Generic Race 50 Service Manual
Service Manual
Holtvej 8-10, Høruphav, 6470 Sydals
Telefon: +45 73 15 11 00
Fax: +45 73 15 11 01
E-mail: info@scanmi.dk · www.scanmi.dk
CVR: 27 73 31 07
November 2010
Race 50
1
User's operation and maintenance manual for
double-wheel motorcycle RACE 50
2
Zhejiang Qianjiang Motorcycle Co., Ltd.
Contents
Contents 2
Preface 4
Documents to be prepared ...................................................................................................................................5
Inspection/adjustment ..........................................................................................................................................6
Inspection and Service of Electrical System 63
I. Battery/ Charging system 67
1.1 Preparation data ...........................................................................................................................................53
1.2 Fault diagnosis.............................................................................................................................................53
1.3 Battery .........................................................................................................................................................71
1.4 Charging system ..........................................................................................................................................72
1.5 Voltage and current regulator....................................................................................................................... 73
1.6 Charge coil of the alternator ........................................................................................................................74
1.7 Disassembly of alternator ............................................................................................................................74
II.
Ignition system 61
2.1 Preparation data ...........................................................................................................................................61
2.2 Fault diagnosis.............................................................................................................................................79
2.3 Ignition system inspection ...........................................................................................................................83
2.4 CDI group .................................................................................................................................................... 84
2.5 Ignition coil..................................................................................................................................................86
2.6 Trigger .........................................................................................................................................................86
III. Startup system 90
3.1 Preparation data ...........................................................................................................................................91
3.2 Fault diagnosis.............................................................................................................................................93
3.3 Start electric machinery ............................................................................................................................... 93
3.4 Start relay..................................................................................................................................................... 96
IV. Bulbs/ switch/instrument 73
4.1 Preparation data ...........................................................................................................................................99
4.2 Fault diagnosis.............................................................................................................................................99
3
4.3 Replace the head light bulb..........................................................................................................................99
4.4 Replace bulb of the front turning light.......................................................................................................100
4.5 Disassembly/replace the bulb of the taillight and rear-right turning light .................................................100
4.6 Instrument..................................................................................................................................................101
4.7 Main switch ...............................................................................................................................................101
4.8 Horn ........................................................................................................................................................... 102
4.9 Handle switch ............................................................................................................................................102
Inspection and Service of Chassis 103
V. Brake 80
5.1 Maintenance instruction............................................................................................................................. 107
5.2 Fault diagnosis...........................................................................................................................................108
5.3 Front hydraulic brake................................................................................................................................. 108
5.4 Rear drum brake ........................................................................................................................................110
VI．Body cover 86
VII. Front wheel/ front suspension 90
7.1 Preparation data ......................................................................................................................................... 119
7.2 Fault diagnosis........................................................................................................................................... 119
7.3 Front wheel ................................................................................................................................................ 120
7.4 Steering bar................................................................................................................................................123
7.5 Front fork...................................................................................................................................................124
VIII. Rear wheel/rear suspension 97
8.1 Preparation data .........................................................................................................................................128
8.2 Fault diagnosis...........................................................................................................................................128
8.3 Real wheel .................................................................................................................................................129
8.4Rear shock absorber.................................................................................................................................... 130
IX. Fuel tank/seat mat 136
9.1 Preparation data .........................................................................................................................................136
9.2 Fault diagnosis...........................................................................................................................................136
9.3 Fuel tank/seat mat......................................................................................................................................137
Inspection and maintenance of engine 139
X. Lubrication system 107
10.1 Preparation data .......................................................................................................................................143
