Saito FG-84R3 User manual

-1-
Specifications
SAITO FG-84R3
4-Stroke Gasoline radial Engine Operating instructions
ThanksforbuyingSAITOFG-84R34-strokegas-engine
exclusivelyformodelairplanes.
Inordertoavoidmisuse,pleasebesuretoreadwellthis
instructionmanualcarefully.Ifthereshouldbeany
deficiency,inconvenience,etc.concerningthemanufac-
ture,ourcompanywillrepairthemwithresponsibility.
Anyfailureortroublecausedbyunnecessarydisassem-
bly,modification,orotherusesthanthoseprovidedin
theinstructionmanualisnotsubjecttothewarranty,
however.
Moreover,allresponsibilitiesfortheuseoftheengine,
andotherobligationsandresponsibilitiesbasedon
laws,regulations,etc.arebornebythepurchaserand
theuser,and
SAITOSEISAKUSHOCO.,LTD.isexemptfromany
responsibilities.
Bore 󱔒36.0mmx3
Body:3,057g/Mufflers:157g/Ignitionsystem:250g/Mountspacer:64g(16gx4)
Stroke 27.6mmx3 84.28cc
Disp.
Weight
Practicalspeed Approx.1,300-7,000rpm
D24”xP10”standard
MaxonGND Approx.5,500-6,500rpm
2stGas-engine60~70ccclass
Propeller Staticthrust Approx.7~9kgf(Dependonprop）
ApplicationsFuel
Fuelconsumption
Batteryforignitionsystem
Standardaccessories
Regulargasoline：Oil＝20:1(Volumeratio)
Approx.40cc/min(Atfullthrottle6,200rpm)
*Fuelflowvariesdependsuponpropload.Morefuelflowwithlargerloadandlessfuelflowwithsmallerload.
Voltage:6-9Vhigherthan1,000mAisrecommended
85.6
70.2
100 221.7 51.5
15.4 36
Ø250
M10×1.25
Mount
Spacer
70
80
Outsidedimensions
Fig.1
SAITOFG-84R3isthegas-versionofexistingglowFA-450R3withboreup.Thisnewdesignedgas-engineisafigureofintegra-
tionofmanyexperiencesonourradialenginesandgas-engines.Additionaldesignsconcentrateondurabilityandhighpower
broughtitpowerfulandbeautifulradialsound.
Notificationabouttreatmentof4-strokemodelgas-engine
◎Sincevalvetimingisdesignedtogethighpowerandhighspeed,theoverlaprangeisrelativelywide.Sosometimesfuelgetflown
backfromthecarburetor.(Itmayspatterintheengineroom.）
◎Sincetheoilforlubricationismixedinthefuel,wasteoilfromthebreathernippleisdirty.Dependingontreatmentofwasteoil,it
canbespatteredontheplane.
◎
Sincelubricationisthroughbreather,sometimestheoiloozesfromeachjointorcommissurehoweveritʼsnoproblemonperformance.
◎Dependingonthequalityoftheoil,sometimestherecanberustinsidethecrankcase.Butitʼsnoproblemonperformanceaslong
astherearenoabnormalnoiseorbacklash.
Enginemountset(Mountspacer)  4pcs
Ignitionsystem（w/sensor）   1set
Sparkplug[NGKCM-6]（Attachedtoengine） 3pcs
Mufflerset(3Flexiblemufflers&Bracket) 1set
Carburetoradjustmentbar   1pc
Chokebar    1pc
Aluminumpropwasher(w/steelwasher)1set
Limitgauge(0.1t)fortappetadjustment1pc
Spannerfortappetadjustinglocknut 1pc
Hexagonalwrenchset  1set
Plugwrench    1pc
Anti-looseningnut   1pc

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1.Propeller
StandardspecisMejzlikD24”xP10”whichbringsapprox.6200rpm.
Dependingontheairframe,pleaseadopttheadequatesizeintherange
of5500~6500rpmfromreliableproductsgenerallyonthemarket.
(Carbonpropisrecommended)
Sincealarge-diameterpropisused,pleasemaintainsufficientbalance.
Sinceanimbalancedpropisvibratoryanddangerouswithlowered
performance,pleasemaintainbalancewithabalancer.Moreover,a
crackedpropisdangerous.Makesuretocheckanytimeandreplaceit
withanewoneifitʼscracked.
