1. GENERAL INFORMATION
MXU 250
1
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
GENERAL INFORMATION
1
__________________________________________________________________________________
SERIAL NUMBER---------------------------------------------------------- 1- 1
SPECIFICATIONS---------------------------------------------------------- 1- 2
SERVICE PRECAUTIONS------------------------------------------------ 1- 3
TORQUE VALUES --------------------------------------------------------- 1-11
SPECIAL TOOLS ----------------------------------------------------------- 1-12
LUBRICATION POINTS -------------------------------------------------- 1-13
CABLE & HARNESS ROUTING ---------------------------------------- 1-16
WIRING DIAGRAM (OFF ROAD) -------------------------------------- 1-20
WIRING DIAGRAM (ON ROAD) --------------------------------------- 1-21
TROUBLESHOOTING----------------------------------------------------- 1-22
1-0
1. GENERAL INFORMATION
r
r
SERIAL NUMBER
MXU 250
(1) Location of Frame Serial Numbe
1-1
(2) Location of Engine Serial Numbe
1. GENERAL INFORMATION
r
m
g
p
t
t
m
m
r
y
r
g
y
y
SPECIFICATIONS
MXU 250
Name & Model No. LB50AD/AA
Motorcycle Name & Type MXU
Overall length 1810 mm (72.4 in)
Overall width (mm) 1050 mm (42 in)
Overall height (mm) 1110 mm (44.4 in)
Wheel base (mm) 1170 mm (46.8 in)
Engine type O.H.C.
Displacement 249 cm3 (15.2 cu-in)
Fuel Used 92# nonleaded gasoline
Front wheel 112 kg (246 lbs)
Dry weight Rear wheel 102 kg (224 lbs)
Total 214 kg (471 lbs)
Front wheel 116 kg (255 lbs)
Curb weight Rear wheel 110 kg (242 lbs)
Total 226 kg (497 lbs)
Tires
Ground clearance 125 mm (5 in)
Min. turning radius 2900 mm (116 in)
Starting system
Type Gasoline, 4-stroke
Cylinder arrangement Single cylinder
Combustion chamber type Semi-sphere
Valve arrangement O.H.C., chain drive
Bore x stroke (mm)
Compression ratio 10.3:1
Compression pressure
Engine
Port
timin
Valve clearance
(cold)
Idle speed (rpm) 1500rpm
Lubrication
S
stem
Cooling Type Liquid cooled
Front wheel 22*7-10
Rear wheel 22*10-10
Electric/Recoil starte
72.7 x 60 mm
(2.9 x 2.4 in)
16 kg/c
Intake
(1mm)
Exhaust
(1mm)
Lubrication type
Oil pump type Trochoid
Oil filter type Full-flow filtration
Oil capacity
Oil exchanging
capacity
Open 8.1° BTDC
Close 41° ABDC
Open 37° BBDC
Close 7.9° ATDC
Intake 0.1 mm (0.004 in)
Exhaust 0.1 mm (0.004 in)
Forced
1.6 L (1.4 lmp qt, 1.7
² (1600kPa,
227 psi)
ressure &
Wet sump
Us qt)
1.4 L (1.23 lmp qt,
1.48 Us q
Air cleaner type & No Wet type element
Fuel S
Fuel capacity 12.5 L (2.63 lmp gal,
stem
Carbureto
Type Piston valve
Main jet NO. 98
Venturi dia. φ22 mm (φ0.88 in)
Throttle type PISTON
I
Electrical Equipment
Power Drive System
Moving Device
Brake syste
type
Damping
Device
Frame type Double cradle
Type Full transistor digital
nition S
Ignition timing 5°BTDC/1000rpm
Contact breaker Non-contact point type
stem
Spark plug DPR7EA-9
Spark plug gap 0.6～0.7mm (0.002～
Battery Capacity 12V12AH
Clutch Type Dry, centrifugal
Transmis-
sion Gear
Type Helical gear/spur gear
Operation
Reduction
Gear
Type Chain drive
Reduction 1st
ratio
Reverse ratio
FR/RR tire rolling
circumference
Tire pressure
Turning Left 40°
angle
Suspension
type
Fron
Rear
Right 40°
Rea
Front Disk brake
Front
Rear
Automatic centrifugal
2nd
1759/1759 mm (71.8/71.8
0.28 kg/c
Double wishbone
Link suspension
3.25 US gal
ignition
0.003 in)
automatic
Type
26.5
10.02
50.9
² (28 Kpa,
3.2 psi)
Disk brake
in)
1-2
1. GENERAL INFORMATION
SERVICE PRECAUTIONS
Make sure to install new gaskets, 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 the specified torque
diagonally.