10.2 Fault diagnosis.........................................................................................................................................144
10.3 Oil pump .................................................................................................................................................. 144
XI. Carburetor 111
11.1 Preparation data .......................................................................................................................................149
11.2 Fault diagnosis.........................................................................................................................................150
11.3 Disassembly of carburetor ....................................................................................................................... 150
11.4 Installation & adjustment......................................................................................................................... 155
XII. Cylinder cover 116
12.1 Preparation data .......................................................................................................................................157
12.2 Fault diagnosis.........................................................................................................................................157
12.3 Cylinder head........................................................................................................................................... 157
12.4 Examination on cylinder head .................................................................................................................159
12.5 Cylinder head installation ........................................................................................................................ 159
XIII. Air cylinder/piston 120
4
13.1 Preparation data .......................................................................................................................................162
13.2 Fault diagnosis.........................................................................................................................................163
13.3 Cylinder body ..........................................................................................................................................163
13.4 Piston .......................................................................................................................................................165
13.5 Installation of piston ................................................................................................................................170
XIV. Drive disk/Clutch/Driven Wheel / Foot start mechanism 174
14.1 Preparation data .......................................................................................................................................174
14.2 Fault diagnosis.........................................................................................................................................174
14.3 Left crankcase cover................................................................................................................................ 175
14.4 Drive disk.................................................................................................................................................175
14.5 Clutch/driven wheel................................................................................................................................. 178
14.6 Disassemble the clutch and the driven wheel .......................................................................................... 180
14.7 Installation ...............................................................................................................................................186
14.8 Foot start mechanism...............................................................................................................................186
XV. Decelerator 137
15.1 Preparation data .......................................................................................................................................189
15.2 Fault diagnosis.........................................................................................................................................189
15.3 Gear Case................................................................................................................................................. 189
15.4 Installation ...............................................................................................................................................191
XVI. Crankcase 140
16.1 Preparation data .......................................................................................................................................194
16.2 Fault diagnosis.........................................................................................................................................195
16.3 Crankcase................................................................................................................................................. 195
16.4 Installation ...............................................................................................................................................199
Exhaust emission system inspection and maintenance 144
XVII. Exhaust emission and control system 145
17.1 Warranty of Exhaust emission and control system.................................................................................. 201
17.2 Regular maintenance guideline................................................................................................................ 202
17.3 Mechanical function of the exhaust control system.................................................................................203
17.4 Catalyst converter system ........................................................................................................................205
17.5Countermeasure of idle speed emission exceeding specified value（Two -stroke）................................ 206
5
Preface
This Manual explains the maintenance of Qianjiang RACE 50.
The documents to be prepared are the maintenance manual and all the operations are included in, please read
the manual prior to operation.
Inspection and Adjustment explains the gist of inspection and adjustment; the maintenance of safety of vehicle
and the performance of each part should come into force since regular inspection.
After Chapter I is the explanation of the gist of disassembly, assembly and inspection of engine, entire vehicle
and electric fittings.
There are exploded view, system diagram, maintenance, fault diagnosis and explanation before each chapter.
Notice：
There is no prior individual notification on the alteration of mode or structure of motorcycle and the actual
product shall prevail if there is discrepancy between the photos, pictures or explanation contained in this Manual
and the actual product.
Zhejiang Qianjiang Motorcycle Co., Ltd.
6
Documents to be prepared
General safety Maintenance regulation
Specififcation sheet Troubleshooting
General safety
Carbon monoxide
If the engine must be activated, make sure that the workplace is well ventilated. The engine can not be running in a
confined place.
Attention
The exhaust contains toxic gas, carbon monoxide, which can numb people and may result in death.
The engine should be started in an open area and the exhaust scavenging system should be applied if the engine has
to be started in a closed area.
Gasoline
The operation should be made in a ventilated area and smoking or lighting fires should be strictly forbidden in
working space or the place stored gasoline.
Battery
Battery could give off explosive gases, so, keep it away from incineration area or open flame or where smoking is
permissible. When charging, keep it well-ventilated.
Battery contains sulphuric acid (electrolyte) which could result in burn if contacting your skin or eye, so, wear
protective clothing and faceshield.
-If electrolyte spatters on your skin, use fresh water to flush immediately.
