Subaru EH72-2D Operating and installation instructions

SERVICE INFORMATION
ISSUE EMD-EU6947
PRINTED IN JAPAN
February 2010
EH72-2D

CONTENTS
Section Title Page
1. SPECIFICATIONS.1
2. FEATURES .2
3. DISASSEMBLY AND REASSEMBLY.3
3-1..PREPARATIONS.AND.SUGGESTIONS.3
3-2..SPECIAL.TOOLS.3
3-3..DISASSEMBLY.PROCEDURES.(DIFFERENCE).                                       4
3-4..REASSEMBLY.PROCEDURES.(DIFFERENCE).                                       6
3-5.BREAK-IN.OPERATION.8
4-1.CARBURETOR.9
4-2.COMPORNENT.PARTS..11
PREFACE
This.manual.covers.the.service.information,.trouble.shooting.procedures.and.so.on.of..
EH72-2.engine
Careful.observance.of.the.instructions.given.herein.will.result.in.better,.safer.and.faster.
service.work
For.more.detailed.instructions.of.disassembling.and.reassembling.procedures,.please..
refer.to.the.service.manual.for.EH63,.64,.65.and.72

-.1.-
1. SPECIFICATIONS
Model EH72-2D
Type Air-Cooled,.4-Stroke,.V-Twin.Cylinder,.Horizontal.PTO.shaft,..
OHV.Gasoline.Engine
Number of Cylinders - Bore × Stroke mm (in.)
2.-.84.×.65.(331.×.256)
Displacement ml (cu.in.) 720.(439)
Compression Ratio 87
Continuous Output kW(HP)/r.p.m. 142.(190)./.3600
Maximum Output kW(HP)/r.p.m. Gross.:.187.(250)./.3600
Maximum Torque N•m / r.p.m.
(kgf•m / r.p.m.)
(ft•lb. / r.p.m.)
510./.2800
.(52./.2800)
(376./.2800)
Direction of Rotation Counterclockwise.as.viewed.from.the.PTO.shaft.side
Cooling System Forced.air.cooling
Valve Arrangement Overhead.Valve.(OHV)
Lubrication Full.pressure.type.with.oil.Cooler
Lubricant Automobile.engine.oil.SAE.#20,.#30.or.10W-30;..
Class.SE.or.higher
Capacity of Lubricant L (U.S. gal.) 155.(041)
Carburetor 2-.Barrel.side.draft.type
Fuel Automotive.unleaded.gasoline
Fuel Feed System Diaphragm.Fuel.pump.(Pulse.type)
Ignition System Flywheel.Magneto.(Solid.state)
Spark Plug BPR5ES(NGK).or.BPR4EY(NGK)
Charging Capacity V - A 12.-.15.or.12.-.30.(Option)
Starting System Electric.Starter
Governor System Centrifugal.Flyweight.type
Air cleaner Double.Element.type
Dry Weight kg (lb.)
with out muffler and control box 46.(1013)
with STD muffler and control box 515.(1134)
Dimensions
(L×W×H) mm (in.)
with out muffler and control box 317×477×480.(125×188×189)
with STD muffler and control box 464×499×480.(183×196×189)
* Specifications are subject to change without notice.

-.2.-
2. FEATURES
HIGH OUTPUT, TORQUE AND DURABILITY
720cc.displacement.which.is.the.largest.among.25.horsepower.classed.engines,.produces.high.
torque.from.the.low.speed.range.High.durability.with.less.than.1%.horsepower.drop.after.300.
hours.of.full-throttle.operation
Furthermore,.the.new.generation.of.EH72.(EH72-2).has.achieved.higher.output.by.adopting..
2-.Barrel.Side.draft.carburetor.system,.which.increases.intake.airflow.and.optimally.distributes..
air-fuel.to.each.cylinder,.as.well.as.optimizing.camshaft.profile.and.increasing.compression.ratio
HEAVY DUTY CONSTRUCTON
Reliable.structure.with.pressure.lubrication,.cast.iron.cylinder.sleeve.and.dual.air.cleaner.element.
Also,.heavy.duty.ball.bearing.installed.on.PTO.side
SUPERIOR OIL CONTROL
In.addition.to.the.excellent.oil.control.by.3.pieces.oil.rings,.adoption.of.valve.stem.seal.and.high.
cooling.capability.reduce.oil.consumption.This.enables.longer.oil.maintenance.interval.together.
with.largest.lubrication.oil.capacity.in.this.class
INTAKE MANIFOLD

