KYMCO Mongoose/KXR 250 User 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
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
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
p
ressure Fron
t
0.28
(kg/cm²)Rear 0.28
Turning Left 40°
angle Right 40°
Brake s
y
ste
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.
Sna
pp
in
g
!

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
En
g
ine Oil
Grease
Gear Oil
Special

1. GENERAL INFORMATION
1-11
Mongoose/KXR 250
TORQUE VALUES
STANDARD TORQUE VALUES
Ite
m
Tor
q
ue
(
k
g
f-m
)
Ite
m
Tor
q
ue
(
k
g
f-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
0.45～0.6
0.8～1.2
1.8～2.5
3.0～4.0
5.0～6.0
6.0～8.0
4mm screw
5mm screw
6mm screw, SH bolt
6mm flange bolt and nut
8mm flange bolt and nut
10mm flange bolt and nut
0.2～0.4
0.35～0.5
0.7～1.1
1.0～1.4
2.4～3.0
3.5～4.5
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
0.7～1.1
1.0～2.0
4.5～5.0
1.0～1.4
2.3～2.7
0.7～1.1
0.8～1.2
1.0～1.4
0.35～0.5
2.4～3.0
2.0～3.0
9.0～10.0
5.0～6.0
5.0～6.0
1.8～2.2
5.5～6.5
1.5～2.0
1.0～1.4
2.0～3.0
0.1～0.3
0.7～1.1
0.7～1.1
0.8～1.0
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
6.0～8.0
4.0～5.0
4.0～5.0
4.0～5.0
6.0～8.0
9.0～11.0
3.5～4.5
3.5～4.5
3.5～4.5
3.5～4.5
6.0～8.0
3.5～4.5
11.0～13.0
3.5～4.5
3.5～4.5
3.5～4.5
3.2～3.8
1.8～2.2
2.5～3.5
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