-If electrolyte spatters in your eye, use fresh water to flush for more than 15 minutes and see a doctor
immediately.
Electrolyte is toxic. In case you drink some electrolyte inadvertently, drink a large volume of fresh water, milk and
milk of magnesia (a kind of laxative antiacid) or vegetable oil and see a doctor immediately. Keep it at a place
where is beyond reach of children.
7
Maintenance regulation
As maintaining this vehicle, the instrument of metric system should be applied as possible for the reason that the
application of incorrect instrument may demage this vehicle.
Before dismantling from or frame cover of vehicle to maintain the dirt of parts or external subassembly should be
purged in order to prevent that falling into engine , chasis or braking system.
After dismantling and before measuring attrition value, please
clean parts and purge it with compressor.
The rubber parts will be deteriorated due to aging which is prone to be damaged by solvent or oil and it should be
inspected (if necessary, it should be replaced) before
reinstallation.
Sleeve
8
Loosen the parts with multiple assemblies that should be made
from outside to inside and started from small one.
The complicated assembly, transmission case, for instance, should
be stored according to proper assembly sequence in order to
facilitate the assembly in the future.
9
For the important assembly position, it should be given special
attention before dismantling. The parts out of use should be
replaced before dismantling in time.
The length of bolts to assemblies and frame cover are different
which should be installed in correct position and the bolts may
placed in the hole to find out whether they are suitable if they are
mixed.
For the installation of oil seal, the grease should be filled in oil
seal groove; as installing oil seal, it should check the smoothness
of oil seal whether it will likely damage the oil seal.
For the installation of rubber hose (fuel, vacuum or coolant), the
ends of which should plug into the bottom of the joint in order to
ensure that there is enough space for hose clamp to clamp the
joint. The rubber or plastic soldering cup should restore its
Grove
Clamp
Joint
10
original design position.
As dismantling ball bearing, please use the tool to withstand one
or two (internal and external) bearing runners. If the strength is
only applied onto a rolling ring (no matter internal or external),
the bearing may be damaged as dismantling and has to be
replaced.
In both instances, the bearings will be broken
11
Loose cable is a hidden trouble to electrical safety. After
clamped, check each cable to ensure electrical safety;
It is not allowed to leave any wire clip bending towards
bonding points;
Bind each cable to its designated position;
It is not allowed to lay a cable to end or a sharp corner on
frame;
It is not allowed to lay a cable to end of a bolt or screw;
When laying a cable, keep it away from any heat source or
any place where may bite it when it is moving;
When laying a cable along a handle, avoid it being strained
too tightly or loosely and it can not interfere with any
adjacent part at any turning point;
All cables should be laid smoothly without twist or knot;
Before butt-jointing a connector, check if its sheath has been
damaged and if it is overstretched;
If a cable is at a sharp corner or outer corner, use tape or hose
to protect it;
After a cable is repaired, use tape to bind it securely;
Keep all control cables from bend or twist because dumb
control will result in case any control cable is damaged.
12
Motorcycle Identification
1. The vehicle identification number (VIN) is inscribed at
① on the frame. See Figure 1-1. Identification number:
LBBB9212?????????. On the VIN, the 10
th
digit shows the year
of manufacture and the 11
th
digit shows the code of the
manufacture plant. The anti-refit name plate is stuck inside the
helmet bucket; the frame name plate is riveted to ② on the
frame.
Figure 1-1
2. The engine series number ① is inscribed on the
crankcase housing. See Figure 1-2.
Figure 1-2
Important Notices
1. Please use genuine parts of Qianjiang Motorcycle. Use of the parts that fail the design specifications of
Qianjiang Motorcycle may cause damage to engine.
13
2. During servicing, use metric tools only. Do not interchange a metric bolt, nut or screw and an English system
fastener.
3. During reassembly, replace with new washers, O-rings, cotter pins and locking pieces.
4. When tightening bolts or nuts, tighten the ones with larger diameters or comparatively located at inside first, and
then tighten all bolts or nuts diagonally to specified torques step by step unless described otherwise.
