Robin EH18V OHV Service Manual
SERVICE
MANUAL
IVIodel
EH18V OHV
396S322
ROBIN
AMERICA, INC.
ROBIN
TO
WISCONSIN
ROBIN
ENGINE
MODEL
CROSS REFERENCE
LIST
ROBIN
EY08
EY15
EY 15V
EY20
EY2OV
EY23
EY28
EY3
5
EY40
-
EY45V
EY2
1
EY44
EY 18-3
EY25
EY27
EH11
EH12
EH15
EH17
EH21
EH25
EH30
EH30V
EH34
EH34V
EH43V
EC13V
DY23
DY27
DY30
DY3
5
DY4 1
WISCONSIN
ROBIN
SIDE
VALVE
W
1-080
W1-145
W1-145V
W1-185
W1-185V
W1-230
W 1-280
W
1-340
W 1-390
Wl-45OV
EY21W
EY44W
EY18-3W
EY25W
EY27W
OVERHEAD
VALVE
WO1-115
wo1-120
WO1-150
WO1-170
wo1-210
WOl-250
WO 1-300
WO1-300V
WO1-340
WO
1
-340V
WO 1-43 OV
TWO CYCLE
WT1-125V
DIESEL
WRD
1-230
WRD
1-270
-1-300
WRD1-350
WRD1-410
0
0
0
CONTENTS
.
Section
Title
Page
1
. SpEClF[CATlONS
.........................................................................................
1
2.
PERFORMANCE ............................................................................................
2
2-1 Maximum Output
....................................................................................
2-2
Maximum Torque
...................................................................................
2
2
2-3 Performance Curves
...............................................................................
2
3
4.GENERAL DESCRIPTION OF ENGINE COMPONENTS .................................
3
3
. FEATURES
...................................................................................................
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-1
0
4-1 1
4-1 2
4-1 3
4-1
4
4-1
5
5
. DISASSEMBLY AND REASSEMBLY
............................................................
11
.
11
11
12
27
5-5
Break-in Operation
...............................................................................
40
41
6-1 Flywheel Magneto
................................................................................
41
41
5-1 Preparations and Suggestions
..................................................................
5-2 Special
Tools
.......................................................................................
5-3
Disassembly Procedures
........................................................................
5-4 Reassembly Procedures
.........................................................................
6 . MAGNETO
..................................................................................................
6-2 Basic The0
ry
.......................................................................................
6-3
Wiring Diagram
....................................................................................
42
7.AUTOMATlC DECOMPRESSlON SYSTEM
..................................................
43
8.CARBURETOR
...........................................................................................
44
.
8-1 Operation and Construction
....................................................................
44
45
47
47
8-2
Disassembly and Reassembly
.................................................................
9 . STARTING SYSTEM
...................................................................................
9-1 Recoil Starter
........................................................................................
Section
Title
Page
10.
TROUBLESHOOTlNG
..............................................................................
51
10-1 Starting Difficulties
................................................................................
51
10-2 Engine Misfires
....................................................................................
52
10-3 Engine Stops
.......................................................................................
52
10-4 Engine Overheats
.................................................................................
10-5 Engine Knocks
.....................................................................................
10-6
Engine BacMires Through Carburetor
........................................................
53
52
53
11
.
lNSTALMTlON
.......................................................................................
11-1 Installing
.............................................................................................
11-2 Ventilation
..........................................................................................
11-3 Exhaust Gas Discharge
.........................................................................
54
54
54
54
12
. SERVICE DATA
......................................................................................
55
55
12-1 Clearance Data and Limits
......................................................................
12-2 Torque Specifications
............................................................................
61
12-3 Oil Grade Chart
....................................................................................
61
13.
MAINTENANCE AND
STORAGE
.............................................................
62
13-1 Daily Maintenance (Every
8
Hours)
............................................................
62
13-2 Initial
20
Hours Maintenance
...................................................................
13-3
Every
50
Hours (10 Days) Maintenance
.....................................................