MXU 250
Use genuine parts and lubricants.
When servicing the motorcycle, be sure
to use special tools for removal and
installation.
After disassembly, clean removed parts.
Lubricate sliding surfaces with engine oil
before reassembly.
1-3
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.
MXU 250
When two persons 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.
1-4
1. GENERAL INFORMATION
m
MXU 250
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.
Confir
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.
1-5
1. GENERAL INFORMATION
The connector shall be inserted
completely.
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.
MXU 250
Snapping!
Check the double connector cover for
proper coverage and installation.
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 contact the wire
harnesses.
1-6
1. GENERAL INFORMATION
N
After clamping, check each wire to make
sure it is secure.
Do not squeeze wires against the weld or
its clamp.
MXU 250
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.
o Contact !
Route wire harnesses to avoid sharp
edges or corners. Avoid the projected
ends of bolts and screws.
Route wire harnesses passing through the
side of bolts and screws. Avoid the
projected ends of bolts and screws.
1-7
1. GENERAL INFORMATION
g
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.
When rubber protecting cover is used to
protect the wire harnesses, it shall be
installed securely.
MXU 250
Do not pull
ht!
too ti
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
.
1-8
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.
MXU 250
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.
Do you understand
the instrument? Is the
instrument set
correctly?
Remove Rust !
1-9
1. GENERAL INFORMATION
Symbols:
The following symbols represent the
servicing methods and cautions included
in this service manual.
: Apply engine oil to the
specified points. (Use
designated engine oil for
Engine Oil
Grease
lubrication.)
: Apply grease for
lubrication.
MXU 250
Gear Oil
Special
: Transmission Gear Oil
(90#)
: Use special tool.
: Caution
: Warning
1-10
1. GENERAL INFORMATION
TORQUE VALUES
STANDARD TORQUE VALUES
MXU 250
Item
5mm bolt and nut
6mm bolt and nut
8mm bolt and nut
10mm bolt and nut
12mm bolt and nut
14mm bolt and nut
Torque specifications listed below are for important fasteners.
ENGINE
Item Q‘ty
Stud bolt
Oil filter screen cap
Seat ball stopper bolt
L cover bolt
Cam shaft holder nut
Tappet ADJ nut
Pivot tensioner bolt
Lifter tensioner bolt
Lifter tensioner cap
Mission case bolt
Mission fill bolt
Driver face nut
Clutch outer nut
Drive plate nut
Oneway clutch bolt
ACG flywheel nut
Spark plug
Water pump impeller
Drain plug
Oil pump screw
Head CYL stud bolt (IN pipe)
Head CYL stud bolt (EX pipe)
A.C.G Startor
kgf-m (N-m, lbf-ft)
Torque
0.5 (5, 3.6)
1 (10, 7.2)
2.2 (22, 16)
3.5 (35, 25)
5.5 (55, 40)
7 (70, 50)
4
1
1
10
4
2
1
2
1
9
1
1
1
1
3
1
1
1
1
1
2
2
3
4mm screw
5mm screw
6mm screw, SH bolt
6mm flange bolt and nut
8mm flange bolt and nut
10mm flange bolt and nut
Thread dia.
