Robin EH18V OHV User manual

SERVICE
MANUAL
IVIodel
EH18V OHV
396S322

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

CONTENTS .
Section Title Page
1 .SpEClF[CATlONS .........................................................................................
1
2. PERFORMANCE............................................................................................ 2
2-1 MaximumOutput ....................................................................................
2-2 Maximum Torque ...................................................................................
2
2
2-3 PerformanceCurves ...............................................................................
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
4-11
4-12
4-13
4-1
4
4-1 5
5 .DISASSEMBLY AND REASSEMBLY ............................................................
11
. 11
11
12
27
5-5 Break-inOperation ...............................................................................
40
41
6-1Flywheel Magneto
................................................................................
41
41
5-1 PreparationsandSuggestions
..................................................................
5-2 Special Tools .......................................................................................
5-3 DisassemblyProcedures ........................................................................
5-4 ReassemblyProcedures .........................................................................
6 . MAGNETO ..................................................................................................
6-2 Basic The0 ry .......................................................................................
6-3 WiringDiagram .................................................................................... 42
7.AUTOMATlC DECOMPRESSlON SYSTEM .................................................. 43
8.CARBURETOR
...........................................................................................
44
. 8-1 Operation andConstruction ....................................................................
44
45
47
47
8-2 DisassemblyandReassembly .................................................................
9 . STARTING SYSTEM ...................................................................................
9-1Recoil Starter ........................................................................................

Section Title Page
10. TROUBLESHOOTlNG ..............................................................................
51
10-1 StartingDifficulties
................................................................................ 51
10-2 Engine Misfires
.................................................................................... 52
10-3 EngineStops
....................................................................................... 52
10-4 EngineOverheats
.................................................................................
10-5 Engine Knocks .....................................................................................
10-6 EngineBacMiresThrough Carburetor ........................................................ 53
52
53
11 . lNSTALMTlON .......................................................................................
11-1 Installing .............................................................................................
11-2 Ventilation ..........................................................................................
11-3 ExhaustGas Discharge .........................................................................
54
54
54
54
12 . SERVICE DATA ......................................................................................
55
55
12-1 Clearance DataandLimits
......................................................................
12-2 Torque Specifications ............................................................................ 61
12-3 Oil Grade Chart
....................................................................................
61
13. MAINTENANCE AND STORAGE ............................................................. 62
13-1 DailyMaintenance(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 HoursMaintenance .......................................................... 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, OverheadValve, GasolineEngine
Bore
X Stroke
67 X 52 mm
(2.64 X 2.05 in.)
Piston Displacement
183 cc
(11.16 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)
MaximumTorque
~ ~ ~~~~
Rotation
' ' ForcedAirCooling
Cooling
Counterclockwise
As Viewd FromPTO Shaft Side
~
Lubrication
HorizontalDraftType
Carburetor
Automobile
Oil SAE #20, #30or 1OW-30
Lubricant
Oil PumpType
Fuel
I
Automobile Gasoline
FuelFeed Gravity Type
~ ~~ ~ ~~
Governor System
FlywheelMagneto (Solid State)
Ignition System
Centrifugal FlyweightType
Spark Plug CHAMPION
L86C
Starting System
17 kg (37.5 Ibs.)
DryWeight
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 changewithout notice.
-1-

2. PERFORMANCE
2-1 MAXIMUMOUTPUT
The maximum output of an engine is such a standard power as produced by the engine with its throttle
valvefullyopenedafteritsinitialbreak-inperiodwhenallthemovingpartsareproperlywornin.
Therefore,anewenginemaynotproducethemaximumoutputinthebeginningbecausethemoving
parts arenot in a properly worn-in condition.
2-2 MAXIMUMTORQUE
The maximum torque indicates the torque at the output shaft when the engine is producing the maximum
output.
2-3 PERFORMANCECURVES
EH18V
5.2;
(7. 0
4.41
(6.0
7.4!
(2. 0
Tn"--r
""_~_ """ """_ """
2000240028003200 3600
REVOLUTlON - r.p.m
"i
-2-

3. FEATURES
1. Theoverheadvalvedesignofferscompactness,lightweightandidealcombustioncharacteristics
2. The parts such as a large capacity muffler, dual element air cleaner reduce noise to a minimum level.
3. The automatic decompression system offers easy and sure starting.
4. Themufflerandcarburetorarelocated on oppositesides,makingthearrangements for coolingair
5. The oilpumpandoilfilterprovideexcellentlubricationregardless of enginepostureduring
6. This engine is offered in two stylish versions.
7. The Pro-Poly version engine is covered with a stylishly designed shroud with the
'8. The Classic Steel version does not have the shroud or combined fuel tank.
resulting in more power
from less fuel and prolonged engine life.
flow much easier in the designof power equipment.
operation.
fuel tank incoroprated intoit.
4. GENERALDESCRIPTION OF ENGINECOMPONENTS
4-1 CYLINDERANDCRANKCASE
Thecylinderandcrankcaseissinglepiecealu-
minumdiecasting.Thecylinderliner,made of
specialcastiron,ismoldedintothealuminum
casting.
Thecrankcasehasamountingsurface
on the
output shaft side, where the main bearing cover is
attached. (See Fig.
4-1.)
4-2 MAINBEARING COVER
The main bearing cover is an aluminum
diecasting,which is mounted
on theoutputshaft
side of thecrankcase.Removethemainbearing
cover
to inspect inside of the engine.
Themainbearingcoveralsofunctionsasanoil
pan, with,atrochoid
oil pump and oil filler.
(See Fig. 4-2.)
..
Fig. 4-1
Fig. 4-2
-3-

