HYOSUNG MS3 250 User manual

ELECTRICAL SYSTEM
COOLING SYSTEM
GROUP INDEX
GENERAL INFORMATION 1
PERIODIC MAINTENANCE 2
ENGINE 3
FI SYSTEM DIAGNOSIS 4
FUEL SYSTEM AND THROTTLE BODY 5
6
7
CHASSIS 8
SERVICING INFORMATION 9
COPYRIGHT S&T Motors Co., Ltd.
FOREWORD
This manual contains an introductory description on
HYOSUNG and procedures
for its inspection/service and overhaul of its main
components.
Other information considered as generally kno n is
not included.
Read GENERAL INFORMATION section to familiar-
ize yourself ith outline of the vehicle and MAINTE-
NANCE and other sections to use as a guide for
proper inspection and service.
This manual ill help you kno the vehicle better so
that you can assure your customers of your optimum
and quick service.
WARNING
This manual is intended for those who have
enough knowledge and skills for servicing
YOSUNG vehicles. Without such knowledge and
skills, you should not attempt servicing by relying
on this manual only.
Instead, please contact your nearby authorized
YOSUNG motorcycle dealer.
This manual has been prepared on the basis of
the latest specification at the time of publica-
tion.
If modification has been made since then,
difference may exist between the content of
this manual and the actual vehicle.
Illustrations in this manual are used to show
the basic principles of operation and work pro-
cedures.
They may not represent the actual vehicle
exactly in detail.

OW TO USE T IS MANUAL
TO LOCATE W AT YOU ARE LOOKING FOR :
1. The text of this manua is divided into sections.
2. As the tit e of these sections is isted on the previous page as
GROUP INDEX, se ect the section where you are ooking for.
3. Ho ding the manua as shown at the right wi a ow you to find
the first page of the section easi y.
4. On the first page of each section, its contents are isted. Find
the item and page you need.
COMPONENT PARTS
Example : Front wheel

SYMBOL
Listed in the tab e be ow are the symbo s indicating instructions and other information necessary for servicing and
meaning associated with them respective y.
App y THREAD LOCK 1324.
App y or use brake f uid.
Measure in vo tage range.
Measure in resistance range.
Measure in current range.
Use specia too .
Use engine coo ant.
Torque contro required.
Data beside it indicates specified torque.
App y oi .
Use engine oi un ess otherwise specified.
App y SUPER GREASE A.
App y SILICONE GREASE.
App y MOLY PASTE.
App y BOND 1215.
Use fork oi .
DEFINITIONSYMBOL DEFINITIONSYMBOL
App y SUPER GREASE C.
Measure in continuity test range.

A
ABDC : After Bottom Dead Center
AC : A ternating Current
API : American Petro eum Institute
ATDC : After Top Dead Center
B
BBDC : Before Bottom Dead Center
BDC : Bettom Dead Center
BTDC : Before Top Dead Center
D
DC : Direct Current
DOHC : Doub e Over Head Camshaft
E
ECU : Engine Contro Unit,
FI Contro Unit
F
FI : Fue Injection, Fue Injector
FP : Fue Pump
I
IAP Sensor : Intake Air Pressure Sensor
(IAPS)
IAT Sensor : Intake Air Temperature Sensor
(IATS)
IG : Ignition
ISC So enoid : Id e Speed Contro So enoid
L
LCD : Liquid Crysta Disp ay
LED : Light Emitting Diode
LH : Left Hand
M
Max : Maximum
Min : Minimum
O
O2Sensor : Oxygen Sensor (O2S)
R
RH : Right Hand
S
SAE : Society of Automotive Engineers
SAV So enoid : Secondary Air Va ve So enoid
T
TDC : Top Dead Center
TO Sensor : Tip Over Sensor (TOS)
TP Sensor : Thrott e Position Sensor (TPS)
W
WT Sensor : Water Temperature Sensor
(WTS)
ABBREVIATIONS USED IN T IS MANUAL

