KYMCO ZX, SCOUT 50 Service Manual

ZX / SCOUT

PREFACE

This Service Manual describes the technical feature.s and servicing
procedures for the KYMCO ZX / SCOUT 50.

In this manual, many illustrations and drawings are used to help
servicemen have better understanding.

Section 2 contains the service precautions for all operations and
troubleshooting stated in this manual. Read them carefully before starting
any operation.

Section 3 describes the inspection/adjustment procedures, safety rules and
service information for each part, starting from periodic maintenance.

Sections 4 through 16 give instructions for disassembly, assembly and
inspection of lubrication system, engine, fuel system and electrical
equipment.

Section 17 is the maintenance and inspection directions for the evaporative/
exhaust emission control system. 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

MARCH 2000

1. SPECIFICATIONS

1-0

ZX / SCOUT

1

TABLE OF CONTENTS

SPECIFICATIONS.................................................................................. 1

GENERAL INFORMATION .................................................................. 2

INSPECTION/ADJUSTMENT............................................................... 3

LUBRICATION SYSTEM ....................................................................... 4

ENGINE REMOVAL/INSTALLATION................................................. 5

CYLINDER HEAD/CYLINDER/PISTON.............................................. 6

A.C. GENERATOR ................................................................................. 7

KICK STARTER/DRIVE PULLEY/CLUTCH/DRIVEN PULLEY....... 8

FINAL REDUCTION............................................................................... 9

CRANKCASE/CRANKSHAFT...............................................................10

CARBURETOR .......................................................................................11

FRAME COVERS....................................................................................12

STEERING HANDLEBAR/FRONT WHEEL/FRONT BRAKE/

FRONT SHOCK ABSORBER/FRONT FORK......................................13

REAR WHEEL/REAR BRAKE/REAR SHOCK ABSORBER ..............14

ELECTRICAL EQUIPMENT.................................................................15

INSTRUMENT/SWITCHES/LIGHTS....................................................16

EVAPORATIVE/EXHAUST EMISSION CONTRAL SYSTEM ...........17

1

1. SPECIFICATIONS

1-1

ZX 50

SPECIFICATIONS

Name & Model SC10AS
Overall length (mm) 1792
Overall width (mm) 690
Overall height (mm) 1053
Wheel base (mm) 1225
Engine type Air cooled 2-stroke
Displacement (cc) 49.4 cc

Net weight (kg)

92.5

Seating capacity 2 riders (110kg)

Gross weight(kg)

150

Front wheel

120/70-12

Tires

Rear wheel

120/70-12

Ground clearance (mm) 170
Braking distance (m)

(Initial speed Km/h)

7m (30km/h)

Min. turning radius (mm) 1940
Starting system

Starting motor &

kick starter

Fuel type

Gasoline, 2-stroke

motor oil
Cylinder arrangement Single cylinder, flat
Combustion chamber type Semi -sphere
Valve arrangement Reed valve & piston
Bore x stroke (mm) 39 x 41.4
Compression ratio 7.3 : 1
Compression pressur e

(kg/cm ² rpm)

11.5kg/cm ²

Max. output (kw/rpm) 3.75/7000kw/rpm
Max. torque (kg-m/rpm) 4.5/6500 kg m/rpm
Open Automatic controlled

Intake

Close Automatic controlled

Port Open 
timing

Exhaust

Close 

Open 

Scavenge

Close 

Idle speed (rpm) 2100±100
Lubrication type Separate type
Oil pump type Plunger type

Oil filter type Full-flow filtration

Lubrication oil capacity (liter) 0.80
Air cleaner type & No. Wet, single
Fuel capacity (liter) 4.9
Type Plunger type
Carburetor Piston dia. (mm) 
Venturi dia. (mm) 14

Ignition system type

CDI electromagnetic

Ignition

Ignition timing F mark 15.5°±2°BTDC/2000rpm

Spark

NGK BR8HSA

plug

ND

Spark plug gap (mm) 0.6 0.7
Battery capacity 12V3AH

Power to transmission gear

Power-transmission

gear-clutch

Reduction ratio of power to
transmission



Clutch type Dry multi-disc clutch
Transmission gear operation

type

Automatic centrifugal
type

Transmission ratio 1 spe

ed



Reduction Type Two-stage reduction
gear 1st reduction ratio 
2nd reduction ratio



Transmission gear type Non-stage transmission

Tire pressure

Front wheel

1.50 1.75

(kg/cm ²)