*Tightenupthepropnutonceinaboutevery10flights.Especiallya
woodenproptendstocompressedsotakecareofitslooseness.
2.Fuel
Thefuelismixtureofcommercialregulargasolineandreliableoilfor
2-stroke.(Unleadedhigh-octanegasolineisnot
necessarilyrequiredforSAITOengine.)
[Exampleofoil]
・POWERLUBE(KLOTZORIGINALTECHNIPLATE)
・KLOTZGSRCmodelLUBE
・CASTROLPOWER1TTSRacing,etc.
Forthemixtureratio,pleasebesuretouse“gasoline:oil=15~20:1”orricherbyvolumeratio.
(ex.1000mlofgasolineshouldbemixedwithmorethan50mlofoil).
Anydamagecausedbythefuelused,inwhichtheoilratioislowerthan20:1ratio,isnotwarranted.
Sincegasolineisdangerousmaterial,becarefulofitsstorage,use,andtransportenough.(Theevaporativeemissionand
exhaustsmokeofgasolinehaveaharmfuleffectonahumanbody.Also,ifgasolineisleaked,thereisdangeroffireetc.)
Pleasenotethatwetakenoresponsibilityforaccidents,healthdamages,etcwhichoccurduringstorage,useandtransportof
gasoline.
3.FuelFilterandfuelpump
Sincecommercialgasolinehasmanyimpurities,pleasebesuretouseareliablefilter
fortheadmissionportofthegasoline-prooffuelpump(Fig.3),andinthefueltankas
well(Fig.4).Withoutusingafilter,theperformanceofthecarburetorisnotdelivered,
resultinginfailures.
Usingoptionalpart“Filterwithweight”ishighlyrecommended.
Firing order
Prop direction
Firing order
１-３-２
Fig.4
Fueltank
Mountspacer
Hollowoutreferringto
thecuttingsheet
Viewfromtherear
Fig.2
#1
#2
#3
Gasoline-prooftube
（Option）
（Option）
Filterwithweight
Gasoline-proof
Pump
Fig.3
4.Fueltankandpiping
Usethegasolineprooftankwhichhasadequatecapacity(Approx.“FuelconsumptionxFlightduration+100~200cc).Pleasebe
suretouseafilterwithweight.Toavoidentrainanyimpuritiestothecarb,pipingwith“Fuelfeedingpipe”and“Airinhalation
pipe”(Fig.5)isrecommended.
*Pleasebesuretouse“gasoline-proof”productsforthetank,lidrubber,piping,andtubing.Someoftheproductsforglowfuel
canʼtbeusedforgasoline.
*Pleasecheckcarefullyifthereʼreanycrackonthepiping,tubing,connection,andtank.Alloftheconnectionpartsshouldbe
boundbythinNylonstraporwiretoavoidfuelleakageorairinductiontothefuelline.(Ifthereareanyleakages,theperfor-
manceoftheenginedecreasesdramatically.)
*Thecarburetorhasapumpbutitspumpingpressureisnotsostrong.Soplacethetankclosetotheengineasmuchas
possible.Andsetthefuellevelslightlylowerthanthecenterofthecarb.
*Whenprovide“Airinhalationpipe”asFig.5,arrangingthetubeabovethefuellevelistheeffectivewayoffuelleakagepreven-
tion.
*Thecarburetorcomesoutfromthebackofthefirewall.Sometimesfuelgetflownbackfromcarburetorandmayspatterinside
thefirewall.Forthatcase,makesuretocoverthebatteries,R/Cequipmentsandallthefoammemberswithgasoline-proof
material.
Fuellevel
above
Fuellevel
toOutsideof
thefuselage
Fig.5
Airinhalationpipe
Firewall
toCarbnipple
Fuelfeedingpipe
Airinhalation
pipe
Rubbercapfor
gasoline-resistant
Gasoline-prooftube Filterwithweight
Centeroffueltank
Closeaspossible

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5.Ignitionsystem
*Becarefulofpossibilityofelectricalshockasitgenerateshighvoltage.
*Theunitincludesaplasticcliptoholdtheconnectorsandspiraltubetoprotecteachwire.
TheignitionsystemisdesignedtomatchSAITO4-strokegas-engineswithautomaticadvancingsystem.
