KYMCO Mongoose/KXR 250, Mongoose 250, KXR 250 Service Manual

PREFACE
This Service Manual describes the technical features and servicing procedures for the KYMCO Mongoose/KXR 250.
Section 1 contains the precautions for all operations stated in this manual. Read them carefully before starting any operation.
Section 2 is the removal/installation procedures for the frame covers which are subject to higher 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 4 through 19 give instructions for disassembly, assembly and inspection of engine, chassis frame and 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.
KWANG YANG MOTOR CO., LTD.
OVERSEAS SALES DEPARTMENT
OVERSEAS SERVICE SECTION
TABLE OF CONTENTS
GENERAL INFORMATION 1 FRAME COVERS/EXHAUST MUFFLER 2 INSPECTION/ADJUSTMENT 3 LUBRICATION SYSTEM 4 FUEL SYSTEM 5
ENGINE REMOVAL 6 CYLINDER HEAD/VALVES 7 CYLINDER/PISTON 8 DRIVE AND DRIVEN PULLEYS
9
FINAL REDUCTION/TRANSMISSION SYSTEM
10
CRANKCASE/CRANKSHAFT/ BALANCE SHAFT
11
COOLING SYSTEM
12
BRAKE SYSTEM
13
FRONT WHEEL/FRONT SUSPENSION/STEERING SYSTEM
14
REAR WHEEL/AXLE/SUSPENSION
15
BATTERY/CHARGING SYSTEM/A.C. GENERATOR
16
IGNITION SYSTEM 17 STARTING SYSTEM 18 BULBSREMOVAL/INSTRUMENT/
HORN
19
The information and contents include
d
in this manual may be different from the motorcycle in case specifications are changed.
CHASSIS
ELECTRICAL
EQUIPMENT
ENGINE
1. GENERAL INFORMATION
1-0
Mongoose/KXR 250
1
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__________________________________________________________________________________
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GENERAL INFORMATION
__________________________________________________________________________________
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-------------------------------------------------------- 1-19 TROUBLESHOOTING----------------------------------------------------- 1-21
1
1. GENERAL INFORMATION
1-1
Mongoose/KXR 250
SERIAL NUMBER
Location of Engine Serial Numbe
r
Location of Frame Serial Numbe
r
1. GENERAL INFORMATION
1-2
Mongoose/KXR 250
SPECIFICATIONS
Name & Model No. LA50AA/AB Motorcycle Name & Type Mongoose/KXR Overall length (mm) 1700 Overall width (mm) 1070 Overall height (mm) 1080 Wheel base (mm) 1180 Engine type O.H.C. Displacement (cc) 249 Fuel Used 92# nonleaded gasoline
Front wheel 93.1
Net weight (kg) Rear wheel 84.9
Total 178
Front wheel 100
Gross weight(kg) Rear wheel 91
Total 191
Front wheel 21*7-10
Rear wheel 20*11-9
Ground clearance (mm) 130 Perform-
Breakin
g
distance
(m)(30KPH)
29.27 below
ance
Min. turning radius (m) 2.865
Starting system
Starting motor
Type Gasoline, 4-stroke Cylinder arrangement Single cylinder Combustion chamber type Semi-sphere Valve arrangement O.H.C., chain drive Bore x stroke (mm) 72.7 x 60 Compression ratio 10.3:1
Compression pressure (kg/cm²)
15.0
Max. output (ps/rpm) 17/7000 Max. torque (kg m/rpm) 2.0/5500
Intake
Open 8.1° BTDC
Port
(1mm)
Close 41° ABDC
timin
g
Exhaust
Open 37° BBDC
(1mm)
Close 7.9° ATDC
Valve clearance
Intake 0.1
(cold) (mm)
Exhaust 0.1
Idle speed (rpm) 1500rpm
Lubrication type
Forced
p
ressure &
Wet sump Oil pump type Inner/outer rotor type Oil filter type Full-flow filtration Oil capacity 1.6 liter Oil exchanging capacity
1.4 liter
Cooling Type Water cooling
Air cleaner type & No Sponge Fuel capacity 13 liters
Type PD Float lever 14.8mm Venturi dia.(mm) φ22 Throttle type PISTON Type CDI Ignition timing 5°BTDC/2000rpm Contact breaker Non-contact point type
Spark plug DPR7EA-9
Spark plug gap 0.6~0.7mm Battery Capacity 12V12AH Clutch Type CVT
Type Helical gear/spur gear Operation
Automatic centrifugal
Type Type Chain drive Reduction 1st
24.7
ratio
2nd
9.33
Reverse ratio
47.4
FR/RR tire rolling circumference(mm)
1675/1596
Tire pressure
Fron
t
0.28
(kg/cm²)
Rear 0.28
Turning Left 40° angle
Right 40°
Brake syste
m
Rea
r
Disk brake
type
Front Disk brake Front
Double wishbone
Suspension type
Rear
Link suspension
Frame type Steel tube frame
Tires
Engine
Lubrication
S
y
stem
Fuel S
y
stem
Carbureto
r
Electrical Equipment
I
g
nition S
y
stem
Power Drive System
Transmis-
sion Gear
Reduction
Gear
Moving Device
Damping
Device
1. GENERAL INFORMATION
1-3
Mongoose/KXR 250
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.