BL : B ack with B ue tracer BBr : B ack with Brown tracer
BG : B ack with Green tracer BO : B ack with Orange tracer
BR : B ack with Red tracer BW : B ack with White tracer
BY : B ack with Ye ow tracer LB : B ue with B ack tracer
LG : B ue with Green tracer LR : B ue with Red tracer
LW : B ue with White tracer LY : B ue with Ye ow tracer
BrB : Brown with B ack tracer BrW : Brown with White tracer
GB : Green with B ack tracer GR : Green with Red tracer
GY : Green with Ye ow tracer GrB : Gray with B ack tracer
GrR : Gray with Red tracer GrW : Gray with White tracer
OB : Orange with B ack tracer OL : Orange with B ue tracer
OG : Orange with Green tracer OR : Orange with Red tracer
OW : Orange with White tracer OY : Orange with Ye ow tracer
RB : Red with B ack tracer RW : Red with White tracer
WB : White with B ack tracer WL : White with B ue tracer
WR : White with Red tracer YB : Ye ow with B ack tracer
YL : Ye ow with B ue tracer YG : Ye ow with Green tracer
YR : Ye ow with Red tracer
B : B ack Gr : Gray Sb : Light b ue
L : B ue Lg : Light green W : White
Br : Brown O : Orange Y : Ye ow
G : Green R : Red
WIRE COLOR

NOTE
D fference between photographs and actual motorcycles depends on the markets.

GENERAL INFORMATION
INFORMATION LABELS  1- 1
GENERAL PRECAUTIONS  1- 2
SERIAL NUMBER LOCATION  1- 3
FUEL, OIL AND ENGINE COOLANT RECOMMENDATIONS  1- 4
BREAK-IN PROCEDURES 1- 6
EXTERIOR ILLUSTRATION  1- 7
SPECIFICATIONS  1- 8
CONTENTS
1

1-1 GENERAL INFORMATION
P ease note, however, that the warning and cautions contained in this manua cannot possib y cover a potentia
hazards re ating to the servicing, or ack of servicing, of the motorcyc e. In addition to the WARNING and CAUTION
stated, you must use good judgement and basic mechanica safety princip es. If you are unsure about how to per-
form a particu ar service operation, ask a more experienced mechanic for advice.
WARNING / CAUTION / NOTE
P ease read this manua and fo ow its instructions carefu y.
To emphasize specia information, the symbo and the words WARNING, CAUTION and NOTE have specia mean-
ings. Pay specia attention to the messages high ighted by these signa words.
CAUTION
Indicates a potential hazard that could result in vehicle damage.
WARNING
Indicates a potential hazard that could result in death or injury.
NOTE
Ind cates spec al nformat on to make ma ntenance eas er or nstruct ons cleaner.

GENERAL INFORMATION 1-2
GENERAL PRECAUTIONS
WARNING
Proper service and repair procedures are important for the safety of the service machanic and the safety
and reliability of the vehicle.
When 2 or more persons work together, pay attention to the safety of each other.
When it is necessary to run the engine indoors, make sure that exhaust gas is forced outdoors.
When working with toxic or flammable materials, make sure that the area you work in is well-ventilated and
that you follow all off the material manufacturer’s instructions.
Never use gasoline as a cleaning solvent.
To avoid getting burned, do not touch the engine, engine oil, exhaust system or radiator during or for a
while after engine operation.
After servicing fuel, oil, engine coolant, exhaust or brake systems, check all lines and fittings related to the
system for leaks.
WARNING
If parts replacement is necessary, replace the parts with YOSUNG 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 removing the battery, disconnect the battery lead wire first and then the battery lead wire.
When reconnecting the battery, connect the battery lead wire first and then the battery lead wire.
Finally, cover the battery terminal with the terminal cover.
When performing service to electrical parts, if the service procedures do not require use of battery power,
diconnect the battery lead wire at the battery.
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, circlips, and cer-
tain other parts as specified, be sure to replace them with new ones. Also, before installing these new
parts, be sure to remove any material left over from the mating surfaces.
Never reuse a circlip. When installing a new circlip, take care not to expand 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.
WARNING
To protect environment, do not unlawfully dispose of used motor oil and other fluids: batteries, and tires.
To protect Earth’s natural resouces, properly dispose of used vehicles and parts.

