KAYO MOTOR AU150, BULL 150 Maintenance Manual

KAYO
AU150
BULL 150
Maintenance Manual
WWW.KAYOMOTO.US
VERSION CODE：20190316
VERSION NAME：AU150 Maintenance Manual
1
ZHEJIANG KAYO MOTOR CO. LTD
March of 2019
Introduction
This manual contains detailed operation for
AU150 (ATV), including maintenance and
adjustment processes, dis-assembly
and installation notes, inspection and
maintenance points, troubleshooting
methods and maintenance technical data,
and graphics.
Please read the manual carefully and follow
the instructions strictly during the inspection
period, following these instructions can
lengthen the service life of parts and enhance
the performance of the ATV.
Chapter1: introduce the normal operation
issue, tools used, basic technique and repair
data.
Chapter2: introduce how to assemble and
dis-assemble the plastics.
Chapter3: introduce the regular maintenance
and adjustment.
Chapter4: introduce how to dis-assemble the
parts in the places around engine.
Chapter5: introduce the method and notes
for dis-assembly, checking, repair and
assembly of engine parts
Chapter 6: introduce ATV chassis related
information.
Chapter7: introduce the detection and repair
of the signal and lighting system.
Appendix: Electrical schematic diagram
All contents in this manual are subject to
improve and update without notice.
Maintenance is subject to actual condition.
CONTENTS
Zhengjiang Kayo Motor., Ltd
RD Department
March of 2019
2
Service Information
1
Plastics
2
Regular Maintenance and
adjustment
3
Places around engine
4
Engine
5
ATV chassis
6
Signal and lighting system
7
Electrical schematic diagram
Append
ix
3
Conversion table
Unit conversion
1kgf/cm2=98.0665kPa；1kPa=1000Pa
2
pressure 1PSI=0.0689kgf/cm
1mmHg=133.322Pa=0.133322kPa
Item
Torque
1kgf·m=9.80665N·m
volume
1mL=1cm3=1cc
1L=1000cm3
Moment
1kgf=9.80665N
Length
1in=25.4mm
Danger/warning/attention
Please take the safety precautions below seriously. During maintenance, and especially during
engine service.
Danger: Be on high alert for danger.
Warn: to be alert to moderate danger.
Attention: to be alert to minor danger.
This manual may doesn’t contain some potential risks in engine work and maintenance, so besides
the above explanations, the service operator should also have basic mechanical knowledge, and if
you are not sure whether can finish the repair, please learn from the experienced workers firstly.
1. Maintenance information
1.1 Operation note………………………………………………………………………………1
1.2 VIN Number……………………………………………………………………………………3
1.3 Main specifications list………………………………………………………………………4
1.4 Maintenance specifications list…………………………………………………………6
1.5 Torque tightening……………………………………………………………………………9
1.6 Lubricant, sealant……………………………………………………………………………10
1.7 Cable, hose and wiring diagram………………………………………………………11
1.1 Operation notes
Safety notes
1. Wear work clothes (coveralls), hat and safety boots suitable for operation. In some conditions
safety glasses, dust masks, gloves and other safety protective supplies are needed to protect you
from injury。
2. Do not run engine in un-ventilated areas.
3. Do not touch the engine or exhaust before cooled down to avoid burns。
4. Battery solution (dilute sulfuric acid) is a strong corrosive agent, which might cause burns or
blindness when get contact with skin or eyes. Once the battery solution is accidentally touched on
clothes or skin, rinse immediately with plenty of water and go to hospital to get treatment in time
when needed. Storage battery and battery solution should be kept strictly out of reach of children.
Battery charging can produce flammable and explosive Hydrogen. There is an explosion risk if
exposed to source of fire or spark. Please charge batteries in well-ventilated places.
5. As gasoline is flammable and explosive, Pay attention to sparks as well as open flames. Vaporized
gasoline may explode or burst into flames, please choose well-ventilated areas when working with
fuel systems.
6. Attention, the rear wheel, clutch or other rotating parts and movable parts may clip hands and
clothes during maintenance. Please tie up any loose clothing or hair when performing maintenance
in these areas
7. Two or more people must constantly greet each other when operating to ensure safety.
Disassembly and installation instructions
1. All the Parts, fluids and lubricants must be Kayo brand parts or Kayo recommends.
2. When disassembling, Please sort out the parts of each system and keep separate to ensure that
all parts can be put back.
3. Clean the vehicle before inspection
4. Gaskets, O-rings, piston rings, circlips, snap-rings, cotter pins and other onetime use parts should
be replaced after disassembling.
1
5. Snap rings can be deformed if opened or closed too much during disassembly. Please do not use
snap rings that have been compromised.
6. After disassembly and inspections, clean the parts and blow the cleaning agent away with
compressed air before measurements. Grease the moving surfaces before assembly.
7. During disassembly, check all the necessary parts for wear and measure. Before re-assembly
make sure all parts are within specification.
8. Bolts, nuts, screws and other fasteners shall be pre-tightened by hand, then torqued to the
specified torque value, In a diagonal sequence from large to small fasteners and from inside to out.
9. Inspect rubber parts before disassembling and replace if necessary. In addition, some rubber
parts are not resistant to gasoline, kerosene and other corrosives. Please keep these rubber parts
away from volatile oil and grease.
10. Smear or inject recommended grease in specific places as required in service manual.
11. Use the correct tools for disassembly and installation.
12. Bearings inner race or outer races can be checked by rotating with finger to confirm whether the
rotation is smooth. If the bearings are a press fit, and the removed bearing is disfigured the bearing
shall not be used again. If there are problems as bellow, please replace bearing.
 Bearing axial and radial clearance is loose
 The bearings if stuck or frozen, Please clean and lubricate. If the bearings still feel stuck after
cleaning, replace it. If it can’t be cleaned, replace it.
 If the bearing is originally compaction fit with vehicle or axle diameter, but it gets unsuitable
after disassembly, replace it.
13. The bearings should be lubricated with oil or grease before assembly. Notice the direction of
installation when assemble one-side dustproof bearing. When assemble open or double-sided
dustproof bearing, make the manufacturer's logo and dimensions outwards.
14. Install snap rings with chamfered side towards force direction. Do not use the rings that have
been deformed. After assembly, rotate the rectangular ring to confirm that it is firmly installed in
the slot.
15. Please check whether all fastening parts are tightened and that function is normal after
assembling.
16. Brake fluid and coolant can damage the coating surface, plastic parts, rubber parts, etc., do not
let it adhere to these parts, in case of adhesion rinse with water immediately.
17. Make the side with manufacturer’s mark outside when install oil seal：
 Pay attention not to make oil seal lips curl, do not let burrs scratch oil seal lip during assembly.
 Grease the oil seal lip before assembly.
18. When installing rubber hoses, insert the rubber hose onto the fitting. If there is a hose clamp,
install the hose clamp in the hose indentation if there is one. Replace the rubber hoses that are
loose, dried or cracking.
18. Keep the inner of engine and brake hydraulic system away from dust and clay.
20. Clean gasket materials on mating surfaces before installation. Any scratches or gouges on the
2
contact surface must be removed uniformly with a whetstone or resurfaced.
21. Do not bend the cables or hoses excessively. Deformed and damaged cables can cause poor
range of motion, leaks or breaks.
22 When assembling the protective cap parts, if there is a groove insert the protective cap into the
groove.
Grinding in of engine
There are many relative motion components in the engine, such as pistons, piston ring, valves
chains, sprockets, mutually meshing gears, etc., it’s very important to have a standard break-in at
the beginning of using. Break-in can help the moving parts adapt to each other, correction work,
form a smooth friction surface which can bear heavy load, by this way the engine will have excellent
performance and reliability.
Recommended break-in time is 10 hours, as follows:
0~10 hours: To avoid continuous operation under the condition of 1/2 throttle, the speed should be
changed frequently, and it is not recommended to operate for a long time with a fixed throttle
position; Cool the engine for 5 to 10 minutes after each hour of operation. Avoid quick acceleration.
The change of throttle should be slow, not sudden. Do not overload or drag/tow goods during the
Break-in period.
Note:
 During break-in period, perform everyday maintenance.to prevent future issues
 Once Break-in period is complete, schedule a service for the vehicle, then put into formal use.
3
1.2 VIN number
① VIN number
② Metal plate
③ Engine number
MODEL
AU150
VIN NUMBER
ENGINE NUMBER
1
2
3
4
1.3 Main Specifications
ITEM
Specification
Model
AU150
Length（mm）
1663
Width（mm）
965
Height（mm）
980
Wheelbase（mm）
1050
Engine model
156FMJ
Displacement（ml）
140
Fuel type
No. 91octane or above
Weight（kg）
141
Rider No.