62
13-4 Every 100-200 Hours (Monthly) Maintenance
.............................................
63
13-5 Every
500-600
Hours Maintenance
..........................................................
63
13-6 Every
1
000
Hours (Yearly) Maintenance
....................................................
63
13-7 Engine Storage
....................................................................................
63
62
..
1.
SPECIFICATIONS
Model
EH18V
TY
Pe
Air-Cooled, 4-Cycle, Vertical Shaft, Overhead Valve, Gasoline Engine
Bore
X
Stroke
67 X 52
mm
(2.64
X
2.05
in.)
Piston Displacement
183
cc
(1 1.1 6
c,u.in.)
Maximum Horsepower
4.4 /3600
KW/
rpm
(6/3600
HP/rpm)
1.29 / 2700
kg-m / rpm
(9.3/2700
ft. Ibs/rpm)
Maximum Torque
~ ~ ~~~~
Rotation
'
'
Forced Air Cooling
Cooling
Counterclockwise
As
Viewd From PTO Shaft Side
~
Lubrication
Horizontal Draft Type
Carburetor
Automobile
Oil
SAE
#20, #30 or 1OW-30
Lubricant
Oil Pump Type
Fuel
I
Automobile Gasoline
Fuel Feed
Gravity Type
~ ~~ ~ ~~
Governor System
Flywheel Magneto (Solid State)
Ignition System
Centrifugal Flyweight Type
Spark Plug
CHAMPION
L86C
Starting System
17
kg
(37.5
Ibs.)
Dry Weight
Recoil
Starter
Dimensions Without
P.T.0
Shaft
LXWXH
409 X 372
x
31 1 mm
(16.10 X 14.65 x 12.24
in.)
Specifications and dimensions are subject to change without notice.
-1-
2.
PERFORMANCE
2-1
MAXIMUM OUTPUT
The maximum output
valve fully opened after its initial break-in period when all the moving parts are properly worn in.
Therefore, a new engine may not produce the maximum output in the beginning because the moving
parts are not in a properly worn-in condition.
2-2
MAXIMUM TORQUE
The maximum torque indicates the torque at the output shaft when the engine is producing the maximum
output.
2-3
PERFORMANCE CURVES
EH18V
of
an engine
5.2;
(7.
0
Tn"--r
4.41
(6.0
is
such a standard power
""_~_
as
produced by the engine with
"""
"""_
"""
its
throttle
7.4!
(2.
0
2000 2400 2800 3200
REVOLUTlON
-
3600
r.p.m
"i
-2-
3.
FEATURES
1.
The overhead valve design offers compactness, light weight and ideal combustion characteristics
resulting in more power
2.
The parts
3.
The automatic decompression system offers easy and sure starting.
4.
The muffler and carburetor are located
flow
5.
The oil pump and oil filter provide excellent lubrication regardless of engine posture during
operation.
6.
This engine
7.
The Pro-Poly version engine is covered with a stylishly designed
fuel tank incoroprated into it.
'8.
The Classic Steel version does not have the shroud or combined fuel tank.
4.
GENERAL DESCRIPTION
4-1
CYLINDER AND CRANKCASE
The cylinder and crankcase is single piece aluminum diecasting. The cylinder liner, made of
special cast iron, is molded into the aluminum
casting.
The crankcase has a mounting surface
output shaft side, where the main bearing cover is
attached. (See Fig.
such
as a large capacity muffler, dual element air cleaner reduce noise
much easier in the design of power equipment.
is
offered in two stylish versions.
4-1.)
from
less fuel and prolonged engine life.
on
opposite sides, making the arrangements
OF
on
ENGINE COMPONENTS
the
shroud
with the
to
a minimum level.
for
cooling air
4-2
MAIN BEARING
The main bearing cover is an aluminum
diecasting, which is mounted
side of the crankcase. Remove the main bearing
cover
to
inspect inside
The main bearing cover also functions as an oil
pan, with,a trochoid
(See Fig.