1-3 GENERAL INFORMATION
SERIAL NUMBER LOCATION
The frame seria number or V.I.N. (Vehic e Identification Number) is stamped on the right downside frame.
The engine seria number is stamped on the eft rearside of the crankcase assemb y.
These numbers are required especia y for registering the machine and ordering spare parts.
FRAME SERIAL NUMBER
ENGINE SERIAL NUMBER

GENERAL INFORMATION 1-4
BRAKE FLUID
Specification and classification (Front brake) : DOT4
(Rear brake) : DOT4
TRANSMISSION OIL
Make sure that the transmission oi you use comes under API c assification of more than SL and that its viscosity
rating is SAE 10W/40.
Classification system
API
SAE
Use a premium qua ity 4-stroke motor oi to ensure
onger service ife of your vehic e.

If an SAE 10W/40 motor o l s not ava lable, select an
alternat ve accord ng to the follow ng chart.
WARNING
Don’t mix the unrecommended oil. It could damage the engine.
When refilling the oil, don’t allow the dust to get inside.
Wipe the spilled oil up immediately.
Don’t put the patch on the filler cap. It could disturb the oil to be provided and damage the engine.
WARNING
Don
t mix the unrecommended oil. It could damage the transmission.
When refilling the oil, don
t allow the dust to get inside.
Wipe the spilled oil up immediately.
Don
t put the patch on the filler cap. It could disturb the oil to be provided and damage the transmission.
WARNING
Since the brake system of this vehicle is filled with a glycol-based brake fluid by the manufacturer, do not use
or mix different types of fluid such as silicone-based and petroleum-based fluid for refilling the system,
otherwise serious damage will result.
Do not use any brake fluid taken from old or used or unsealed containers.
Never re-use brake fluid left over from a previous servicing, which has been stored for a long period.
FUEL, OIL AND ENGINE COOLANT RECOMMENDATIONS
FUEL
Gaso ine used shou d be graded 91 octane (Research Method) or higher. An un eaded gaso ine type is recom-
mended.
ENGINE OIL
ENGINE OIL SPECIFICATION
Grade
Over SL
10W/40
ENGINE
OIL
Temperature


-30
-22
-20
-4
-10
14
0
32
10
50
20
68
30
86
40
104
5W30
10W30
10W40 10W50
15W40 15W50
20W50

1-5 GENERAL INFORMATION
FRONT FORK OIL
Use fork oil : TELLUS #22
ENGINE COOLANT
Use an anti-freeze / engine coo ant compatib e with an a uminum radiator, mixed with disti ed water on y.
WATER FOR MIXING
Use disti ed water on y. Water other than disti ed water can corrode and c og the a uminum radiator.
ANTI-FREEZE / ENGINE COOLANT
The engine coo ant perform as a corrosion and rust inhibitor as we as anti-freeze. Therefore, the engine
coo ant shou d be used at a times even though the atmospheric temperature in your area does not go down to
freezing point.
Hyosung recommends the use of HYOSUNG COOLANT anti-freeze / engine coo ant. If this is not avai ab e, use
an equiva ent which is compatib e with an a uminum radiator.
LIQUID AMOUNT OF WATER / ENGINE COOLANT
For engine coo ant mixture information, refer to coo ing system section, page 6-1.
CAUTION
Mixture of anti-freeze / engine coolant should be limited to 60%. Mixing beyond it would reduce its efficien-
cy. If the anti-freeze / engine coolant mixing ratio is below 50%, rust inhabiting performance is greatly
reduced. Be sure to mix it above 50% even though the atmospheric temperature does not go down to the
freezing point.

