Robin ECO2 User manual

ROBIN AMERICA, INC.
ROBIN TO WISCONSIN ROBIN
ENGINE MODEL CROSS REFERENCE LIST
ROBTN
EY08
EY15
EY 15V
EY20
EY20V
EY23
EY28
EY35
EY40
EY45V
EY2 I
EY44
EY25
EY27
EY18-3
EH11
EH12
EH15
EH17
EH21
EH25
EH3 0
EH30V
EH34
EH34V
EH43V
EC13V
DY23
DY27
DY30
DY35
DY41
WISCONSIN ROBIN
-
W1-080
W1-145
W1-145V
W1-185
W1-185V
W1-230
Wl-280
W1-340
W1-390
W1-450V
EY2 1 W
EY44W
EY25W
EY27W
EY18-3W
v
WOI-115
wo1-120
WO1-150
WO1-170
wo1-210
WO1-250
WO 1 -300
WO1-340
WO1-300V
WO 1 -340V
WO 1-43 OV
TWO CYCLE
WT1-125V
DIESEL
WRD 1-230
WRD 1-270
-1-300
WRD1-350
WRD1-410

CONTENTS
.
.
Section Title Page
1 . SPECIFICATIONS ........................................... 1
2 . PERFORMANCE ............................................ 2
2.1 . Maximum Output ...................................... 2
2.2 . ContinuousRated Output ................................ 2
2.3 . Maximum Torque and FuelConsumption Ratio and Max .Output ...... 2
3 . FEATURES ............................................... 3
4 . DISASSEMBLY and REASSEMBLY ............................... 4
4.1 . Preparationand Suggestions ............................... 4
4.2 . Special Tools ......................................... 4
4.3. DisassemblyProcedures .................................. 5
4.4 . ReassemblyProcedures .................................. 6
5 . BREAKERPOINTADJUSTMENTPROCEDURES ..................... 9
6 . CARBURETORADJUSTMENT .................................. 10
7 . OPERATION OF FLOATDIAPHRAGMCARBURETOR ................ 11
8 . TROUBLESHOOTING ........................................
13
9 . CHECKS and CORRECTIONS ...................................
16
10 . MAINTENANCEand STORING ................................... 19
10-
1 . Daily ChecksandMaintenance .............................
19
10.2
. Every 50HoursChecksandMaintenance ......................
19
10.3 . Every 150 HoursChecksandMaintenance ......................
19
10.4 . Yearly ChecksandMaintenance ............................ 19
10.5
. Preparation for LongAbeyance ............................. 19

SPARKPLUG
CARBURETOR
\
AIRCLEANER \ \-
\ /
TICKL
STARTERKNOB
(Recoil
Starter)
MUFFLER.COVER
/ FUEL TANK CAP
,FUEL TANK
FUEL COCK
. MUFFLERCOVER

1. SPEC1 FlCATlONS
-1-

2. PERFORMANCE
2-1 MAXIMUMOUTPUT
The maximum outputof the EC02-A and ECOZ-R is such standard power as developed by theengine, after itsrun-in period
with all themoving parts properly worn-in, when operating with the fully open throttlevalve. Therefore, it follows thata new
engine may not develop this maximum output in the beginning, because moving parts are not
in a properly worn-in condi-
tion.
,"
2-2CONTINUOUSRATEDOUTPUT
The continuous rated output of the EC02-A and EC02-R is such power as developed by the engine when running at an opti-
mum speed most favorable inview
of engine life and fuel consumption ratio. Therefore, it follows that whendesigning adriv-
ing system
for any mechanism, with the engine, asa prime mover,the continuous power requirement of that mechanism must
be kept below the continuous rated output specified.
2-3 MAXIMUM TORQUE and FUELCONSUMPTIONRATIO at MAX.OUTPUT
The maximum torque of the EC02-Aand EC02-R is that driving torque of the driving shaft at which the engineis driving an
external load, while the engine
is pulling its rnax. output. The fuel consumption ratio at max. output is that fuel consump-
tion ratio
of the engine while the engine is running at the max.output.
MODEL ECO2-A and ECOP-R PERFORMANCE CURVE
ft-LbS
HP
-2-