4-2.)
COVER
of
the engine.
oil
pump and
..
on
the output shaft
oil
filler.
-3-
Fig.
Fig.
4-1
4-2
4-3
CRANKSHAFT
The crankshaft is a forged carbon steel, and the
crank pin
is
induction-hardened. The PTO end
the shaft has a crankshaft gear which is pressed
into position. (See
44
CONNECTING
Fig.
ROD
4-3.)
AND PISTON
of
Fig.
CRANKSHAFT
4-3
r,
GEAR
The connecting rod
is
a forged aluminum alloy,
and its large and small ends function as bearings.
The piston
4-5
CAMSHAFT
The camshaft is a hollow shaped
is
an aluminum alloy casting, and
and
made of
special cast iron with the camshaft gear casted
together.
A
centrifugal decompression lever is assembled
the camshaft. The lubrication oil
by the groove
(See Fig.
4-5.)
on
the end of the camshaft.
pump
is driven
on
Fig.
4-4
-4-
Fig.
4-5
4-6
VALVE ARRANGEMENT
The intake valve is located at flywheel side
'
cylinder head.
of
the
Hard alloy valve seats are molded in the cylinder
head and stellite is fused to the exhaust valve face.
The cylinder baffle leads cooling air to the exhaust
valve area for the optimum cooling.
(See
Fig.
4-6.)
4-7
CYLINDER HEAD
The cylinder head ,is an aluminum die casting,.
which utilizes wedge type combustion chamber for
the highest combustion efficiency.
(See Fig.
4-7.)
EXHAUST
Vi
Fig.
II
4-6
n
4-8
GOVERNOR SYSTEM
The governor is a centrifugal flyweight type which
ensures constant operation at the selected speed
against load variations.
The governor gear with governor weights is installed on the bearing cover and driven
camshaft gear. (See Fig.
4-8.)
by'
the
-5-
Fig.
Fig.
4-7
4-8
4-9
COOLING SYSTEM
The large fins
on
the flywheel provide sufficient cooling air capacity for the inlet and exhaust area and
cylinder.
The cylinder baffle helps the cooling air flow efficiently.
4-1
0
LUBRICATION
EH18V
EH18V
has a trochoid pump outside the main bearing cover that is driven by the camshaft.
uses
forced
splash
type lubrication.
(See
Fig.
4-9.)
/
M6
FLANGE BOLT
OIL
SHELTER
...
PLATE
1
pce.
CAMSHAFT
M,
AIN BEARING
COVER
OIL PUMP
COVER
Fig.
4-9
-6-
&-
M6
FLANGE
BOLT
...
4pcs.
4-1
1
IGNITION
SYSTEM
The
ignition system
is
a transistor controlled
magneto ignition system which consists of a
fly-
wheel and an ignition coil with a built in transistor
mounted on the crankcase.
This system has an automatic ignition timing
advancing for easier starting. (See Fig.
4-10.)
For details, refer to page
39,
section
6.
4-12
CARBURETOR
The engines are equipped with a horizontal draft
carburetor
that
has a float controlled
fuel
system
and a fixed main jet.
The carburetors are calibrated carefully for the
sure starting,
good
acceleration, low fuel consumption and sufficient output.
For the- datails, refer
to
page 42, section
“8
CARBURETOR”.
(See
Fig.
4-11.)
4-13
AIR
CLEANER
The air-cleaner
is
a heavy-duty type with a dual
.
element system. (See
Fig.
4-12.)
-7-
Fig.
4-1
1
WING
BOLT
I;’
<
CLEANER COVER
PRIMARY ELEMENT
GROMMET
eo
#(URETHANE FOAM)
SECONDARY ELEMENT
(PAPER ELEMENT)
.
:’
.
.’
J
SECONDARY ELEMENT
PAPER ELEMENT)
Fig.
4-12
4-14
DECOMPRESSION
An
automatic decompression mechanism which
opens exhaust valve
compression top is assembled
easy starting. (See
For details, refer
to
Fig.
page
SYSTEM
before
4-13)
41,
the piston reaches
on
section
the camshaft for
7.