GENERAL INFORMATION 1-6
Upon reaching an odometer reading of 1,600 km (1,000 mi es) you can subject the motorcyc e to fu thrott e
operation.
Do not maintain constant engine speed for an extended period during any portion of the break-in.
Try to vary the thrott e position.
BREAK-IN PROCEDURES
During manufacture on y the best possib e materia s are used and a machined parts are finished to a very high
standard but it is sti necessary to a ow the moving parts to BREAK-INbefore subjecting the engine to maximum
stresses.
The future performance and re iabi ity of the engine depends on the care and restraint exercised during its ear y ife.
The genera ru es are as fo ows :
Keep to these break-in procedures :
Interval Maximum throttle opening
Less than 1/2 thrott e
Initia 800 Km (500 mi es)
Less than 3/4 thrott e
Up to 1,600 Km (1,000 mi es)

1-7 GENERAL INFORMATION
EXTERIOR ILLUSTRATION
765 (WIDTH)
750
120
1,365 (HEIGHT)
640
740
735
300455
2,125 (LENGTH)
Position amp
Rear ref ector Tai / Brake amp
Turn signa amp (Rear)
Turn signa amp
(Front)
Head amp
1,500 (WHEEL BASE) 425
775
875

GENERAL INFORMATION 1-8
2,125 mm (83.7 in)
765 mm (30.1 in)
1,365 mm (53.7 in)
1,500 mm (59.1 in)
120 mm (4.7 in)
180 kg (397 bs) 175 kg (386 bs)
Overa ength
Overa width
Overa height
Whee base
Ground c earance
Mass
ITEM
ITEM
Four-stroke, DOHC, Liquid-coo ed
1 cy inder
73.0 mm (2.87 in)
59.6 mm (2.35 in)
249.5  (15.2 in3)
Fue injection
E ectric starter
Wet sump
57.0 mm (2.24 in)
48.8 mm (1.92 in)
124.5  (7.6 in3)
Type
Number of cy inder
Bore
Stroke
Piston disp acement
Fue system
Starter system
Lubrication system
Dry shoe, automatic, centrifuga type
7.31
0.900 ~ 2.333
V-be t drive
10.82
0.804 ~ 2.414
C utch
Reduction ratio
Transmission
Drive be t
SPECIFICATIONS
DIMENSIONS AND DRY MASS
ENGINE
TRANSMISSION
ITEM

1-9 GENERAL INFORMATION
Te escopic type
Swingarm type
37(right & eft)
26
88.5 mm (3.5 in)
Doub e disk brake
Disk brake
120/70 - 13M/C 53S
140/60 - 14M/C 64S
85 mm (3.35 in)
Front suspension
Rear suspension
Steering ang e
Caster
Trai
Front brake
Rear brake
Front tire size
Rear tire size
Front fork stroke
ECU
10B.T.D.C. at 2,000 rpm and 30B.T.D.C. at 5,000 rpm
CR8E
12V 8Ah (MF)
Main : 30 A
Head amp : 15 A
HI : 12V - 55 W 1
LO : 12V - 55 W 1
Position : 12V - 5 W 2
LED type
12V - 21 / 5 W 1
12V - 5 W 1
10B.T.D.C. at 2,000 rpm and 28B.T.D.C. at 4,000 rpm
Ignition type
Ignition timing
Spark p ug
Battery
Turn signa amp
Brake / Tai amp
License p ate amp
LED : Light Emitting Diode
Fue tank
Engine oi , oi rep ace
with oi fi ter rep ace
overhau
Transmission oi , oi rep ace
overhau
Coo ant
Front fork oi capacity (One side)
8.0 
800 
900 
1,000 
400 
410 
1.15 
120 cc
NOTE
The spec f cat ons are subject to change w thout not ce.
C ASSIS
ELECTRICAL
CAPACITIES
Fuse
Head amp
ITEM
ITEM
ITEM