4-3 CRANKSHAFT
Thecrankshaftisaforgedcarbonsteel,andthe
crank pin
is induction-hardened.ThePTOend of
theshafthasacrankshaftgearwhichispressed
intoposition.(See
Fig. 4-3.) CRANKSHAFT GEAR
Fig. 4-3
44 CONNECTING ROD ANDPISTON
Theconnectingrod is aforgedaluminumalloy,
and its large and small ends function as bearings.
The piston
is analuminumalloycasting,and
4-5 CAMSHAFT
Thecamshaft isa hollowshaped and made of
specialcast iron withthecamshaftgearcasted
together.
A centrifugal decompression lever is assembled on
thecamshaft.Thelubricationoil pump isdriven
by the groove
on the endof the camshaft.
(See Fig.
4-5.)
Fig. 4-4
Fig. 4-5
r,
-4-

4-6 VALVEARRANGEMENT
The intake valve is located at flywheel side of the
Hardalloyvalveseatsaremolded in thecylinder
' cylinderhead.
II n
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.)
EXHAUST Vi
Fig. 4-6
4-7 CYLINDER HEAD
Thecylinderhead,isanaluminumdiecasting,.
which utilizes wedge type combustion chamber for
the highest combustion efficiency.
(See Fig.
4-7.)
Fig. 4-7
4-8 GOVERNORSYSTEM
The governor is a centrifugal flyweight type which
ensuresconstantoperationattheselectedspeed
against load variations.
Thegovernorgearwithgovernorweightsis in-
stalledonthebearingcoveranddriven
by' the
camshaft gear. (See Fig.
4-8.)
Fig. 4-8
-5-

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 has a trochoid pump outside the main bearing cover that is driven by the camshaft.
EH18V uses forced splash type lubrication. (See Fig. 4-9.)
/ CAMSHAFT
M6 FLANGE BOLT ... 1 pce.
OIL SHELTER PLATE
M, AIN BEARING COVER
OIL PUMP COVER
&- M6 FLANGE BOLT ... 4pcs.
Fig. 4-9
-6-

4-1 1 IGNITION SYSTEM
The ignitionsystem is atransistorcontrolled
magnetoignitionsystemwhichconsists of a
fly-
wheel and an ignition coil with a built in transistor
mounted on the crankcase.
Thissystemhasanautomaticignitiontiming
advancing for easier starting. (See Fig.
4-10.)
For details, referto page 39, section 6.
4-12 CARBURETOR
Theenginesareequippedwithahorizontaldraft
carburetor
that hasafloatcontrolled fuel system
and a fixed main jet.
Thecarburetorsarecalibratedcarefullyforthe
surestarting,
good acceleration,lowfuelcon-
sumption and sufficient output.
Forthe-datails,refer
to page42,section “8
CARBURETOR”. (See Fig. 4-11.)
4-13 AIR CLEANER
Theair-cleaner is aheavy-dutytypewithadual
. elementsystem.(See Fig. 4-12.)
-7-
Fig. 4-1 1
WING BOLT I;’ < CLEANERCOVER
PRIMARYELEMENT
GROMMET eo #(URETHANE FOAM)
SECONDARYELEMENT
(PAPER ELEMENT)
. :’ . .’ J
SECONDARYELEMENT
PAPER ELEMENT)
Fig. 4-12

4-14 DECOMPRESSION SYSTEM
An automaticdecompressionmechanismwhich
opensexhaustvalve
before thepistonreaches
compressiontop is assembled
on thecamshaftfor
easy starting. (See
Fig. 4-13)
For details, refer to page 41, section 7.
[ AUTOMATICDECOMPRESSION SYSTEM
&$
RETURNSPRING
n
-a-

4-15 SECTIONAL VIEW OF ENGINE
RECOIL STARTER
\
BLOWER HOUSING
I
MAIN BEARINGCOVER CRANKSHAFT
-9-

SPARK PLUG MUFFLER CONNECTING ROD
- 10 -

5. DISASSEMBLY AND REASSEMBLY
5-1 PREPARATIONSANDSUGGESTIONS
1)
When disassembling the engine, remember the locations of the individual parts so that they can be
reassembledcorrectly. If youareuncertain of identifyingsomeparts,
it issuggestedthattags 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 Pistonring compressor I For placing piston ring
I
I Market parts I Flywheel puller 1 For pulling off the flywheel I
PISTON RING COMPRESSOR
/
/
FLYWHEELPULLER
Fig. 5-1
- 11 -

