Rato R80 User manual

R80-R420 Type V Horizontal Axis
Maintenance Manual
Chongqing RATO Technology Co., Ltd.

This Manual covers specifications that shall be followed in the process of regular maintenance
and troubleshooting of general-purpose gasoline engines.
Make sure the equipment's maintenance staff can refer to this Manual at any time.
This Manual describes correct methods to repair this equipment. The Company does not
undertake any liability for any personal casualty and equipment damage caused due to ignoring
these rules.
Attention:
The copyright of this Manual belongs to the Company. It is not allowed to reproduce this
Manual without written consent of the Company, and corresponding responsibility will be
taken for violation.

Safety Warnings
The personal and property safety of you and others is very important. Please carefully
read the three kinds of extremely important safety warnings that we have described in the
Maintenance Manual and on the decals of the gasoline engines. There is the symbol in
front of each safety warning. Details are as follows:
Failure to follow instructions will lead to extremely serious injuries.
Failure to follow instructions may lead to very serious injuries.
Failure to follow instructions may lead to minor injuries.
Failed to follow instructions, your gasoline engine and other properties may be
damaged.

CONTENTS
Part I Introduction..................................................................................................................... 1
1-1 Components of general-purpose gasoline engine ........................................................ 1
1-2 Parameters ................................................................................................................... 2
1-3 Maintenance standards ................................................................................................ 3
Part II Dimension and Torque ................................................................................................. 12
2-1 Dimensions of general-purpose gasoline engine ....................................................... 12
2-2 Torque parameters ..................................................................................................... 16
2-3 Standard torque parameters ....................................................................................... 18
Part III Maintenance ............................................................................................................... 19
3-1 Maintenance list......................................................................................................... 19
3-2 Oil .............................................................................................................................. 20
3-3 Air filter ..................................................................................................................... 21
3-4 Cleaning of fuel filter ................................................................................................ 22
3-6 Adjustment of valve clearance................................................................................... 22
3-7 Governor.................................................................................................................... 24
Part IV Disassembly and Maintenance ................................................................................... 25
4-1 Fault judgement ......................................................................................................... 25
4-2 Pre-maintenance Preparations ................................................................................... 31
4-3 Disassembly chart...................................................................................................... 36
4-4 Gasoline engine (electric starting type is taken as an example in the following figure.
manual starting type is installed with different parts, and disassembled in a similar manner)
.......................................................................................................................................... 37
4-5 Electrical schematic diagram (electric starting type) ................................................ 73

Part I Introduction
1
Part I Introduction
1-1 Components of general-purpose gasoline engine
Starter
handle
Fuel drain
bolt
Oil level
gauge
Fuel
tank
cover
Fuel
tank
Air
filter
Governing
handle
Hand-
operated
starter
Choke
handle
Spark
plug
Muffler

Part I Introduction
2
1-2 Parameters
Model
Parameters
R80-V
L×W×H
310×290×310 mm
Net weight
10 kg
Type of gasoline engine
Four-stroke, overhead valve, single-cylinder
Displacement
78.5cm3
Compression ratio
9.0:1
Cylinder diameter x
stroke
52×37 mm
Maximum output power
1.8kw / 3600rpm
Maximum torque
4N.m / 2500rpm
Cooling system
Forced air cooling
Ignition system
Breakerless transistorized coil ignition (TCI)
Spark plug
E4TC
Lubrication system
Splash type
Power take-off shaft
direction
Counterclockwise
Model
Parameters
R210-V
R300-V
L×W×H
390×320×345mm
420×395×430mm
Net weight
16.5 kg
26kg
Type of gasoline engine
Four-stroke, overhead valve, single-cylinder
Displacement
212 cm3
301 cm3
Compression ratio
9.0 : 1
8.5 : 1
Cylinder diameter x
stroke
70×55 mm
80×60 mm
Maximum output power
5.0 kw / 3600rpm
7.0 kw / 3600rpm
Maximum torque
13.5 N.m / 2500rpm
21 N.m / 2500rpm