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. GENERAL INFORMATION
1-4
Mongoose/KXR 250
Apply or add designated greases and
lubricants to the specified lubrication points.
After reassembly, check all parts for
proper tightening and operation.
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. GENERAL INFORMATION
1-5
Mongoose/KXR 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.
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.
Confir
m
Capacity
1. GENERAL INFORMATION
1-6
Mongoose/KXR 250
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.
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.
Snapping!
1. GENERAL INFORMATION
1-7
Mongoose/KXR 250
After clamping, check each wire to make
sure it is secure.
Do not squeeze wires against the weld or
its clamp.
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.
Route wire harnesses passing through the
side of bolts and screws. Avoid the projected ends of bolts and screws.
N
o Contact !
1. GENERAL INFORMATION
1-8
Mongoose/KXR 250
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.
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 pull too ti
g
ht!
Do not press or squeeze the wire.
1. GENERAL INFORMATION
1-9
Mongoose/KXR 250
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.
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. GENERAL INFORMATION
1-10
Mongoose/KXR 250
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 lubrication.)
: Apply grease for
lubrication.
: Transmission Gear Oil
(90#)
: Use special tool.
: Caution
: Warning
Engine Oil
Grease
Gear Oil
Special
1. GENERAL INFORMATION
1-11
Mongoose/KXR 250
TORQUE VALUES
STANDARD TORQUE VALUES
Ite
m
Torque (kgf-m
)
Ite
m
Torque (kgf-m
)
5mm bolt and nut 6mm bolt and nut
8mm bolt and nut 10mm bolt and nut 12mm bolt and nut
14mm bolt and nut
0.450.6
0.81.2
1.82.5
3.04.0
5.06.0
6.08.0
4mm screw 5mm screw
6mm screw, SH bolt 6mm flange bolt and nut 8mm flange bolt and nut 10mm flange bolt and nut
0.20.4
0.350.5
0.71.1
1.01.4
2.43.0
3.54.5
Torque specifications listed below are for important fasteners.
ENGINE
Item Q‘ty Thread dia.(mm) Torque (kgf-m) Remarks
Stud bolt Oil filter screen cap Seat ball stopper bolt L cover Cam shaft holder 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
4 1 1
10
4 2 1 2 1 9 1 1 1 1 3 1 1 1 1 1 2 2 3
8 30 14
6
8
5
8
6
6
8 12 14 12 28
8 14 12
7 12
3
6
8
5
0.71.1
1.02.0
4.55.0
1.01.4
2.32.7
0.71.1
0.81.2
1.01.4
0.350.5
2.43.0
2.03.0
9.010.0
5.06.0
5.06.0
1.82.2
5.56.5
1.52.0
1.01.4
2.03.0
0.10.3
0.71.1
0.71.1
0.81.0
Apply oil Apply oil
Apply oil
Apply thread lock
1. GENERAL INFORMATION
1-12
Mongoose/KXR 250
FRAME
Item Q‘ty Thread dia.(mm) Torque (kgf-m) Remarks
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 Engine hanger bracket bolt Exhaust muffler lock bolt (frame) Exhaust muffler lock nut (engine) Rod-end nut
1 8 8 8 2 2 2 2 1 1 1 2 2 1 1 1 2 2 4
14 10 12 12 14 16 10 10 10 10 14 10 40 10 10 10
8 8 8
6.08.0
4.05.0
4.05.0
4.05.0
6.08.0
9.011.0
3.54.5
3.54.5
3.54.5
3.54.5
6.08.0
3.54.5
11.013.0
3.54.5
3.54.5
3.54.5
3.23.8
1.82.2
2.53.5
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
1. GENERAL INFORMATION
1-13
Mongoose/KXR 250
LUBRICATION POINTS
ENGINE
Lubrication Points Lubricant
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. GENERAL INFORMATION
1-14
Mongoose/KXR 250
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.