1 person（Only the rider, no passenger）
Max loading quality
1 person ＋ 60kg = 120kg
Tire spec
Front tire
AT20×7-10
Rear tire
AT19×10-9
Ground clearance
135mm
Turning radius（mm）
2350mm
Engine
Start
Electric
Engine type
Single cylinder, 4-stroke, oil cooling.
Transmission
CHOHO/Chain
Bore stroke（mm）
57×57
Compression ratio
8.8:1
Lubrication mode
Splash and pressure
Oil pump type
Rotor
Lubricating oil filter type
All-flow rotating filter
Oil
SAE15W-40/SF or above
Cooling
Oil cooling
4
ITEM
Specification
Air filter type
Paper filter core
Throttle Body
Type
Plunger throttle
Mix valve diameter
30mm
Fuel tank volume
Transmission
Steering
equipment
7L
Clutch
Automatic
Speed changing way
3 gears+ reverse gear
Gears
Forward gears:1 2 3
Gear changing order
By foot/ R N 1 2 3
Drive mode
Chain driven rear axle
Engine drive rotating
direction
clockwise
Biggest steering angle
46°±1°
Brake
buffered mode
Frame type
Suspension mode
Reverse gear:R
Front
Hydraulic disc
Rear
Hydraulic disc
Front double A-arm independent, Rear single
shock swingarm
MIG welded steel tube and plates
5
1.4 Maintenance Specs list
Lubricating device
Item
Engine oil
capacity
Change oil
Change oil
Standard
Limits
600ml（No oil filter core replaced） －
700ml（replace the oil filter core）
Full capacity
800ml
Recommended engine oil
Radial clearance of inner
and outer rotors
Oil
pump
rotor
－
Only use SAE 15W/40-SE oil. Don’t use
other brand of mixing use different
brand as this will cause engine
damaged and may cause accidents
－
0.12mm
Radial clearance between
－
outer rotor and pump body
0.12mm
Axial clearance between
rotor surface and pump
body
0.2mm
0.05~0.1
Air intake system（see 05-engine section）
Wheel (front and rear wheels)
Item
Rim jump
Tire
Vertical
Horizontal
Residual
groove
Air pressure
Standard
Limits
0.8mm
2.0mm
0.8mm
2.0mm
－
3mm
35kPa（0.35kgf/cm2）
－
Brake system
Item
Front brake
Rear brake
Disc thickness
Brake bar stroke
Disc thickness
Standard
Limits
3.5mm
10~20mm
4.0mm
3.0mm
6
－
3.5mm
Battery/charging device/Trigger coil
ITEM
Type
Output
Magneto trigger coil resistance
Magneto No-load voltage（engine in
Magneto cold condition）
STANDARD
Permanent-magnet alternator
Three-phase full wave
150
N/A
Magneto maximum output power
180w
Regulated voltage
14.5 ± 0.5V
trigger coil peak voltage
≥1V，200r/min；≥8.5V，2000r/min
Rectifier type
Full wave rectification
Capacity
12V 7Ah
Full charge 14.4V
Battery
Voltage
Not full
小于11.8V
charge
Ignition device
STANDARD
ITEM
Ignition method
Sparking plug
Ignition coil
resistance
Peak voltage
Type
Standard
Gap
Spark character
Primary
Secondary
D8RTC
0.6~0.7mm
Blue and white light
0.3 Ω
3.8 kΩ
Primary ignition
300~450V
coil
Pulse
Start relay coil resistor
CDI electric ignition
Resistor type spark plug
20kV~30kV
3.5 Ω
7
Light / Meter / Switch
ITEM
STANDARD
Fuse
10A
Light, bulb
Front light
12V—35W
Tail light/brake light
12V—2.8W
Valve mechanism + cylinder cover（ see 05-engine section）
Cylinder + piston + piston ring + crank connecting link（see 05-engine section）
Clutch + Transmission mechanism （see 05-engine section）
8
1.5 Tightening torque of fasteners
Note: When installing threads, please put antirust grease on the thread and connecting
surface.
Tightening torque at specified position-whole vehicle
No
Install position
Bolt specification
Qty
Torque（N·m）
1
Suspension lower rocker
arm bolt
GB5789
M10×1.25×70
4
45~59
2
Front shock bolt
GB5787
M10×1.25×40
4
45~59
3
Rear shock bolt
GB5787
M10×1.25×50
1
45~59
4
Rear shock bolt
GB5787
M10×1.25×45
1
45~59
5
Front hub mounting
slotted nut
GB9457
M14×1.5×H18
2
126~218
6
Steering pulling rod ball pin
GB9457
slotted nut
M10×1.25
4
33~45
7
Handle bar gland screw
GB70-85 M8×30
4
22~30
8
Front brake bolt
GB5789
4
22~30
9
Front brake bolt
M8×1.25×20
8
22~30
10
Rear brake caliper bolt
GB5789
M8×25
2
22-30
11
Rear brake disc mounting
screw
GB70-85 M8×16
4
22~30
12
Handle bar raisers mounting
GB5783
bolt
M10×1.5×30
2
45~59
13
Oil cooler mounting bolt
GB5789
M6×25
4
9~12
14
Towing ball head fix plate
mounting screw
GB70-85 M10×1.5×30
4
45~59
15
Rear hub mounting slotted
nut
GB9457
M16×1.5
2
199~311
16
Steering column mounting
slotted nut
GB9457
M10×1.25
1
110~130
17
Steering column clip plate
mounting bolt
GB5787
M8×60
2
22~30
18
Oil tank front mounting bolt GB5789
M6×25
2
9~12
19
Oil tank rear mounting bolt GB5789
M6×30
2
9~12
20
Horn mounting bolt
GB5787
M6×16
1
9~12
21
Negative pressure
switch bolt
GB5787
M6×16
1
9~12
22
Engine mounting bolt
GB5787
M10×1.25×160
1
45~59
23
Sprocket holder mounting
screw
GB70-85 M8×20
4
38~51
24
Plastic bottom tray mounting
GB70-85 M6×45
screw
4
13~16
M8×25
9
25
Cross head tapping screw
GB845-85
ST4.2
—
—
26
Cross head machine screw
GB828-88
M5×16
2
—
27
Cross head big fat machine
screw
TM6
—
—
28
Rim mounting nut
GB6187-86 M10×1.25
16
45~59
10
Tightening torque at specified position - engine（see 05-engine section）
Tightening torque for fastener in non-specified position
Spec
Spec
torque N·m
5mm bolt, nut
5mm bolt
4.5~6
6mm bolt, nut
6mm bolt
8~12
8mm bolt, nut
6mm Convex bolt
18~25
10mm bolt, nut
8mm Convex bolt, nut
30~40
12mm bolt, nut
10mm Convex bolt, nut
35~50
Torque N·m
3.5~5
7~11
10~14
20~30
30~40
Engine service tools（see 05-engine section）
Engine special tools（ see 05-engine section ）
1.6
lubricating grease and sealant
Position
Note point
Steering bearing
Throttle perch connecting place
A-arm bushing
Steering column inner surface
Seat lock move part
Gear shift mechanism move part
Grease
Lightweight lithium
soap-based grease
Lubricating grease for Hand le cable, bearding and all rotating parts
Position
Contents
Grease
Steering axle spherical surface axle
sleeve
Rear wheel axle bracket
Front and rear shock joint place
Throttle, bar steering axle and pulling
Car use general
Lubricating
Lithium grease
GB/T5671
cable connector
Left and right handle bar turning axle
place
Parking cable connect place
Engine operating materials and installation accessories (see 05 -engine section)
Engine operating materials includes lubricating oil (engine oil), Grease and cooling liquid. The
installation accessories contain assembly grease or lube, screw thread sealant etc.
10
1.7 Wiring diagram of cable, hoses and cable
2
1
3
4
5
6
3
7
1. Reverse indicator connector(older models 2017 ) 2. Digital gear indicator connector 3.
Headlight connector 4. Neutral indicator connector (older models 2017 )5. Key switch
connector 6.Multifunction switch Connector 7. CDI connector
Note: To inspect the above parts, must remove the front rack and hood. Please refer to
02-Plastics.
11
8
9
10
8. Brake switch (left and right) 9. Throttle cable 10. Front and Rear brake lines
1
2
4
3
5
6
7
1.Carburetor 2. carburetor overflow hose 3.Starter motor cable 4. Crankcase vent hose
5.Stator/ignition pickup connector 6. Gear indicator connector 7.Voltage regulator connector
Note: To inspect the above parts, must remove the shift lever, and left footrest. Please refer
to 02-Plastics.