Howeverthisignitionsystemisdesignedtobeananti-noiseproduct,pleaseisolateitcompletelyfromthereceiver,servo,and
batterytoavoidaradio-interferencetrouble.Moreover,itisdesirabletoutilizeanoisefilter(linefilter).Especially,eachswitch
(forIgnitionandforReceiver)shouldbeisolatedandsetfarfromeachones.
6.Sparkplug
NGKCM-6sparkplugisthestandard
equipment.
Dimensionsareasfollows;
Hexagonwidth:14mm
Screwsize :10mm
Reach :8.5mm
Spark-gap :0.7-0.8mm
Forreplacement,pleasereplacewitha
reliableproductasNGKCM-6.
SinceSAITO4-strokeengineusesmixed
gasoline,pleasedecidethenumbersof
flightsbyyourselftocleanthesparkplug.
Pleasereplace,whenitisdegraded.
(Considertheplugasconsumable.)
7.Carburetor
Equippedwithasuitablecarburetorbytechnicalcooperationwith“Walbro”thatprovideshighlyreliablecarburetorsforother
gas-engines.Becauseofitsstructure,insomecaseperforming“Airpurging”justbeforeflightisrecommended.Regardingthis
pleaserefertotheattacheddocument.
Plugcap
Switch(notincluded)
Capacity:morethan3A
Sensor
(2)Sensorcord
(1)Plugcord Mainunit
(3)Batterycord
(4)Tachometercord
Recommendedbattery
5cell-NiMHor2cell-LiPo
Voltage:6-9V
Capacity:1,000mA~
Fig.6
Caution:Agas-enginegeneratesanoisewhichhasanadverseeffectonRCadjustment.Pleasebesuretocarryoutanoise
checkeachtimewhiletheengineisrunningbeforeflight.Sinceanoisewhichoccursduringflightmayleadtoalarge-scale
accident,pleasecarryoutanoisecheckwithoutfail.Asasimplemethod,afterstartingengineyoucancheckbyremoving
theantennaofthetransmitterandoperateitabout50mawayfromtheairplane.Ifthereisnomalfunction,itisnormal.
Thefunctionofeachcord;
(1)Plugcord(meshedhightensioncord)
AsFig.6showstherearethreecordsavailableforthreecylinders.Makesuretoattacheachnumberdescribedonthemain
unittothecylinder.(RefertoFig.2regardingcylindernumber).Whenyouputontheplugcap,insertdeepintotheplugto
avoidcomingoffduringflight.Andthenpulltheplugcaptoconfirmthatitwonʼtcomeoff.
(2)Sensorcord(Graycordwithexclusiveconnector)
Connectwiththecordfromthesensorattachedtotheengine.
(3)Batterycord(black/redcord)
Pleaseusethefullychargedbatterythathasadequatespec.(6-9V,morethan1000mAisrecommended.).Betweenthe
batteryandmainunit,makesuretosetanignitionswitchwhosecapacityishigherthan3A.
(4)Tachometercord(black/red/whitecord)
Connectthedigitaltachometer(Option).Otherwisetheconnectorisnormallyvacant.
Note：Toavoidentrainingairlockinthecarb,itisbettertoleavefuelinthecarbafterrunning.Butinsuchwayofstoring,
gasolineacceleratedegradationofrubberpartssuchasdiaphragm.
Thecarburetorforagas-engineiselaborateanddelicate.Pleaseneverdisassembleit.Ifitʼsoutofcondition,
pleaseconsulttheshopyouboughtfrom.
Fig.7
Chokebar
Temporary
fixedbyclip
Throttlelever
M3.5threadfor
Chokebar
Slowneedle
Throttlevalve
(Movetotheleft)
Cowling
Methodofchoking(Formanualstartonly)
(1)AsshowninFig.7,passthechokebar(withM3.5threadonitstip)
thoroughtheholeonthecowling.Thenturnthebartoinsertinto
theM3.5internalthreadatthecenterofthethrottlelever.
(2)PullthechokebarandfixitbyusingacliporclampasshowninFig.7
sothatitmaynotgobacktothepreviousposition.
(3)Graspthepropbyhandandturnittotheforwarddirection(CCW)for
severaltimes,untilthecarburetorgenerateshissing-likesounds.
(4)Afterhearingthissoundforabout5times,quicklyflickthepropby
crankingitsome10times.Thenchokingiscompleted.
(5)Removethechokebar.