Steering Column Uppe
r
Throttle Cable
Steering Column Lowe
r
Front Swing Arm Bush
Front Swing Ar
m
1. GENERAL INFORMATION
1-15
Mongoose/KXR 250
Sprocket hub/Rea
r
Axle Hub Collar/Oil Seal/Bearing
Driven Sprocket
Rear Swing Ar
m
Axle
1. GENERAL INFORMATION
1-16
Mongoose/KXR 250
CABLE & HARNESS ROUTING
Headlight Wire
Pilot Lamp Wire
Handlebar Switch Wire
Ignition Switch Wire
Rear Brake Fluid Hose
Harness Wire
Motor Fan Cor
d
Thermostatic Switch Wire
Left Front Brake Fluid Hose
Right Front Brake Fluid Hose
Thermostatic Sensor Wire
Front Brake Fluid Hose
Stop Switch Cor
d
Throttle Cable
1. GENERAL INFORMATION
1-17
Mongoose/KXR 250
Air Vent Tube
Coolant Reservoi
r
Breather Hose
Outlet Water Hose
Temperature Sensor Wire
Inlet Water Hose
Water Hose
Carburetor Drain Tube
Start Motor Cable
Radiator Overflow Tube
A.C.G Cor
d
REG.REC Cor
d
Tail Light Cor
d
Stop Switch Cor
d
1. GENERAL INFORMATION
1-18
Mongoose/KXR 250
Motor Fan Cor
d
Handlebar Switch Cor
d
Rear Brake Fluid Hose
Harness Wire
Blow By Hose
Rear Brake Fluid Hose
Start Motor Cable
Battery Cable
Crankcase Breather Hose
Rear Brake Fluid Hose
1. GENERAL INFORMATION
1-19
Mongoose/KXR 250
WIRING DIAGRAM (OFF ROAD)
1. GENERAL INFORMATION
1-20
Mongoose/KXR 250
WIRING DIAGRAM (ON ROAD)
1. GENERAL INFORMATION
1-21
Mongoose/KXR 250
TROUBLESHOOTING
ENGINE WILL NOT START OR IS HARD TO START
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
Air leaking through intake pipe Leaking intake manifold Incorrect ignition timing Incorrectly adjusted air screw
Flooded carburetor Clogged air cleaner Throttle valve excessively open
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
Inspection/Adjustment
Probable Cause
Spark jumps
Normal
compression
Engine does no
t
fire
Weak or no spark
Low or no
compression
Engine fires bu
t
does not start
Test cylinde
r
compression
Start engine by follow­ing normal starting
p
rocedure
Remove spark plug and inspect again
Symptom
Fuel reaches
carburetor
Fuel does no
t
reach carburetor
Wet spark plug
Dry spark plug
1. GENERAL INFORMATION
1-22
Mongoose/KXR 250
ENGINE LACKS POWER
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
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
Start engine and accelerate lightly for
Inspection/Adjustment
Symptom
Probable Cause
Engine speed
Correct timin
g
Engine speed does no
t
increase sufficientl
y
Incorrect timin
g
Check ignition timing (using a timing light)
Test cylinder compression
Check carburetor fo
r
clogging
Rapidly accelerate or run at hi
g
h speed
Remove spark plug and inspec
t
Check if engine overheats
Check valve clearance
Correc
t
Incorrec
t
N
ormal
com
p
ression
Abnormal
compression
Remove oil dipstick and check oil level and condition
Remove cylinder head oil
pip
e bolt and inspec
t
Engine overheats
Engine does no
t
overheats
Plug not fouled o
r
discolored
Plug fouled o
r
discolored
Correct and no
t
contaminated
Incorrect o
r
contaminated
Valve train lubricated
prop
erl
y
Valve train no
t
lubricated properl
y
Engine does not knock
Engine knocks
Not clogged
Clogged
1. GENERAL INFORMATION
1-23
Mongoose/KXR 250
POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS)
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
Remove spark plug and install it into spark plug cap to test spark by connecting it to engine
g
round