3. FEATURES
1. COMPACT, LIGHTWEIGHT, HIGH PERFORMANCE and LOW FUEL CONSUMPTION
2. TROUBLE FREE because of simple design and easy to handle
3. HIGH DURABILITY engine withstand long severe operation
4. TILTEDOPERATIONAVAILABLE
Be able tooperate at any position dueto diaphragm carburetor.
5. EASY STARTING with recoil starter
6. ForgedsteelCrankshaft
7. Ball main bearings at both ends
8. Forged steel connecting rod.
9. With CHROME PLATED CYLINDER, HEATCONDUCTIVITYand WEAR PROOF are quite excellent.
-3-

4. DISASSEMBLY and REASSEMBLY
4-1 PREPARATION and SUGGESTIONS
1) When disassembling the engine, memorize the locations of individual parts so as to be able to reassemble them correct-
ly. Tag partsif there
is a possibility of confusion.
2) Prepare several boxes to keep parts belonging to certain groups together.
3) Group those parts related each other, tentatively assemblingwhere they belong, immediately after removing, in order
to prevent missing and misplacing.
4)Handle the disassembled parts carefully and wash them in kerosene.
5) Use thecorrecttoolsinthecorrectway.
6) Standardtoolsrequiredfor disassemblingand reassembling:
a) Work table
b) Washing pan
c) Disassembling tools
d) Washing oil (kerosene orgasoline),
2 cycle-oil
e) Emery paper, cloth
7) Beforestarting to disassemble the engine,drainfuel.
8) Tighten the screws of the cylinder, crankcase, connecting rod, spark plug, and flywheel to the specified torque values.
9) Use new packings and gasketsinreassembly.
10) Immediately before assembling parts, wash them in fresh gasoline orkerosene and blow them dry.
11) Apply
2 cycle-oil on rotating andsliding parts.
12) Takecarenot to contaminatethepartsbydustduring assembling.
13) Tighten bolts, nuts and screws with proper torque according to the their sizes. If small screws are tightened too tight,
they may get broken.
14) After completely assembling the engine; turn it byhand and check if there
is any abnormality orloose members.
,-
4-2 SPECIAL TOOLS (Fig. 1)
Fig. 1
-4-

-
4-3 DISASSEMBLY PROCEDURES
-
4-3-1FUELDRAIN
Drain fuel from the fuel tank,
4-3-2 THROTTLE Wl RE (See Fig. 2)
Remove throttle wire from carburetor together with piston
valve.
.-
Fig. 2
4-3-3 FUEL TANK and RUBBER TUBE
L 1) Disconnectfuelpipebetweenfueltankandcarbure-
I
tor at carburetor side.
2) Removefueltankbyunscrewingbolts.
3) Onlyfor EC02-R
Afterremovingfuelpump,pushthehead of rubber
tube toward arrow mark
in Fig. 3 with ascrewdriver
of minus top (preferably not sharpened) and remove
rubber tube.
CA U TION:
NEVERREMOVE RUBBER TUBE EXCEPT AT RE-
P LACEMENT.
BE SURE
TO REPLACE WITH MEW ONEWHEN RE-
MOVED.
BE CAREFUL NOT TO DAMAGE THE HOLE IN WHICH
RUBBER TUBE WILLBE IMSERTED.
4-3-4 KILL SWITCH WIRE
Disconnect stop buttonwire terminal.
4-3-5 RECOl L STARTER
Removestarter case fromcrankcasebyunscrewingbolts.
4-3-6 MAGNETO FLYWHEEL (See Fig. 4)
After removing nut, pull out flywheel from crankshaft,
Turn cenler bolt clockwiw
FLYWHEEL' ~LYWHEEL PULLER . .
*...
-
I.
Fig. 4
4-3-7 BREAKER, C'ONDENSER, and COIL (See Fig. 5)
Remove breaker cover, condenser, breaker, and ignition coil
from crankcase byunscrewing bolts.
IGNITION COIL .*
Fig. 3
Fig. 5

