Suzuki GN125F User manual

GN125F
99500H3030DE001

DACHANGJIANG GROUP CO.,LTD.
DECEMBER, 2014
(The 1st Edition)
©COPYRIGHT DA 2014CHANGJIANG GROUP CO.,LTD.
FOREWORD
8
This manual contains an introductory description on the
SUZUKI and procedures for its inspec-
tion/service and overhaul of its main components. Other
information considered as generally known is not
included.
Read the GENERAL INFORMATION section to familia-
rize yourself with the motorcycle and its maintenance.
Use this section as well as other sections to use as a
guide for proper inspection and service.
This manual will help you know the motorcycle better so
that you can assure your customers of fast and reliable
service.
GN125F
This manual has been prepared on the basis of the
latest specifications at the time of publication. If
modifications have been made since then, differ-
ences may exist between the content of this manual
and the actual motorcycle.
Illustrations in this manual are used to show the
basic principles of operation and work procedures.
They may not represent the actual motorcycle
exactly in detail.
This manual is written for persons who have enough
knowledge, skills and tools, including special tools,
for servicing SUZUKI motorcycles. If you do not
have the proper knowledge and tools, ask your
authorized motorcycle dealer to help you.SUZUKI
*
*
*
WARNING
Improper repair may result in injury to the
mechanic and may render the motorcycle unsafe
for the rider and passenger.
CAUTION
Inexperienced mechanics or mechanics without
proper tools, not to able to properly perform the
services described in this manual.
GROUP INDEX
GENERAL INFORMATION
PERIODIC MAINTENANCE
ENGINE
ELECTRICAL
CHASSIS
FUEL AND LUBRICATION
1
2
3
4
5
6
7
SERVICING INFORMATION

COMPONENT PARTS AND WORK TO BE DONE
Under the name of each system or unit, is its exploded view. Work instruction and tightening torque,
lubricating points and locking points, are provided.
Example: Front wheel
1
2
3
4
5
6
7
A
8
B
N•m Kgf•m
18-28
36-52
1.8-2.8
3.6-5.2
Front axle shaft
Spacer
Dustcover
Washer
Front brake disc
Oil seal
Roller bearing
Spacer
ITEM
9
10
Front tire
Front wheel rim
Speedometer gear driver
Oil seal
HOW TO USE THIS MANUAL
TO LOCATE WHAT YOU ARE LOOKING FOR:
1.The text of this manual is divided into 7 sections.
2.The section titles are listed in the GROUP INDEX.
3.Holding the manual as shown as at the right will allow you to find
the first page of the section easily.
4.The contents are listed on the first page of each section to help
you find the item and page you need.
A
B
Speedometer gear box
Brake disc bolt
Front axle nut
11
12
13

SYMBOL
The following symbols are instructions and necessary information for maintenance.
Torque control required.
Data beside it indicates specified
torque.
Apply oil. Use engine oil unless
otherwise specified.
Apply MOLY PASTE
99000-25140
Apply or use the absorber oil
Apply THREAD LOCK “1342"
99000-32050
Apply THREAD LOCK “1303"
99000-32030
Apply or use the brake fluid
Measure voltage
Apply sealant “1215”
99000-31110
Apply sealant “1207B”
99000-31140 Measure continuity test range
Use special tool
OIL
Apply SUPER GREASE “A”
99000-25010
Measure in resistance
Apply THREAD LOCK “1360"
99000-32130
SYMBOL DEFINITION SYMBOL DEFINITION
The data of maintenance

