5AMaintenanceManualOverview
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Technical Data of Main Performance
Item
Data
Dimension & Weight
Length
Width
Height
Wheelbase
Min. ground clearance
Complete vehicle weight
1780mm
775mm
1050mm
1230mm
165mm
Non-loaded weight: 107kg, Curb weight:157kg,
Vehicle body
Frame type
Rake angle
Front suspension device
Rear suspension device
Front Tire size
Rear Tire size
Front wheel pressure
Rear wheel pressure
Front brake
Rear brake
Fuel tank volume
Fuel grade
Cradle type
26°
spring & hydraulic composite damping
spring & hydraulic composite damping
120/70-12
120/70-12
Normally loaded: 225kPa,
Normally loaded: 225kPa,
Single disc type ModelΦ220
Single disc type ModelΦ190
11L
92#
Engine
Mode
Cylinder bore ×Stroke
Cylinder displacement
Compression ratio
Max. power
Max. torque
Valve clearance (cold)
Valve driving gear
Air filter
Cooling method
Lubrication method
Engine oil grade
Engine oil charge volume
Engine oil filter element
Electricmotor starting
Idle speed
Net weight of engine
Single-cylinder force air –cooling4-stroke engine
39.0mm ×40.0mm
47.8cc
8.8:1
2.2kw/7500rpm
2.5N.m/6000rpm
IN: (0.05)mm
EX: (0.05)mm
Chain drive
Oilpaper filter
force air-cooling
Please apply Shell 10W/40-SF engine oil in summer and 10W/30-SF in
winte
0.8L
Oilpaper filter
Electric / foot start
1500±150r/min
20±1kg

YG48Q-5AMaintenanceManualOverview
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Driving system
Clutch
Clutch operating system
Variable speed gear
Primary reduction ratio
Transmission gear ratio
Final reduction ratio
Gear shifting mode
Wet clutch, coil clutch, paper friction wafer
Manual mechanical
4-speed constant mesh
4.059
Ⅰ3.273
Ⅱ1.938
Ⅲ1.350
Ⅳ1.043
3.846
Left foot operated to and back type
Sequence: I－N－Ⅱ－Ⅲ－Ⅳ
Electrical system
Electric generator
Accumulator capacity
Power supply system
Fusible cutout
Spark plug
Spark plug gap
Ignition coil type
Fuel supply mode
Ignition mode
Ignition advance angle
Ignition timing
Front lamp
Turn lamp
Stop / Rear-position lamp
permanent magnet DC magneto
12V4A.h
DC power supply, and the electric generator is only used to recharge
the accumulator
10A
A7RTC
(0.6-0.7)mm
Open magnetic circuit
Breathe in naturally
CDI
15°
/
12V 35W/35W
Front: P1.5W 12V Rear: P1.5W 12V
12V 1/0.5WLED 0.5W 12V

YG48Q-5AMaintenanceManualOverview
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Standard Torque Values
ENGINE
Item
Quantity
Thread diameter
(mm)
Torque value (N.m)
Thread locker
Cylinder head cover connecting bolt
13
8
8～12
Cylinder bolt
4
10
40～50
2
6
8～12
Valve adjusting screw nut
4
10
8～12
Timing driven sprocket bolt
2
7
7～11
Rocker-arm shaft cover
2
14
24～28
Magneto flywheel fastening nut
1
12
38～45
LOCTITE 243
Clutch fastening nut
1
18
114～126
LOCTITE 243
Primary driving gear fastening nut
1
18
143～157
LOCTITE 243
Oil drain plug
1
12
28～32
Crankshaft, main-shaft bearing baffle screw
5
6
8～12
LOCTITE 648
Stud
1
6
8～12
Stud
4
10
40～50
Exhaust valve stud bolt
2
8
10～14
LOCTITE 243
Stator connecting bolt
3
6
8～12
LOCTITE 648
Stator leads pressure plate bolt
2
6
8～12
LOCTITE 648
Spark Plug
1
12
18～25
Pensioner plate fastening bolt
1
6
7～10
Vehicle body
Item
Quantity
Thread diameter
(mm)
Torque value (N.m)
Thread locker
Front wheel spindle
1
14
50～60
Front vibration damper plate
1
10
30～40
Real wheel spindle nut
1
16
60～90
Rear fork shaft nut
1
14
50～60
Engine hanging bolt
3
10
30～40
4
8
20～30
Steering handle set bolt
4
8
20～30
Front fork vertical pipe cap nut
1
22
60～90
Lower connection plate set bolt
2
10
30～40
Upper connection plate set bolt
2
6
8～12
Rear sprocket nut
6
8
20～30
LOCTITE 243
Brake disc fastening nut
8
8
20～30
LOCTITE 243
Speed signal panel screw
4
8
20～30
LOCTITE 243
Front brake caliper screw
2
8
20～30
LOCTITE 243
In addition to the torque values of the important parts as listed above, the torque values for other standard
fasteners are as follow:

YG48Q-5AMaintenanceManualOverview
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Name and dimensions
Torque value (N.m)
5mm bolt & nut
4.5 ～6
6mm bolt & nut
8 ～12
8mm bolt & nut
18 ～25
10mm bolt & nut
30 ～40
12mm bolt & nut
50 ～60
5mm Screw
3.5 ～5
6mm Screw
7 ～11
6mm spool bolt & nut
10 ～15
8mm spool bolt & nut
20 ～30
10mm spool bolt & nut
30 ～40
Bar Tool
Motorized gun: special power tool for mantling/
dismantling bolt and nut
Pawl socket: for mantling/dismantling oil filtering element
nut and clutch nut
A and B bolt socket: for mantling/dismantlingAand B
bolt and exhaust muffler bolt
Adaptor: electric special tool for cross,hexagon gun tip
Valve adjusting socket: for valve clearance adjustment
Socket: for mantling/dismantling nuts andbolts
Cutting plier, Nipper plier, expansion plier: for mantling/
dismantling flexible retainer
T-socket wrench

YG48Q-5AMaintenanceManualOverview
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Magnetic generator rotor puller: for dismantling
magnetic generator rotor
Rubber hammer, Iron hammer, Copper hammer
Feeler gauge: to measure the clearance of piston,
cylinder, valve, etc.
Micrometer: to measure the dimensions of piston, piston
pin, etc.
Dial gauge: to measure the wheel bouncing, cylinder
inner diameter, etc.
Cylinder barometer: to measure the cylinder pressure
Wrench: measure tighteness of ad bolt
Vernia caliper: measure size of rear wheel hub internal
diameter
Tire barometer: to measure the tire pressure

YG48Q-5AMaintenanceManualOverview
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Maintenance Period Table
Maintenance times
Maintenance Items
Period
Odometer km (Remark 2)
1000
k m
4,000
km
8,000
km
12,000
km
Remarks
* Fuel system passage
I
I
I
* Throttle operating system
I
I
I
I
* Throttle valve body
I
I
I
I
Air filter element
Remark 1
C
C
Replace every 12,000km driving
Spark Plug
I
I
Replace every 12000km driving
Engine lubricant oil
For a motorcycle, change every 1000km, and then change it every
2000km driving
Oil filter
R
Replace every 12,000km driving
* Tensioner
Remark 3
I
I
I
I
both intake and exhaust
Remark 3
I
Check every 4,000km driving
Clutch
I
I
I
I
* Driving chain
Proceed with I and L for every 500km driving
** Front and rear brake system
I
I
I
I
** Brake Pad
I
I
I
I
** Brake fluid
Change every 2 years
* Front and rear brake lamp
switch
I
I
I
I
* Accumulator
Monthly
I
I
I
I
* Suspension system
I
I
I
I
* Nut and bolt fastening
I
I
I
I
** Wheel & tire
I
I
I
I
** Steering column bearing
I
I
I
I
** Steering backstay cable
Inspect every 5000km driving and replace every 10000km driving
Maintenance shall be carried out to the motorcycle in a specified period. The meanings of various symbols in the list are
as follows: I:Carry out inspection, cleaning, adjustment, lubrication or replacement.
C: Cleaning. R: Replacement. A: Adjustment. L: Lubrication.
* This item is subject to maintenance by persons from YINGANG TECNOLOGY Service Station. If the user has
special service tools, maintenance accessories or maintenance ability, it can repair it by itself.
** To ensure safety, this item is only subject to maintenance by persons from YINGANG TECNOLOGY Service
Station.
Remarks:
①While driving in a dusty area, it shall be cleaned more often.
②When the odometer reads more than the given maximum value, its maintenance period shall still repeat as per the
mile interval as stipulated in the table.
③To ensure safety, the adjustment of timing chain and valve clearance shall only be carried out by persons from