(mm)
8
30
14
6
8
5
8
6
6
8
12
14
12
28
8
14
12
7
12
3
6
8
5
Item
kgf-m (N-m, lbf-ft)
0.15 (15, 10.8)
Torque
0.9 (9, 6.5)
1.5 (15, 11)
4.8 (48, 35)
1.2 (12, 8.6)
2.5 (25, 18)
0.9 (9, 6.5)
1 (10, 7.2)
1.2 (12, 8.6)
0.4 (4,2.9)
2.7 (27, 20)
2.5 (25, 18)
9.5 (95, 68)
5.5 (55, 40)
5.5 (55, 40)
2.0 (20, 14)
6.0 (60, 43)
1.8 (18, 13)
1.2 (12, 8.6)
2.5 (25, 18)
0.9 (9, 6.5)
0.9 (9, 6.5)
0.9 (9, 6.5)
Torque
kgf-m (N-m, lbf-ft)
0.3 (3, 2.2)
0.4 (4, 2.9)
0.9 (9, 6.5)
1.2 (12, 9)
2.7 (27, 20)
4 (40, 29)
Remarks
Apply oil
Apply oil
Apply oil
Apply thread lock
1-11
1. GENERAL INFORMATION
gf-m
(
)
FRAME
MXU 250
Item Q‘ty
Steering stem nut
Front swing arm nut
Front wheel nut
Rear wheel nut
Front wheel hub nut
Rear wheel hub nut
Front shock absorber upper mount bolt
Front shock absorber lower mount bolt
Rear shock absorber upper mount bolt
Rear shock absorber lower mount bolt
Rear swing arm axle
Rear hub nut
Rear wheel shaft nut
Rear engine bracket upper bolt
Rear engine bracket lower bolt
1
8
8
8
2
2
2
2
1
1
1
2
2
1
1
Thread dia.
(mm)
14
10
12
12
14
16
10
10
10
10
14
10
40
10
10
Torque
K
7 (70, 50)
4.5 (45, 32)
4.5 (45, 32)
4.5 (45, 32)
7 (70, 50)
10 (100, 72)
4 (40, 29)
4 (40, 29)
4 (40, 29)
4 (40, 29)
7 (70, 50)
4 (40, 29)
12 (120, 86)
4 (40, 29)
4 (40, 29)
N-m, lbf-ft
Remarks
Engine hanger bracket bolt
Exhaust muffler lock bolt (frame)
Exhaust muffler lock nut (engine)
1
2
2
SPECIAL TOOLS
Tool Name Tool No. Remarks Ref. Page
Flywheel puller E003
Valve adjuster E012
Valve spring compressor E040
Oil seal and bearing install E014
Universal holder E017
Flywheel holder E021
Clutch spring compressor E034
Bearing puller E037
Nut wrench F010
Ball join remover F012
10
8
8
4 (40, 29)
4 (40, 29)
2 (20, 14.4)
1-12
1. GENERAL INFORMATION
LUBRICATION POINTS
ENGINE
Lubrication Points Lubricant
MXU 250
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 right side oil seal
Crankshaft one-way clutch movable part
Oil pump drive chain
Balance gear
A.C. generator
Starter one-way clutch
Bearing movable part
O-ring face
Oil seal lip
•Genuine KYMCO Engine Oil (SAE15W -40)
•API SG Engine Oil
Transmission gear and movable parts Gear oil: SAE90#
1-13
1. GENERAL INFORMATION
r
r
m
FRAME
The following is the lubrication points for the frame.
Use general purpose grease for parts not listed.
Apply clean engine oil or grease to cables and movable parts not specified. This will avoid
abnormal noise and rise the durability of the ATV.
MXU 250
Front Swing Ar
Throttle Cable
Steering Column Uppe
Front Swing Arm Bush
Steering Column Lowe
1-14
1. GENERAL INFORMATION
r
g
m
MXU 250
Rear Swing Ar
Axle
1-15
Sprocket hub/Rea
Axle Hub Collar/Oil
Seal/Bearin
Driven Sprocket
1. GENERAL INFORMATION
/
r
d
r
CABLE & HARNESS ROUTING
Throttle Cable
MXU 250
Multi-function Connecto
Stop Switch Cor
Front Brake Fluid Hose
Thermostatic Senso
Wire
Ignition Switch
Connector
Horn (ON ROAD)
Front Right Turn
Signal Light (ON
ROAD)/Headlight
Connectors
Handlebar Switch Wire
Rear Brake Fluid Hose
Speed Cable
Harness Wire
Motor Fan Wire
Thermostatic Switch Wire
Front Left Turn Signal Light
(ON ROAD)/Headlight
Connectors
Right Front Brake Fluid Hose
Left Front Brake Fluid Hose
1-16
1. GENERAL INFORMATION
r
r
r
r
MXU 250
Turn Signal Light/Stop
Light Connectors (ON
ROAD)
Coolant Reservoi
Breather Hose
License Light
Connector
(ON ROAD)
Ground Wire
Main Wire Harness
REG.REC
A.C.G Connecto
Gear Change
Switch Wire
A.C.G Wire
Temperature Sensor Wire
Turn Signal Relay
Hazard Unit
Horn (ON
ROAD)
Right Turn
Signal Light
(ON
ROAD)/Tail
Light
Connector
Stop Switch Wire
1-17
Gear Change
Switch Connector
Radiator Overflow
Tube
Carbureto
Drain Tube