PERIODIC MAINTENANCE SCHEDULE  2-1
PERIODIC MAINTENANCE CHART  2-1
LUBRICATION POINTS  2-4
MAINTENANCE PROCEDURES  2-5
AIR CLEANER  2-5
EXHAUST PIPE NUTS AND MUFFLER BOLTS  2-6
VALVE CLEARANCE  2-7
SPARK PLUG  2-10
FUEL HOSE  2-11
THROTTLE CABLE PLAY  2-11
ENGINE IDLE SPEED  2-11
ENGINE OIL AND OIL FILTER  2-12
TRANSMISSION OIL  2-14
ENGINE COOLANT  2-15
RADIATOR HOSE 2-17
BRAKE SYSTEM  2-1
STEERING  2-22
FRONT FORK  2-22
REAR SHOCK ABSORBER  2-22
TIRE  2-23
CHASSIS BOLTS AND NUTS  2-23
COMPRESSION PRESSURE  2-24
AUTOMATIC CLUTCH INSPECTION  2-25
CONTENTS
2
PERIODIC MAINTENANCE

2-1 PERIODIC MAINTENANCE
Item Initial 1,000 km Every 4,000 km Every 8,000 km pa e
Interval
Air cleaner element
Exhaust pipe nuts and muffler bolts
Valve clearance adjust
Cylinder head bolt
Cylinder head & Cylinder
Spark plug
Fuel hose
Engine oil filter
Engine oil
hrottle cable
Idle speed
Engine coolant
Radiator hoses
ransmission oil
Drive belt
ighten
Inspect
ighten

Clean
Inspect
Replace
Replace
Inspect
Inspect

Inspect




Remove carbon
Replace






Inspect
Inspect
2-5
2-6
2-7
3-43
3-18
2-10
2-11
2-12
2-12
2-11
2-11
2-15
2-17
2-14
3-34
Replace every 4 years
Replace every 2 years
Replace every 4 years
Item Initial 1,000 km Every 4,000 km Every 8,000 km pa e
Interval
Brake
Brake hoses
Brake fluid
ires
Steering
Front forks
Rear shock absorber
Chassis bolts and nuts
General lubrication
Inspect
Inspect
Inspect
Inspect
Inspect


ighten
Lubricate
Inspect
Inspect
Inspect
Inspect
Inspect
Inspect
Inspect
ighten
Lubricate









Replace every 4 years
Replace every 2 years
CHASSIS
2-18
2-18
2-18
2-23
2-22
2-22
2-22
2-23
2-4
PERIODIC MAINTENANCE SCHEDULE
he chart below lists the recommended intervals for all the required periodic service work necessary to keep the motor-
cycle operating at peak performance and economy.
ighten
Inspect
ighten

Clean
Inspect
Replace
Replace
Inspect
Inspect
Inspect


Clean every 3,000 kmReplace every 12,000 km
CAUTION
Usin poor quality replacement parts can cause your motorcycle to wear more quickly and shorten its useful life.
Use only enuine Hyoun replacement parts or their equivalent.
CAUTION
More frequent servicin should be performed on motorcycles that are used under severe conditions.
PERIODIC MAINTENANCE CHART
ENGINE

PERIODIC MAINTENANCE 2-2
SIDE COVER STAY
have the “Side cover stay”
inside the side cover.
Use the “Side cover stay” to inspect the engine or the
other parts easily.
USE OF SIDE COVER S AY
Position the motorcycle on the center stand.
Raise the seat.
Remove the two bolts in the personal trunk.
Remove the two bolts of the rear carrier.
Push the side cover for the rear side.
Disconnect the tail lamp coupler.
Lift the front end of the side cover and prop it up
as shown side.
Insert the crank end of the side cover stay into
the hole of the side cover.
CAUTION
Proceed with care.
Do not dama e the cover, reflector and lamp.
Handle plastic and paint-finished parts with care
to avoid scratchin or dama e.
CAUTION
Upon reassembly, install the bolts and cover cor-
rectly in the appropriate seats.




2-3 PERIODIC MAINTENANCE
HELMETBOX INNER COVER
have the “Helmetbox inner
cover” inside the personal trunk.
Use the “Helmetbox inner cover” to inspect the fuel
injection system easily.
USE OF HELME BOX INNER COVER
Position the motorcycle on the center stand.
Raise the seat.
Lift the helmetbox inner cover knob carefully.
CAUTION
Proceed with care.
Do not dama e the personal trunk and helmetbox
inner cover.
Handle plastic parts with care to avoid dama e.
