Robin EH12 User manual

ROBIN AMERICA, INC.
ROBIN TO WISCONSIN ROBIN
ENGINE MODEL CROSS REFERENCE LIST
ROBIN
EY08
EY15
EY15V
EY20
EY2OV
EY23
EY28
EY3
5
EY40 -
EY45V
EY2
1
EY44
EY18-3
EY25
EY27
EH11
EH12
EH15
EH17
EH21
EH25
EH30
EH30V
EH34
EH34V
EH43V
EC13V
DY23
DY27
DY30
DY3
5
DY41
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 1-43OV
TWO CYCLE
WT1-125V
DIESEL
WRD 1-230
WRD 1-270
-1-300
WRD1-350
WRD1-410
0
0
0

NTEN'TS
Section Title Page
1 .
2 .
3 .
4 .
5 .
6 .
7 .
8 .
SPEClFlCATlONS ............................................................................
PERFORMANCE ............................................................................
2-1 MaximumOutput .......................................................................
2-2 ContinuousRatedOutput ..............................................................
1
4
4
4
4
5
8
GENERAL DESCRlPTlON OF ENGINE COMPONENTS ............................ 8
2-3
M~~~~~~T~~~~~ .......................................................................
2-4 performance curves ...................................................................
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

13-1
13-2
13-3
13-4
13-5
13-6
13-7
..
"

1. SPECIFICATIONS
~~ ~~ ~
EH12
EH12B EH12DS EH12D EH12BS
Model
TY Pe Air-Cooled,4-Cycle, Single-Cylinder. Horizontal P.T.O. Shaft, Gasoline Engine
Bore
X Stroke
121 cc (7.38cu.in.)
PistonDisplacement
60
X 43 mm (2.36 X 1.57in.)
CompressionRatio
output
8.5
Continuous
4.0 /4000 HP/rpm
4.0/2000 HP/rpm
Max.
2.5/3000 HP/rprn 2.813600 HP/rpm2.5/1500 HP/rpm 2.8/1800 HP/rpm
Max. Torque 0.76/2600 kg*m/rpm
1.52
/ 1300 kgm/rpm
Direction
of Rotation Counterclockwise As Viewd From P.T.O. Shaft Side
Coolingsystem ForcedAir Cooling
Valve Arrangement Overhead Valve
Lubrication SplashType
Lubricant Automobile Oil
SAE #20, #30 or 1OW-30
Capacity of Lubricant
HorizontalDraft, FloatTypeCarburetor
0.6 liters (0.16
U.S. gal.)
Fuel
230 gr/HP-h At Continuous RatedOutputFuelConsumptionRate
AutomobileGasoline
Fuel FeedSystem
3.6 liters (0.95
U.S. gal.)
FuelTank Capacity
GravityType
IgnitionSystem
NGK B6HS
Spark Plug
Flywheel Magneto (Solid State)
ChargingCapacity
i 12V- 1.3~ 1
1 12V- 1.3A
StartingSystem
Starter
Recoil Starter Recoiland Electric
Starter Recoiland Electric
Recoil Starter
Speed Reduction
Centrifugal Flyweight System
Governor System
-
21 Cam Shaft Drive
Dry Weight
366mm (14.41in.)366mm (14.41in.)
366mm (14.41
in.)
366mm (14.41in.)Height
345mm (13.58in.)
330rnm (12.99in.)
345mm (13.58in.)
330mm (12.99in.)
Width
Dimensions
301mm(11.85in.)
301rnm (11.85in.)
303mm (11.93in.)303mm (11.93in.)Length
16.5kg (36.3Ib.)
14.0kg (30.8Ib.)
17.0kg (37.4Ib.)
14.5kg (31.91b.)
-1-