Rear wheel 1.75 2.25

Turning angle Right & left 45°

Brake system

Front wheel

Expanding/hydraulic

type

Rear wheel

Expanding

Suspension

Front wheel

Telescope

type

Rear wheel

Unit swing

Shock absorber

Front wheel

Telescope

type

Rear wheel

Unit swing

Frame type Pipe under bone

CO 4.5% Exhaust

emission

concentration

HC 7000ppm Max

2. GENERAL INFORMATION

2-0

ZX / SCOUT

1

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

GENERAL INFORMATION

__________________________________________________________________________________

ENGINE SERIAL NUMBER/IDENTIFICATION............................2- 1

SERVICE PRECAUTIONS ............................................................2- 2

SERVICE INFORMATION ............................................................2- 6

TORQUE VALUES........................................................................2- 8

SPECIAL TOOLS ..........................................................................2- 9

LUBRICATION POINTS...............................................................2-11

WIRING DIAGRAM......................................................................2-12

CABLE & HARNESS ROUTING...................................................2-13

TROUBLESHOOTING ..................................................................2-17

2

2. GENERAL INFORMATION

2-1

ZX / SCOUT

ENGINE SERIAL NUMBER/IDENTIFICATION

Location of Engine Serial Number

2. GENERAL INFORMATION

2-2

ZX / SCOUT

SERVICE PRECAUTIONS

n Make sure to install new gaskets, O-rings,

circlips, cotter pins, etc. when reassembling.

n When tightening bolts or nuts, begin with

larger-diameter to smaller ones at several
times, and tighten to the specified torque
diagonally.

n Use genuine parts and lubricants.

n When servicing the motorcycle, be sure to use

special tools for removal and installation.

n After disassembly, clean removed parts.

Lubricate sliding surfaces with engine oil
before reassembly.

n Apply or add designated greases and

lubricants to the specified lubrication points.

n After reassembly, check all parts for proper

tightening and operation.

n When two persons work together, pay

attention to the mutual working safety.

n Disconnect the battery negative (-) terminal

before operation.

n When using a spanner or other tools, make

sure not to damage the motorcycle surface.

n After operation, check all connecting points,

fasteners, and lines for proper connection and
installation.

n When connecting the battery, the positive (+)

terminal must be connected first.

n After connection, apply grease to the battery

terminals.

n Terminal caps shall be installed securely.

n If the fuse is burned out, find the cause and

repair it. Replace it with a new one according

2. GENERAL INFORMATION

2-3

ZX / SCOUT

to the specified capacity.

n After operation, terminal caps shall be installed

securely.

n When taking out the connector, the lock on

the connector shall be released before
operation.

n Hold the connector body when connecting or

disconnecting it.

n Do not pull the connector wire.

n Check if any connector terminal is bending,

protruding or loose.

n The connector shall be inserted completely.

n If the double connector has a lock, lock it

at the correct position.

n Check if there is any loose wire.

n Before connecting a terminal, check for

damaged terminal cover or loose negative
terminal.

n Check the double connector cover for proper

coverage and installation.

n Insert the terminal completely.
n Check the terminal cover for proper coverage.
n Do not make the terminal cover opening face

up.

n 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.

n After clamping, check each wire to make sure

it is secure.

Easy confirm

2. GENERAL INFORMATION

2-4

ZX / SCOUT

n Do not squeeze wires against the weld or its

clamp.

n After clamping, check each harness to make

sure that it is not interfering with any moving or
sliding parts.

n When fixing the wire harnesses, do not make it

contact the parts which will generate high heat.

n Route wire harnesses to avoid sharp edges or

corners. Avoid the projected ends of bolts
and screws.

n Route wire harnesses passing through the side

of bolts and screws. Avoid the projected
ends of bolts and screws.

n Route harnesses so they are neither pulled

tight nor have excessive slack.

n Protect wires and harnesses with electrical

tape or tube if they contact a sharp edge or
corner.

n When rubber protecting cover is used to

protect the wire harnesses, it shall be installed
securely.

n Do not break the sheath of wire.
n If a wire or harness is with a broken sheath,

repair by wrapping it with protective tape or
replace it.

n When installing other parts, do not press or

squeeze the wires.

n After routing, check that the wire harnesses

are not twisted or kinked.