[
AUTOMATIC DECOMPRESSION
RETURN SPRING
&$
SYSTEM
n
-a-
4-15
SECTIONAL
VIEW
OF
ENGINE
RECOIL
STARTER
\
BLOWER
I
HOUSING
MAIN
BEARING COVER
CRANKSHAFT
-9-
SPARK
PLUG
MUFFLER
CONNECTING
-
10
-
ROD
5.
DISASSEMBLY
AND
REASSEMBLY
5-1
PREPARATIONS AND SUGGESTIONS
1)
When disassembling the engine, remember the locations
of
the individual parts
so
that they can be
reassembled correctly. If you are uncertain of identifying some parts,
it
is suggested that tags
be
attached to them.
Have boxes ready to keep disassembled parts
by
group.
To
prevent missing and misplacing, temporarily assemble each group
of
disassembled parts.
Carefully handle disassembled parts, and clean them with
oil
if
necessary.
Use the correct tools
in
the correct way.
5-2
SPECIAL
TOOLS
I
Tool No.
I
Tool
I
Use
I
I
228-
95003-07
I
Piston ring compressor
I
For placing piston ring
I
I
Market
parts
I
Flywheel puller
1
For
pulling
off
the flywheel
I
PISTON
RING
COMPRESSOR
/
/
FLYWHEEL PULLER
Fig.
5-1
-
11
-
5-3
DISASSEMBLY PROCEDURES (CLASSIC STEEL) / (PRO POLY)
~~
Step
I
Part
to remove
Spark
plug
I
Remove spark plug cap and spark plug.
Procedures
'I
Oil
drain,
oil
(1)
filter
and
Remove
(2)
Remove
(3)
Remove oil filter. bracket
(4)
Remove
M6X
oil
gauge.
oil
drain
oil
filter bracket.
12mm
bolt
plug
....
and
2pcs.
drain
oil.
II
I
~~
Remarks
I
19mm
14mm box wrench
lOmm
Tool
plug wrench
box
wrench
OILGAUGE
y
T
OILGAUGE
p
T
SPARK PLUG LTER
OIL FILTER BRACKET
OIL DRAIN PLUG
'
M6
BOLT
'..
2pC~.
-
mm
SPARK PLUG
,
'
OIL FILTER BRACKET
Fig.
5-2
-
LTER
'
12-
OIL
~AC
clni
DRAIN
r
...
PLUG
gnrc
5-3
DISASSEMBLY PROCEDURES (CLASSIC STEEL) -CONTINUED
Part
to
remove
Procedures
Recoil starter
Fuel tank
M6
FL
Remove recoil starter from the engine.
M6X8mm
bolt
-0..
4pcs.
(1) Remove fuel tank.
M6X 12mm
bolt
.-**
2pcs.
(2) Remove fuel pipe from the fuel tank.
(3)
Remove side guard.
M6
X
12mm
bolt
*
-
Zpcs.
(4)
Remove bracket (fuel tank)
....
(stop
lpce.
switch).
RECOIL
STARTER
M6X 14mm bolt
(5)
Remove cover
ASS’Y
lOmm box wrench
M6
FLANGE
BOLT
-8-
GPCS.
COVER
(stop switch)
HOSE
CLAMP
-
Fig.
13’
-’
5-3
I.
M6
SIDE
GUARD
FLANGE
BOLT
. .
.
1
pce.
5-3
DISASSEMBLY PROCEDURES (CLASSIC STEEL) -CONTINUED
-
Part to remove
Step
Procedures
-
5
Air cleaner
(1) Remove air cleaner cover and air cleaner
element
M6 wing bolt
(2) Remove breather hose from cleaner
and crankcase.
(3)
Remove air cleaner base from air cleaner
bracket.
M6X12mm bolt
(4) Remove cleaner base and gasket (air
cleaner) from carburetor.