(6)Powerontheignitionsystemandopenthethrottlevalveabout1/4
fromthefullclosepositionbyusingthethrottlestick.(Startingwith
excessivelyopenedthrottleisdangeroussincetheairplanejumps
forward.)
(7)Flickthepropquicklyandenginewillstart.Iftheenginedoesnʼtstart,repeatthechokingprocedure(1)to(6).
*Afterstarting,runtheenginefor10to20sectowarmup.

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8.Enginemounting,mufflerattachment,andbreatherwastedisposal
FG-84R3canbeinstalledwithmountspacers.Asthecarbcomesoutfrombackofthefirewall,
hollowoutthefirewallaspossibleasminimumreferringtothecuttingsheetincluded.
Makethefirewallrobustenoughbecausethisparthastoendurevibrationandtorquecausedby
proprotation.Especiallywithalowloadprop,enginetendtogeneratelargevibrationthatis
verydangerous.
Itispreferabletoapplysomeadhesives(suchasscrewlock)onthetipofeachcapscrewto
avoidloosenesswhenyouinstalltheengine.
Toensurethatcoolingwindpassesthroughtheengine,thecowlingshouldbedevised.Also
maketheairflowoutletlargerthantheinlet.
Buildingsomebafflesinsidethecowlingtoflowthecoolairthroughthesurfaceoftheengine
effectivelythatishighlyrecommended.Insufficientcoolingmaycauseenginetroublesuchas
overheat,percolation,ormufflerlooseness.
Themufflersshouldbesecurelyinserteddeeplyintothecylinderandtightenedupusing
spanners.(Adhesives,suchasascrewlockagent,areeffectiveagainstloosenessandleakage.)
Makesuretofixtheoutletoftheflexiblemufflersoutsideofthecowlingusingthebracket
included.(Regardingmufflerinstallation,pleaserefertotheattacheddocument.)
Forbreathertreatment,thereisalsoamethodinwhichthealuminumpipe,etc.arefixedatthe
muffleroutlettodiffusethehotairtogetherwithexhaustgasintotheair.(Breathermay
functionbysimplyejectingthetubefromtheengine).
Fig.8
Firewall
Mountspacer
Hollowout
minimumarea
From
Breathernipple
Exhaust
Muffleroutlet
Aluminumpipe
Baffle
Cowling
Coolair
Fig.9
9.Preparationforenginestart(assumingbreak-in)
(1)Mounttheengineonarobustandparallelizedtestbenchoronthefuselage.(Eitherway,the
engineshouldbefixedandimmobile.)
(2)Checkwhetherthethrottlevalvebecomesfullyclosedandopenedcertainly.
(3)Checkwhethereachcodeoftheignitionsystemisconnectedcertainly.
(4)Useabout1000cctankforthetestbench,oratankwhichhasappropriatecapacityforthefuselage.
(5)Forpiping,onlyconnectingthecarburetorwiththetankisneeded.(Makesurethere'snoleakageat
alltheconnections.)Inordertocheckdischargeofthebreather,attachaheat-proofandgasoline-
prooftransparenttubetothebreathernipple.
(6)Forfuel,prepareamixedgasolinewithavolumeratioof“gasoline:oil”=“15~20:1”.
(7)Prepareawellbalanced24”x10”carbon-madeprop(Mejzlikisrecommended).
*Propattachingposition
SinceSAITO4-strokegas-enginecanbemanuallystartedinforwarddirectionoftherotation,fixthe
propinthepositionwhichfacilitatesvigorouscranking.
(8)Whenstartingwithanelectricstarter,alsoattachaspinner.(Thiswayofstartisrecommendedfor
safety.)
(9)Asitisdifficulttojudgeclearlythepeakconditionof4-strokeengines,prepareatachometerto
preventover-throttlingoroverheat.Youcanalsousedigitaltachometer(Option).
(10)Prepareafuelpumpforgasoline.(Besuretoattachafiltertotheintakeport.Itisavailableasanoption.)
Caution:Ifthereʼsanyonestandinfrontoftheengine,besuretohavethemmovebehindtheairplanebeforestartingthe
engine.Alsokeepinmindthattheexhaustsmokeisharmfulforhealth.Keepawayoneofyourarmholdingtheairplane
awayfromtheprop.Oncetheenginestarts,movebehindtheairplane.Makeneedleadjustmentorothercontrolfromrear.If
theairplanecannotbefixed,askyourassistanttoholdtheairplaneforsafety.