Part I Introduction
3
Cooling system
Forced air cooling
Ignition system
Breakerless transistorized coil ignition (TCI)
Spark plug
BPR6ES(NGK), NHSP LD F7RTC, F7TC
Lubrication system
Splash type
Power take-off shaft
direction
Counterclockwise
Model
Parameters
R420-V
L×W×H
465×415×440 mm
Net weight
28kg
Type of gasoline engine
Four-stroke, overhead valve, single-cylinder
Displacement
420cm3
Compression ratio
8.5：1
Cylinder diameter x
stroke
90×66mm
Maximum output power
9.5kw / 3600rpm
Maximum torque
28N.m / 2500rpm
Cooling system
Forced air cooling
Ignition system
Breakerless transistorized coil ignition (TCI)
Spark plug
BPR6ES(NGK), NHSP LD F7RTC, F7TC
Lubrication system
Splash type
Power take-off shaft
direction
Counterclockwise
1-3 Maintenance standards
1-3-1R80-V
Part
Item
Standard
Service limit
Gasoline
engine
Maximum no-load speed
Cylinder pressure
3850rpm
≧0.9Mpa（1400rpm）
--

Part I Introduction
4
Cylinder
Cylinder bore diameter
52-52.015mm
52.165
Cylinder
head cover
Warping
--
0.1
Piston
Outer diameter of piston skirt
Piston-cylinder clearance
Inner diameter of piston pinhole
Outer diameter of piston pin
Piston pin-piston pinhole clearance
51.975-51.985mm
0.015-0.04mm
10 .002-10.008mm
9.992-9.998mm
0.004-0.016mm
51.9
0.12
10.048
9.954
0.03
Piston ring
Piston ring side clearance: top
ring/ring 2
Oil ring
Piston ring closing clearance: top
ring/ring 2
Oil ring
Piston ring width: top ring/ring 2/oil
ring
0.03-0.07 mm
--
0.15-0.3mm
0.1-0.6mm
1.5mm
2.5mm
0.15
--
1
1
1.37
2.37
Connecting
rod
Inner diameter of small end
Inner diameter of big end
Big end oil film clearance
Small end side clearance
10.011-10.022mm
23.02-23.03mm
0.035-0.055mm
0.1-0.7mm
10.05
23.05
0.12
1.1
Crankshaft
Outer diameter of main journal
22.975-22.985mm
22.945
Valve
Valve clearance
Outer diameter of
valve stem
Conduit inner
Intake
Exhaust
Intake
Exhaust
Intake/exhaust
0.15±0.02mm
0.20±0.02 mm
5.465-5.48mm
5.445-5.46mm
5.50-5.512mm
--
--
5.318
5.275
5.572

Part I Introduction
5
diameter
Lifter clearance
Valve seat contact
width
Free length of
spring
Intake
Exhaust
0.015-0.052mm
0.015-0.052mm
0.8mm
25.0mm
0.1
0.12
2.0
24
Camshaft
Cam height Intake
Exhaust
Outer diameter of journal
29.4mm
29.4mm
12.966-12.986mm
29.2
29.2
12.91
Crankcase
cover
Inner diameter of camshaft bore
13.0-13.018mm
13.048
1-3-2 R210-V
Part
Item
Standard
Service limit
Gasoline
engine
Maximum no-load speed
Cylinder pressure
3750-3810rpm
≧1.17Mpa（1400rpm）
--
Cylinder
Cylinder bore diameter
70.0mm
70.165mm
Cylinder
head cover
Warping
--
0.10mm
Piston
Outer diameter of piston skirt
Piston-cylinder clearance
Inner diameter of piston pinhole
Outer diameter of piston pin
Piston pin-piston pinhole clearance
69.985mm
0.015-0.05mm
18 .002mm
18.0mm
0.002-0.014mm
69.845mm
0.12mm
18.048mm
17.954mm
0.06mm

Part I Introduction
6
Piston ring
Piston ring side clearance: top
ring/ring 2
Oil ring
Piston ring closing clearance: top
ring/ring 2
Oil ring
Piston ring width: top ring/ring 2/oil
ring
0.015-0.045mm
--
0.2-0.4mm
0.15-0.35mm
1.5mm
2.5mm
0.15mm
--
1.0mm
1.0mm
1.37mm
2.37mm
Connecting
rod
Inner diameter of small end
Inner diameter of big end
Big end oil film clearance
Small end side clearance
18.011mm
30.02mm
0.040-0.063mm
0.1-0.7mm
18.07mm
30.066mm
0.12mm
1.1mm
Crankshaft
Outer diameter of main journal
29.98mm
29.92mm
Valve
Valve clearance
Outer diameter of
valve stem
Conduit inner
diameter
Lifter clearance
Valve seat contact
width
Free length of
spring
Intake
Exhaust
Intake
Exhaust
Intake/exhaust
Intake
Exhaust
0.15±0.02mm
0.20±0.02 mm
5.48mm
5.44mm
5.50mm
0.02-0.044mm
0.06-0.087mm
0.8mm
34.0mm
--
--
5.318mm
5.275mm
5.572mm
0.1mm
0.12mm
2.0mm
32.5mm