M6
nut
(5)
Remove bracket
M6X 12mm bolt
(6)
Remove bracket
M6
X
14mm bolt
M6x 14mm tapping
....
**--
.--.
2pcs.
(A/C)
....
(NC
lpce.
Ipce.
from the engine.
lpce.
cover)
-
1 pce.
bolt
....
lpce.
base
-
PROCEED TO STEP
7
OF DISASSEMBLY PROCEDURES
M6
X
14mm
BOLT
...
lpce.
M6
Remarks
WING BOLT
...
Ipce.
Tool
lOmm box wrench
lOmm
box wrench
lOmm box wrench
lOmm box wrench
M6 x 14mm
AIR
CLEANER
COVER
AIR CLEANER
AIR CLEANER BASE
HOSE
Fig.
5-4
-
14-
CLAMP
M6
NUT
...
~PCS.
BREATHER HOSE
5-3
DISASSEMBLY PROCEDURES (PRO POLY) -CONTINUED
Part
to
Step
3
4
5
remove
Top cover
Recoil starter
Air
cleaner
cover and
engine shroud
(with fuel
tank)
L
TOP
Procedures
Remove top cover from the engine.
MSX 16mm tapping screw
Remove recoil starter from the engine.
M6
X
12mm bolt
(1)
Remove air cleaner cover and element
M6 wing bolt
(2) Remove fuel pipe
(engine shroud).
(3)
Remove engine shroud.
M6X 12mm
(4)
Remove bracket
M6X14mm bolt
M6X 14mm tapping bolt lpce.
COVER TAPPING SCREW
.
- -
90.-
bolt
-
-
4pcs.
1
pce.
from
....
lpce.
(NC
....
lpce.
. .
2pcs.
the
cover)
fuel
tank
Remarks
I
RECOIL STARTER
...
~PCS.
Tool
(+)
driver
lOmm box wrench
lOmm
box wrench
lOmm box wrench
M6
X
14mm BOLT
...
lpce.
X
12mm BOLT
AIR
CLEANER COVER
-
BRACKET (A/C
m TAPPING BOLT
...
.
.
.
4pcs.
1
pce.
cover)
-
15-
5-3
DISASSEMBLY
-
Step
Part to remove
-
6
Air
cleaner
PROCEDURES (PRO POLY) -CONTINUED
Procedures
(1)
Remove air cleaner element
bolt
....
M6 wing
(2)
Remove breather hose from cleaner base
and crankcase.
(3)
Remove air cleaner base from air-cleaner
bracket.
M6X12mm
(4)
Remove cleaner base and gasket
cleaner) from carburetor.
M6
nut
- -
(5)
Remove bracket
M6X12mm
lpce.
bolt
----
2pcs.
(AK)
bolt
....
lpce.
from
lpce.
the
(air
engine.
AIR
CLEANER ELEMENT
Remarks
M6
WING
BOLT
\
Tool
lOmm
box
wrench
lOmm
box
wrench
lOmm box wrench
'1.
1
pce.
r:
Fig.
5-4
-
16-
5-3
DISASSEMBLY PROCEDURES (CLASSIC STEEL) / (PRO POLY)
Step
r
'art
7
Speed control
Governor
8
lever
to
remove
Procedures
(1)
Remove speed control assembly from the
crank case, then remove governor spring
from the governor lever.
M6X
12mm bolt
(2)
Remove choke rod from speed control
assembly, then remove choke rod from
choke
shaft
(1)
Remove governor lever from the governor
shaft.
M6
X
25mm
(2)
Remove rod spring and governor
governor lever, then remove rod spring
and governor rod from throttle shaft of the
carburetor.
.-..
2pcs.
of
the carburetor.
bolt
and
washer
assy
- - -
rod
Remarks
1
pce.
from
SPEED CONTROL LEVER
Tool
lOmm box wrench
box
lOmm
wrench
W
Fig.
\
5-6
-
Fig.
17-
5-5
'
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