5. Clean the removed parts with washing fluid. Before assembly, lubricate all sliding planes.
6. After assembly, check all parts for proper installation and correct operation.
7. Before measurement, remove dirt and oil; during assembly, add recommended lubricants to oil sites.
8. When engine and driveline require a long-term storage after dismounted, please apply lubricant to surfaces of
parts to prevent rust and dust accumulation.
14
Specific tools
The so-called specific tools refer to those specifically designed for assemble or dismantle of certain
components of the motorcycle. These tools are usually used in specific locations. Appropriate specific tools are
indispensable in the complete and accurate adjustment as well as in the assembly operations. By taking advantage
of specific tools, the components can be safely, reliably and quickly assemble or dismantle, thus enhancing the
work efficiency and saving lots of efforts.
1．tools used for the engine-overhaul
When assembling or dismantling the engine, specifically designed tools should be used for some certain
components to guarantee a smooth dismounting.
The list of specific tools for the assembly and dismantling of engine components and the figure of real objects
can be seen in table 1-1 and table 1-2.
Table 1-1
Name Remarks
Specialized circular wrench
Clutch holder
Flywheel extractor
Spacer gauge
Dismounting tools for bearing
Assembling tools for bearing
Oil-seal dismounting tool
Handle of dismounting tools
Piston pin exhaustion apparatus
Piston ring opening pincer
Heating plug circular wrench
Measure the thickness of clutch
Cylinder diameter tester
Dial dictator
Used for the assembly and dismantle of flywheel
bolt ,figure 1-3
Figure 1-4
Figure 1-5
Figure 1-6
Figure 1-7
Figure 1-8
Figure 1-9
Figure 1-10
Figure 1-11
Figure 1-12
Figure 1-13
Figure 1-14
Figure 1-15
Measure the inner canon of piston pin,Figure 1-16
Successive table 1-2
Figure 1-3 Figure 1-4
15
Figure 1-5 Figure 1-6
Figure 1-7 Figure 1-8
Figure 1-9 Figure 1-10
①Handle
Figure 1-11 Figure 1-12
Thickness gauge (clearance gauge)
16
① opening pincer ② piston
Figure 1-13 Figure 1-14
Figure 1-15 Figure 1-16
2．Tools used for the underpan-overhaul
The list of general tolls and specific tools for the dismounting of underpan components as well as the figure of
real objects can be seen in table 1-17 and table 1-18.
Figure 1-17
Name Remarks
rest wrench
inner hexagon wrench
circular wrench
micrometer
magnetic stand, V-shape block
dial indicator
square caliper
spring clip-ring clipper
whack-type screw drive
front fork oil seal dismounting tools
front part seal element driving-in tools
steering nut wrench
Figure 1-19
Figure 1-20
Figure 1-21
Figure 1-22
Figure 1-23
Figure 1-24
Figure 1-25
Figure 1-26
Figure 1-27
Figure 1-28
Figure 1-29
Figure 1-30
（1）General tools for the underpan-overhaul
Successive table 1-18
17
Figure 1-19 Figure 1-20
Figure 1-21 Figure 1-22
Figure 1-23 Figure 1-24
Figure 1-25 Figure 1-26
Figure 1-27 Figure 1-28
1. Bush-head 2.Shake-handle
3.Ratchet type wrench 4.Connecting-rod
18
（2）Specific tools for underpan-overhaul: front fork seal element driving-in tools
Figure 1-29
（3）Steering nut wrench
Figure 1-30
3．Tools used for electric apparatus components
The list of specific tools for the testing of electric apparatus components, as well as the figure of real objects
can be seen in table 1-31 and table 1-32.