Don’t touch

2. GENERAL INFORMATION

2-5

ZX / SCOUT

n 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.

n When a testing device is used, make sure to

understand the operating methods thoroughly
and operate according to the operating
instructions.

n Be careful not to drop any parts.

n When rust is found on a terminal, remove the

rust with sand paper or equivalent before
connecting.

n 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.

: Use special tool.

: Caution

: Warning

(ð12-3) : Refer to page 12-3.

Engine Oil

Grease

Special

*

Remove the rest

2. GENERAL INFORMATION

2-6

ZX / SCOUT

SERVICE INFORMATION

ENGINE

Standard (mm) Service Limit (mm)

Item SC10AS SC10AS

Cylinder head warpage  0.10
Piston O.D.(5mm from bottom of piston skirt) 38.955 38.970 38.90
Cylinder-to- piston clearance 0.10
Piston pin hole I.D. 12.002 12.008 12.03
Piston pin O.D. 11.994 12.0 11.98
Piston -to-piston pin clearance ← ←
Piston ring end gap (top/second) 0.10 0.25 0.40
Connecting rod small end I.D. 17.005 17.017 17.03
Cylinder bore 39.039.025 39.05
Drive belt width 18 17
Drive pulley collar O.D. 20.01 20.025 ←
Movable drive face ID. 20.035 20.085 19.97
Weight roller O.D. 13.0 12.4
Clutch outer I.D. 107 107.2 107.5
Driven face spring free length 87.9 82.6
Driven face O.D. ← ←
Movable driven face I.D. ← ←
Connecting rod big end side clearance ← ←
Connecting rod big end radial clearance ← ←
Crankshaft runout A/B  ←

CARBURETOR

SC10AS
Venturi dia. 14mm
Identification number 014A
Float level 5.0mm
Main jet #80
Slow jet #35
Air screw opening 1 ±¼
Idle speed 2100±100rpm
Throttle grip free play 2 6mm
Jet needle clip notch 1st notch

2. GENERAL INFORMATION

2-7

ZX / SCOUT

FRAME

Standard (mm) Service Limit (mm)

Item SC10AS SC10AS

Axle shaft runout  0.2

Radial

Front wheel rim runout

Axial
Front shock absorber spring free length 200.0 182.8
Rear wheel rim runout 2.0
Brake drum I.D. Front/rear 110 111
Brake lining thickness Front/rear 4.0/4.0 2.0/2.0
Brake disk runout Front/rear  0.30
Rear shock absorber spring free length 235.7 218.7

ELECTRICAL EQUIPMENT

SC10AS

Capacity 12V3AH

Voltag e 13.0 13.2V

Charging Standard 0.4A/5H

Battery

current Quick 4A/0.5H

Spark plug (NGK) BR8HSA

Spark plug gap 0.6 0.7mm

Primary coil 0.153 0.187Ω

Secondary coil
(with plug cap)

6.99 10.21KΩ

Ignition coil resistance

Secondary coil
(without plug cap)

3.24 3.96KΩ

Pulser coil resistance (20 ) 80 160Ω

Ignition timing 15.5°±2°BTDC/2000rpm

2. GENERAL INFORMATION

2-8

ZX / SCOUT

TORQUE VALUES

ENGINE

Item Thread dia. (mm)

Torque (kg

-m)

Remarks

Cylinder head bolt
Clutch drive plate nut
Clutch outer nut
Drive face nut
Oil check bolt
Engine mounting bolt
Engine hanger bracket bolt
Exhaust muffler joint lock nut
Exhaust muffler lock bolt
Spark plug

BF7x115

10
NH10
NH12

10

BF10x95
BF10x50

NC6mm

BF8x35

1.5 1.7

3.5 4.0

3.5 4.5

5.0 6.0

1.0 1.5

4.5 5.5

3.5 4.5

1.0 1.4

3.0 3.6

1.1 1.7

(cold)