YG48Q-5AMaintenanceManualOverview
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YINGANG TECNOLOGY Service Station.
Symbol Descriptions
Meanings of various symbols in this manual:
Each time reassembled after being removed and disassembled, it must be replaced with a new
one.
Use special service tools (SST)
Use general-purpose tools.
Tightening torque of 50 N.m.
Use suggested engine oil.
Use the mixtures of engine oil and molybdenum disulfide
Use thread locker.
Use sealant.
Use lithium base grease.
1
Measures to be prompted during operating, inspecting and
maintaining.
2
Special instructions or disposal measures given to prevent
motorcycle from being damaged.
3
Special instructions or measures given to avoid serious
damages or personal injuries.
Explanation
NOTICE:
WARNING:

YG48Q-5AMaintenance Manual Lubrication system
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2 、 Lubrication system
Maintenance notice
Inspection of lubricating oil
Troubleshooting
Replacement of lubricating oil
Lubricating Position of Complete Vehicle
Cleaning of Lubricating Oil Strainer
Lubrication of Control Lines
Cleaning and Replacement of Lubricating Oil Filter
Engine Lubrication System Diagram
Oil Pump
Maintenance notice
This section introduces the inspection and replacement method of engine lubricating oil as well as the cleaning method of
lubricating oil strainer and lubricating oil filter. It also introduces various lubricating positions of the complete vehicle of this
model.
As an important factor that influences the engine’s performance and life span, the lubricating oil must be selected as per
regulations; ordinary engine oil, gear oil, vegetable oil, etc. are not allowed to be used instead of it. This engine was filled
with gasoline engine oil of 10W/40EG grade when leaving factory for sale. If you want to use other lubricating oil, its
quality scale must reach Grade SG, and its viscosity shall be selected according to the accompanying diagram depending
upon region and air temperature changes. While replacing lubricating oil, fully discharge the original lubricating oil in the
crankcase and clean it up with washing kerosene, and then refill fresh lubricating oil as per regulations.
The lubricating oil inside the engine must be fully discharged before inspection and cleaning.
Technical specifications: Lubricating oil charge volume:0.8L
Oil pump flow rate: 8L/min (when engine speed is at 4000 rpm).
Tightening torque of oil drain plug(28-32)N.m
Selecting viscosity as per temperature conditions
Low temperature property
�Fuel economical efficiency
�Lubricating property under high temperature
High temperature property
�Low temperature starting property
�Noise reduction property under high temperature
WARNING:
Repeatedly contacting the engine lubricating oil
for a long period may cause skin cancer.
Although such possibility is small when you
deal with used engines oil every day, Care
must be taken to fully cleanse your hands with
soap and water after dealing with the used
engine oil. Children are strictly prohibited from
getting near to it.