10.Methodofstartingtheengine
Thefollowingistheprocedurewiththeenginemountedontheairplane.Fillupthetankwithfuel.
(Besuretoturnofftheswitchoftheignitionsystemuntiljustbeforetryingtostartuptheengine.)
(A)Startingmethodwithastarter(Recommended)
(1)Afterconfirmthatthethrottlestickislocatedatthefull-closeposition,turnonthetransmitterswitch.Thenturnonthereceiver
switchtocheckthrottlevalveandotheroperation.Afterthat,fullyclosethethrottlevalve.
(2)Powerontheignitionsystem.
(3)Openthethrottlevalveabout1/4fromthefullclosepositionbyusingthethrottlestick.(Startingwithexcessivelyopened
throttleisdangeroussincetheairplanejumpsforward.)
(4)Applythestartertothepropandactivateforabout5secondstostarttheengine.
(B)Manualstartingmethod(Forsafety,wearglovesanduseasafetystick)
(1)Sameas(1)notedabove.(Thethrottlevalvemustbefullyclosed.Otherwise,thefuelcannotbemanuallyintroduced.)
(2)Makesuretoturnofftheignitionswitch.
(3)FollowingChapter7,performchokingmethod.(”Choking”-”IgnitionON”-”Throttle1/4open”-”Flick”)
11.Break-in(ReferringFig.10,checkinadvancewheretheMainneedleandSlowneedleareplaced.)
AsBreak-inisanimportantproceduretopulloutthemaximumperformanceoftheengine,itmustbecautiouslydone.
Thepurposeofbreak-inisinitiallubricationandadjustingofthemobilepartsundertheconditionwithrichfuelmixture.
Nevermakethefuelmixturelean.Leanfuelmixturecouldcauseseizureevenduringidlingorlowspeedrunning.
Thereʼsnoneedtoadjusttheslowneedleatthisstepasitʼsalreadysetadequately,soyouwilladjustonlythemainneedle
duringbreak-in.
Procedure;
(1)Afterfillingupthefueltank,starttheengineasdescribedintheaboveChapter10andrunitfor10secinlowspeed.
(2)Openthemainneedle2turnsfromthatstateandusethethrottlesticktofullyopenthethrottlevalve.Ifrichair-fuel
mixturecanʼtbeobtained,openthemainneedleadditionally.Thencontinuerunningformorethan1tank.
Duringthisinitialoperation,contactofeachpartinsidetheenginewillbematched.Somakethefuelmixturerichasmuch
astheenginedoesnʼtstop.Donotcareaboutrunningsmoothnessatthisstep.

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13.Normaloperation,maintenance,andadditionalinformation
(1)Justafterstartuptheengine,performwarmuprunninginrichconditionforabout1minute,andjustbeforestoprunitat
idlingfor1minutetocooldownaswell.Whenstoptheengineafterthefinalflightoftheday,besuretostopbycuttingthe
fueltoremovefuelfromthecarburetor.Andremovethefuelfromthetankandreserveitwithspecialcare.
*Whenstarttheenginefirstafterstopitbyfuelcut,performingairpurgingisrecommended.(Refertotheattacheddocu-
ment.)
(2)ChargethebatteryfortheignitionsystemandRCdevicefully.(Sincetheignitionsystemgenerateshightension,becareful
ofelectricalshock.)
(3)Lubricationforpiston,connectingrod,bearingorcamgearisablow-bylubricationinwhichtheoilinthefuelgoesintothe
crankcasefromtheclearancebetweenthecylinderandpiston.Thereforetheenginelifeisaffectedbythepropertyofthe
fueloil.Pleaseusereliableoil.
(4)Sinceoverclosingthemainneedlecausesoverheating,adjustalittlemorerichthanpeak.Overclosingleadstoknockingor
overheatandhasanadverseeffectontheconnectingrodandcamgear.Wheretheairplaneachievespeakcompletelyat
theattitudeofascentshouldbeaproperpeakoftheengineduringflight.
(5)Whenconnectingtheexhaustpipetothecylinderorattachingthepropnut,applythincoatofsiliconrubber(notexces-
sively)oradhesiveonthethreadsectionbeforetightening.Thispreventsleakageorloosening.
(3)Refillthetankandruntheenginewiththemainneedletoachievepeakandlessspeed(richer)alternatelyabout5times.