WIRE COLOR
O/Bl
O/W
O/Y
R/B
R/Y
W/B
W/R
Y/G
Y/R
Y/W
Orange with Blue tracer
Orange with White tracer
Orange with Yellow tracer
Red with Black tracer
Red with Yellow tracer
White with Black tracer
White with Red tracer
Yellow with Green tracer
Yellow with Red tracer
Yellow with White tracer
.............
.............
.............
.............
.............
.............
.............
.............
.............
.............
B/Bl
B/Br
B/G
B/R
B/W
B/Y
Bl/W
Bl/Y
Br/Y
G/Y
O/B
Black with Blue tracer
Black with Brown tracer
Black with Green tracer
Black with Red tracer
Black with White tracer
Black with Yellow tracer
Blue with White tracer
Black with Yellow tracer
Brown with Yellow tracer
Green with Yellow tracer
Orange with Black tracer
.............
.............
.............
.............
.............
.............
.............
.............
.............
.............
.............
Black
Blue
Brown
Deep green
Green
.............
.............
.............
.............
.............
B
Bl
Br
Dg
G
Grown
Light blue
Light green
Orange
Pink
.............
.............
.............
.............
.............
Gr
Lbl
Lg
O
P
Red
Violet
White
Yellow
.............
.............
.............
.............
R
V
W
Y

GENERAL INFORMATION
1
CONTENTS
1
1-1
1-1
1-2
1-2
1-2
1-3
WARNING/CAUTION/NOTE
GENERAL PRECAUTIONS
SERIAL NUMBER LOCATION
FUEL AND OIL RECOMMENDATION
BREAK-IN PROCEDURE
SPECIFICATIONS

GENERAL INFORMATION
WARNING/CAUTION/NOTE
Indicates a potential hazard that could result in death or injury.
Indicates a potential hazard that could result in motorcycle damage.
NOTE:
Indicates special information to make maintenance easier or instructions clearer.
GENERAL PRECAUTION
WARNING
WARNING
Please read this manual and follow its instructions carefully. To emphasize special information, the
symbol and the words WARNING,CAUTION and NOTE have special meanings. Pay special attention to
the messages highlighted by these signal words.
Please note, however, that the warnings and the cautions contained in this manual cannot possibly cover
all potential hazards relating to the servicing, or lack of servicing of the motorcycle. In addition to the
WARNING and CAUTION stated, you must use good judgment and basic mechanical safety principles. If
you are unsure about how to perform a particular service operation, ask a more experienced technician for
advice.
Proper service and repair procedures are important for the safety of the service technician and the
safety and reliability of the motorcycle.
When 2 or more persons work together, pay attention to safety of each other.
When it is necessary to run the engine indoors, make sure that exhaust gas is forced outdoor.
When working with the toxic or flammable materials, make sure that the area you work in is well-
ventilated and that you follow all of the material manufacturer's instructions.
Never use gasoline as a cleaning solvent.
To avoid getting burned, do not touch the engine, engine oil or exhaust system during or for a while
after engine operation.
After servicing fuel, oil, exhaust or brake system, check all lines and fittings related to the system
for leakage.
1-1

1-2
GENERAL INFORMATION
NOTE:
If parts replacement is necessary, replace the parts with SUZUKI GENUINE PARTS or their
equivalent.
When removing parts that are to be reused, keep them arranged in an orderly manner so that they
may be reinstalled in the proper order and orientation.
Be sure to use special tools when instructed.
Make sure that all parts used in reassembly are clean, and also lubricated when specified.
When use of a certain type of lubricant, bond, or sealant is specified, be sure to use the specified
type.
When performing service to electrical parts, if the service procedures not require used of battery
power, disconnect the positive terminal.
When removing the battery, disconnect the negative cable first and then the positive cable.
When reconnecting the battery, connect the positive cable first and then the negative cable, and
replace the terminal cover on the positive terminal.
Tighten cylinder head and case bolts and nuts, beginning with larger diameter and ending with
smaller diameter, from inside to outside diagonally, to the specified tightening torque.
Whenever you remove oil seals, gaskets, packing, O-rings, locking washers, cotter pins, cir-clips,
and certain other parts as specified, be sure to replace them with new ones. Also, before installing
these new parts, be sure to remove any odd material from the mating surfaces.
Never reuse a circlip. When installing a new circlip, take care not to expend the end gap larger than
required to slip the circlip over the shaft. After installing a circlip, always ensure that it is completely
seated in its groove and securely fitted.
Do not use self-locking nuts a few times over.
Use a torque wrench to tighten fasteners to the torque values when specified. Wipe off grease or oil
if a thread is smeared with them.
After reassembly, check parts for tightness and operation.
To protect environment, do not unlawfully dispose of used motor oil and other fluids,
batteries and tires.
To protect earth's natural resources, properly dispose of used motorcycles and parts.
*
*