Model
TY Pe
Bore
X Stroke
Piston Displacement
Compression Ratio
Continuous
output
Max. Torque
Directionof Rotation
Cooling system
Valve Arrangement
Lubrication
Lubricant
Capacity of Lubricant
Carburetor
Fuel
FuelConsumption Rate
FuelFeed System
FuelTank Capacity
IgnitionSystem
Spark Plug
Charging Capacity
StartingSystem
Speed Reduction
Governor System
Dry Weight
Dimensions
Length
Width
Height
EH17
EH17BEH17BSEH17DEH17DS
Air-Cooled, 4-Cycle,Single-Cylinder, Horizontal P.T.O. Shaft, Gasoline Engine
67
X 49 mrn (2.64 X 1.93 in.)
172
cc (10.50 cu.in.)
8.5
6.0/2000 HP/rprn 6.0/4000 HP/rpm
3.5
/ 1500HP/rpm 4.0 / 1800HP/rpm I 3.5 13000 HP/rpm4.0/3600 Wrpm
2.18 / 1300 kgm/rpm 1.09/2600 kg*m/rpm
Counterclockwise As ViewdFrom
P.T.O. Shaft Side
Forced Air Cooling
Overhead Valve
Splash Type
Automobile Oil
SAE #20, #30or 1OW-30
0.65 liters (0.17 U.S. gal.)
Horizontal Draft,Float Type
Automobile Gasoline
230 gr/HP-h At Continuous Rated Output
Gravity Type
3.6 liters (0.95 U.S. gal.)
Flywheel Magneto (SolidState)
NGK B6HS
- 12V - 1.3A - 12V - 1.3A
Recoil Starter
Starter
Recoil and Electric Recoil Starter 1 Starter Recoil and Electric
I I I
2:l Cam Shaft Drive
-
Centrifugal Flyweight System
16.0kg
(35.2 Ib.) 1 18.5kg (40.7 Ib.) I 15.5kg (34.1Ib.) I 18.0kg (39.6 Ib.)
~~~~ ~~
315rnrn (12.40in.) 315mm (12.4Gin.) 313mrn (12.32in.) 313mrn(l2.32in.)
330mrn (12.99in.) 361
mm (14.21in.) 330mm (12.99in.) 361 rnm (14.21in.)
380mrn (14.96in.)
380rnm (14.96in.) 380mm (14.96in.) 380rnrn (14.9Sin.)
,-
-2-

I Et125
Model
EH25BEH25BSEH25DEH25DS
TY Pe
1 Air-Cooled, 4-Cycle, Single-Cylinder,Horizontal P.T.O. Shaft, Gasoline Engine
Bore
X Stroke 75
X 57 mm (2.95 x 2.24 in.)
PistonDisplacement
251 cc(15.31cu.in.)
Compression Ratio
8.5
Output
Max.Torque
3.38 I1 300 kgWrpm 1.69 / 2600 kg-mlrpm
Continuous 8.5/2000 HP/rpm 8.5/4000HP/rprn
Max. 5.5/1500 HP/rpm 6.411800 HP/rpm 5.5/3000 HP/rpm6.4/3600 HP/rpm
Direction
of Rotation Counterclockwise As Viewd From P.T.O.Shaft Side
Coolingsystem ForcedAir Cooling
Valve Arrangement OverheadValve
Lubrication SplashType
Lubricant Automobile Oil
SAE #20, #30 or 1OW-30
Capacity
of Lubricant 1 .O liters (0.26 U.S. gal.)
Carburetor HorizontalDraft, FloatType
Fuel Automobile Gasoline
FuelConsumption Rate
230 gr/HP-h At Continuous RatedOutput
Fuel Feed System GravityType
FuelTank Capacity 6.0 liters (1
59 US. gal.)
IgnitionSystem FlywheelMagneto(Solid State)
Spark Plug
NGK B6HS
Charging Capacity
- 12V - 1.3A - 12V - 1.3A
Starting System
~~~ ~~
Recoil and Electric
Starter
Recoil Starter
~~ ~~_____
Recoil Starter Recoil and Electric
Speed Reduction 2:l Cam Shaft Drive
-
Governor System CentrifugalFlyweightSystem
Dry Weight24.5 kg (53.9
Ib.) 28.5 kg (62.7 Ib.) 24.0kg (52.8 Ib.) 28.0kg(61.6 Ib.)
Length 360rnm (14.17in.) 360mrn (14.17in.) 360rnm (14.17in.) 360mm(l4.17in.)
Dimensions
Width
385mm (15.15in.) 405mm (15.94in.) 385mm (15.15in.) 405mrn (15.94in.)
Height 440mm (17.32in.) 440rnm (17.32in.) 440mm (17.32in.) 440mm (17.32in.)
I-
-3-