Andthenmaintainthepeakconditionlonggradually.Whenitgetsstable,thenoperatethethrottlesticktovaryslowspeed
tohighspeedseveraltimestochecktheresponse.Afterthatrunitfor1tankkeepinghighspeed.
(4)Whenitcomestorunsmoothlyatpeak,break-inonthegroundiscompleted.Thenperformtappetadjustingreferringto
Chapter13andadjustthecarburetorreferringtoChapter12.Afterthat,flyitforabout20timesinrichconditiontofinish
break-inintheair.
Alsoafterbreak-in,pleaseruntheengineinrichconditionaslongasitdoesnʼtaffecttotheflight.
12.Adjustmentofcarburetor
Beforeadjustment,pleasesetbothneedlesasthestandardvalues.
Inprinciple,thecarburetorshouldfirstachievepeakbyadjustingthemainneedle.Thenperformingidlingwiththethrottle
valveandtheslowneedle.(Unlessthepeakiscertainlyachieved,idleadjustmentwillbedifficultandnotstabilized.)
*Theslowneedleissetastokeeparound1,300~1,500rpmatidlingatfactorydefault.
(1)Afterfillingupthefueltank,starttheengineasdescribedinChapter10andrunitfor1minutesinrichcondition.Thenfully
openthethrottlevalvewiththethrottlestick.
(2)Byturningthemainneedlewiththeadjustmentbarobservingtachometerandexhaustsound,achievepeakcarefully.
(3)Next,closethethrottlevalveuntiltheenginerunsstablywithanidlingrotationaround1,300rpmbyadjustingtheslow
needlewiththeadjustmentbarcarefully.(Duringflight,itʼsratherstablewithslightlyhighadjustedatidling.)
*Thebestrichnessoftheair-fuelmixtureatslowspeedisdependontheflightstyle.Generally,Scaleflightrequiresstabilityin
lowspeedsoslightlyleanconditionispreferable.OntheotherhandAcrobaticflightrequiresquickresponsefromlow
throughhigh,soslightlyrichconditionispreferable.
(4)Oncetheidlingisset,getthethrottlevalvefullyopenedgradually.Iftherevolutionbecomessloworgoesupsuddenly,
adjusttheslowneedlecarefullyuntilrpmraiseslinearlyfromidlingtopeakbyfine-tuning.
(5)Afteradjustmentof(4)iscompleted,performtheprocessfromidlingtopeakquickly.Ifrevolutiongetsdelayedtoachieve
peakevenifthethrottlevalveisfullyopened,fine-tunethemainneedleandperformthesameprocess.Repeatthis
fine-tuneandresponsecheckcarefullyuntiltheresponseimproves.
*Tipforadjustmentoftheslowneedleistomakeleanaspossibleastheenginedonʼtgetstolewhenopenthethrottlevalve
quickly.Atthesametime,sinceagas-enginehasnarrowrangeofair-fuelratio,adjustmentoftheneedlesisstricterthana
glow-engine.Andbothneedlesareinterferedslightlyfromeachothersoconfirmthebalanceofpeakandresponseafter
adjustment.
*Tokeeptheenginelifelonger,adjustthefuelmixtureasrichaspossibleintherangeitdoesnʼtaffecttotherunning.Carb
adjustmentisaffectedbymanyfactorssuchasprop,flightstyle,atmosphere(humidity,temperature,...),oil,plug,fuel,and
soon.Pleasekeeptryingtofindthebestconditiontomatchyourplane.
Note：Duringearlystageofflights,taketheheighthighenoughtolandsafelyincasetheenginestopintheairsuddenly.It
willreducetheriskofcrashorlandingaccident.
Caution：Toomuchthrottlingthemainneedleisverydangerousbecauseitmightcauseknockingandthepropnutmightbecame
off.Onceyounoticeabnormalvibrationorsoundduringthrottlingthemainneedle,justreturntoopentheneedleimmediately.
Throttlelever
Slowneedle
CCW
torich CW tolean
Mainneedle
CCW
torich CW tolean
Fig.10 Standardvaluefortheneedles
Incasesuchlikefollows,resettheneedletothe
Standardvalue(SDV).
・Afterbreak-in
・Whenadjustmentcanʼtbedonecorrectly.
・Whenbyfailure,turningtheneedletoomuch.
TosetSDV,firstfullyclosetheneedle.