SERIAL NUMBER LOCATIONS
The frame serial number or V.I.N. (Vehicle
Identification Number) 1 is stamped on the right
side of the steering head pipe. The engine serial
number 2 is located on the left side of the
crankcase. These numbers are required
especially for registering the machine and
ordering spare parts.
FUEL AND OIL
RECOMMENDATIONS
FUEL
Use fuel with an octane number of 90-97
(Research method), preferably unleaded.
NOTE:
Unleaded fuel will extend spark plug life.
ENGINE OIL
Be sure that the motorcycle engine oil you use
comes under API classification of SF or SG and its
viscosity rating is SAE 10W-40. If SAE 10W-40
engine oil is not available, select the oil viscosity
according to the following chart:
SAE
20W/50
10W/50
10W/30
20W
10W
40
30
C
F
-20
-4
-10
14
0
32
10
50
20
68
30
86
40
104
Temp.
BREAK-IN PROCEDURE
During the manufacture only the best ossible
are used and all machined parts are
finished to a very high standard
allow the moving part to “BREAK-IN”
subjecting the engine to maximum stresses
s the care and restraint exercised during
its early life The general rules are as follows:
p
materials
, it is still necessary
to before
.The
future performance and reliability of the engine
depend on
.
GENERAL INFORMATION
The throttle must not be opened to the full during
the new motorcycle's break-in period. Throttle
opening should be limited to less than 3/4 of its
maximum, while violent acceleration should be
avoided.
Do not maintain constant engine gear and
speed for an extended time period during any
portion of the break-in. Try to vary the throttle
position. During the period of break-in, increase
the throttle opening properly to enable break-in
fully.
When engine is running at constant low speed
(low load), parts will wear rapidly leads to bad
brake-in.
1-2
ABSORBER OIL
SUZUKI ABSORBER OIL #32 OR EQUIVALENT
BRAKE FLUID
DOT4

GENERAL INFORMATION
1-3
SPECIFICATIONS
DIMENSIONS AND CURB WEIGHT
2 000 mm
815 mm
1 100 mm
1 300 mm
175 mm
113 kg
Overall length
Overall width
Overall height
Wheelbase
Ground clearance
Curb weight
ENGINE
Single cylinder, vertical, air-cooled, four stroke
1
57 mm
48.8 mm
124 ml
9.2:1
BS type
P
Wet sump
olyurethane foam element
Electric
Type
Number of cylinders
Bore
Stroke
Piston displacement
Compression ratio
Carburetor
Air cleaner
Starter system
Lubrication system
TRANSMISSION
Clutch
Transmission
Primary reduction ratio
Final reduction ratio
Gear ratios, Low
2nd
3rd
4th
Top
Drive chain
Wet multi-plate type
5-speed constant mesh
3.470
2.867
3.000
1.857
1.368
1.143
0.957
KMC 428H 116 links

GENERAL INFORMATION
1-4
ELECTRIC
Ignition type
Ignition timing
Spark plug
Battery
Fuse
Headlight
Tail light/brake light
Turn signal light
Position light
CDI
13° B.T.D.C below 2 000 r/min
NGK CR8E
12V 7Ah
15 A
12V, 35W/35W
12V, 5W/21W
12V, 10W
12V, 5W
CHASSIS
Front absorber
Rear absorber
Steering angle
Caster
Trail
Turning diameter
Front brake
Rear brake
Front tire size
Rear tire size
Front absorber stroke
Telescopic coil spring, oil damped
Swingarm type, 5 level adjustable coil spring oil damped
42°
°
,
27 50'
105 mm
4 200 mm
Disc brake
Drum brake
2.75-18 4PR
3.50-16 4PR
130 mm
CAPACITIES
Fuel tank
Reserve
Engine oil, oil change
with filter change
Overhaul
Front absorber oil (single)
10 L
2L
850 ml
950 ml
1 300 ml
168 ml
*The specifications subject to change without notice.