5-3 DISASSEMBLY PROCEDURES (CLASSIC STEEL) / (PRO POLY)
~~
Step I Part toremove I Procedures
I
~~
Remarks I Tool
'I
Spark plug
Remove spark plug cap and sparkplug.
19mm plug wrench
II
Oil drain, oil
14mmboxwrench
(2) Remove oil drain plug and drain oil.
filter and
(1) Remove oil gauge.
(3) Remove oil filter.bracket
(4) Remove oil filter bracket.
lOmm box wrench
M6X 12mm bolt .... 2pcs.
OILGAUGE y
T
mm
SPARKPLUG , '
OILGAUGE p
T
SPARKPLUGLTER
OIL FILTER BRACKET '
OIL DRAIN PLUG
-
M6 BOLT '.. 2pC~.
LTER
~AC clni r ... gnrc
OIL FILTERBRACKET ' OIL DRAIN PLUG
Fig. 5-2
- 12-

5-3 DISASSEMBLY PROCEDURES (CLASSIC STEEL) -CONTINUED
M6 FL
Part to remove
Recoil starter
Fuel tank
Procedures
Remove recoil starter from the engine.
M6X8mm bolt -0.. 4pcs.
(1) Removefuel tank.
(2) Remove fuel pipe from the fueltank.
(3) Remove side guard.
M6 X 12mm bolt * - Zpcs.
(4) Remove bracket(fueltank)
M6X 14mm bolt
.... lpce.
(5) Remove cover (stop switch).
M6X 12mm bolt .-** 2pcs.
lOmm box wrench
RECOIL STARTER ASS’Y
M6 FLANGE
BOLT
-8- GPCS.
COVER (stop switch)
HOSE CLAMP
I. SIDE GUARD
M6 FLANGE BOLT .. . 1 pce.
Fig. 5-3
- 13’ -’

5-3 DISASSEMBLY PROCEDURES (CLASSIC STEEL) -CONTINUED
-
Step
5
-
-
Parttoremove
Air cleaner
Procedures
(1) Remove air cleaner cover and air cleaner
element
M6 wingbolt
**-- lpce.
and crankcase.
bracket.
M6X12mm bolt .--. Ipce.
cleaner) from carburetor.
M6
nut .... 2pcs.
(5) Remove bracket (A/C) from the engine.
M6X 12mm bolt
.... lpce.
(6) Remove bracket (NC cover)
M6 X 14mm bolt - 1pce.
M6x 14mm tapping
bolt .... lpce.
(2) Removebreatherhosefromcleaner
base
(3) Remove air cleaner base from air cleaner
(4) Removecleaner baseand gasket (air
PROCEED TO STEP 7 OF DISASSEMBLY PROCEDURES
Remarks Tool
lOmm box wrench
lOmm box wrench
lOmm box wrench
lOmm box wrench
M6 WING BOLT ... Ipce.
M6 X 14mm BOLT ... lpce.
AIR CLEANER COVER
AIR CLEANER
M6 x 14mm
AIR CLEANER BASE
HOSE CLAMP
M6 NUT ... ~PCS.
BREATHER HOSE
Fig. 5-4
- 14-

5-3 DISASSEMBLY PROCEDURES (PRO POLY)-CONTINUED
Step
(+) driver
Remove top cover fromthe engine.
Top cover
3
Tool
Remarks
Procedures
Part to remove
MSX 16mmtappingscrew .. 2pcs.
4
lOmm box wrench
Remove recoil starter from the engine.
Recoil starter
M6 X 12mm bolt - - - - 4pcs.
5 Air cleaner
cover and
engine shroud
(with fuel
tank)
L
M6 X
(1) Remove air cleaner coverand element
M6wing bolt
90.- 1 pce.
(2) Remove fuel pipe
from the fuel tank
(engine shroud).
(3) Remove engine shroud.
M6X 12mm
bolt .... lpce.
(4) Remove bracket (NC cover)
M6X14mm bolt
.... lpce.
M6X14mmtapping bolt lpce.
I
lOmm box wrench
lOmm box wrench
TOP COVERTAPPINGSCREW ... ~PCS.
.
RECOILSTARTER
X 12mm BOLT ... 4pcs.
AIR CLEANER COVER
14mm BOLT
... lpce. -
BRACKET (A/C cover)
m TAPPING BOLT . . . 1 pce.
- 15-

5-3 DISASSEMBLY PROCEDURES (PRO POLY)-CONTINUED
-
Step
6
-
Partto remove
Air cleaner
Procedures
(1) Remove air cleaner element
M6 wing
bolt .... lpce.
(2) Removebreatherhosefromcleanerbase
and crankcase.
(3) Remove air cleaner base from air-cleaner
bracket.
M6X12mm
bolt ---- lpce.
cleaner) from carburetor.
M6
nut - - 2pcs.
M6X12mm
bolt .... lpce.
(4) Removecleanerbase and gasket (air
(5) Remove bracket (AK) from the engine.
Remarks Tool
lOmm box wrench
lOmm box wrench
lOmm box wrench
M6 WING BOLT '1. 1 pce.
AIR CLEANERELEMENT \
r:
Fig. 5-4
- 16-