4-3-8 CARBURETOR and CARBURETOR BRACKET
(EC02-A),CARBURETOR and HEAT BLOCK
(EC02-R)
(See Fig. 6)
Remove carburetorandcarburetorbracketby unscrewing
bolts
(EC02-A), andremove carburetor and heat blockby
unscrewing bolts
(EC02-R).
HEAT BLOCK
Fig. 6
4-3-9 MUFFLER
Remove muffler from cylinder by unscrewing bolts.
4-3-10 CYLINDER (See Fig. 7)
Removecylinderquietly so asnot to damageslidingsur-
faces of cylinder and
piston.
CRP
Fig. 7
4-3-11 DIVISION of CRANKCASE (See Fig. 8)
After unscrewing bolts, disassemble frontandrearcrank-
cases fromcrankshaftbytappingwith
a soft hammer.
Washing crankcasewith gasoline, applythe film
of oil to
crankcase ball bearing bore and grease
to oil seal bore,
KCASE
FRONT C~ANKCASE I
CRANKSHAFT
Fig. 8
44 REASSEMBLY PROCEDURES
4-4- 1 CRANKCASE (See Fig. 9)
1) Insertcrankshaftintofrontcrankcase bearing.
2) Assemble the crankcase.
3) Use newgasket.
4) Tightenbolts to 40-50 kg-cm (2.9-36 ft-lbs)torque.
5) Cut off crankcasegasketsstuck out to the mating sur-
face of cylinder.
CRANKSHAFT
Fig. 9
-6-

-
4-4-2 CYLINDER (See Fig. 10)
-
1) Replacecylindergasketwithnewone.At the same
time,
try to mate the tapper hole with the groove on
the contact surface of crankcase.
CAUTION:
TAKE CARE THAT GASKET
IS PLACED IN RIGHTPO-
SITION AND ON RIGHTSIDE.
2) In assemblingcylinder, takecare of theposition of
piston rings and cylinder.
3) Tightenbolts to40-50 kg-cm (2.9-3.6 ft-lbs).
"A
Fig. 10
4-4-3 SPARK PLUG
Tightensparkplug to 220-300 kgcm (15.9-21.7ft-lbs).
4-4-4CARBURETORBRACKET OR HEATBLOCK
1) Use new gasket.
2)Tightenbolts to 50-70kg-cm (3.6- 5.1ft-lbs)torque
for EC02-Aand to 40-5Okgcm (2.9-3.6 ft-lbs) tor-
que
for ECO2-R.
4-4-5 CARBURETOR (See Fig. 11)
Tightennutsto50-7Okgcm(3.6-5.1ft-lbs)torquefor
ECO2-A and to40-50kgcm(2.9-3.6 ft-lbs)torquefor
EC02
-R .
II
4-4-6 IGNITIONCOIL
Tightenignition coil tentatively,putting hightension
on the right side.
4-4-7BREAKER
Insert knock pin of breaker into thehole of crankcase.
Tightening torque: 25 kg-cm
(1.8 ft-lbs).
wire
Regarding the adjustment of spark timing, refer to
Section 5.
Breaker Point adjustmentProcedure.
4-4-8 CONDENSER
Assemble it, running stop wire through the bottom of con-
denser.
Tightening torque: 25
k2 kgcm
Tool: Plus driver, Torque wrench
4-4-9 POINT COVER
Afterinsertingstop wire andprimarywire into the groove
of crankcase, assemble point cover,
Tightening torque: 25 kgcm (1.8 ft-lbs).
4-4-10FLYWHEEL
Mount flywheel on crankshaft and tighten flywheel nut.
Flywheeltighteningtorque
is 150-180 kgcm (10.8-13.0
ft-lbs).
4-4-1.1 IGNITION COIL (See Fig. 12)
Tightenignitioncoil,keeping'aclearance of 0.4-0.6mm
from flywheel.
Tightening torque: 25 kg-cm
(1.8 ft-Lbs).
/
,NIT1
-YWI
ON COIL
HEEL
Fig, 12
Fig, 1 1
-7-