12
8
9
10
11
12
2
8. Starter Relay 9. Battery negative terminal 10. Starter cable 11. Battery positive terminal
12.Voltage regulator/rectifier
1
2
1. Tail light connector 2.Tail light
13
2 Plastics
2.1 Inspection item………………………………………………………………………15
2.2 Mounting torque…………………………………………………………………15
2.3 Dis-assembly and Assembly of seat and racks
2.3.1 Seat………………………………………………………………………16
2.3.2 Front rack……………………………………………………………………16
2.3.3 Rear rack……………………………………………………………………17
2.4 Dis-assembly and Assembly of hood, gear display front cover, gear display, foot
gear rod mounting combination
2.4.1 Front number plate……………………………………………………………………17
2.4.2 Gear display front cover…………………………………………………………18
2.4.3 Gear display……….………………………………………………………18
2.4.4 Shift lever mounting combination…………………………………………18
2.5 Disassembly and Assembly of left and right footrest
2.5.1 Left footrest plate…………………………………………………………………19
2.5.2 Right footrest plate…………………………………………………………………19
2.6 Disassembly and Assembly of front ventilation plate and bumper
2.6.1 Front ventilation plate…………………………………………………………………19
2.6.2 Bumper……………………………………………………………………20
2.7 Dis-assembly and Assembly of Front and rear assy. plate
2.7.1 Front assy. plate…………………………………………………………………20
2.7.2 Rear assy. plate…………………………………………………………………21
14
2.1 Inspection information
Working notes.
 When replacing plastics with warning stickers, please reapply new stickers
accordingly.
 Refer to this chapter when plastics need to be dis-assembled to inspect inner
parts



This chapter describes the order of dis-assembly and assembly of plastics
This chapter describes the dis-assembly and assembly of racks, seat, outer
plastic parts.
Hoses, cables, brake lines should be through the right positions as per the
“Wiring diagram of cable, hosepipe and pulling cable”.
2.2 Mounting torque
M8 bolt
M6 bolt
M5 bolt
Self-tapping nail
torque N·m(kgf·m)
torque N·m(kgf·m)
torque N·m(kgf·m)
torque N·m(kgf·m)
21（2.1）
10（1.0）
5（0.5）
4（0.4）
2
2.3 Dis-assembly and assembly of seat and racks
2.3.1 Seat
Dis-assembly
Lift the seat latch 1
Lift up the rear of seat, and then pull it
backward. 2
Remove the seat.
2
Assembly
Install in reverse order from
dis-assembly
Check if the seat is installed in place and
firm
1
2.3.2 Front rack
Dis-assembly
Dis-assemble the mounting bolts from
rack 3(left and right each one）
Dis-assemble mounting bolts 1
Dis-assemble front rack 2
1
2
Assembly
Install in reverse order from disassembly
3
3
2.3.3 Rear rack
Dis-assembly
Dis-assemble mounting bolt from rear
rack 1(left and right）
Dis-assemble rear rack 2
2
Assembly
Install in reverse order from
dis-assembly
1
2.4 Front plate, gear display front
cover, gear display, foot gear rod
mounting combination
2.4.1 Hood
Dis-assemble front rack（→ 2.3.2）
Dis-assemble Hood 1
Assembly
Install in reverse order from
dis-assembly
1
4
2.4.2 Gear display front cover
Dis-assembly
Pull out oil breather pipe 1
Dis-assemble front cover 2
Assembly
Install in reverse order from
dis-assembly
2
2.4.3 Gear display
1
Dis-assembly
Dis-assemble meter front cover（→
2.4.2）
Back out 2 nuts 3
Dis-assemble gear display 4
3
Assembly
Re assemble in reverse order from
dis-assembly
4
2.4.4 Shift lever mounting
combination
Dis-assembly
Dis-assemble Shift lever mounting bolt 6
Dis-assemble foot gear rod 5
Assembly
Install in reverse order from
dis-assembly
6
5
5
2.5.1 Left footrest plate
Dis-assembly
Dis-assemble foot gear rod（→ 2.4.4）
Dis-assemble fasten screw 1
Dis-assemble fasten screw 2
Dis-assemble left footpeg from lower to
upper 3
Assembly
Install in reverse order from
dis-assembly
1
2
3
2.5.2 Right footrest plate
4
Dis-assembly
Dis-assemble fasten screw 4
Dis-assemble fasten screw 5
Dis-assemble right footrest from lower
to upper 6
Assembly
Install in reverse order from
dis-assembly
2.6 Dis-assembly of front
ventilation plate and bumper
5
2.6.1 Front ventilation plate
Dis-assemble front rack（→2.3.2）
Dis-assemble mounting bolt 7（left and
right each 2）
Dis-assemble front ventilation plate 8
Assembly
Install in reverse order from
dis-assembly
6
8
6
7
2.6.2 Bumper
Dis-assembly
Dis-assemble front rack（→ 2.3.2）
Dis-assemble mounting screw1（left and
right each 2）
Dis-assemble bumper 2
1
Assembly
Take it back in reverse order from
dis-assembly
2
2.7 Dis-assembly and Assembly of
fuel tank cover plate, front and
rear assy. plate
2.7.1 Front assy. Plate
Dis-assembly
Dis-assemble gear display front cover
（→2.4.2）
Dis-assemble front rack（→2.3.2）
Dis-assemble front plate（→ 2.4.1）
Dis-assemble foot gear rod（→2.4.4）
Dis-assemble left footrest plate（→
2.5.3）
Dis-assemble right footrest plate（→
2.5.4）
Dis-assemble front Plate mounting
screw 1
Dis-assemble screw 2（left and right 1）
4
Dis-assemble screw 3
Dis-assemble front assy. Plate 4
Assembly
Install in reverse order from
dis-assembly
Note:
Before dis-assembly, remove and label
wires and connectors to avoid mistake.
1
3
2
2.7.2 Rear assy. plate
7
Dis-assembly
Dis-assemble front plate（→ 2.4.1）
Dis-assemble front assy. Mounting
screw（→2.7.1）
Dis-assemble foot gear rod（→ 2.4.4）
Dis-assemble left footpeg plate（→
2.5.3）
Dis-assemble right footpeg plate（→
2.5.4）
Dis-assemble mounting screw 2
Dis-assemble rear assy. plate3
Assembly
Re install in reverse order from
dis-assembly
Note:
Disconnect battery and necessary wires
before removal. Check cable, hose and
wire routing once assembly is complete.
2
8
3
Regular maintenance and adjustment
Maintenance information…………………………………………………………………22
3.1 Maintenance circle……………………………………………………………………23
3.2 Way of maintenance……………………………………………………………………24
3.3 Steering column, brake system………………………………………………………27
3.4 Wheels…………………………………………………………………………………32
3.5 Suspension system……………………………………………………………………………34
3.6 Gear shift mechanism, fuel device………………………………………………………………35
3.7 Throttle inspection……………………………………………………………………………36
3.8 Gear display…………………………………………………………………………37
3.9 Light device……………………………………………………………………………37
Maintenance information
Operation cautions
Note:
 Do not run the engine in unventilated areas, exhaust contains carbon monoxide (CO) and
other toxic components.
 Do not touch the engine or exhaust. Please wear long sleeves work clothes and gloves.
 As gasoline is flammable and explosive. Pay attention to sparks as well as open flames.
Vaporized gasoline may explode, please choose well-ventilated sites when working with
fuel systems.
Note:
Being careful of drive system and rotating parts, tie up loose hair and clothing if possible
Note:
Keep the vehicle on a flat and stable place
9
3.1 Maintenance Schedule
Engine maintenance is a regular periodic work, according to a certain time interval for engine
maintenance is very important, standard maintenance is helpful for well engine performance,
reliable work, economic and durable, the following is the AU150 engine maintenance period
table.：
Note: the contents in the table is based on normal condition, if in bad condition, dirty or
showing wear inspect or replace earlier.
Item
Milometer(km)
Circle
1000km
Maintenance item
4000km
8000km
12000km
I
I
I
C
C
C
C
I
I/R
I
I/R
Sparking plug
I
I
I
I
Valve gap
I
I
I
I
R
R
R
R
Fuel system access
Fuel filter
Remarks
Carburetor chock
①
Air filter
Lubricating oil
Each year
Lubricating oil filter
Each year
net
R
C
Clutch
I
I
I
I
Carburetor idle
I
I
I
I
The vehicle should be maintained regularly as per stipulated time, here is the
meaning of each Abbreviation：
C：Clean
R：Replace
A：Adjust
L：Lubricate
I：Inspect
Remarks①: Clean more frequently when riding in the place of too much dust.
3.2 Wayofmaintenance
Maintenanceitem
Steering
device
Braking
device
Steering wheel Operating flexibility
○
Damage
○
Installation status of steering ○
Steering
system
Ball pin shaking
○
Pedal travel
○
Brake pedal
Braking effect
○
Connecting rod Slackness, looseness and
○
and oil pipe
damage
Hydraulic
brake and
brake disc
Brake pad
Brake fluid
Tear and damage of brake disc
Tear and damage of brake pad
One year
position
Half year
Maintenance item
Daily
Maintenance
Maintenan
cecircle
○
○
○
○
○
○
○
○
○
○
○
Above the brake fluid
lower limit
Replace the disc in time,
when front or rear brake
working disc’s thickness is
less than 3mm.