Start Moto
Cable
Outlet Water Hose
Water Hose
Headlight Control Unit
Inlet Water Hose
1. GENERAL INFORMATION
Ignition Coil
MXU 250
Rear Brake Fluid Hose
Handlebar Switch Wire
Motor Fan Wire
Harness Wire
Blow By Hose
Crankcase Breather Hose
Start Motor Cable
Battery Cable
Throttle Cable
Rear Brake Fluid Hose
Left Turn Signal Light (ON
ROAD)/ Tail Light Connector
Rear Brake Fluid Hose
1-18
1. GENERAL INFORMATION
N
MXU 250
Ground Wire
Gear Change Control Unit
Fuse Box
Starter Motor Cable
Ignition Control Module
Starter Relay
egative Terminal Cable
Positive Terminal Cable
Battery
1-19
1. GENERAL INFORMATION
WIRING DIAGRAM (OFF ROAD)
MXU 250
1-20
1. GENERAL INFORMATION
WIRING DIAGRAM (ON ROAD)
MXU 250
1-21
1. GENERAL INFORMATION
t
t
r
p
t
TROUBLESHOOTING
ENGINE WILL NOT START OR IS HARD TO START
MXU 250
Inspection/Adjustment
Check if fuel reaches
carburetor by loosening
drain screw
Remove spark plug and
install it into spark plug
cap to test spark by
connecting it to engine
ground
Test cylinde
compression
Fuel reaches
carburetor
Spark jumps
Normal
compression
Symptom
Fuel does no
reach carburetor
Weak or no spark
Low or no
compression
Probable Cause
Empty fuel tank
Clogged fuel line between fuel
tank and carburetor
Clogged float oil passage
Clogged fuel tank cap breather
hole
Clogged fuel filter
Clogged fuel valve passage
Faulty spark plug
Fouled spark plug
Faulty ignition unit
Faulty change gear control unit
Faulty pulser coil
Broken or shorted ignition coil
Broken or shorted exciter coil
Faulty ignition switch
Weak or dead battery
Faulty starter clutch
Valve clearance too small
Valve stuck open
Worn cylinder, piston and piston
rings
Leaking cylinder head gasket
Start engine by following normal starting
rocedure
Remove spark plug and
inspect again
Engine does no
fire
Dry spark plug
Engine fires bu
does not start
Wet spark plug
Air leaking through intake pipe
Leaking intake manifold
Incorrect ignition timing
Incorrectly adjusted air screw
Flooded carburetor
Clogged air cleaner
Throttle valve excessively open
1-22
1. GENERAL INFORMATION
g
t
y
g
r
g
t
t
t
N
p
pip
t
t
r
r
t
r
prop
y
t
y
ENGINE LACKS POWER
MXU 250
Inspection/Adjustment
Start engine and
accelerate lightly for
Check ignition timing
(using a timing light)
Check valve clearance
Test cylinder compression
Check carburetor fo
clogging
Engine speed
Correct timin
Correc
ormal
com
ression
Not clogged
Symptom
Engine speed does no
increase sufficientl
Incorrect timin
Abnormal
compression
Incorrec
Clogged
Probable Cause
Clogged air cleaner
Restricted fuel flow
Clogged fuel tank cap breather hole
Clogged exhaust muffler
Carburetor fuel level too low
Faulty ignition unit
Faulty pulser coil
Improper valve clearance
adjustment
Excessively worn valve seat
(protruded valve stem)
Improper valve and seat contact
Worn cylinder and piston rings
Leaking cylinder head gasket
Improper valve timing
Clean and unclog
Remove spark plug and
inspec
Remove oil dipstick and
check oil level and condition
Remove cylinder head oil
e bolt and inspec
Check if engine overheats
Rapidly accelerate or run
at hi
h speed
Plug not fouled o
discolored
Correct and no
contaminated
Valve train lubricated
erl
Engine does no
overheats
Engine does not knock
Plug fouled o
discolored
Incorrect o
contaminated
Valve train no
lubricated properl
Engine overheats
Engine knocks
Fouled spark plug
Incorrect heat range plug
Oil level too high
Oil level too low
Oil not changed
Clogged oil line
Faulty oil pump
Coolant level too low
Worn cylinder and piston rings
Mixture too lean
Poor quality fuel
Excessive carbon build-up in
combustion chamber
Ignition timing too early