4-4-1'2 MUFFLER
Tighten muffler to 90- 1 lOkgzm (6.5-8.3 ft-lbs).
Use newgaskets.
4-4-13 TENTATIVELY TIGHTENING OF CYLINDER
COVER
Mount the both ends of cylinder covers on the mating por-
tions of the crankcaseandtentativelytighten withscrews.
In Type A,
also mount fuel tank stay together on thecylin-
der head with flat washers.
Tool: Plus Driver
4-4-14 RECOIL STARTER, STOP BUTTON AND
GROMMET
Install stopbuttonto starter case withtoothed washer on
its reverse side.Run high tension cord through the grommet
and assembleplugcapspring andplugcap. Run the grom-
met through the groove
of starter case andtightenstarter
case tocrankcase with three screws.
Tightening torque: Stop button
25 +-2 kgcm
Starter case
45 +3kg-cm
Tool: Plus driver,Torque wench
A- . ,?
4-4-16 RUBBERTUBE IN FUELTANK (EC02-R)
Insert the rubber tube in the holeof fuel tank from the end
of feltside
of rubber tube. Use spacer or backingplate to
gently put in withvice or
squill vice as shown in thefigures.
Completely put in theridge of rubber tube. After inserting,
pinch the outerside
of rubber tube and turn ittoassure that
the ridge has been completely inserted.
Fig. 14
CA U TI0 N:
AFTERINSERTING,
BE SURETOCONFIRMTHE IN-
SERTION OF THE RIDGE OF RUBBER TUBE.
4-4-15 TIGHTENING OF CYLINDERCOVER
Tighten the cylinder cover.
Tightening torque:
45 *3 kg-cm
Tool: Plus driver, Torque wrench
Fig. 15
4-4-17 FUEL TANK
Put spacer into fuel tank and install withscrews. (Use a large
type flatwasher.) Connect fuel lineto carburetor.
Tightening torque:
45 * 3kg-cm (3.3 * 0.2 ft-lbs)
Tightening torque:
45 k3 kg-cm
Tool: Plus driver, Torque wrench
- 8-

5. BREAKERPOINT ADJUSTMENT PROCEDURES
1) Remove starter case.
2) Removeflywheelfromcrankshaft. (Flywheelnutisleft-handthreads).
3) Take off woodruff key from crankshaft and point cover.
4) Remove carbon deposits on breaker point and clean mating surface by cloth orpaper.
5) Fitwoodruffkeytocrankshaft,
6) Tackflywheel,andset “F” on flywheel tothemarkon cfankcase. Thengentlyremoveflywheelfromcrankshaft
again.
(See Fig. 16)
7) Adjust as per the Fig. 17 (under the condition stated in item 6).
a) Loosen breaker fittingscrew.
b) Confirm open/close condition of pointby pushing breaker in the direction of arrow. Adjust breaker
so that point may
be about
to open. (Normal ignitiontiming will be 23O-27O)
Notice that ignition timingwill be over 30’ if point is opening under the condition shown in Fig. 17.
8) Point cover, magneto, starter case shall be assembled in order after point has been adjusted.
IGNITION COIL
\n
CRANKCASE
Fig. 16
Point
Point cover
Breaker-installing screw
Fig. 17
-9-

6. CARBURETOR ADJUSTMENT
Since thecarburetor hascarefullybeen adjustedatshopbeforeshipment, avoid adjustingit unless absolutely necessary.
If adjustment are needed, refer to thefollowing.
r
1) Idle adjustment (See Fig. ?8) EC02-A,EC02-R
Adjust idling revolution with throttle stop screw, If turn throttle stopscrew clockwise, revolution will increase. If turn
it counter-clockwise, revolution will reduce.
CUATION: DO NOT IDLE UNDER 2,800r.p.m.
2) Fuel flow adjustment (See Fig. 18) EC02-R
a) At lowspeed (at thesmall opening of the throttle)
When fuel
is too RICH, turn the lowspeed fuel adjusting screw to the LEFT. When it is too LEAN, turn lowspeed fuel
adjustingscrew
to the RIGHT.
b) At high speed (at thelarge opening of the throttle)
When fuel
is too RICH, turn high fuel adjustingscrew to the RIGHT. When it is too LEAN, turn high speed fuel adjust-
ing screw to the LEFT.
CAUTION: LOW SPEED FUELADJUSTING SCREW IS FORADJUSTMENT OF AIRAMOUNT, SO IT IS NOTED
THAT THE DIRECTION
OF TURNING SCREW IS REVERSE TO THATOF HIGH SPEED FUEL ADJUST-
ING SCREW.
i
THROTTLE STOPSCREW
LOWSPEED FUEL ADJUSTING SCREW
HIGH SPEED
FUEL ADJUSTING SCREW
Fig. 18
/"
- 10 -