The minimum brake pad
（ friction plate ）
thickness≥1mm ； less
than 1mm, replace it.
Front wheel：35kPa（
0.35kgf/ cm2）(5PSI)
Rear wheel： 35kPa（
0.35kgf/ cm2）(5PSI)
Tire pressure
Driving
device
Wheel
Crack and damage of wheel
Tire tread depth and
abnormal wear
○
○
○
Buffer
device
Suspension
arm
Shock
Front axle
Transmissi Rear axle
on device Gearbox
Loose of wheel nut and axle ○
Front wheel bearing vibration ○
Rear wheel bearing vibration ○
Shaking of connection part
○
and damage of rocker arm
Leakage and damage
○
Function
Transmission and lubrication ○
Transmission and lubrication ○
Fuel leakage and leakage qty ○
11
Standard
○
If there’s no wear
indicator on the tire, the
tread depth should
greater than3mm
○
○
○
○
○
○
○
○
○
Loose Refueling port bolt,
fuel should be reach the
opening
12
Maintenance item
○
Output shaft Loose of connecting place
Transmissi (transmission
Shacking of Spline part
on device shaft）
State of spark plug
Ignition device Ignition period
Terminal connection status
Electrical Battery
device
Electric circuit Looseness and damage of
joints
Fuel leak
Fuel device
Throttle condition
Light device and turning
indicator
Alert and lock device
Meter
Exhaust pipe and muffler
Function
○
Function
Function
Whether the installation is loose or
damaged
Function of muffler
Frame
Other
state of grease in frame each part
Exception can be identified in
Make sure relevant parts are normal. ○
operation.
13
One year
Maintenance item
Half year
Daily
Maintenance
position
Circle
Standard
○
○
○
○
Spark plug gap：0.6mm~0.7mm
○
○
○
○
○
○
○
○
○
○
○
Throttle knob clearance：
2 ~ 6mm
3.3 Steering column and brake
system
With the vehicle on a sturdy flat surface hold
handlebar firmly and push up and down as it
shown in the picture. Check for rattles, shaking or
excessive play.
If there is, check steering column, bearings,
and fastening parts.
Tighten any loose fasteners and replace
worn bearings or bushings.
With the vehicle on a sturdy flat surface. Turn the
handlebar slowly all the way left then all the way
right to check if it turns smoothly.
If it is rough, hard to turn or loose, check the wire
and cable routing, if there is no problem, check
steering rod, ball joints for damage or wear.
Note: the steering handlebar must be smooth,
accidents may occur due to lack of control.
Clearance for front and rear handlebars：
Operate the front handle bar to check the
brake effectiveness and movement of
handle bar
Check the clearance of handlebars
14
Front master cylinder
Check the fluid level.
Check the fluid level in the sight glass 3,
If the fluid level drops below the lower limit,
stop using the vehicle. Check for leaks in master
cylinder, brake line and all connections, if they are
all normal, then check the brake caliper and
pistons and replace if necessary. It should be a
routine to check brakes condition and brake
function before using the vehicle.
1
Remove screws 1
Remove master cylinder cover 2
Add brake liquid to the upper limit
2
Note:
● When adding brake fluid, do not mix with
dust, dirt or water.
● Use brake fluid from a new unopened
container.
● Brake fluid can damage plastic, rubber and
painted surfaces, Be careful not to spill. If
brake fluid spills dilute with water and wipe
clean immediately.
Turn the handle bar left and right, until the master
cylinder is level, then remove cover to refill
3
15
Front brake disc and brake pads (break pad wear)
Note:
Brake pads should be changed as a set.
Checking brake rotors
Check the surface of brake disc blueing,
discoloration or warping 1
If its thickness ≤3.0mm, replace.
Front brake disc thickness limits: no less
than 3.0mm.
Check the brake pad thickness 2
The minimum thickness should be ≥1 mm at
grooves, if less replace.
If the brake pads are damaged or showing
cracks,or abnormal wear replace them.
1
Note:
Please check brake fluid levels frequently,
Check brake line connecting points for leaks
or damage replace if necessary. Check
master cylinder and caliper for leaks or
damage, replace if necessary.
Note: Do not leave the master cylinder cap
off for prolonged periods of time.
Brake fluid should be flushed every two
years.
2
16
Rear brake master cylinder
Check the fluid level.
Check the fluid level in the sight glass 3,
If the fluid level drops below the lower limit,
stop using the vehicle. Check for leaks in master
cylinder, brake line and all connections, if they are
all normal, then check the brake caliper and
pistons and replace if necessary. It should be a
routine to check brakes condition and brake
function before using the vehicle.
1
Dis-assembly
Remove screws 1
Remove master cylinder cover 2
Add brake liquid to the upper limit
Note:
● When adding brake fluid, do not mix with
dust, dirt or water.
● Use brake fluid from a new unopened
container.
● Brake fluid can damage plastic, rubber and
painted surfaces, Be careful not to spill. If
brake fluid spills dilute with water and wipe
clean immediately.
Turn the handle bar left and right, until the master
cylinder is level, then remove cover
2
Note:
Please check brake fluid levels frequently,
Check brake line connecting points for leaks
or damage replace if necessary. Check
master cylinder and caliper for leaks or
damage, replace if necessary.
Note: Do not leave the master cylinder cap
off for prolonged periods of time.
Brake fluid should be flushed every two
years.
3
17
Rear brake disc and brake block〈wear of brake
block〉
Check the wear condition of brake block, if
condition is bad, then replace it.
Note:
Brake pads should be changed as a set.
Checking brake rotors
Check the surface of brake disc blueing,
discoloration or warping 1
If its thickness ≤3.0mm, replace.
Rear brake disc thickness limits: no less than
3.0mm.
1
Check the brake pad thickness 2
The minimum thickness should be ≥1 mm, if
not, then replace it.
If the brake pads are damaged or showing
cracks, then replace it.
Brake fluid should be flushed every two
years.
2
18
3.4 Wheels
Lift the front wheel with the tool in a
horizontal position, and make sure there is
no force on the wheel. Shake the front
wheel left and right to check whether the
connection of the front wheel is tight.
If there is movement, check and fasten the
rocker arm, axle, rim bolt and nut.
If there is still a movement, check and replace the
bearing, ball joints, or A-arm bushings.
Front wheel size
Put the atv in a horizontal position and
measure the size of the front wheel toe-in.
The front wheel relative to the forward
direction of the vehicle is: A in front and B
behind the wheel
Toe-in size：A-B=1.5 ~ 2.5mm
F is the forward direction
F
1
If not within spec, adjust lock nut(2) of
steering rod:1, adjust the wheel toe-in to
4~10mm, locking.
Note: after the adjustment of front toe-in
size, drive the vehicle slowly then measure
and adjust again.
2
19
Tire pressure
Check the tire pressure with a barometer.
Note: Check the tire pressures while the
tire is cold for a more accurate reading
Appointed pressure/Tire
Pressure
Tire size
Front tire
Rear tire
35kPa（0 .35kgf/cm2）
35kPa（0.35kgf/cm2）
See chapter 1
See chapter 1
Wheel pattern
Check tread depth if is less than 3mm, replace.
Note
When tread is less than 3mm, please
replace immediately .
Wheel nut and wheel axle
20
Check the loose of front wheel axle, rear
wheel axle nut: 1 and pin, if there is loose,
fasten it as per the appointed torque.
Torque:
Front wheel axle nut：126N·mm～218N·mm
（12.6kgf·mm ～ 22kgf·mm）
Rear wheel axle nut：199N·mm～311N·mm
（20kgf·mm ～ 31kgf·mm）
1
Shaking of Wheel hub
Use tools to hang up the front wheel, turn
the wheels as per the axle direction when
there is no other acting force on the vehicle,
then check whether the vehicle will shake.
If there is shack, then dis-assemble the front
wheel and check the hub.
3.5 Suspension system
Keep vehicle in a horizontal position and compress up and down for several times according to the
pictures. If there is shaking or abnormal sound, check for oil leaks in the shock absorber, and whether
there is damage or loose fasteners.
21
Rear shock pre-load adjustment
Use Shock spanner wrench to adjust the
adjust cam of shock according to the load
capacity: 1
Clockwise turning is from high to low.
1
3.6 Gear box and fuel system
3
Gear box
Shift lever Click through the forward gears
with your heel operation should be smooth
with firm clicks between each gear. Shift
down with toe until you reach neutral come
to a complete stop then shift down with toe
to engage neutral. If shift lever is
misadjusted remove #3 bolt and adjust
accordingly.