Excessive carbon build-up in
combustion chamber
Poor quality fuel
Clutch slipping
Mixture too lean
Ignition timing too early
1-23
1. GENERAL INFORMATION
g
t
r
MXU 250
POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS)
Inspection/Adjustment Symptom Probable Cause
Check ignition timing
Check carburetor ai
screw adjustment
Check carburetor gaske
for air leaks
Remove spark plug and
install it into spark plug
cap to test spark by
connecting it to engine
round
Correct timing
Correctly adjusted
No air leak
Good spark
Incorrect timing
Incorrectly adjusted
Air leaks
Weak or inter-
mittent spark
Faulty ignition unit
Faulty pulser coil
Mixture too rich (turn screw
out)
Mixture too lean (turn screw in)
Deteriorated O-ring
Carburetor not securely
tightened
Damaged insulator rubber
Faulty or fouled spark plug
Faulty ignition unit
Faulty A.C. generator
Faulty ignition coil
Broken or shorted spark plug
wire
Faulty ignition switch
1-24
1. GENERAL INFORMATION
r
t
t
MXU 250
POOR PERFORMANCE (AT HIGH SPEED)
Inspection/Adjustment Symptom Probable Cause
Check ignition timing
Check valve clearance
Check fuel pump fo
fuel supply
Check carburetor jets
for clogging
Check valve timing
Correct timing
Correctly adjusted
Fuel flows freely
Not clogged
Incorrect timing
Incorrectly adjusted
Fuel flow restricted
Clogged
Faulty ignition unit
Faulty pulser coil
Improperly adjusted valve
clearance
Worn valve seat
Empty fuel tank
Clogged fuel tube or filter
Clogged Fuel tank cap breather
hole
Clean and unclog
Check valve spring
tension
1-25
Correc
Not weakened
Incorrec
Weak spring
Cam timing gear aligning marks
not aligned
Faulty spring
1. GENERAL INFORMATION
t
g
B
t
B
h
g
MXU 250
POOR CHARGING (BATTERY OVER DISCHARGING OR OVERCHARGING)
Undercharging
Inspection/Adjustment
Start engine and tes
limit voltage of battery
terminals
Measure resistance
between AC generator
coil terminals
Connect battery (+) wire
to regulator/rectifier
coupler red wire and
battery (-) wire to engine
round and test voltage
Check regulator/rectifier
coupler for loose
connection
Symptom
Normal voltage
Normal
Normal voltage No voltage
Voltage does no
Resistance too high
Probable Cause
Dead battery
Faulty battery
Faulty A.C. generator coil
Broken yellow wire
Shorted pink and yellow
wires
Broken red wire
Overcharging
Inspection/Adjustment
Connect battery (+) wire
to regulator/rectifier
coupler green wire and
battery (-) wire to engine
round and test voltage
Check regulator/rectifier
coupler for loose
connection
Normal
attery has voltage
with ignition
switch “ON”
Normal
Symptom
attery has no
voltage with ignition
switc
Abnormal
“ON”
Abnormal
Faulty regulator/rectifier
Poorly connected coupler
Faulty A.C. generator
Probable Cause
Broken green wire
Poorly connected coupler
Faulty regulator/rectifier
1-26
1. GENERAL INFORMATION
g
g
r
r
NO SPARK AT SPARK PLUG
MXU 250
Inspection/Adjustment Symptom
Replace with a new
spark plug and inspect
ain
a
Weak or no spark
Check spark plug cap
and high-tension wire
for looseness
Not loose
Check ignition unit
coupler for looseness
Good
Measure resistance
between terminals of
nition unit couple
i
Good spark
Loose
Good
Probable Cause
Faulty spark plug
Loose spark plug cap
Poorly connected coupler
Check related parts
Check ignition unit
with a ignition unit
teste
Check ignition coil with
a ignition unit tester
Normal
Normal
Normal
Abnormal
Abnormal
Abnormal
Abnormal
Faulty ignition switch
Weak battery
Faulty pulser coil
Faulty ignition coil
Faulty charging system
Broken wire harness
Poorly connected coupler
Faulty ignition unit
Faulty change gear control
unit
Faulty ignition coil
1-27
Loading...