Table 1- 3 1
Name Remarks
universal meter
ignition tester
Figure 1-33
Figure 1-34
Successive table 1-32
Figure 1-33
19
Figure 1-34
20
Specififcation Sheet (RACE 50)
Model RACE 50 Engine Type QJ1E40QMB-4
Full length mm 1820 Fuel type
Unleaded gasoline
（92/95）
Full width mm 695
Number of
cylinders
1
Full height mm 1140
Inside measure
* stroke
40×39.2
Wheelbase mm 1280 Total flow rate 49.2
Front axle 37 Start mode
Start by electricity
Foot start
mechanism
Rear axle 55 Cooling mode Wind-cooling
Vehicle weight kg
(serving quality)
To ta l
92
Outer
cover of
front wheel
120/70-12
Lubrication
Lubricate
separatly
Front rim
3.50×12
Outer
cover of
rear wheel
130/70-12
Air cleaner
3XG
Tyre specification
Rear rim 3.50×12
Petrol capacity 5±0.2L
Clutch type
Dry-centrifugal type
Engine
Carburetor type IIF-45
Transmission Stepless shift
Idling speed -
rpm
1750±100rpm/min
Gearing
Driving mode Belt drive
Maximum
torque
4.3 N.m/5500rpm
Battery
capacity/type
12V-4AH/
dry-charged type
Maximum
torque
2.50kW/6000 rpm
Capacity of
alternator
90W/8000rpm
Compression
ratio
6.9：1
Spark plug
NGK/TORCH，
BR7ES
Perform
ance
Maximum speed 45km/h
Spark plug 0.6-0.7mm
Diameter of
front brake
disk（mm）
φ190mm
Electrical
installation
Ignition mode CDI
Brake
Inner diameter
of rear brake
drum
（mm）
φ110mm
21
RACE 50
22
23
N Y
N Y
Y N
Y N
Troubleshooting
Trouble diagnosis program for engine start failure or difficulty
Engine fails or is difficult to
start
Check ignition
s
y
ste
m
Remove spark plug to check between its
electrodes for carbon connection
Perform spark over test of
s
p
ark plug
Clear carbon deposit
Sparks between electrodes weak or
none at all
Strong blue or purple blue sparks can jump out
from between electrodes
Screw off spark plug cap to perform
s
p
ark over test of ignition coil
Use an ignition timing light to detect if engine
i
g
nition timing is correct
Strong blue sparks can
jump
out
Sparks weak or none at
all
Check spark plug and its cap for
malfunction
Check
supply of
ignition
power
Check
ignition coil
for short
circuit or
open circuit
Check internal
wiring of
ignition system
for short circuit
or open circuit
Check CDI
igniter for
malfunction
Use a cylinder
pressure gauge to
check and measure
com
p
ression
Check
inside of
fuel tank
for
presence
of
Com
press
ion
press
ure
of
cylin
Com
press
ion
press
ure
of
cylin
Fill
gasol
ine
No-contact magneto
i
g
nition system
1. Check ignition power
coil for short circuit or
open circuit
2. Check trigger coil for
short circuit or open
circuit
1. Check CDI igniter for
malfunction
2. Check magneto flywheel
and trigger coil for
looseness
Loosen drain screw
on carburetor to
check if gasoline
flows out from
overflow pipe on
carburetor
24
Y N
Spark plug electrode wet Spark plug electrode dry
Check carburetor for flooding
Drip a little gasoline into cylinder to
perform experimental starting
1. Check between needle
valve and valve seat of
carburetor float for ajar
position caused by foreign
materials
2. Check cone of float
needle valve of carburetor
for steps caused by wear
3. Check for broken
carburetor float
4. Check carburetor float
for insufficient height
Check air cleaner
for clogging
Engine shuts down
in a very short time
after start
Engine can
continue to work
after start
Inside of carburetor
clogged or float
height excessive
Carburetor
starting device