Fuel device
Condition of fuel system
Remove the seat (→ 2.3.1)
Check fuel and vacuum lines for aging,
cracking, kinks or damage. If any damage is
found replace the hose. Replace fuel lines
every two years
2
3.7 Throttle check
22
Throttle Free-play : 1
Clearance：2 ~ 6 mm
When the freeplay is not within the range, adjust
throttle at the cable.
Remove sleeve: 3
1
Loose throttle cable nut: 2
Adjustment, adjust the freeplay of the
throttle to within spec.
After adjustment, fasten lock nut: 2 and
then assemble the sleeve: 3
3-5mm
*Replace throttle cable if cable adjustment is
adjusted all the way out and throttle is still out of
spec.
3
2
Throttle limiting device:
Throttle limiting device is used to restrict throttle
opening. Inspect the thread length limit of the
limiting screw. Factory set thread length should be
12mm:
To adjust Loosen the lock nut, then adjust with a
phillips screwdriver. For beginners, Throttle limiter
should be adjusted inward to limit throttle as much
as possible for safety.
As the rider’s skills progress the limiter screw can
be adjusted outward.
*Throttle limiter is set from the factory at with a
tamper proof screw. If necessary, the screw can be
removed with pliers and replaced with a phillips
head screw.
4
23
Horn checking.
3.8 Gear display
Checking the gear display
The Gear indicator should power up as soon
as the key is turned on. Shift through the
gears to make sure the gear indicator shows
the correct gear. R-N-1-2-3
**When shifting into or out of reverse come
to a complete stop before changing gears
3.9 Lighting system
Headlight Operation
Headlights will illuminate with the key on.
On the combination switch slide the light
switch 1 back to turn lights off, slide
forward one position to illuminate fog lights,
slide all the way forward to illuminate
headlights. Push high beam 3 button in to
turn high beams on. If any of the lights do
not illuminate check connections, If
connections are good check bulb filaments
replace if necessary
Tail light operation/check.
Squeeze brake levers one at a time while
checking for brake light illumination. Tail
light should illuminate when the atv is
started. If either is not working check
connections at tail light connector and at
brake switches. If connections are good
check bulb filaments
1
2
24
3
4
Engine components
Maintenance information…………………………………………………………………38
4.1 Fuel system………………………………………………………………………39
4.2 Air intake system………………………………………………………………………39
4.3 Exhaust system………………………………………………………………………40
4.4 Disassembly and assembly of engine…………………………………………………………41
Maintenance information
Precautions
● Before operation and maintenance, please ensure that the vehicle is shut down and cooled
completely, to avoid injury.
● Do not damage the frame, engine body, bolts and cables during maintenance.
● In order to protect the engine frame, please wrap the engine before operating.
● When the engine is removed, the corresponding containers should be prepared to receive
coolant, oil and fuel oil for environmental protection, and the coolant and oil should be
supplemented as required during installation.
Tightening torque
Engine bracket mounting bolt: GB5787
M10×1.25×160 45~59N·m
2
4.1 Fuel system
Dis-assembly
Dis-assemble foot gear, seat, gear
display front cover, front assy. Plate(see
02: plastics)
Dis-assemble mounting bolt: 1
Turn the fuel switch 3: to OFF position
Dis-assemble fuel pipe: 4(connecting to
carburetor position)
Remove fuel tank 2
1
Note
Gasoline is flammable; fireworks are strictly
prohibited in workplace. Not only open fire,
but also electric spark shall be given high
attention.
Besides, as there is a risk of explosion after
the evaporation (vaporization) of gasoline, the
operation should be carried out in a
well-ventilated place.
When disassemble the plastic parts, loose the
tube 1 of oil throttle, then dismount the oil
switch bolt 2 and remove switch, remove tank
mounting bolt last.
When dis-assemble fuel tank, if there is fuel in
the tank, then turn the fuel switch 3 to OFF
position to avoid fuel leaking, then
dis-assemble the fuel tank.
2
3
4
Assembly
Take it back in reverse order from
dis-assembly
Plug should be inserted well, there
should be a sound “Ta”.
Check the wellness of the fuel pipes
during assembly.
4.2 Air intake system
5
Dis-assembly
Dis-assemble seat, rear assy. Plate( see
02: plastics)
Dis-assemble mounting bolt: 5( left and
right each 1)
Dis-assemble carburetor 6
6
3
Dis-assemble fuel tank（→4.1
Dis-assembly and Assembly of fuel
tank）
Loose hoop 1
Dis-assemble air filter 2
Assembly
In reverse order from dis-assembly
Re-install all components
2
4.3 Exhaust system
3
Dis-assembly
Dis-assemble foot gear rod, seat, gear
display front cover, front assy. Plate,
rear assy. Plate(see 02: plastics)
Remove 2 bolts: 3
Remove heat shield parts: 4
4
Remove mounting lock nuts: 5
5
4
Remove muffler pipe clamp bolt: 3
Remove muffler pipe mounting bolt: 2
Remove muffler pipe 4
Remove exhaust head pipe 1
Assembly
Re-assemble in reverse order from
dis-assembly
4
4.4 Dis-assembly and assembly of
2
3
1
3
engine
Dis-assembly
Dis-assemble shift lever, seat, gear
display front cover, left and right
footpeg plate, rear assy. Plate(see 02:
plastics)
Dis-assemble fuel tank (see 4.1)
Dis-assemble air filter, carburetor (see
4.2)
Dis-assemble muffler/exhaust
assy.(see 4.3)
4
Remove 3 bolts: 4
Remove front sprocket cover: 3
Remove chain: 5
5
5
Remove spark plug cap: 2
Disconnect oil cooler hoses banjo bolts:
1, reinsert bolts after lines are removed
to prevent oil leaking.
1
2
Disconnect gear display connect wire
（→1.7）
Disconnect magneto trigger connect
wires （→1.7）
Disconnect starter motor plug: 4
Disconnect carburetor hoses: 3
3
4
Remove engine mounting bolts: 8
remove engine from left side: 9
Assembly
Re-assemble reverse order from
dis-assembly
9
6
8
5 Engine
5.1 Maintenance information……………………………………………………………….……….………44
5.2 Introduction to fuel and engine oil……………………………………………………………………46
5.3 Grinding-in of engine……………………………………………………………………….……46
5.4 Maintenance of engine………………………….....………………………………………….………47
5.5 Maintenance of machine……………………………………………………………………........……695.6 Dis-assembly, assembly and maintenance of carburetor...............……………………….……78
5.7 Maintenance of air in-take and out-put system…………………………………………………….……81
5.8 Dis-assembly, assembly and maintenance of air out-put system……………………………….…..…82
5.9 Dis-assembly, assembly and maintenance of air adding system…………………………………….….83
5.10 Dis-assembly, assembly and maintenance of start motor……………………………………………..85
7
5.1 Maintenance information
Conversion table refers
Item
Unit conversion
1kgf/cm =98.0665kPa
1kPa=1000Pa
1mmHg=133.322Pa=0.133322kPa
2
Pressure
Torque
Volume
Torque
1 kgf · m = 9 .8 0 6 6 5 N ·m
1mL=1cm3=1cc
1L =1000cm3
1kgf=9.80665N
维
Danger/warning/attention
Take below definitions seriously, which are very important for maintenance
Danger: Be on high alert for danger.
Warn: to be alert to moderate danger.
Attention: to be alert to minor danger.
This manual may doesn’t contain some potential risks in engine work and maintenance; the service
operator should also have basic mechanical knowledge.
General precautions
Warning:
Proper maintenance is very important to engine reliability and personnel safety.
● When there is two or more people working together, more attention should be paid for
safety.
● When starting the engine indoors, be sure to vent the exhaust outside.
● If toxic or flammable substances are used, handle in accordance with the manufacturer's
instructions strictly and make sure workplace must be well ventilated.
● Don't use gasoline as a cleaning fluid
● To avoid burns, do not touch uncooled engine oil, exhaust system parts
● If the fuel, lubrication and exhaust systems are serviced, please check for leaks ·
● In order to protect the environment, oil replacement parts must be disposed of properly .
8
Warning:
·If parts need to be replaced during maintenance, please choose parts which
recommended or provided by Kayo.
·Disassembled parts that need to be reused should be arranged in order, to aid in
assembly.
·Use special tools as specified in the maintenance manual.
·Ensure that parts used in assembly are clean and lubricated where required.
·Use special lubricants, binders and sealants.
·When fastening bolts, screws and nuts, tighten the large to small, and tighten
from inside to outside in a cross pattern to the specified torque.
·Use a torque wrench to tighten the torque required bolts, before tightening
clean all grease and oil from threads.
·Clean disassembled parts before inspection and measurement.
·After assembly, check fastening and running status of components
·Do reuse oil seals, O-rings, gaskets, self-locking nuts, lock
washers, cotter pins, elastic baffle and other onetime use parts.