Inspection/Adjustment Symptom Probable Cause
Check ignition timing
Check carburetor gaske
t
for air leaks
Check carburetor ai
r
screw adjustment
Correct timing
Incorrect timing
Correctly adjusted
No air leak
Air leaks
Good spark
Weak or inter-
mittent spark
Incorrectly adjusted
1. GENERAL INFORMATION
1-24
Mongoose/KXR 250
POOR PERFORMANCE (AT HIGH SPEED)
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
Cam timing gear aligning marks not aligned
Faulty spring
Inspection/Adjustment Symptom Probable Cause
Check ignition timing
Check carburetor jets for clogging
Check fuel pump fo
r
fuel supply
Correct timing
Incorrect timing
Check valve spring tension
Check valve clearance
Fuel flows freely
Fuel flow restricted
Correc
t
Incorrec
t
Not clogged
Clogged
Correctly adjusted
Incorrectly adjusted
Not weakened
Weak spring
Check valve timing
1. GENERAL INFORMATION
1-25
Mongoose/KXR 250
POOR CHARGING (BATTERY OVER DISCHARGING OR OVERCHARGING) Undercharging
Dead battery Faulty battery
Faulty A.C. generator coil Broken yellow wire Shorted pink and yellow wires
Broken red wire
Faulty regulator/rectifier Poorly connected coupler
Faulty A.C. generator
Overcharging
Broken green wire
Poorly connected coupler
Faulty regulator/rectifier
Start engine and tes
t
limit voltage of battery terminals
Connect battery (+) wire to regulator/rectifier coupler red wire and battery (-) wire to engine
g
round and test voltage
Inspection/Adjustment
Inspection/Adjustment
Symptom
Symptom
Probable Cause
Probable Cause
Normal voltage
B
attery has voltage with ignition switch “ON”
Normal
Voltage does no
t
B
attery has no voltage with ignition switc
h
“ON”
Resistance too high
Normal voltage No voltage
Measure resistance between AC generator coil terminals
Normal
Abnormal
Check regulator/rectifier coupler for loose connection
Normal
Abnormal
Connect battery (+) wire to regulator/rectifier coupler green wire and battery (-) wire to engine
g
round and test voltage
Check regulator/rectifier coupler for loose connection
1. GENERAL INFORMATION
1-26
Mongoose/KXR 250
NO SPARK AT SPARK PLUG
Faulty spark plug
Loose spark plug cap
Poorly connected coupler
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
Replace with a new spark plug and inspect a
g
ain
Check ignition unit coupler for looseness
Inspection/Adjustment Symptom
Probable Cause
Normal
Abnormal
Normal
Abnormal
Normal
Abnormal
Abnormal
Measure resistance between terminals of i
g
nition unit couple
r
Check related parts
Check ignition coil with a ignition unit tester
Weak or no spark
Not loose
Good spark
Loose
Good
Good
Check spark plug cap and high-tension wire for looseness
Check ignition unit with a ignition unit teste
r
2. FRAME COVERS/EXHAUST MUFFLER
2-0
Mongoose/KXR 250
2
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FRAME COVERS/EXHAUST MUFFLER
__________________________________________________________________________________
SERVICE INFORMATION------------------------------------------------ 2- 2 TROUBLESHOOTING----------------------------------------------------- 2- 2 FRAME COVERS----------------------------------------------------------- 2- 3 EXHAUST MUFFLER REMOVAL-------------------------------------- 2- 7
2
2. FRAME COVERS/EXHAUST MUFFLER
2-1
Mongoose/KXR 250
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