(cold)

FRAME

Item Thread dia. (mm)

Torque (kg

-m)

Remarks

Handlebar lock nut
Steering stem lock nut
Steering top cone race
Front axle nut
Rear axle nut
Rear brake arm bolt
Front shock absorber:
upper mount bolt
lower mount bolt
hex bolt
Front damper nut
Front pivot arm bolt
Rear shock absorber:
upper mount bolt
lower mount bolt
lower joint nut

10

25.4

25.4
12
16

8

8

10

8
8

4.5 5.0

8.0 12.0

0.5 1.3

5.0 7.0

11.0 13.0

3.3

3.3

1.5 3.0

1.5 3.0

3.5 4.5

2.4 3.0

1.5 2.5

Flange bolt/U-nut

Flange U-nut
Flange U-nut
Flange nut

Flange bolt/U-nut
Cross head
Apply locking agent

Flange screw/U-nut

Flange nut

Torque specifications listed above are for important fasteners. Others should be tightened to standard
torque values below.

STANDARD TORQUE VALUES SH bolt: 8mm Flange 6mm bolt

Item Torque (kg

-m)

Item Torque (kg

-m)

5mm bolt, nut
6mm bolt, nut
8mm bolt, nut
10mm bolt, nut
12mm bolt, nut

0.45 0.6

0.8 1.2

1.8 2.5

3.0 4.0

5.0 6.0

5mm screw
6mm screw, SH bolt
6mm flange bolt, nut
8mm flange bolt, nut
10mm flange bolt, nut

0.35 0.5

0.7 1.1

1.0 1.4

2.4 3.0

3.5 4.5

2. GENERAL INFORMATION

2-9

ZX / SCOUT

SPECIAL TOOLS

Tool Name Tool No. Remarks

Universal bearing puller E030 Crankshaft bearing removal
Lock nut socket wrench F001 Top cone race holding
Lock nut wrench, F002 Stem lock nut tightening
Crankcase puller E026 Crankcase disassembly
Bearing remover set, 12mm

(Spindle assy, 12mm)
(Remover weight)

E020

Drive shaft bearing removal/installation

Bearing remover set, 15mm
(Spindle assy, 15mm)
(Remover head, 15mm)
(Remover shaft, 15mm)

E018

Drive shaft bearing removal/installation

Bearing outer driver, 28x30mm E014 Bearing installation
Clutch spring compressor E027 Driven pulley disassembly/assembly

Crankcase assembly collar E023

Driven shaft, crankshaft & crankcase

assembly
Crankcase assembly tool E024 Crankshaft & crankcase assembly
Ball race remover F005 Steering stem bearing races
Rear shock absorber compressor F004 Rear shock absorber disassembly/assembly
Universal holder E017 Flywheel holding
Flywheel puller E001 Flywheel removal

Bearing outer driver, 32x35mm E014

Drive shaft bearing installation

Final shaft bearing installation

Bearing outer driver, 37x40mm E014

Drive shaft bearing installation Final shaft

bearing installation Crankshaft bearing

installation

Universal bearing puller E030 Crankshaft bearing removal

LUBRICATION POINTS

2. GENERAL INFORMATION

2-10

ZX / SCOUT

ENGINE

NO.

Lubrication Points Lubricant Remarks
1 Crankcase sliding & movable parts JASO-FC or API-TC
2 Cylinder movable parts JASO-FC or API-TC
3 Transmission gear (final gear) SAE-90#
4 Kick starter spindle bushing Grease
5 Drive pulley movable parts Grease
6 Starter pinion movable parts Grease

FRAME
Apply clean engine oil or grease to cables and movable parts not specified. This will avoid abnormal

noise and rise the durability of the motorcycle.