5.2 Engine oil and fuel
9
Fuel: Use octane 91# or higher unleaded
gasoline
Engine oil：Use sae15w-40 oil for 4 stroke
motorcycle, quality grade according to the
classification of the API SG level or by the superior,
if no SAE15W - 40 oil, according to the engine
using the environment temperature, as the picture
on the right is shown.
Warning: Do not mix oils from different
brands or weights
5.3 Engine Break in
Engine has many relative motion components, such as piston, piston ring, cylinder block, mutually
meshing transmission gear wheel, etc. therefore, a standard break-in is very important at the beginning of
the its use, it can make the moving parts to adapt to each other, correction work, form good heavy load to
bear a smooth friction surface. Through this process the engine will has excellent performance and
reliability. Recommended break-in time: 20 hours, details as follows:
0～10 hours
Avoid continuous operation, constantly changing speed and not operating in a fixed throttle position when
the throttle is more than 50%; Cool the engine for 5 to 10 minutes after each hour of operation. Avoid
rapid acceleration, throttle change should be slow.
10～20 hours
Avoid operating longer than 3/4 throttle. Use freely but do not use full throttle.
1
5.4 Maintenance of engine
Details
maintain times
Odometer reading
1000km
4000km
8000km
12000km
Fuel system
Clean
Clean
Clean
Clean
Oil filter
Clean
Clean
Clean
Clean
Control
Adjust
Adjust, clean
Adjust, clean
Adjust, clean
Carburetor
Clean
Clean
Clean
Clean
Air cleaner
Clean
Clean
Clean
Clean
Spark plug gap
Adjust
Adjust, clean
Adjust, clean
Adjust, clean
Valve clearance
Adjust
Adjust
Adjust
Adjust
Engine lubrication
Replace
Filter media
Clean
Clean
Clean
Clean
Timing chain
Check
Adjust
Adjust
Adjust
Carburetor idle speed
Adjust
Adjust
Adjust
Adjust
Battery
Charge
Charge
Charge
Charge
Brake disc
Check
Adjust
Adjust
Replace
Brake system
Adjust
Adjust
Clean
Clean
Brake light switch
Adjust
Adjust
Adjust
Adjust
Illuminating system
Check
Check
Adjust
Adjust
Clutch
Adjust
Adjust
Adjust
Adjust
Shock absorber
Adjust
Adjust
Clean
Clean
Nuts/bolts
Tighten
Tighten
Tighten
Tighten
Front and rear wheel
Turn handlebar bearing
Check
Check
Check
Adjust
Check
Adjust
Replace
Replace
Items
Replace once per 2000km
Drive chain
Adjust and lubricate per 5000km
2
5.4.1 Disassemble, assemble and maintenance cylinder head
Right view of the 150 engine.
Left view of the 150 engine
Remove the locknut of cylinder head from its
holding place
Remove cylinder head. Check the state of paper
pad. Replace .
3
Dismantle the fixing bolt of left cover.
Remove left cover and inspect the paper
pad for damage. Replace.
Dismantle the fixing bolt of right cover.
4
Remove the right cover of cylinder head.
Inspect the gasket for damage and replace.
Remove inlet/exhaust valve cap .Check the state
of seal ring of valve cap and replace if worn or if
reuse is questionable.
5
Remove the fixing bolt of timing driven
sprocket.
Remove the connecting bolt of
cylinder head.
Remove cylinder head assembly.
6
Remove timing driven sprocket. Inspect the timing
driven sprocket for wear and damage. Replace if
necessary.
Check whether there is excessive carbon
deposit in combustion chamber. Clean and
replace if necessary
Remove the cylinder head. Pour gasoline into
inlet/exhaust pipe to inspect the seal condition.
Grind the valve and valve seat if there is gasoline
leaking into the combustion chamber.
7
Remove inlet/exhaust valve spring and check
the state. Replace if necessary.
Inspect the oil seal of inlet/exhaust valve for
damage. Replace if necessary.
Remove the spark plug to clean the carbon,
deposit and dust .Check the spark plug gap and
set it to 0.6 to 0.7 if necessary.
8
For the troubleshooting of cylinder head ,please refer to the following table
Description
Damage Form
Problem
Too much oil dirt or sand
Poor heat
on the cooling fins.
radiation of
Cause
The engine overheats.
the
Correction
Remove the oil dirt or
sand
fins on cylinder
head.
Carbon
deposit
in
Overheating head
The engine overheats
the combustion
Remove
the
carbon
deposit
chamber
Failure of sparking plug
Air leakage between
The engine starts hard or
Repair the threaded
threaded hole
the sparking plug and
fails to start
hole or replace the
cylinder head
Serious
deformation
cylinder head
leakage
between
The engine starts hard or fails to
ofAir
cylinder
head
end surface缸头末端面变形严重
Grind the cylinder head
the cylinder head and
start. Insufficient engine
end surface or replace
cylinder
output ;Engine speed changes
the cylinder head
during idle run
Cylinder
head
There are pits, ablation or
Air leakage between
The engine starts hard or fails to
pock marks, damages on
the valve and valve
start. Insufficient engine output;
the working surface of
seat due to improper
engine speed changes during
valve
tightness
idle run
The inner hole of valve
The fitting clearance
Thick blue and white fume form
guide is over worn
between the valve and the exhaust muffler pipe
seat.
Repair the valve seat
Replace the valve guide
the valve is too large
The cylinder gasket is
Air leakage between
The engine starts hard or fails to
Replace the cylinder
broken
the cylinder head and
start. Insufficient engine output;
head gasket更
cylinder
Engine speed changes during
idle run
9
The fixing nut is not
Air leakage between
The engine starts hard or fails to
properly tightened
the cylinder head and
start. Insufficient engine output;
cylinder
Engine speed changes during
Tighten the fixing nut
idle run
Improper clearance
Weak or no sparking
Oil leakage between the
Adjust electrode gap to
between electrodes
from the spark plug
cylinder and crankcase
0.6~0.7mm
electrodes
The spark plug electrodes
No sparking from the
The engine starts hard or fails to
Remove the carbon
are joined by carbon
spark plug electrodes
star
deposit between the
deposit
Spark plug
electrodes
Excessive carbon deposit
Weak or no sparking
The engine starts hard or fails to
Remove the carbon
or oil dirt in the spark plug
from the spark plug
start. Insufficient engine output;
deposit or oil dirt
electrodes
Engine speed changes during
idle run
The spark plug insulator is
Weak or no sparking
The engine starts hard or fails to
Replace with a new
damaged
from
start. Insufficient engine output;
spark plug of the same
Engine speed changes during
type
the spark plug
electrodes
idle run
The spark plug is not
Air leakage between
The engine starts hard or fails to
properly tightened
the spark plug and
start. Engine speed changes
cylinder head
during idle run
10
Tighten the spark plug
5.4.2Disassemble, assemble and maintain cylinder block
Dismantle connecting bolt of cylinder block.
Remove cylinder gasket and dowel pin to check for
wear and damage. Replace if necessary.
Dismantle the fixing bolt of timing chain of guide
wheel.
Remove the cylinder block.
Remove the guide wheel of timing chain to inspect
for wear and damage. Replace if necessary.
Remove the circlip of piston pin.
11
Remove the piston of piston pin to check
whether it is damaged. Replace if necessary.
Inspect the paper pad for worn or
damage .Replace if necessary.
Check whether there is residual gasket on
cylinder. Clean with gasoline if necessary.
12
Check the state of cylinder inner
wall .Replace if worn or if reuse is
questionable.
Check whether the internal diameter has
exceed the limit value. Measure the diameter
form upper, middle and lower position. The
limit value is 50.05mm.Replace the cylinder
block if it has beyond this value.
13
Troubleshooting of the cylinder body, please refer to the following table
Maintenance of Cylinder Body
Description
Damage form
Trouble
Cause
Correction
Excessive oil dirt
Poor heat
The engine overheats
Remove the oil
or sand on the
radiation of the
radiating fins
fins on cylinder
dirt or sand
body
Cylinder end
Air leakage
The engine starts hard or fails to
Grind the
surface badly
between the
start .Insufficient engine output;
cylinder end
distorted
cylinder and
poor idle speed and high fuel
surface or
cylinder head
consumption
replace the
cylinder body
Cylinder
body
The cylinder is
The fitting
The engine starts hard or fails to
Repair with
badly worn
clearance
start .Insufficient engine output;
boring machine
between the
Poor engine idle speed. Thick blue
or replace the
cylinder and
and white fume form the
cylinder body
position, position
exhaust muffler pipe
ring is too wide
The
cylinder
gasket
is damage
14
Oil leakage between the cylinder
Replace the
and crankcase
cylinder gasket
5.4.3Disassemble, assemble and maintain crankcase
Remove the cover of right crankcase half.
Check whether the oil seal of starting shaft
and seal edge of gearshift lever are worn.