Part I Introduction
7
Camshaft
Cam height Intake
Exhaust
Outer diameter of journal
27.7mm
27.75mm
13.984mm
27.45mm
27.50mm
13.916mm
Crankcase
cover
Inner diameter of camshaft bore
14.0mm
14.048mm
Carburetor
Master nozzle
Float height
Turning circle of adjusting screw of
mixing ratio
0.85
13.7±1.5mm
2-1/8 circle
--
--
--
Spark plug
Clearance
0.7-0.8mm
--
Spark plug
cap
Resistance
7.5-12.5kΩ
--
Ignition coil
Resistance
Ignition coil
clearance
Primary side
Secondary
side
0.8-1.0Ω
5.9-7.1kΩ
0.4-0.6mm
--
--
--
1-3-3 R300-V
Part
Item
Standard
Service limit
Gasoline
engine
Maximum no-load speed
Cylinder pressure
3750-3850rpm
≧1.1Mpa（1400rpm）
--
--
Cylinder
Cylinder bore diameter
80.0-80.015mm
80 .17mm
Cylinder
head cover
Warping
--
0.10mm
Piston
Outer diameter of piston skirt
Piston-cylinder clearance
Inner diameter of piston pinhole
Outer diameter of piston pin
79.975-79.985mm
0.015-0.04mm
15 .002-15.008mm
14.992-14.998mm
79.85mm
0.12mm
15.242mm
14.95mm

Part I Introduction
8
Piston pin-piston pinhole clearance
0.004-0.016mm
0.08mm
Piston ring
Piston ring side clearance: top
ring/ring 2
Oil ring
Piston ring closing clearance top ring
Ring 2
Scraping ring
Piston ring width: top ring / ring 2
Oil ring
0.025-0.06mm
--
0.20-0.40mm
0.30-0.50mm
0.2-0.7mm
2.8-3.0mm
2.45-2.75mm
0.15mm
--
1.0mm
1.0 mm
1.0mm
1.37mm
2.0mm
Connecting
rod
Inner diameter of small end
Inner diameter of big end
Small end oil film clearance
Big end side clearance
15.011-15.022mm
33.025-33.039mm
0.013-0.03mm
0.25-0.65mm
15.27mm
33.07mm
0.12mm
1.0mm
Crankshaft
Outer diameter of main journal
32.975-32.985mm
32.92mm
Valve
Valve clearance
Outer diameter of
valve stem
Conduit inner
diameter
Valve stem clearance
Valve seat contact
width
Free length of spring
Intake
Exhaust
Intake
Exhaust
Intake/ex
haust
Intake
Exhaust
0.10-0.15mm
0.15-0.20mm
5.468-5.48mm
5.43-5.445mm
5.485-5.5mm
0.005-0.032mm
0.04-0.07mm
0.8-1.0mm
38.5-39.5mm
--
--
5.34mm
5.3mm
5.56mm
0.10mm
0.12mm
2.0mm
37.5mm
Camshaft
Cam height Intake
Exhaust
6.045mm
5.766mm
5.95mm
5.65mm

Part I Introduction
9
Outer diameter of journal
16.166-16.184mm
16.12mm
Crankcase
cover
Inner diameter of camshaft bore
16.2-16.218mm
16.248mm
Carburetor
Master nozzle
Float height
Turning circle of adjusting screw of
mixing ratio
Φ2
1-3mm
2-7/8 circle
--
--
--
Spark plug
Clearance
0.7-0.8mm
--
Spark plug
cap
Resistance
9.5-10.5kΩ
--
Ignition coil
Resistance
Ignition coil
clearance
Primary
side
Secondary
side
0.6-0.9Ω
5.6-6.9kΩ
0.3-0.5mm
--
--
--
1-3-4 R420-V
Part
Item
Standard
Service limit
Gasoline
engine
Maximum no-load speed
Cylinder pressure
3750-3850rpm
≧1.2 Mpa (1400 rpm)
--
Cylinder
Cylinder bore diameter
90-90.015mm
90.17mm
Cylinder
head cover
Warping
--
0.10mm
Piston
Outer diameter of piston skirt
Piston-cylinder clearance
Inner diameter of piston pinhole
Outer diameter of piston pin
Piston pin-piston pinhole clearance
89.96-89.97 mm
0.03-0.055 mm
20.002-20.008 mm
19.992-19.998 mm
0.004-0.016 mm
89.85mm
0.27mm
20.042mm
19.95mm
0.08mm
Piston ring
Piston ring side clearance: top
0.02-0.06 mm
0.15mm