SC10AS WIRING DIAGRAM

Front/Rear Brake Lever

Seat Lock

Rear Wheel Bearing

Throttle Cable

Main Stand Pivot

Grease

Engine Oil

Grease

Engine Oil

Speedometer Gear/

Brake Cam/Front
Shock Absorber
Lower Mount
Bushings/Pivot

Grease

Grease

Grease

Grease

Engine Oil

Rear Brake Cable

Brake Cam/

Anchor Pin

2. GENERAL INFORMATION

2-11

ZX / SCOUT

CABLE & HARNESS ROUTING

2. GENERAL INFORMATION

2-12

ZX / SCOUT

Front Brake Reservoir

Rear Brake Cable

Throttle Cable

Ignition Switch

Regulator/Rectifier

Front Brake Fluid Tube

Resistor

Front Stop Switch Wire

Rear Stop Switch Wire

Speedometer Cable

Speedometer Cable

Front Brake Fluid Tube

Horn

2. GENERAL INFORMATION

2-13

ZX / SCOUT

Ignition Coil

Fuel Unit

Wire Harness

Rear Brake Cable

Throttle Cable

Front Brake Fluid Tube

Speedometer Cable

Speedometer Cable

Front Brake Fluid Tube

2. GENERAL INFORMATION

2-14

ZX / SCOUT

Fuel Filter

Oil Tank Cap

Starter Relay

CDI Unit

Battery

Wire Harness

Ignition Coil

Oil Tube

2. GENERAL INFORMATION

2-15

ZX / SCOUT

TROUBLESHOOTING

Vacuum Tee

Oil Pump

Ignition Coil

Oil Tube

Fuel Unit

Fuel Tank Cap

2. GENERAL INFORMATION

2-16

ZX / SCOUT

ENGINE WILL NOT START OR IS HARD TO START

• Empty fuel tank
‚ Clogged float valve
ƒ Clogged fuel filter
„ Faulty auto fuel valve

• Faulty spark plug
‚ Fouled spark plug
ƒ Faulty CDI unit
„ Faulty A.C. generator
… Broken or shorted ignition coil
† Broken or shorted exciter coil
‡Faulty ignition switch

• Burned or worn cylinder

piston

‚ Faulty reed valve
ƒ Blown cylinder head gasket
„ Leaking crankcase
… Faulty crankcase oil seal

• Incorrectly adjusted idle speed
‚ Air leaking through intake

pipe

ƒ Incorrect ignition timing

• Flooded carburetor
‚ Throttle valve excessively

open

• Faulty auto bystarter

ENGINE STOPS IMMEDIATELY AFTER IT STARTS

Inspection/Adjustment Symptom Probable Cause

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 Symptom Probable Cause

Fuel reaches

carburetor

Spark jumps

Dry spark plug

Not clogged

Normal

compression

Engine does not

fire

Fuel does not

reach carburetor

Weak or no spark

Wet spark plug

Clogged

Low or no

compression

Engine fires but

does not start

Test cylinder

compression.

Remove spark plug and

inspect again.

Wait for

30 minutes and

then remove the
carbu-retor auto choke
circuit hose and blow
the hose with mouth.

Start engine by

follow-ing normal
starting procedure.

2. GENERAL INFORMATION

2-17

ZX / SCOUT

• Empty fuel tank
‚ Clogged float valve
ƒ Clogged fuel filter
„ Faulty auto fuel valve

• Fouled spark plug
‚ Incorrect heat range plug

• Fouled spark plug
‚ Faulty CDI unit
ƒ Faulty A.C. generator
„ Faulty ignition coil
… Broken or shorted high

tension wire

† Faulty ignition switch

• Worn cylinder and piston rings
‚ Blown cylinder head gasket
ƒ Flaws in cylinder head
„ Faulty reed valve
… Seized piston

• Clogged carburetor jets

• Faulty CDI unit or A.C.

generator

‚ A.C.G. flywheel not aligned

• Mixture too rich (turn screw

out)

‚ Mixture too lean (turn screw

in)

Check if fuel reaches

carburetor by loosening
drain screw.

Fuel reaches

carburetor

Good spark

Remove spark plug and

install it into spark plug
cap to test spark by
connecting it to engine
ground.

Correct timing

Correctly adjusted

Plug not fouled or

discolored

Normal

compression

Not Clogged

Fuel does not

reach carburetor

Weak or inter

-

mittent spark

Incorrect timing

Incorrectly adjusted

Plug fouled or

discolored

Abnormal

compression

Clogged

Inspection/Adjustment

Symptom Probable Cause

Test cylinder

compression (using a
compression gauge).