Replace if necessary.
Check the state of right crankcase cover
and replace if necessary.
Left view of right crankcase half is
shown in figure and check whether
bearing of main shaft and
countershaft are worn. Replace if
necessary.
15
Dismantle fixing bolt of left crankcase
cover.
Remove the neutral indicator and
check the state. Replace if necessary.
Dismantle the fixing bolt of magneto
stator and remove the stator.
16
Check the condition of left crankcase cover and
replace if necessary.
Troubleshooting of crankcase, please refer to the following table.
Description
Problem
Trouble
Consequences
Correction
Oil leakage from the
Repair or replace
crankcase
the crankcase
Oil leakage from the
The crankcase gasket is
Replace the gasket
joint of left and
worn out
Crack in the crank case
right crankcase
Crankcase
The threaded hole of
Oil leakage from the
Repair of replace
oil drain plug screw is
threaded hole of
the crankcase
ineffective
plug screw
The threaded holes
Cylinder head retaining
The engine starts hard
Repair the threaded
of cylinder bolt are
nut is impossible to
or fails to start.
or replace the
ineffective
screw up firmly,
Insufficient engine
crankcase
resulting in air leakage
output; Engine speed
between the cylinder
changes during idle run
head and cylinder
The bolt of the
The same as front
cylinder is broken
17
The same as front
Replace the cylinder bolt
The oil seal is damaged
Oil leakage is ineffective
or the oil seal edge is
Oil leakage from the oil
Replace the oil seal
seal
damage/worn/aged
Right crankcase
The right crankcase
Oil leakage form the
Repair or replace
cover
cover is worn or cracked
case cover
the case cover
The gasket of right
Oil leakage between
Replace the gasket
crankcase is
the case cover and
broken
the case
Left crankcase
The left crankcase cover
Oil leakage form the
Repair or replace
cover
is worn or cracked
case cover
the case cover
The gasket of left
Oil leakage between
Replace the gasket
crankcase is
the case cover and
broken
the case
5.4.4Maintenance of Crankshaft Connecting Rod
Disassemble, assemble and maintain crankshaft connecting rod
Remove the fixing bolt of crankcase from its holding
place.
18
Remove left crankcase half. Take care not to
forget the washer of main shaft and
countershaft when removing the left
crankcase.
Remove the paper pad to inspect for wear
and damage. Replace if necessary.
Remove the connecting rod assembly.
Inspect connecting rod bearing for wear
and damage. Replace if necessary.
19
Check gap of big-end of connecting rod.
Reset the gap if necessary.
Check diameter of piston pin using a
micrometer. Replace the piston pin if the
value is over the maintenance limit value.
Check the axial and radial jumping of
connecting rod bearing. Replace the
conrod if the jumping is large.
Check the side gap between
piston ring and piston groove
using a feeler gauge. Replace the
piston if the gap is too wide.
20
Check whether there is excessive carbon
deposit on piston top and groove. Remove if
necessary.
Check the state of piston and replace if worn
or if reuse is questionable. Measure
diameter of piston skirt. Replace it if the
value is beyond the maintenance limit value.
Assemble the piston ring according to the
figure and check whether piston ring is
damaged or the elasticity is weaken.
Replace if necessary.
21
For the troubleshooting of crankshaft connecting rod mechanism, please
refer to the following table.
Maintenance of Crankshaft Connecting Rod Mechanism
Description
Damage from
Trouble
Cause
The engine over- heats
Carbon deposit on piston
top 活塞顶部积碳
Carbon deposit in the ring
The piston ring is seized in ring
The engine starts hard or fails to
groove
groove
start. Insufficient engine output;
环槽中积碳
Scuffing
or scratches on
活塞环卡在环形槽中
Scuffing
or scratches on the surface
Thick blue and white fume form
the surface of piston skirt
of piston skirt
The
Excessive fitting clearance between
The engine starts hard or fails to
the piston and the cylinder
start. Insufficient engine output;
Correction
Remove the carbon
deposit
the exhaust muffler pipe
Piston
piston
and
ring
groove are over worn
Replace the piston
Thick blue and white fume form
the exhaust muffler pipe
Crank pin
Bearing
The piston pin hole is over
Excessive fitting clearance between
Striking sound of the piston pin
worn
the piston ring and the hole.
and of the cylinder
The crank pin is over worn
Radial and axes gap of the
Striking sound of the big-end
Replace the
connecting rod big end is too large
bearing; Striking sound of the
crankshaft
cylinder
connecting rod
The big-end needle
Radial and axes gap of the
Striking sound of the big-end
Replace the
bearing is over worn
connecting rod big end is too large
bearing; and of the cylinder
crankshaft
connecting rod
更换曲轴连杆
22
The crankshaft bearing is
Abnormal sound during the
Replace the
over worn or damaged
crankshaft bearing transmission
crankshaft bearing
The engine starts hard or fails to
Replace the piston
start. Insufficient engine output;
ring set
The piston ring is
The piston ring is fractured
fractured
Thick blue and white fume form
Piston ring
The piston ring is over
The piston ring opening gap or the
set
worn
side gap is too wide
活塞环磨损过度
Insufficient elasticity of
活塞环开口间隙或侧隙太宽
It is impossible to tight the piston
piston ring
ring and the cylinder properly
Improper fixing
The piston ring gap is not staggered
Piston pin
Connecting
the exhaust muffler pipe
Thick blue and white fume form
Fixing again the
the exhaust muffler pipe
piston ring set
The piston pin is over
The fitting clearance between the
Striking sound of the piston pin
Replace the piston
worn
piston pin and the hole is too wide
and of the cylinder
pin
The connecting rod
The fitting clearance between the
Striking sound of the piston and
Replace the
small-end hole is over
piston pin and the small-end is too
of the cylinder
connecting rod
worn
wide
The connecting rod is
The connecting rod is crooked or
Striking sound of the cylinder
Replace the
crooked or twisted
twisted
The big-end hole is over
Radial and axes gap of the
Striking sound of the big-end
Replace the
worn
connecting rod big end is too large
bearing and of the cylinder
connecting rod
rod
connecting rod
23
Timing
The gear is over worn of
Abnormal sound during sprocket
Replace the timing
sprocke
damage
driving
sprocket
t
5.5 Maintenance of Mechanism
5.5.1Disassemble, assemble and maintain valve mechanism
Remove rocker arm shaft
Remove the rocker arm of inlet/exhaust
valve and check the state
24
Remove the timing cam, rocker arm ,
rocker arm shaft to inspect for wear.
Replace if necessary.
Remove the circlip of inlet and exhaust
valve. Remove inlet vale stem and exhaust
valve stem take care and don`t miss the
valve clip.
Measure length of valve spring to check
whether the spring is damaged or worn.
Replace if necessary.
Remove the spring of inlet and exhaust
valve to inspect for wear and damage.
Note: when assemble the valve spring ,
make sure its dense end downward.
25
Check the external diameter of valve stem
using a wedge. Replace the valve stem if the
valve is beyond the maintenance limit valve.
Measure the width of valve contact surface
to check whether the contact surface is
rough or abnormal. Replace the valve stem
if the valve is large than 1.5mm.
Check whether the valve stem is distorted.
Replace if necessary.
26
Inspect the timing camshaft bearing for
wear and check the state of camshaft.
Replace if necessary.
Check the gap of rocker arm shaft and
rocker arm. Replace the rocker arm shaft
and rocker arm if the gap is large.
Check the external diameter of rocker arm
using a micrometer. Replace the rocker arm
shaft if the valve is beyond the maintenance
limit valve.
Remove the guide wheel of timing chain to
inspect for wear and damage. Replace if
necessary.
27
Remove the fixing bolt of timing tensioner
and check the state. Replace if worn or if
reuse is questionable.
Remove the timing tensioner arm to inspect
for wear and damage. Replace if necessary.
Remove the oil tube and spring and check the
state. Replace if necessary.
Remove the small timing chain and check the
state. Replace if necessary.
28
Adjust valve clearance as follows; Remove the
valve cap and check the condition.
Adjust valve clearance of front cylinder. Turn
magnetic rotor counterclockwise to make
piston locate at top dead center and make T
mark aimed to the mark of left crankcase
cover.
Check whether the O-mark on cam sprocket is
aimed to the gap of cylinder head. Readjust if
necessary.
Set the valve clearance of rear cylinder to
0.05mm~0.06mm.