-.3.-
3. DISASSEMBLY AND REASSEMBLY
3-1 PREPARATIONS AND SUGGESTIONS
(1)..When.disassembling.the.engine,.memorize.the.locations.of.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
(2)..Have.boxes.ready.to.keep.disassembled.parts.by.group
(3)..To.prevent.losing.and.misplacing,.temporarily.assemble.each.group.of.disassembled.parts
(4)..Carefully.handle.disassembled.parts,.and.clean.them.with.washing.oil.if.necessary
(5)..Use.the.correct.tools.in.the.correct.way
(6)..When.disconnecting.electric.wirings,.be.sure.to.hold.and.disconnect.the.connector.housing
3-2 SPECIAL TOOLS
No.Special.Tool.is.needed.for.disassembling.and.reassembling.the.engine
For.pulling.off.the.flywheel,.universal.type.puller.being.popular.in.the.market.place.as.shown.in.
the.illustration.is.needed.
Description Parts number
Flywheel.puller.for.pulling.off.the.flywheel
Flywheel puller with bolt
228-95001-17

-.4.-
3-3 DISASSEMBLY PROCEDURES (DIFFERENCE)
Step Parts to remove Remarks and procedures Parts Fasteners
8
Chock.control.
lever.and.link
(1) Disconnect the choke rod holder and remove
the choke control rod. (See Fig. 3-1)
(2) Remove the choke knob.
CONTROL BOX
CHOKE
CONTROL ROD
RETURN
SPRING
LINK PIVOT
CHOKE
CONTROL
LINK
CHOKE
KNOB
CLAMP
M5 TAPPING
SCREW
BLOWER HOUSING
M6 FLANGE BOLT
M6 FLANGE
BOLT
STEP 8
Fig.3-1

-.5.-
Step Parts to remove Remarks and procedures Parts Fasteners
9
Carburetor (1)..At.first.remove.fuel.pipe.(See.Fig3-2).
(2)..Remove.the.governor.rod.spring.from.rod.holder.
(3)..Pick.up.the.rod.holder.and.remove.the.governor.rod
(See.Fig3-3)
(4)..Remove.the.nuts,.adapter.and.Carburetor.from.the.
intake.manifold.(See.Fig3-4)
.
.
.
M6.Flange.nut.:.4pcs
FUEL PIPE
GOVERNOR ROD
ROD HOLDER
Turn the rod holder
clockwise to loosen.
VIEW A
Fig.3-2 Fig.3-3
Fig.3-4
SPARK PLUG CAP
GROMMT (PLUG CAP)
#2 CYLINDER SIDE ONLY
AS OPTION #1 CYLINDER SIDE
#1 CYLINDER SIDE
#2 CYLINDER SIDE
A
STEP 9

-.6.-
22) CARBURETOR
Set.gasket.onto.intake.manifold.and.install.
carburetor
M6.Flange.nut.:.4pcs
23) CHOKE CONTROL
Attach.chock.control.link.between.carburetor.
chock.lever.and.chock.control.lever
Attach.governor.spring.between.governor.
lever.and.speed.control.lever
3-4 REASSEMBLY PROCEDURES (DIFFERENCE)
#2 CYLINDER SIDE
SPARK PLUG CAP
GROMMT (PLUG CAP)
#2 CYLINDER SIDE ONLY
GASKET
(CARBURETOR)
CARBURETOR
GASKET
(ADAPTER)
CLEANER
ADAPTER
CHOKE
CONTROL ROD
RETURN
SPRING
LINK PIVOT
CHOKE
CONTROL
LINK
CHOKE
KNOB
CLAMP
M5 TAPPING
SCREW
Tightening torque
166.-.186.N•m
(170.-.190.kgf•cm)
(123.-.137.ft•lb)
The marking down wards.
GASKET (ADAPTER) GASKET (CARBURETOR)