7. OPERATIONOFFLOAT AND DIAPHRAGMCARBURETORS
PRESSI
JRE
DIAPHRAGMCARBURETORFLOATCARBURETOR
LOW SPEED FUEL ADJUSTING SCREW
HIGH SPEED FUEL ADJUSTING SCREW
FROM FUEL TANK
IDLE ADJUSTING SCREW
CARB VENTURI
TICKLERBUTTON
CHANGE
IN CRANKCA
PRIMER PUMP
OVERFLOW
VALVE
JETNEEDLE
ATMOSPHERIC PRESSURE
STEEL BALL
- "".-
\
' PRESSURE COMPENSATINGDIAPHRAGMCHAMBER
fig. 19
7-1 OPERATION OF FLOAT CARBURETOR
1) Fuel from the fuel tank enters the float chamber through the needle valve, whichis kept open while the fuel levelis
low.
2) When the fuellevel rises, the float is allowed to move up and lift thearm connected to the needlevalve.
3) The arm lifted by the floatraises the needle valve, which shuts off the supplyof fuel.
4) When the fuel in the float chamber is suctioned into the engine through the carb venturi, the fuel amount is measured
by the main je't and the jet needle the fuellevel falls low, causing the float tomove down.
5) The falling of the floatlowers the arm connectedto theneedle valve, which admits the fuel to enter thefloat chamber.
After this, the same operations in 1)
- 5) are repeated.
- 11 -

7-2 OPERATION OF DIAPHRAGMCARBURETOR
f-
1) When the engineruns,positive pressure and negative pressure will alternately occur in the crankcase.This alternation
in pressure
is led to thereverse side of fuel pumpdiaphragm so that the topside will work as fuel pump.
2) The fuel drawn up by fuel pump enterspressure compensating diaphragm chamber throughthe felt, rubber tube in fuel
tank, fuel pipe and needlevalve.
3) Thefuel in pressurecompensatingdiaphragmchamber is sentby pressure, so thatthefuelpressure becomes higher
than atmosphericpressure and pushes down thepressure compensating diaphragm.
4) When the pressureCompensatingdiaphragm is pushed downwards, the arm connected to needle valve turns clockwise
by the strength of spring andpushes up the needle valve, which shuts out thesupply of fuel.
5) The fuel in pressure compensating diaphragm chamber is measuredbyhigh speed fuel adjusting screw and jet needle,
entering the engine through the carb venturi. Then, thepressure in pressure compensating diaphragm chamber becomes
lower than atmosphericpressure and the diaphragmis pushed up against the strength
of spring.
6) When the pressure compensating diaphragm is pushed up, the arm turns counterclockwiseagainst the spring and lowers
needle valve, which admits fuel to enter. After this, thesame operations in
1) - 6) are repeated.
NOTE:
I. OPERATION OF LOW SPEED FUEL ADJUSTING SCREW
When the openingof the throttle is small, it is notsufficient tomeasure the fuel only by highspeed fuel adjustingscrew
and jet needle.Therefore,even by lowspeed fueladjustingscrew, fuel
is measuredandsent to the venturi toadjustthe /"
density of fuel. Accordingly, inhigh andlow speed fuel adjustingscrews, the direction of turning thescrew is reverse to
each other. For instance, when the openingof the throttle
is LARGE and thefuel is RICH, turn high speed fuel adjust-
ing screw TO THE RIGHT tomake the fuel lean,but when the openingof the throttle
is SMALLand thefuel is RICH,
turn lowspeed fuel adjustingscrew TO THE LEFT tomake the fuel lean.
2. OPERATlON OF TICKLER BUTTON
1) When tickler button is pushed up, the lever connected to needlevalve turns left against thestrength of spring,
loweringneedle valve, whichallows fuel toenter.
At thesame time, when the tickler button
is pushes up, overflow valve is also held open through thelever.
2) In acondition of 1/, if primer pump is repeatedly pushed,fuel is pumped upfrom the tank and air inpressure com-
pensating diaphragm chamber
is exhaustedthrought theoverflow valve, so thatthepressure compensating diaphragm
chamber
is filled withfuel.
3) Further, when primer pump is operated continuously, fuel is forced to flow into the overflow pipe throughthe
overflow valve and, at the same time, a
little amount of fuel is sent tocarb venturi through the highspeed fuel ad-
justing screw andjet needle.
4) A little amount of fuel sent to carb venturi by the operation of 31, if recoil starter is pulled, it is taken into the
engine, and becomes somewhatrich and suitablefuel for easy startingof the engine.
- 12 -