PERIODIC MAINTENANCE
PERIODIC MAINTENANCE
MAINTENANCE PROCEDURES
CONTENTS
2
2-1
2-3
2-3
2-4
2-5
2-5
2-5
2-6
2-7
2-7
2-8
2-8
2-8
2-9
2-9
2-9
2-10
2-11
2-14
2-14
2-14
2-15
2-15
2-17
2-18
BATTERY/FUSE
AIR FILTER
MUFFLER NUT AND BOLT
CYLINDER HEAD, CYLINDER BOLTS AND NUTS
VALVE CLEARANCE
SPARK PLUG
ENGINE OIL
ENGINE OIL FILTER
OIL SUMP FILTER
CLUTCH CABLE PLAY
CARBURETOR(IDLING)
THROTTLE CABLE PLAY
FUEL HOSE
FUEL STRAINER
DRIVE CHAIN
BRAKES
TIRES
STEERING
FRONT AND REAR ABSORBER
LIGHTING AND SIGNAL
CHASSIS AND ENGINE MOUNTING BOLTS AND NUTS
COMPRESSION PRESSURE INSPECTION
OIL PRESSURE INSPECTION

PERIODIC MAINTENANCE
2-1
PERIODIC MAINTENANCE
The chart below lists recommended intervals for all the required periodic service work necessary to keep
the motorcycle operating at peak performance and economy. Mileages are expressed in terms of kilometer
and time for your convenience.
NOTE:
More frequent servicing may be performed on motorcycles that are used under severe conditions.
PERIODIC MAINTENANCE CHART
Valve clearance (when cold)
Fuel hose
Engine oil
Oil sump filter
Inspect
Inspect
Inspect
2-3
2-5
2-9
2-9
2-7
Air cleaner 2-4
2-7
Spark plug Inspect Inspect 2-6
Replace every 10 000 km
Muffler bolts
2-5
Tighten Tighten
Clutch
2-8
Throttle cable clearance Inspect
2-8
Fuel strainer
Inspect 2-9
Inspect
Drive chain Inspect, clean and lubricate every 1 000 km 2-10
Tighten Tighten 2-5
Cylinder head and cylinder nuts
Clean every 3 000 km
Inspect Inspect 2- 51
Tire
Steering
Front and rear absorber
Chassis bolts and nuts
Inspect
Inspect
Inspect Inspect
Inspect
Inspect
Brakes Inspect Inspect
2-14
2-14
2-14
2-15
Inspect
Lighting and signal
Brake fluid
Brake fluid hose Inspect Inspect 2-11
Replace every 4 years
Replace every 4 years
Change every 2 years.
Brakes
Inspect Inspect
Clean
Inspect Inspect
Inspect
Interval
Item PAGE
Initial1 000 Every 5 000 Every 10 000
Month
Km
3612
Battery / Fuse
Carburetor
2-8
Inspect Inspect
Engine oil filter
Change Change
Replace Replace

PERIODIC MAINTENANCE
2-2
LUBRICATION CHART
Throttle cable
Throttle grip
Clutch cable
Drive chain
Tachometer cable
Brake cam shaft
Steering
Swing arm bearings
Initial and Every 5 000
Engine oil
Engine oil
Motor oil, every 1 000 km
Every 10 000
Grease
Grease
Grease every 2 years or 20 000 km.
Be careful not to apply too much grease to the brake cam shafts. If grease gets on the
linings, break slippage will result.
Interval
Item
Month
Km
612
Speedometer cable
Speedometer gear box
Grease
Grease
Lubricate exposed parts which are subject to rust, with either motor oil or grease whenever the
motorcycle has been operated under wet or rainy conditions. Before lubricating each part, clean
off any rusty spots and wipe off any grease, oil dirt or grime.
Brake pedal Grease or motor oil
Grease
CAUTION
WARNING