2.
PERFORMANCE
2-1 MAXIMUM OUTPUT
A.
The maximumoutput is the output of an engine with its throttle valve fully opened under the condition
that all the moving parts are properly worn in after the initial break-in period.
A new engine may not produce full maximum output while its moving parts are still not broken-in.
2-2 CONTINUOUS RATED OUTPUT
Thecontinuous rated output is theoutput ofan engine at optimum governedspeedwhich is most
favorable from the view point of engine’s life and fuel consumption.
When the engine
is installed on acertainequipment, it is recommended that thecontinuousoutput
required from the engine bekept below
this continuous rated output.
2-3MAXIMUM TORQUE
The maximum torque is the torque at the output shaft when the engine is producing maximum output at
certainrevolution.
-4-

2-4 PERFORMANCE CURVES
0 EH12D, B
4.0
(2.98 KW)
3.5
(2.61KW)
3.0
(2.24 KW)
2.5
(1.87 KW)
2.0
(1.49 KW)
1.5
(1.21KW)
1
.o
(0.75 KW)
0.5
(0.37 KW)
( ) for B type
-
MAXIMUM TORQUE
1
2000
(1
000)
3000
(1 500)
REVOLUTION --s) r.p.m.
0.8 (1.6) kg-m
0.7 (1.4) I
W
t
I
0.6 (1.2)
0
I-
CONTINUOUS
RETED
HP
RECOMMENDED
HORSEPOWER
\ RANGE
4000
(2000)
i
f
-5-

0 EHf7D, B
n
( ) for B type
.. "
REVOLUTION "-+ r.p.m.
kg-m
1 .I 0 ,(2.2)
t
I
1-00 (2.0) I
W
Y
0.9 (1.8) 6
CT
0
I-
CoNTiNuous
RETE0 HP
1 RECOMMENDED
\ RANGE
HORSEPOWER
- 6-

0 EH25D, 6
-7-

3.
FEATURES
1. The overheadvalve design offersacompactness, light weight and ideal combustioncharacteristics
2. An optimum lubrication and better tilted operation thanks to upright cylinder design.
3. A crossflowarrangement of intake and exhaust ports ensuresstableperformance under high ambient
4. Theautomatic decompressiomsystemlightens therecoilpull force by 40% comparing to the
5. An easy operation thanks to integratedengine controlsystem.
6. Combustionandmechanicalnoiseshave been carefullyreviewedforbetter tonal quality and lower
7. Optimallydesignedreciprocatingpartsreducethe vibration level of theengine. EH25 engineequips
resulting
in more power from less fuel and prolonged engine life.
F.
temperature.
conventional
SV engines.
cnginc noise.
sjnglc through-balancer shaft.
4. GENERAL DESCRIPTION OF ENGINE COMPONENTS
4-1 CYLINDER AND CRANKCASE
The cylinderandcrankcase is single piecealu-
minum diecasting.Thecylinderliner,made of
special cast iron, is molded into thealuminum
casting.
Thecrankcase has
21 mountingsurface on the
output shaft side, where the main bearingcover is
attached. (See Fig. 4-1 .)
Fig. 4-1
i OILGAUGE OIL GAUGE
I-GKR CENTERING
"" "" ~
/,"
Fig. 4-2
-8-

4-3 CRANKSHAFT
Thecrankshaft is forgedcarbonsteel,and the
crank pin is induction-hardened.
0 Theoutputend of the shafthas a crankshaft gear,
and balancer gear for
EH25 which are pressed into
position. (See Fig. 4-3.)
4-4 CONNECTtNG ROD AND PISTON
The connecting rod is forged aluminum alloy, and
its largeand small ends function as bearings. The
piston is analuminum alloycasting,andcarries
two compression rings and one oil ring.
(See Fig. 4-4.)
4-5 PISTONRINGS
The Piston rings are made of special cast iron.
The profile of the top ringisbarrelfaceand the
second ring has
a tapered face with an under-cut.
The oilringconsists
of a cutter ring and a coil
expander
for bettersealing and less oil consump-
tion.
I B TYPE
1
D TYPE
Fig. 4-3
Fig. 4-4
--
TOP RING
SECOND RIN(
OIL
RING
r
-9-