8. TROUBLE SHOOTING
For a gasoline engineto start and runsatisfactorily, the following three requirements must be met:
1)Thecylinder filled with a proper fuel-air mixture.
2) Anappropriatecompressioninthecylinder.
3) Goodspark at correct time to ignite the mixture.
If all the three requirements are not met simultaneously, an engine can not be started. There are also other factors
such as
heavy loadatstartingand
too longanexhaustpipe causingahighbackpressure,which contributetohardstarting.The
most common causes of engine troubles aregiven below.
8-1 STARTING DIFFICULTIES
Cause
Defects
in spark plug
Defects in contact
cable
Defects in contact
breaker
Defects in magneto
Other defects in
electric system
Gas leak from
combustion chamber
Defects in piston
assembly
Defects in fuel tank
system
Remedy
1) If contaminated, wash in gasoline, remove
2) If spark plug is brokenandlostinsulation,
3)Adjust spark gap to 0.6-0.7mm
(.024-
foreign material and dry.
replace plug.
,027").
If cable is burnt, replacecable along with coil.
1) If breakerpoints are rough,smoothout
surface withemery paper
(#400).
2) If breaker point gap is incorrect, adjust it to
specified0.35t0.05mmby looseningcon-
tact support plate lockscrews.
3)
If spark timing is incorrect,adjust it to
23" - 27' before TDC.
4) If breaker is defective ininsulation, replace
breaker.
5) If condenser is defective, replace.
1) Ifwireorinsulation is broken, replace
2) If magnetism is weak,re-magnetize (atthe
magneto.
magneto maker)
or replace.
1) Ifkillswitch is faulty,(shortcircuiting)
replace or repair.
2) Ifprimarywire is grounded to theengine
body,insulate
it withinsulating adhesive
tape.
1) If spark plugs are loose, tighten.
2) If spark plugs are defective, replace.
1) If piston is worn, replace.
2) If piston rings are worn, replace.
31 Ifpiston rings are stuck, clean or replace
rings.
1) Cleanclogged tankoutlet.
2) Cleancloggedfuelstrainer.
3) Ifincorrectfuel is pouredintotankor
water is mixed,draintankcompletelyand
fill
it with correct fuel.
4) When fuel pipe is locked with air, expel1air.
5) If there is any crack or damage in the
rubber components of fuel line system,
due
to their deteroriation,replace.
- 13 -
Preventive measure
1) Use sparkplugs of specifiedheat range. Do
not
use poor grade oil. Clean air cleaner and
avoid dust entry.
2) Whenspark gap isadjusted, if center elec-
trode
is hit or bent,insulatormay get
damaged.
1 ) Keep air cleaner always clean.
2) Do not use poor grade oil. Change oil
regularly.
1) Be sure to use a filter when adding fuel.
2) Use mixture (gasoline 20 - 25 : oil 1 I as fuel