YG48Q-5AMaintenance Manual Lubrication system
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Troubleshooting
●Lubricating oil contaminated
1. Fail to replace lubricating oil according to the
maintenance period table;
2. The pouring orifice thread is damaged thus causing
poor seal;
3. The piston ring is worn.
●Lubricating oil pressure low
1. The oil level is too low;
2. Oil through, orifice port or oil strainer is clogged;
3. Oil pumps failure.
Lubricating Position of Complete Vehicle
●Lubricating oil consumes too fast
1. There is leakage with the engine;
2. The piston ring is worn.
3. The inlet/exhaust valve guide is worn;
4. The oil shield is worn or damaged.
Among the positions shown in the above diagram, besides applying dedicated lubricating oil for chain to
the driving chain, apply lithium base grease to all other positions.
All lubricating oils not specified for use in this manual shall be ordinary common lubricating oil.
All sliding surfaces and cables not shown in this diagram shall be coated with lubricating oil or lubricating grease.
Lubrication of Control Lines
Regular lubrication shall be carried out to the clutch control line, throttle control line and steering cable. To do this, remove
the upper joining parts of all control lines, sufficiently lubricate and maintain their hoisting cables and all points of support
with lithium base grease.
Engine Lubrication System Diagram
Front wheel bearing
Rear wheel bearing
Engine lower hanging bolt
Rear fork shaft lever
Side stand shaft
Driving chain
Upper/lower retainers of vertical pipe

YG48Q-5AMaintenance Manual Lubrication system
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Crankshaft oil
through
Camshaft oil through
Oil pump
FILTER, OIL
Oil outlet
Oil injection port

YG48Q-5AMaintenance Manual Lubrication system
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Replacement of lubricating oil
While replacing lubricating oil, it shall be carried out before the engine has cooled down. This will ensure quick and
complete discharge of the engine oil inside the crankcase.
When replacing, unscrew the oil drain plug and discharge the waste engine oil, and then clean the oil drain plug, engine oil
strainer, engine oil filter, etc. Finally, insert the oil drain plug. Unscrew the oil filter plug and slowly refill 0.8L new engine oil
of the specified trademark into the crankcase, then insert the oil filter plug.
CAUTION
Application of engine oil of poor quality will have an impact on the functional performance and life span of the
motorcycle engine.
Cleaning of Lubricating Oil Strainer
It shall be carried out while replacing lubricating oil.
While cleaning, you should unscrew the oil drain plug to drain the waste engine oil, and flush the strainer with cleaning
agent; place the motorcycle side down to facilitate cleaning as required. Then insert the oil drain plug, and proceed with
the remaining steps according to the method of “Replacement of Lubricating Oil".
Waste engine oil flow into the oil collector
Lubricating oil draining

YG48Q-5AMaintenance Manual Lubrication system
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Cleaning and Replacement of Lubricating Oil Filter
Remove the engine oil filter cover to detach the engine oil filter element, clean the filter cover and filter element with
cleaning agent, and then mount the clean engine oil element. Replace with a new one as required.
Check for damage of the engine oil filter cover and its O-shaped sealing ring; replace with a new one as required.
Mount the engine oil filter cover and screw up the bolt to the specified torque.
Notice
Before the crankcase is refilled with fresh engine oil, the engine oil filter must be cleaned.
Oil Pump
In case of failure, the oil pump needs to be removed for repair or replacement.
This section includes the following contents:
Steps and illustration for oil pump removal;
Steps and illustration for oil pump installation;
Disassembly and assembly of oil pump, etc.
Steps for oil pump removal:
1. Remove the oil drain plug to drain the engine oil
inside the crankcase.
Flush the strainer with cleaning agent
Cleaning
Remove oil filter cover
Replacement of Filter
Cleaning of Strainer
BOLT

YG48Q-5AMaintenance Manual Lubrication system
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2. Loosen the right crankcase cover connecting bolts to
detach the right crankcase cover components.
3. Use the clutch push rod extractor to
remove the clutch push rod assembly; use the fixing
tool to prevent the clutch and the primary
driving gear from rotating; loosen the nut to remove
the clutch component,
4. Remove the oil pump。
Steps for oil pump installation:
The installation procedures are the removal procedures in reverse order. Pay attention to the following points during the
installation:
1、The spare parts shall be clean and intact；
2、Install clutch assembly, and the retaining nut M18shall be coated with thread retaining adhesive LOCTITE243;
Remove the oil pump