PERIODIC MAINTENANCE
2-3
MAINTENANCE PROCEDURES
BATTERY / FUSE
Inspect Initial 1 000 km and every 5 000 km
When installing the battery lead wires, fix the lead first
and lead last.
09900-28403 : Hydrometer
FUSE
BATTERY
The battery must be removed to check the electrolyte level
and specific gravity.
Remove the right frame cover.
Remove battery lead at the battery terminal.
Remove battery lead.
Remove battery from the chassis.
Check electrolyte for level and specific gravity. Add
distilled water, as necessary, to keep the surface of the
electrolyte above the LOWER level line but not above the
UPPER level line . For checking specific gravity, use a
hydrometer to determine the charged condition. An S.G.
reading of 1.28 (20 C) or under means that the battery
needs recharging off the machine: take it off and charge it
from a recharger. Charging the battery in place can lead to
failure of the regulator/rectifier.
O
To install the battery, reverse the procedure described above.
Make sure that the breather pipe is tightly secured and
undamaged, and is routed as shown in the figure.
The fuse locates on the belt of the battery. In case of engine
stop suddenly or opened circuit, the fuse must be inspected.
Standard specific gravity: 1.28 ± 0.01 at 20 C
O
This section describes the service procedures for each
section of Periodic Maintenance.
2
1
Breather pipe
Battery
CAUTION
Do not use a fuse of a different specification , or it will
incur negative effect to electric, fire and power loss of
engine which is very dangerous.
Do not use aluminum, iron wire or any other substitute for
the fuse. If the fuse blows frequently, it indicates the
electric system may has problem. Always investigate the
cause, correct it and then replace the fuse.
WARNING
1
2

PERIODIC MAINTENANCE
2-4
AIR CLEANER
Clean every 3 000 km
Do not twist or wring the element because it will tear
or the individual cells of the element will be damaged.
If driving under dusty condition clean the air cleaner
element more frequently.
,
Make sure the drain plug is fitted correctly after
cleaning
If driving under humidity condition clean the air
cleaner more frequently.
.
,
Non-flammable
Cleaning
Solvent
AB
C
D
Motor oil
If the air filter is clogged with dust, intake resistance will be
increased with a resultant decrease in output and an increase
in fuel consumption.
Remove the plug and drain water and oil at the periodic
maintenance interval.
Remove the left frame cover.
Remove the screws and take off the air filter cover.
Separate the polyurethane foam element form the element
frame.
Fill a washing pan of a proper size with nonflammable clean-
ing solvent. Immerse the element in the cleaning solvent and
wash it.
Squeeze the cleaning solvent out of the washed element by
pressing it between the palms of both hands.
Immerse the element in motor oil, and squeeze the oil out of
the element leaving it slightly wet with oil.
Check and clean the element in the following manner.
Reassemble the air cleaner in the reverse order of removal.
CAUTION
CAUTION

PERIODIC MAINTENANCE
2-5
MUFFLER BOLTS
Muffler bolt : 11~15 N•m
Inspect initial 1 000 km and tighten every 5 000 km
Inspect initial 1 000 km and every 5 000 km.
Cylinder head nut: 21~25 N•m
Tighten the muffler bolts to the specified torque.
Tighten four M10 nuts to the specified torque when the
engine is cold.
VALVE CLEARANCE
Inspect initial 1 000 km and every 5 000 km
Excessive valve clearance results in valve noise, insufficient
valve clearance results in valve damage and reduced power.
At the distances indicated above, check and adjust the valve
clearance to the following specification.
Remove the spark plug, and
valve inspection caps .
Remove the generator cover cap and rotate the generator
rotor with wrench anticlockwise until the line on the rotor is
aligned with the center(arrow mark) of hole on the crankcase
to set the piston at TDC fo the compression stroke.
valve timing inspection plug
CYLINDER HEAD AND CYLINDER NUTS
Cylinder nut: 8-12 N m•
Tighten the cylinder nut and to the specified torque.
T
1
1
23
1
CAUTION
Valve clearance shoukld be checked when the engine is
cold. Both the intake and exhaust valve must be
checked and adjusted when the piston is at TDC of the
compression stroke.