29
For the troubleshooting of engine distribution mechanism, please refer to the following table
Maintenance of Distribution Mechanism
Descriptions
Valve
oil seal
Damage form
Trouble
Cause
The edge of valve oil seal is
Thick blue and white fume
worn, age or damage.
the exhaust muffler pipe
Correction
form
Replace the
complete set of
valve oil seal
The cam is cover worn
Insufficient engine output
Replace the camshaft
Replace he camshaft
Camshaft
The bearing of the camshaft
The axial or radial
Abnormal sound heard during
is over worn or damaged
clearance of the bearing is
camshaft transmission.
too wide. Ineffective
bearing swiveling or
abnormal sound during
Rocker arm
The working surface is
swiveling.轴承的轴向或径
Valve striking sound
Replace the rocker
向间隙太宽。旋转时轴承
scratched or over worn
arm
旋转不正常或声音异常
The rocker arm shaft hole is
Big gap between the rocker
over worn
arm and rocker arm shaft
The rocker arm shaft is over
Big gap between the rocker
worn
arm and rocker arm shaft
30
Valve striking sound
Replace the rocker
arm
Valve striking sound
Replace the rocker
arm shaft
Valve
The valve clearance is
too
small
The valve is
impossible to
close completely
The engine starts hard or fails to
Readjust
the valve
start. Insufficient engine output;
clearance to
Engine speed changes during idle
0.05~0.06mm
run
The valve clearance is
Valve striking sound
too
big
Readjust
the valve
clearance to
0.05~0.06mm
Carbon
deposit
on
working surface
It is impossible to fit the
The engine starts hard or fails to
Remove the carbon
valve and the valve seat
start. Insufficient engine output;
deposit
tightly.
Engine speed changes during idle
run
The working surface is over
It is impossible to fit the
The engine starts hard or fails to
worn or has pits, pock
valve and the valve seat
start. Insufficient engine output;
marks, ablation or damage
tightly.
Engine speed changes during idle
Replace the valve
run
The valve stem is over worn
The fitting clearance
Sound of valve leakage, Thick blue
between the valve stem
and white fume form the exhaust
and the valve
muffler pipe
guide
too wide
31
is
Replace the valve
The valve stem is deformed
It is impossible to close the
The engine starts hard or fails to
valve completely
star
Replace the valve
Valve
The spring is ineffective or
It is impossible to fit the
The engine starts hard or fails to
Replace the valve
spring
fractured
valve and the valve seat
star. Sound of the cylinder head
spring
tightly
32
5.6 Disassemble, assemble and maintain carburetor
Dismantle the fixing bolt of carburetor
and circlip of air cleaner. Remove the
carburetor .Remove and clean throttle
cap
Clean the carburetor as
follows: 。Remove the dirt
and clean inner oil way.
Dismantle the fixing bolt of
float chamber cap.
Remove the float chamber cap. Remove
the water and debris in the cap if
necessary. Check the state of seal ring
and replace if it is aging
Remove the float needle valve to
inspect for wear and damage. Replace if
necessary.
33
Remove the throttle and oil needle and
check the condition replace if
necessary.
Check the state of float case and
replace as necessary. Adjust the height
of float case by moving the float up or
down.
Take out the main jet to check whether
the jet hole is clogged. Clean if
necessary.
Remove the main nozzle to check
whether small hole is clogged. Clean
with compressed air if necessary.
34
Remove the idle jet and check for
plugged. Clean the jet with compressed
air if necessary
Dismantle the mixture adjustment
screw and inspect for worn. Replace if
necessary. Adjust mixture screw of
carburetor as the following. Standard:
Tighten mixture screw, and turn it one
And a half turns clockwise
Measure height of float case to check
whether it is distorted or there is oil
in the case If height is incorrect which
indicates carburetor leaks or the oil
supply is insufficient.
Adjust the oil needle to the third tier. If the clip rises, concentration of mixture becomes
dilute and if falls it becomes thick.
35
5.7 Maintenance of Intake/Exhaust System
5.7.1 Disassemble, assemble and maintain intake system
Dis-assemble hoop of air filter
Dis-assemble air filter
Clean dust on the air filter surface and then dis-assemble the air filter and clean inside.
As the air filter core is made of paper, can’t be cleaned. So replace the air filter core.
For the troubleshooting of the air cleaner, please refer to the following table.
Description
Air filter
Damage
form
Too much dust
on the filter
core
Trouble
Engine hard to start, or
fail
start.
Engine
output
power
inadequate;
performance not god
at idle station. Fuel
consumed too much;
muffler smoke strong.
The filter core
is fractured or
chapped.
36
Cause
Correction
The engine starts hard or
fails to start. Insufficient
engine output; poor
performance of engine
during idle run. Excessive
fuel consumption. The
exhaust muffler pipe fumes
strongly (black).
Clean the filter core
Engine air suction noise is
too loud
Replace the
filter core
5.8 Disassemble, assemble and maintain exhaust system
Dismantle locknut of muffler
Dismantle suspension bolt of muffler to
check whether the suspension support
is damaged. Repair or replace if
necessary.
Remove the muffler to inspect for broken and
damage. Replace or repair if necessary.
Remove the washer of muffler to inspect
for damage. Replace if necessary.
37
For the troubleshooting or the exhaust muffler, please refer
to the following table.
Description Damage form
Trouble
Cause
Exhaust pipe
Exhaust pipe leakage
Engine exhaust noise is
修理方法
Replace exhaust pipe
too loud.
gasket
The muffler
Engine exhaust noise is
Replace exhaust
enclosure is broken
too loud.
muffler.
The gasket is
gasket
broken
Exhaust
enclosure broken
muffler
Correction
Maintenance of Exhaust Muffler
5.9 Disassemble, assemble maintain the environmental protection
valve
Inspect the locknut for tightness and tighten
as necessary
Inspect the connecting circlip of
air pump for tightness. Tighten
if necessary.
38
Dismantle the fixing bolt of air pump and
check the state of air pump. Replace the air
pump if it is worn or if reuse is questionable.
Remove the secondary inlet air cleaner
and inspect for wear and damage. Clean and
replace if necessary.
For the troubleshooting of environment protection valve, please refer to the following table.
Maintenance of environment protection valve
Parts
Damage form
Trouble
Cause
Correction
air pump
air pump broke or
defective air pump
Emission fails to
Replace
plugged
air cleaner
air cleaner damaged or
meet the standard
defective air cleaner
plugged
Emission fails to
meet the standard
39
Replace
connectin
connecting hose get loose noise is too big
g hose
Emission fails to
Replace
meet the standard
Gasket
Replace
large noise from
air leaks form secondary
Emission fails to
secondary inlet
inlet
meet the standard
muffler
too much carbon deposit
Poor combustion
Emission fails to
Remove
exhaus
on muffler exhaust
meet the standard
and clean
t
5.10 Dis-assembly, assembly, maintenance and management of electric start motor
Dis-assemble fixing bolt on
left crankcase
Dis-assemble gear indicator fixing bolt
Dis-assemble gear indicator to check damage
and wear. Change if necessary.
40
Dis-assemble left crankcase cover
Dis-assemble gasket to check condition.
Change if damage or can’t use.
Dis-assemble magneto stator fixing bolt trigger bolt.
41
Check stator condition with a
multiple-use meter. Replace if
damage or can’t use.
Dis-assemble rotor fixing bolt
Dis-assemble rotor with a
dedicated tool.
Check if rotor is with magneto. Change if necessary.
42
Dis-assemble over running clutch fixing bolt.
Dis-assemble clutch, check clutch holder, ball
and spring for damage and ware. Change if
necessary.
Check transmission sprocket and gear for
damage and ware, change if necessary.
Dis-assemble start sprocket paper pressing paper.
43
Dis-assemble tension band of clutch
and check condition for damage and
problem, change if necessary.
Dis-assemble retainer ring of start
motor sprocket.
Dis-assemble driving sprocket and
chain.
44
Dis-assemble start motor fixing bolt.
Dis-assemble start motor.
Check if the start motor winding is
damaged, change if necessary.
Dis-assemble oil separating plate and
check condition, change if necessary.
45
Check the oil seal edge if damaged,
change if necessary.
Dis-assemble seal ring and check
condition, change if damaged.
46
For the troubleshooting of engine electric starter, please refer to the following table
Maintenance of Electric Starter
Description
Damage form
Trouble
Cause
Carbon brush is over
Starter motor has insufficient
worn. The carbon brush
rotation force or it is out of work.
Correction
Replace carbon brush
spring is
fractured or has
Starter motor has insufficient
insufficient elastic force.
rotation force
Armature
Starter motor has insufficient
commentator surface
rotation force
Replace carbon brush spring
Start
motor
Clean the commentator
surface with gasoline or
alcohol
is fouled.
电枢表面污垢。
Armature commentator
Starter motor has insufficient
surface is spotted, burnt
rotation force.
or damaged.
Armature commentator
Starter motor has insufficient
surface is ablation or
rotation force or is out of work.
over worn.
6- 1
Polish the surface against
the
Commentator with fine
abrasive
Paper. Make the cut on
the mica plate between each
commentator piece with broken
saw bit 0.5~0.8mm deeper than
the commentator surface.
Remove the chip and burr
between each commentator.
Replace starter motor