Part I Introduction
10
ring/ring 2
Oil ring
Piston ring closing clearance: top
ring/ring 2
Oil ring
Piston ring width: top ring/ring 2/oil
ring
--
0.2-0.4 mm
0.2-0.7 mm
3.7-3.9 mm
2.95-3.15 mm
--
1.0mm
1.0mm
1.37mm
2.0mm
Connecting
rod
Inner diameter of small end
Inner diameter of big end
Big end oil film clearance
Small end side clearance
20.011-20.022 mm
36.025-30.039 mm
0.25-0.65 mm
0.013-0.03 mm
20.07mm
36.07mm
0.12mm
1.0mm
Crankshaft
Outer diameter of main journal
35.975-35.985 mm
35.92mm
Valve
Valve clearance
Outer diameter of
valve stem
Conduit inner
diameter
Lifter clearance
Valve seat contact
width
Free length of
spring
Intake
Exhaust
Intake
Exhaust
Intake/exhaust
Intake
Exhaust
0.013-0.017 mm
0.018-0.022 mm
6.565-6.580 mm
6.545-6.560 mm
6.6-6.615 mm
0015-0.055mm
0.015-0.055mm
0.65-0.95
38.8-39.2mm
--
--
6.44mm
6.4mm
6.66mm
0.11mm
0.13mm
2.0mm
37.5mm
Camshaft
Cam height Intake
Exhaust
Outer diameter of journal
6.59 mm
6.07 mm
15.966-15.984 mm
33.58mm
32.88mm
15.92mm
Crankcase
Inner diameter of camshaft bore
16-16.018
16.048mm

Part I Introduction
11
cover
Carburetor
Master nozzle
Float height
Turning circle of adjusting screw of
mixing ratio
Φ2
1-3
--
--
--
--
Spark plug
Clearance
0.7-0.8mm
--
Spark plug
cap
Resistance
9.5-10.5kΩ
--
Ignition coil
Resistance
Ignition coil
clearance
Primary side
Secondary
side
0.6-0.9Ω
5.6-6.9kΩ
0.3-0.5mm
--
--
--

Part II Dimension and Torque
12
Part II Dimension and Torque
2-1 Dimensions of general-purpose gasoline engine
2-1-1 R80-V
2-1-2 R210-V

Part II Dimension and Torque
13
2-1-2 R300-V

Part II Dimension and Torque
14
2-1-3 R420-V

Part II Dimension and Torque
15

Part II Dimension and Torque
16
2-2 Torque parameters
2-2-1
Serial
No.
Fastening
position
Model
Fastener name
Specifications &
model
Torque
value
Connecting
components
1
Fuel drain bolt
R80-V
R210-V
R300-
R420-V
Hexagon
flange bolt
M10×1.5×15 8.8-A
M10×1.5×15 8.8-A
M12×1.5×18 8.8-A
22 ±
2
Fuel drain bolt
- flat washer -
crankcase
2
Oil sensor
R80-V
R210-V
R300-
R420-V
Hexagon
flange bolt
M6×14 8.8-A
M6×14 8.8-A
M6×16 8.8-A
8±2
Oil sensor -
crankcase
R80-V
R210-V
R300-
R420-V
Hexagon
flange nut
M10×1.5 8-A
7 ± 1
3
Connecting
rod
R80-V
R210-V
R300-
R420-V
Hexagon
flange bolt
M6×25 10.9-A
M7×32 10.9-A
M8×35 10.9-A
12±1
13±1
15±1
Connecting
rod cover -
crankshaft
components -
connecting rod
4
Crankcase
cover
R80-V
R210-V
R300-
R420-V
Hexagon
flange bolt
M6×25 8.8-A
M8×32 8.8-A
M8×32 8.8-A
11±2
28±2
28±2
Crankcase
cover -
crankcase
gasket -
crankcase
5
Flywheel
assembly
R80-V
R210-V
R300-
R420-V
Hexagon
flange nut
M12×1.25 8-A
M14×1.5 8-A
M16×1.5 8-A
55±4
75±4
95±4
Starter cup -
impeller -
flywheel
assembly -
crankshaft
components
6
Ignition coil
R80-V
R210-V
R300-
R420-V
Hexagon
flange bolt
M6×20 8.8-A
M6×25 8.8-A
M6×28 8.8-A
11±1
Ignition coil -
crankcase
7
Cylinder head
assembly
R80-V
R210-V
Hexagon
flange bolt
M6×20 10.9-A
M8×32 10.9-A
32±2
32±2
Cylinder head
assembly -
cylinder head