PERIODIC MAINTENANCE
2-6
09900 20803 Thickness gauge
11F14-017: Valve adjust spring
-:
VALVE CLEARANCE SPECIFICATIONS
Hook the valve rocker arm with the special tool, insert the
thickness gauge to the valve stem end and the adjusting
screw on the rocker arm.
If the clearance is off the specification, bring it into the
specified range by using the special tool.
Valve clearance (when cold)
IN.: 0.04-0.07 mm EX.: 0.13-0.18 mm
0.7-0.8 mm
SPARK PLUG
Inspect initial 1 000 km and every 5 000 km, replace
every 10 000 km.
TYPE
Hot type
Standard
Cold type
NGK
CR7E
CR8E
CR9E
Remove the carbon deposits with a wire of pin and adjust the
spark plug gap to 0.7-0.8 mm, measuring with a thickness
gauge.
When removing the carbon deposits, be sure to observe the
appearance of the plug, noting the color of the carbon
deposits. The color observed indicates whether the standard
plug is suitable or not. if the standard plug is apt to get wet, a
hotter plug should be used. If the standard plug is apt to
overheat (porcelain is whitish in appearance), replace with a
cooler one.
09900-20803: Thickness gauge
Spark plug gap: 0.7-0.8 mm

PERIODIC MAINTENANCE
2-7
ENGINE OIL
Change initial 1 000 km and every 3 000 km
Engine oil should be changed while the engine is hot.
Start up the engine and allow it to run for several minutes at
idling speed.
Shut down the engine and wait about two minute. Then check
the oil level in the oil level window. The motorcycle must be in
a level, upright position for accurate measurement. If the
level is below the “F” mark, add oil until the level reaches the
“F” mark.
Support the motorcycle by the center stand
Drain the oil by removing the drain plug and filler cap
/ gauge.
Tighten the drain plug and pour new engine oil through the oil
filler. The engine will hold about 1 000 ml of oil. Use of SF/SG
in API with an oil viscosity of SAW 10W-40.
.
engine
Required amount of engine oil:
Oil change: 850 ml
Oil filter change: 950 ml
Overhaul: 1 300 ml
⑤
ENGINE OIL FILTER
Clean initial 1 000 km and every 5 000 km
Replace the oil filter in the following manner:
Drain the engine oil by removing the drain plug.
Remove the two screws securing the filter cap.
Take off the cap , and pull out the filter .
Replace with the new engine oil filter.
Before installing on the filter, check to be sure that the O-
ring is properly installed.
Before putting on the filter cap make sure that spring
and o-rings are installed correctly.
Install the filter cap and tighten the screws securely.
Add the engine oil and inspect the engine oil level.
,
When reassembly the oil filter, make sure to check the
oil filter installed as shown in illustration.
If the filter is installed improperly, serious engine
damage may result.
4
1
CAUTION
5
1
32
1

PERIODIC MAINTENANCE
2-8
OIL SUMP FILTER
Clean every 10 000 km
Clean the sump filter to remove any foreign matter that may be
collected there. Inspect the screen to insure that it is free of
any sign of damage.
CLUTCH
Inspect initial 1 000 km and every 5 000 km.
4mm4mm
The clutch play should be 4 mm as measured at the clutch
lever holder before the clutch begins to disengage. If the play
in the clutch is incorrect, adjust it in the following way:
Loosen the lock nut and screw the adjuster on the
clutch lever holder all the way in.
Loosen clutch cable adjuster lock nut .
Turn the clutch cable adjuster in or out to acquire the
specified play.
Use the adjuster for minor adjustment.
Tighten lock nut while holding the adjuster in position.
CARBURETOR
Inspect initial 1 000 km and every 5 000 km
IDLING ADJUSTMENT
Make this adjustment when the engine is hot.
Excessive clutch cable play makes clutch dragging
easily lead to the damage or wear of the clutch and gear
shifting mechanism.
Stable carburetor performance is the basis requirement for
engine. The carburetor is pre-set at the factory for the best
carbureting. Do not attempt to alter its setting. There are two
items of adjustment, engine idle speed and throttle cable play.
Start up the motorcycle, maintain the low engine speed until
the motorcycle is preheated fully.
After preheating set its speed at anywhere between 1 400
and 1 600 r/min by turning adjust screw.
,
Engine idle speed: 1500±100 r/min
CAUTION
12
3
4
2
CAUTION