4-6 CAMSHAFT
‘I’he camshaft for the D-type engine is made of
special cast iron and camshaftgearsarecasted
togcther in one piece.
Both sides of theshaft fit into the plane bearings
on the crankcase and main bearing cover.
‘I’hc camshaft for the B-type engine is made of
forged carbon stcel and also functions as PTO
shaft.
The cam gear
is pressfitted on the shaft and the
ball bearings arc employed on both sides for sup-
porting the shaft.(See Fig. 4-6.)
4-7 VALVE ARRANGEMENT
‘I’he intake v;llve is located on flywheel side of the
cylinder hcad.
‘I’hc
hard alloy valvc seatsare molded in the
cylinder head andstcllite
is fused lo the exhaust
valvc
f;KC.
‘I’hc cylindcr bafflc leads cooling airto the exhaust
valvc
arca for the optimum cooling. (See Fig. 4-7.)
4-8 CYLINDER HEAD
‘I’hc cylindcr hcadis a11 aluminurn diecasting
which utilizcs
wcdgc type combustion chamber for
thchighcst combusl.ion cli‘icicncy. (See Fig. 4-13,)
I
B TYPE
I
I
D li’PE
Fig. 4-6
Fig. 4-7
h.
Fig. 4-8
- 10 -

4-9 GOVERNOR SYSTEM
The governor is a centrifugal flyweight type which
ensuresconstantoperation
at theselectedspeed
against load variations.
The governorgear
with governorweightsis in-
stalled on the main bearing cover. (See Fig. 4-9.)
/
GOVERNOR GEAR
Fig. 4-9
4-10 COOLING SYSTEM
The largefins on the flywheelprovide sufficientcoolingair capacityfor the inlet and exhaustarea and
cylinder.
The cylinder baffle helpsthe cooling air
flow efficiently.
4-1 1 LUBRICATION
All the rotating and slidingpartsaresplash-
lubricated
by the oil scraper on the connecting rod.
(See Fig.
4-10.)
I
OIL SCRAPER
Fig. 4-10
1‘
- 11 -

4-12 IGNITION SYSTEM
The ignition system is a transistorcontrolled
magneto ignition systemwhichcosists
of a fly-
wheel and an ignition coil with a built in tran-
sistor.
Thissystem has an ignition timingadvance
for
easy starting. (See Fig. 4-1 1.)
Fig. 4- 1 I
4-13 CARBURETOR
The enginesareequippedwith a horizontal draft
carburetor that
has a float controlled fuel system
and
a fixed main jcl.
The carburetors are calibratedcarefully for easy
starting,
good acceleration, low fuel consumption
and sufficient
output.
For datails, see page 47, section 8.
“CAKBUKE‘I’OR”. (SCC Fig. 4-12.)
4-14 AIR CLEANER
‘I’hc air clcancr is a singleurcthine foam elementsystem. As an option, heavy duty type with a double
elemcnI type is available. (See Fig.
4-13-1 and 4-13-2.)
Single element type
__ .. ” ~.~ ~
Fig. 4- 13-1
COVER
Double element type
Fig. 4- 13-2
/”
- 12 -

4-15 SECTIONAL VIEW OF ENGINE
/
FLYWHEEL
FUEL
TANK
/
I II + . PISTON
I
MAIN BEARING COVER
- 13 -

ROCKER ARM
I
L
- 14 -

5.
5-1 CAUTIONS
1) Because some matingpartswithwear surfaces weremachinedtogether when the enginewas
manifactured,
or haveestablishedwearpatternsduringoperation, the reassembly of engineparts, is
critical to theperformance andlife expectancy of the engine. MARK AND SORT ALL PARTS SO
THAT THEY WILL BE DISASSEMBLED AND INSTALLED IN THEIR ORIGINAL POSITIONS.
2) Crankshaftandcamshaftbearingsshouldbecleaned and inspected,and removed only if they appear
to bedamaged
or excessivelyworn.Removebearingsthatarepitted,nicked,burred,discolored, or
that rotate roughly or noisily.
3) Keepcleanandhandlecarefullythedisassembledparts,Cleanthemthoroughlywithwashingoil
before the reassembly.
4) Use correct tools in the proper way
The use
of non-specified tools could cause permanent damage to the engine or components.
5-2 SPECIALTOOLS
Tool No. Use
Tool
209 - 95004 - 07
For pulling off the flywheelEli1 7, EH25
Flywheel puller
with bolt
Market parts For pulling
off the flywheel EH12
Flywheel puller
FLYWHEEL PULLER
FLYWHEELPULLER
- 15 -

5-3 DISASSEMBLY PROCEDURES
Step
Tool Remarks
ProceduresPart to remove
I
14mm box wrench
Be careful not to lose the
(I) Remove oil drain plug and drain oil. Oil drain
(2) ‘To discharge oil quickly,remove oil
gasket.
gauge.
GASKET
I
Fig. 5-2
DRAIN PLUG
- 16 -