-.7.-
25) SPEED CONTROL LEVER
(1)..Install.speed.control.bracket.onto.intake.
manifold
(2)..Attach.return.spring,.spacer,.friction.
washer,.wing.nut,.etc.to.speed.control.lever.
as.shown.in.the..ilustration
(3)..Connect.governor.spring.to.governor.lever.
and.speed.control.lever
STOP PLATE
SPRING WASHER
SPEED CONTROL
LEVER
M6 FLANGE
BOLT
M6 SELF LOCK
NUT
FRICTION
WASHER
FRICTION
WASHER
BRACKET UNIT,
speed control
E





D
*29(5125
*($5
*29(5125635,1*
$'-867,1*
6&5(:
63(('&21752//(9(5
*29(5125
/(9(5
*29(5125
52'
52'635,1*
&/($1(5$'$37(5
&$5%85(725
)8//23(1
)8//&/26(
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,17$.(0$1,)2/'
/ 5
Fitting location of governor rod and governor spring
50 Hz 60 Hz (STD)
COLOR Silver Gold
POSITION A-3(a)
GOVERNOR ROD ROD HOLDER
Turn the rod holder
counter clockwise
and fix it.
Then hook the rod
spring as shown
on the diagram.
VIEW A
ROD
SPRING
24) GOVERNOR LEVER
Attach.governor.rod.and.rod.spring.between.
governor.lever.and.carburetor.throttle.lever,.
and.insert..the.governor.lever.to.governor.
lever.shaft.Tighten.locking.bolt.temporarily
GOVERNOR
SHAFT
GOVERNOR
LEVER
ROD SPRING
GOVERNOR
ROD ROD HOLDER
THROTTLE LEVER
A
CLEANER ADAPTER
L
R

-.8.-
29) AIR CLEANER and BREATHER PIPE
(1).Connect.breather.pipe.to.air.cleaner.base.
(2)..Set.gasket.onto.cleaner.adapter.and.install.
cleaner.base
(3).Fit.air.cleaner.base.onto.carburetor.
M6.x.12.Flange.bolt.:.3.pcs
(4).Connect.breather.pipe.to.#1.cylinder.head.
(5)..Set.air.cleaner.element.along.with.urethane.
foam.onto.base.
(6).Install.air.cleaner.cover.with.knob
CLEANER BASE CP
GASKET
(CLEANER)
CLEANER
ADAPTER
Tightening torque
68.-.88.N•m
(70.-.90.kgf•cm)
(50.-.65.ft•lb)
3-5 BREAK-IN OPERATION
An.engine.that.has.been.completely.overhauled.by.being.fitted.with.a.new.piston,.rings,.valves.
and.connecting.rod.should.be.thoroughly.BREAK-IN.before.being.put.back.into.service.Good.
bearing.surfaces.and.running.clearances.between.the.various.parts.can.only.be.established.by.
operating.the.engine.under.reduced.speed.and.loads.for.a.short.period.of.time.
While.the.engine.is.being.tested,.check.for.oil.leaks
Make.final.carburetor.adjustment.and.regulate.the.engine.operating.speed.
STEP EH72-2 Engine.speed.(rpm) Time.(minute)
1
No.Load
2500 10
2 3000 10
3 3600 10
4 71kW.(95HP) 3600 30
5 142kW.(190HP) 3600 30

-.9.-
4-1 CARBURETOR
OPERATION AND FUNCTION
[EH72-2]
Main System
Slow System
FUEL NIPPLE
DRAIN
VALVE COMPL,
SOLENOID
JET COML, MAIN(L) JET COML, MAIN(R)
FLOAT
SCREW, THROTTLE
ADJUST
SLOW JET
VALVE, THROTTLE VALVE, CHOKE
MIXTURE
FUEL
AIR
MIXTURE
FUEL
AIR
FUEL
AIR
MIXTURE
FUEL
AIR
MIXTURE
L - R