Check carburetor for
clogging.

Check carburetor
gasket for air leaks.

Check ignition timing.

Check carburetor air
screw adjustment.

Remove spark plug and

install it into spark plug
cap to test spark by
connecting it to engine
ground.

2. GENERAL INFORMATION

2-18

ZX / SCOUT

• Carburetor not securely
tightened

‚ Faulty intake manifold gasket
ƒ Deformed or broken

carburetor O-ring

• Broken cable

‚ Dirty auto bystarter
ƒ Faulty auto bystarter

• Faulty auto bystarter

ENGINE LACKS POWER

Inspection/Adjustment Symptom

Probable Cause

No air leak

Not clogged

Clogged

Air leaks

Clogged

Not Clo gged

Connect auto bystarter

wire to battery. Wait for
5 minutes, then connect
a hose to fuel enriching
circuit and then blow
the hose with mouth.

Remove auto bystarter

connecting wire and
check if bypass fuel line
is clogged.

Start engine and

accelerate lightly for
observation.

2. GENERAL INFORMATION

2-19

ZX / SCOUT

• Clogged air cleaner

‚ Clogged fuel filter
ƒ Clogged exhaust muffler
„ Faulty auto bystarter

• Faulty CDI unit

‚ Faulty A.C. generator

• Worn cylinder and piston rings

‚ Blown cylinder head gasket
ƒ Faulty reed valve

• Clogged carburetor jets

• Fouled spark plug

‚ Incorrect heat range plug

• Mixture too lean

‚ Poor quality fuel
ƒ Excessive carbon build -up in

combustion chamber

„ Ignition timing too early

• Excessive carbon build -up in

combustion chamber

‚ Poor quality fuel
ƒ Clutch slipping
„ Mixture too lean

POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS)

Engine speed

increases

Engine overheats

Correct timing

Inspection/Adjustment

Engine does not

knock

Symptom

Plug not fou

led or

discolored

Probable Cause

Normal

compression

Not Clogged

Engine speed does

not increase
sufficiently

Engine does not

overheats

Incorrect timing

Engine knocks

Plug fouled or

discolored

Abnormal

compression

Clogged

Check ignition timing

(using a timing light).

Rapidly accelerate or
run at high speed

Test cylinder

compression (using a
compression gauge)

Check carburetor for
clogging

Remove spark plug and
inspect

Check if engine
overheats

2. GENERAL INFORMATION

2-20

ZX / SCOUT

• Faulty CDI unit

‚ Faulty A.C. generator

• Mixture too rich (turn screw

out)

‚ Mixture too lean (turn screw

in)

• Carburetor not securely
tightened

‚ Faulty intake manifold gasket
ƒ Deformed carburetor O-ring

• Faulty or fouled spark plug

‚ Faulty CDI unit
ƒ Faulty A.C. generator
„ Faul ty ignition coil
… Broken or shorted high

tension wire

† Faulty ignition switch

• Broken auto bystarter wire

‚ Faulty auto bystarter

POOR PERFORMANCE (AT HIGH SPEED)

Clogged Not clogged

Inspection/Adjustment Symptom Probable Cause

Check ignition timing.

Remove spark plug and

install it into spark plug
cap to test spark by
connecting it to engine
ground.

Check ignition timing.

Connect auto bystarter

wire to battery. Wait for
5 minutes, then connect
a hose to fuel enriching
circuit and then blow
the hose with mouth.

Remove auto bystarter

connecting wire and
check if bypass fuel line
is clogged.

Check carburetor
gasket for air leaks.

Check carburetor air
screw adjustment.

Correct timing

Incorrect timin g

Correctly adjusted

Incorrectly adjusted

No air leak

Air leaks

Good spark

Weak or inter

-

mittent spark

Not clogged

Clogged

2. GENERAL INFORMATION

2-21

ZX / SCOUT

• Faulty CDI unit

‚ Loose A.C.G. stator
ƒ Faulty A.C. generator

• Empty fuel tank

‚ Clogged fuel tube or filter
ƒ Clogged charcoal canister

• Clean and unclog

• Broken auto bystarter wire

‚ Faulty auto bystarter

• Faulty auto bystarter

CLUTCH, DRIVE AND DRIVEN PULLEYS

• Worn or slipping drive belt
‚ Broken ramp plate
ƒ Broken driven face spring
„ Separated clutch lining

Clogged Not clogged

Engine starts but
motor-cycle does not

Symptom

Probable Cause

Connect auto bystarter

wire to battery. Wait for
5 minutes, then connect
a hose to fuel enriching
circuit and then blow
the hose with mouth.