(i.e. starting
richer system)
malfunctioning
1. Check all joints outside
engine for air leak
2. Check for the piston ring
locked in groove or having
insufficient elastic force
3. Check piston ring and
cylinder for wear
1. Check breather on
fuel tank cap for
clogging
2. Check fuel filter and
fuel cock for clogging
3. Check fuel cock for
proper operation
4. Check oil inlet on
carburetor for clogging
5. Check carburetor
float for height excess
Remove spark
plug for
inspection
25
Y N
Y N
Y N
N Y
Y N
Trouble diagnosis program for engine overheat
Engine
overheats
Check for improper method of
o
p
eration and usage
1. Check gasoline for inferior
brand or extended storage
2. Check if engine has ever run at
high speed or worked under
overload during running
Check cooling
s
y
ste
m
Air cooling
en
g
ine
Check radiating fins for sticking mud
and sand or excessive oil stains
Clea
n
Check cooling fan and its
cowl for damage (forced air
cooling engine)
Check and
troublesho
Use an ignition timing
light to detect if engine
ignition timing is
correct
1. Check CDI
igniter for
malfunction
2. Check magneto
flywheel and trigger
coil for looseness
Check for clutch slip
Clutch slips
Refer to
handling of
clutch slip
26
Remove spark plug, observe
color of spark plug insulator
skirt and determine mixture
ratio of combustible mixture
according to various abnormal
situations.
Spark plug insulator skirt
renders black; in addition,
exhaust muffler gives off black
fume or blasts, accelerating
ability is poor or idle speed is
instable and engine is liable to
shutdown when it is running
under medium low speed
(comparatively normal when it is
Spark plug insulator skirt
renders chocolate-
b
rown
Spark plug insulator skirt
renders white; in addition,
intermittent engine stop,
carburetor backfire, or power
lack of engine, etc. occurs
during acceleration.
Combustible
mixture too rich
1. Check air cleaner for clogging
2. Check carburetor starting device
(i.e. starting richer system) for
proper operation
3. Check carburetor float for
insufficient height
Mixture ratio of
combustible mixture
normal
Check exhaust port of
cylinder block and
exhaust muffler for
clogging caused by
excessive carbon
de
p
osit
Check
lubrication
s
y
ste
m
Combustible
mixture too thin
Lubrication system
on 2/4 stroke engine
1. Check fuel cock for
proper operation
2. Check carburetor
float for height excess
3. Check all orifices
and tunnels on
carburetor for clogging
1. Check if volume of engine oil
in crankcase is sufficient
2. Check if viscosity of engine
oil in crankcase is too low or
engine oil is too dirty
3. Check oil filter for clogging
4. Check oil pump for proper
operation
5. Check lubricant ducts for
clogging
27
Y N
Trouble diagnosis program for engine power lack
Engine power lacks
Erect main jiffy stand to enable wheels to be lifted
off
g
round and then rotate them by han
d
Wheels rotate
freel
y
Wheels rotate
dull
y
Check tire
p
ressure
1. Check brake for retard
2. Check wheel bearing for
excessive wear or damage
3. Check for missing or
comparatively short intermediate
spacer of wheel hub
Air pressure
too low
Air pressure
normal
Check tire valve core for air
leak and check for pierced
or cracked tire
Remove spark plug, block its threaded
hole by finger, and then depress start
button or rapidly depress starting lever.