-.10.-
FLOAT SYSTEM
The.float.system.is.consists.of.a.float.and.a.needle.valve,.and.maintains.a.constant.fuel.level.
during.engine.operation.
The.fuel.flows.from.the.fuel.tank.into.the.float.chamber.through.needle.valve.
When.the.fuel.rises.to.a.specific.level,.the.float.rises,.and.when.its.buoyancy.and.fuel.pressure.are.
balanced,.the.needle.valve.closes.to.shut.off.the.fuel,.thereby.keeping.the.fuel.at.the.predetermined.level.
Air.vent.hole.of.float.chamber.is.provided.around.the.carburetor.air.hone.and.the.fuel.vapor.is.
sucked.into.the.combustion.chamber.This.closed.system.has.unti-dust.feature
PILOT SYSTEM
The.pilot.system.feeds.the.fuel.to.the.engine.during.idling.and.low-speed.operation
The.fuel.is.fed.through.the.main.jet.to.the.pilot.jet,.where.it.is.metered,.and.mixed.with.the.air.
metered.by.the.pilot.air.jet
The.fuel-air.mixture.is.fed.to.the.engine.through.the.pilot.outlet.and.the.by-pass
At.idling.speed,.the.fuel.is.mainly.fed.from.the.pilot.outlet.
MAIN SYSTEM
The.main.system.feeds.the.fuel.to.the.engine.at.medium-and.high-speed.operation
The.fuel.is.metered.by.the.main.jet.and.fed.to.the.main.nozzle.The.air.metered.by.the.main.
air.jet.is.mixed.with.the.fuel.through.the.emulsion.tube,.and.the.mixture.is.atomized.out.of.the.
main.bore.It.is.mixed.again.with.the.air.taken.through.the.air.cleaner.into.an.optimum.fuel-air.
mixture,.which.is.supplied.to.the.engine.
CHOKE
The.choke.is.used.for.easy.start.when.engine.is.cold
When.the.starter.is.operated.with.a.choke.valve.fully.closed,.the.negative.pressure.applied.to.
the.main.nozzle.increases.and.draws.much.fuel.accordingly;.thus.easily.start.up.the.engine.
FUEL CUT VALVE
Fuel.cut.valve,.operated.with.starter.key.switch,.is.equipped.with.main.system.of.carburetor.for.
preventing.engine.running.on.and.after.burning.
When.the.key.switch.is.on,.the.valve.is.activated
. and.the.plunger. is.pulled.in.to.open.the.main.jet
When.the.key.switch.is.off,.the.power.source.to.the.valve.is.off.The.plunger.is.pushed.out.by.
the.return.spring.and.stop.the.fuel.flow.of.main.jet.
SOLENOID (for Fuel Cut Off of Carburetor)
.● .Measure.the.resistance.between.the.two.terminals
(Ω.±10%.when.20˚C)
Resistance
32.Ω
.● .
Check.the.operation.of.the.solenoid.independently
Check.operation.at.the.terminals.(Applied.voltage.:.9V)
Faulty.operation..→..Replace.the.solenoid
.● .As.the.solenoid.is.a.constant.pull-in.type.when.the.engine.is.running,.If.the.battery’s.power.is.
low,.it.may.not.work.when.starting.the.engine.because.all.the.available.electricity.is.occupied.
by.the.starting.motor..
.→.Charge.or.replace.the.battery

-.11.-
4-2 COMPORNENT PARTS
..1VALVE,THROTTLE
..2SCREW.SET(VALVE)
..3VALVE,.CHOKE
..4SHAFT.ASSY,CHOKE
..5SHAFT.COMPL,THROTTLE
..6VALVE,.FLOAT
..7PIN,.FLOAT
..8CHAMBER.ASSY,.FLOAT
..9GASKET,.FLOAT.CHAMBER
10FLOAT
11SCREW,.DRAIN
12SPRING,.DRAIN
13SCREW,.THROTTLE.ADJUST
14SPRING(ADJUST.SCREW)
15SCREW
16COLLAR,.CHOKE
17SEAL,CHOKE
18SEAL,THROTTLE
19COLLAR,.THROTTLE
20VALVE.COMPL,SOLENOID
21
GASKET(MATERIAL.:.ALUMINUM)
22O-RING
23GASKET,.SPACER
24SPACER,.CARB
25O-RING
26COVER,.SLOW.PASSAGE
27GASKET,.SLOW.PASSAGE
28SCREW
29JET.COML,MAIN(L)(#132)
30JET.COML,MAIN(R)(#133)
10
21
12
11
8
25
30
29
23
24
15
4
5
14
13
16
17
19
18
1
2
3
9
7
6
22
26
27
28
20
(With locktight)
2(With locktight)
(TIGHTENING TORQUE 1.5~2.5N•m)

SERVICE INFORMATION
ISSUE EMD-EU6947
PRINTED IN JAPAN
February 2010
EH72-2D