Remove auto bystarter

connecting wire and
check if bypass fuel line
is clogged.

Check carburetor jets
for clogging.

Check auto fuel valve
for fuel supply.

Correct timing

Incorrect timing

Fuel flows freely Fuel flow restricted

Not clogged

Clogged

Not clogged Clogged

2. GENERAL INFORMATION

2-22

ZX / SCOUT

… Damaged driven pulley shaft splines
† Damaged final gear
‡ Seized final gear

• Broken shoe spring
‚ Clutch outer and clutch weight stuck
ƒSeized pivot

• Worn or slipping drive belt
‚ Worn weight rollers
ƒ Seized drive pulley bearings
„ Weak driven face spring
… Worn or seized driven pulley bearings

• Worn or slipping drive belt
‚ Worn weight rollers
ƒ Worn or seized driven pulley bearings

• Oil or grease fouled drive belt
‚ Worn drive belt
ƒ Weak driven face spring
„ Worn or seized driven pulley bearings

STEERING HANDLEBAR DOES NOT TRACK STRAIGHT

(Front and rear tire pressures are normal)

• Steering stem nut too tight
‚ Broken steering steel balls

• Excessive wheel bearing play
‚ Bent rim
ƒ Loose axle nut

• Misaligned front and rear wheels
‚ Bent front fork

POOR SUSPENSION PERFORMANCE

(Front and rear tire pressures are normal)

• Weak shock spring
‚ Excessive load

Engine lacks power at

start of a grade (poor

slope performance)

Steering is heavy

Suspension is too soft

Front or rear wheel is

wobbling

Symptom

Symptom

Probable Cause

Probable Cause

Engine lacks power at

high speed

There is abnormal noise
or smell while running

Motorcycle creeps or

engine starts but soon
stops or seems to rush
out (Rear wheel rotates
when engine idles)

Steering handlebar pulls

to one side

2. GENERAL INFORMATION

2-23

ZX / SCOUT

ƒ Shock damper oil leaking

• Bent fork tube or shock rod
‚ Fork slid er and tube binding

• Fork tube and spring binding
‚ Fork slider and tube binding

POOR BRAKE PERFORMANCE

(Adjust brake according to standards)

• Worn brake linings
‚ Worn brake cam contacting area on

brake shoes

ƒ Worn brake cam
„ Worn brake drum

• Worn brake linings
‚ Foreign matter on brake linings
ƒ Rough brake drum contacting area

• Sluggish or elongated brake cables
‚ Brake shoes improperly contact

brake drum

ƒ Water and mud in brake system
„ Oil or grease on brake linings

• Faulty brake master cylinder
‚ Faulty brake caliper
ƒ Oil or grease on brake disk
„ Deformed brake disk
… Leaking brake fluid tube

OIL METER

1. Motor oil indicator light does not come on when there is no motor oil (Ignition switch ON)
Inspection/Adjustment Symptom Probable Cause