/"
CaUSe
Defects in carburetor
Defects incarburetor
Piston or Connecting
Rod seized
Remedy
1) If clogged with dust, clean.
2) If defective. replace.
Clean
jets andotherorifices. if they are
clogged.
1) Startengine with fully openchoke valve and
fully open throttlevalve.
2) Removespark pluganddisconnectfuelpipe,
repeat starting operationseveral times to evac-
uate excess fuel.
If fueloverflows,checkneedle valve seat for
wear. Replace. if necessary.
1) Ifpiston seizes, correct orreplace.
2) If connectingrod large endorsmallend
seize, replace.
Preventive measure
~ ~~ ~~ ~
1) Neverclose choke valve whenengine is
warm.
2) Whenstoppingtheengine, run it at slow
speed Tor a while.Thispractice notonly
favourablyaffectsnextstarting,
but also
improves engine life.
3) Clogged aircleanerresults in toorichair-
fuel mixture.
Clean
it thoroughly.
Be careful clogged carburetor.
1) Do not use poor grade oil.
2) Use fuel of proper mixing ratio.
8-2 OVERHEATING
1) If the ignition timing is too far advanced, correct to 23' - 27'
2) If too much carbon deposits in the combustion chamber, remove it.
3) If the heatrange of the spark plug is too cool, replace it with correct one (NGK BM7A).
4) If the air-fuel mixture is too lean, clean jets and other holes in the carburetor.Clean the aircleaner also.
5) If the load is in excess, reduce it below the specified continuous load.
POWER DROP
If the cylinder, piston or piston rings are worn, replace them.
If the carburetoris out of order, re-adjust orclean it.
If the spark plug is faulty (contamination,gas leakage or faulty insulation),clean it orreplace it.
If the magneto or the contact breaker is faulty, replace them or re-adjust them.
If the aircleaner is clogged, clean it.
If the fuel system is clogged, clean it.
If the oil seals at the crankshaft are worn and let the compressed gas through, replace them.
8-4 EXCESSIVEFUEL CONSUMPTION
1) If toorich air-fuel mixture, clean jets and small holes in carburetor.
2) If fuel leakage, re-tighten screws orreplace.
3) If besidethesecauses, also caused bypowerdrop,performremediesforpowerdrop,accordingto 7-3. POWER -
DROP.
- 14 -

- 8-5 ENGINEHUNTING
- If the fuel-air mixture is too lean.Clean thecarburetor.
8-6 OTHER COMPLAINTS
1)Fueloverflowfromcarburetor
If the fuel flows towards the aircleaner or much fuel flows into the crankcase while theengine
is standingstill (over-
flowing), the needle valve or the floatis faulty. Correct
or replace them.
2) If the engine suddenly stops with abnormal noise, the piston or the crankshaft and connecting rodassemblyisseized.
Correct them orreplace them.
3) If the engine produces abnormal noise during operation, be sure to stop theengine and do not start itagain before the
cause
is found.
If the cause forthetrouble is not found, contact our distributor and entrust the engine in the hand
of our service
engineer.
- 15 -

9. CHECKS and CORRECTIONS
/"
After disassembling and cleaning the engine parts, check them, and if necessary, correct them according to the correction
table.Thecorrectiontable applieswheneverenginearerepaired. Its contents should be thoroughlyunderstood by those
who undertake therepairing. Its specifications must be abided by to effect correct maintenance.
Below, terms employedin thecorrecrion tableas explained.
1) CORRECTION
All operationsperformedonthe engine partsforthepurpose
of improving or recovering the engine performance,
consisting
of repairs, readjustments, and replacements.
2) STANDARD SIZE
The design dimensions of the part without the tolerance.
3) CORRECTIONTOLERANCE
The tolerance on there-finished part dimension or
on the readjusted dimension.
4) CORRECTIONLIMIT
The limit on the part and adjustment, beyond which any dimensional and functional changes, due
to wear, burn, and
other causes will adversely affect the normal engine performance.
5) USE LIMIT
The limit, beyondwhich the part is nolonger usable, due to defects in function or strength.
NOT€: ALL DlMENSlONS IN THE '%ORRECTION TABL€"are given in millimeter, exceptwhereotherwisespecified.
,"--
ITEM
TOOL ft-lbS
kg-crn
Breaker, condenser point cover, & ignition coil
3.0 - 3.5
42 - 48Crankcase
3.0 - 3.5 42 - 48
Carburetor
1.7 - 1.9
23 - 27
E
Tank, starter case
42 - 48
3.0 - 3.5
2
3.0 - 3.5
I-
42 - 48
Heat Block
10.8 - 12
150 - 180
Flywheel
g
'c
3.0 - 3.5
42 - 48Cylinder & muffler
2 .-
0.
g
.-
c-
c
Wrench
Torque
r
0
v)
Spark plug
15.9 - 21.7
220
- 300
- 16-