Fingers feel that gas dashes out
making “pow…pow” sounds
Fingers do not feel that gas dashes out
Compression pressure of
c
y
linder normal
Compression pressure of
c
y
linder insufficient
1. Check all joints outside
engine for air leak
2. Check for the piston ring
broken or locked in groove or
having insufficient elastic
force
3. Check piston ring and
cylinder for wear
Start engine, increase throttle opening
slowly and observe for speed change of
engine
Engine speed rises with increase of
throttle o
p
ening
Engine speed can not rise with increase
of throttle o
p
enin
g
Use an ignition timing light to
detect if engine ignition
timing is correct
1. Check for clutch slip
2. Check drive belt for excessive wear
3. Check centrifugal rollers on head
pulley for excessive wear
4. Check cones on driving wheels and
moving friction wheels for excessive
wear or grooves caused by wear
5. Check cones on driven wheels and
moving driven wheels for excessive
wear or grooves caused by wear
6. Check raceway on inner end face of
moving friction wheel for excessive
wear or pits caused by extrusion
1. Check fuel supply system for
unobstructed fuel supply
2. Check carburetor, air cleaner and
exhaust muffler for clogging
3. Check vacuum diaphragm on
plunger valve of carburetor for map
cracking or breakage
4. Check carburetor float for
improper height
1. Check CDI igniter
for malfunction
2. Check magneto
flywheel and trigger
coil for looseness
28
Y N Y N
N Y
Y N
Y
N
Trouble diagnosis program for poor engine idle speed
Engine idle speed is
poor
Engine idle speed
too hi
g
h
Engine idle
s
p
eed disable
d
Engine idle speed
unstable
Check compression
p
ressure of cylinder
Pull carburetor throttle valve
by hand to check if it has been
completely closed
Use an ignition timing
light to detect if engine
ignition timing is correct
Compression pressure
of c
y
linder insufficient
Compression pressure
of c
y
linder normal
1. Check all joints
outside engine for
air leak
2.
5. Check for the
piston ring broken
or locked in groove
or having
insufficient elastic
force
6. Check piston ring
and cylinder for
wear
Readjust idle speed of
carbureto
r
Check for
oversize
idling jet
Check if cable
wire of throttle
control cable
can be pulled
to move
smartly in
cable jacket
and if throttle
valve spring is
too soft
Chec
k for
under
size
clear
ance
betw
een
spark
plug
electr
odes
1. Check CDI
igniter for
malfunction
2. Check magneto
flywheel and
trigger coil for
looseness
Engine idle
speed is
enabled after
ad
j
ustment
Engine idle
speed is still
disabled after
ad
j
ustment
Air adjust
screw on
carburetor or
adjusting screw
on throttle
valve adjusted
improperly
Check idling jet, fuel
way and air way on
carburetor for clogging
Clean and
dred
g
e
Check carburetor float for height
excess
Adjust float
height to
standard value
1. Check insulating body on carburetor for
cracks
2. Check connecting and fixing nut on
carburetor for looseness
3. Check negative pressure pipe of fuel cock
for breakage
4. Check leaf valve for air leak
Adjust
clearance
between
electrodes
Check mixture
ratio of
combustible
mixture
29
Y N
Y N
Y N
Y N
Trouble diagnosis program for excessive fuel consumption
Engine fuel consumption
is excessive
Check for correct method of
o
p
eration and usage
Erect main jiffy stand and rotate
wheels b
y
hand
1. Check if motorcycle has ever run
under overload, at non economical
vehicle speed, or in low gear
2. Check if brand of the gasoline
used is correct
Wheels rotate
dull
y
Wheels rotate
freel
y
1. Check brake for
retard
2. Check wheel
bearing for excessive
wear
3. Check for missing
or comparatively short
intermediate spacer of
wheel hub
Check tire
p
ressure
Air pressure
too low
Air pressure
normal
Inflate until
full as re
q
uire
d
Check fuel tank, fuel cock, oil
delivery pipe, carburetor, etc.
for oil leak
Troubleshoot as
a
pprop
riate
Check mixture ratio of
combustible mixture
Mixture ratio of combustible
mixture normal
Combustible
mixture too rich
Combustible
mixture too thin
Check engine for too high
idle s
peed
1. Check air cleaner for
clogging
2. Check carburetor float for
insufficient height
3. Check for oversize main jet
on carburetor
1. Check inside of
carburetor for clogging
2. Check carburetor float
for height excess
Check and adjust
carbureto
r
Use an ignition timing
light to detect if engine
ignition timing is
correct
Check for clutch
drive belt slip
Check ignition
s
y
ste
m
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