Brake squeaks

Symptom

Probable Cause

Suspension is too hard

Suspension is noisy

Brake performance is

poor

Index mark on brake

panel aligns with wear

indicator arrow

Expanding

Brake

Hydraul

ic

Brake

2. GENERAL INFORMATION

2-24

ZX / SCOUT

Faulty

• Burned out fuse
‚ Weak or dead battery
ƒ Faulty ignition switch

„ Loose or disconnected

connector

… Broken wire harness

•Burned out bulb

• Loose wire connector
‚ Broken wire harness
ƒ Incorrectly connected wire

• Faulty float
‚ Broken or shorted wire in

meter

2. Motor oil is sufficient but the indicator light remains on (Ignition switch ON)

• Loose or disconnected

connector

‚ Broken wire harness
ƒ Incorrectly connected wire

• Faulty float
‚ Broken or shorted wire in

meter

• Damaged oil tank
‚ Foreign matters in oil tank

FUEL GAUGE

1. Pointer does not register correctly (Ignition switch ON)

• Burned out fuse
‚ Weak or dead battery
ƒ Faulty ignition switch

Inspection/Adjustment Symptom

Inspection/Adjustment Symptom Probable Cause

Signals operate

properly

Signals dim, remain

on or don‘t operate

Signals operate

properly

Signals dim, remain

on or don‘t operate

Bulb lights Bulb does not light

Good

Faulty

Remov

e oil meter and

check operation of
indicator light by moving
float

Check connectors for
proper connection.

Good

Probable Cause

Good

Faulty

Remove oil meter and

check operation of
indicator light by moving
float

Check connectors for
proper operation.

Connect indicator light

bulb to battery for bulb
inspection.

Check battery circuit by
operating turn signals.

Good

Faulty

Check battery circuit by

operating turn signals.

Float up = Light off

Float down = Light on

Float up = Light off

Float down = Light on

2. GENERAL INFORMATION

2-25

ZX / SCOUT

„ Loose or disconnected

connector

… Broken wire harness

• Faulty float

• Broken or shorted fuel unit

wire

• Loose or disconnected

connector

‚ Incorrectly connected

connector

• Broken or shorted wire in

fuel gauge

2. Pointer fluctuates or swings (Ignition switch ON)

• Burned out fuse
‚ Weak or dead battery
ƒ Faulty ignition switch
„ Loose or disconnected

connector

… Broken wire harness

• Poor contact in fuel unit

• Insufficient damping oil in

fuel gauge

• Loose or disconnected
connector

• Broken or shorted wire in

fuel gauge

STARTER MOTOR

1. Starter motor won‘t turn

• Burned out fuse
‚ Weak or dead battery
ƒ Faulty stop switch
„ Loose or disconnected

connector

… Broken or shorted ignition

Inspection/Adjustment

Symptom

Inspection/Adjustment Symptom

Stoplight does not

come on

Stoplight comes on

Signals operate

properly

Signals

dim, remain

on or don‘t operate

Pointer does not

move

Pointer does not

move

Good

Good

Pointer moves

Pointer moves

Pointer moves

Pointer does not

move in

accord

-

ance with

Probable Cause

Faulty

Faulty

Pointer does not

move

Pointer moves in

accordance with
float

Probable Cause

Check operation of

stop switch by
applying brake.

Check battery circuit

by operating turn
signals.

Remove fuel unit and

check operation of
pointer by moving float
up and down.

Check operation of

pointer by opening and
shorting fuel unit
terminal on wire
harness side.

Check connectors for
proper connection.

Chec

k operation of

starter relay by

Remove fuel unit and

check operation of
pointer by moving float
up and down.

Check battery circuit by

operating turn signals
and horn.

Move float up and down

rapidly (1 round /sec.)
to check the operation
of pointer.

Check connectors for
proper connection.

2. GENERAL INFORMATION

2-26

ZX / SCOUT

switch wire

• Faulty or weak battery

• Poor starter button connection
‚ Faulty starter relay
ƒ Loose or disconnected

connector

• Faulty starter motor

• Faulty wire harness

2. Starter motor turns slowly or idles

• Weak or dead battery

• Loose or disconnected

connector

‚ Faulty starter relay

• Seized cylinder

• Broken or shorted starter

motor cable

‚ Faulty starter pinion

3. Starter motor does not stop turning

• Faulty starter pinion

• Starter relay shorted or stuc k

closed

Inspection/Adjustment

Inspection/Adjustment

Symptom

Symptom

Signals o

perate

properly

Signals operate

properly

Signals dim, remain

on or don‘t operate

S

ignal

s dim, remain

on or don‘t operate

Starter motor turns

Turns easily

Not stopped

Starter does not

Hard to turn

Stopped

Relay operates

properly

Starter motor

turns slowly

Probable Cause

Probable Cause

Relay does not

operate

Starter motor

turns normally

Check battery circuit

by operating turn
signals.

Turn ignition

switch

OFF.

Connect starter

motor directly to
battery.

Rotate crankshaft.