(DONOTclosetootightly.Theneedlescanbetorn
easily).
AfterthatopentheneedletoSDVasfollows.
Throttlevalveshouldbefullyclosedduringsetting
toSDV.
SDVforMainneedle：
2turnsopenfromfullclose
SDVforSlowneedle：
4.5turnsopenfromfullclose

-6-
(6)Occasionallytightenthepropnutandexhaustnut.
(7)Takeanextremecareforsafetywhenoperatingtheengineorflyingthemodelairplanenottobotherothers.
(8)Anengineforamodelairplaneisnotatoy.Handleitwithanextremecare.
(9)Aftercompletinggroundbreak-inoroperatingtheenginefor1hour,adjusttappetgaps(valveclearances)byfollowing
proceduretocompensateinitialwearing,whiletheengineiscold.

#1cylindershouldbeadjustedfirst,next#3,finally#2cylindershouldfollowinorderbythesameprocedure.
(a)Removetheplugandrockercoversfromthe#1cylinder.
(b)Turnthepropslowlyforwardbyhanduntiltherockerarmofintakestops.Furtherturntheproptobringthepistonto
theTDC(TopDeadCenter)ofcompressionstroke.
(c)Usetheattachedwrenchandhexagonalwrenchtoadjustthegapsindefi-
nitelyclosetozerowithintherangecompressionexists.Ifthegapislower
than0,thevalvehastobeopenedatallphasessothecompression
doesnʼtoccur(then,loosenthescrewtoreset).
Afteradjustment,putonthesparkplugandturnthepropforwardtocheck
ifthecompressionisenough.
(d)Checkingthegap,securelytighten(butnotexcessively)thelocknut.
(e)Dothesameadjustmentfor#3cylinder.
(f)Finallydothesameadjustmentfor#2cylinder.
*Inthecaseoftheenginesforvehicle,smallgapisgiventotappetstoabsorbvalveelongation.HoweverforSAITOengines,
gapbecomeslargerduringoperationsduetothermalexpansionofthecylinder(madeofaluminum).Thereforesetthegap
indefinitelyclosetozerowhentheengineiscold.
(10)Sincethefuelcontainsmorethan5%ofoil,sometimestheexhaustvalvegetsdullbycarbonorsludgeespeciallyincold
atmosphere.Thenturnofftheignitionswitchandrotatethepropbyelectricstarter.Afterdilutetheoilcontentbythisway,
removethefuelfrominsidethecarbandtheengine.Ithelpsthevalvetomovesmoothly.
Or,removetherockercoverandapplyingsomeanti-rustspraytotheexhaustvalveiseffectiveaswell.
(11)Pleasenoticethatourguaranteewillnotcoveranybreakageortroubleontheengine
causedbyuserʼsdisassemblingormodification.
(12)Notesforpurchasingparts:
Pleasegiveorderstotheshopyoupurchasedfromwith“Enginemodel”,“PartNo.orpartname”,and“Quantity”.
Optionalparts
・Filterwithweight[36-154]  ・Neoprenetubeforgasoline(1m)[36-155]
・SparkplugCM-6[36-120]  ・Aluminumspinnernut[57T-30]
・Coolingcover（1pair)[120S-166] ・Tappetadjustingkit[120S-161]
・Digitaltachometer[17-168]
Tappetadjustment
Fig.11
Mustnotbeinserted
(overgap)
Limitgauge
(0.1mm)
Closeto"0"withnolimit
Note:Occasionallychecktappetgapbythoseprocedure.Whentheattachedgauge(limitgauge,t=0.1mm)comestobeinserted,gaphas
beenenlargedbeyondtheallowablelimit.Makeanadjustmenttolessenthegap.Tappetgapisoneofthemostimportantfactorsinthe
maintenanceof4-strokeengines.Operatingtheenginewiththetappetgapenlargedexcessivelywillcausepoorperformanceortroubles.
All specifications and models are subject to change without notice.
SAITO SEISAKUSHO, CO., LTD.
22-7, 3-chome, Tokagi, Ichikawa-shi, Chiba prefecture 272-0024, Japan
Phone: [phone] FAX: [phone]
http://www.saito-mfg.com

38
39
14-4
31-5
32-8
48
152
44
40-2
36
78-178-3
07
40-1
06
46
09
08
32-2
14-3
42-143
47-1
14-2
47-2
45
14-1
37-232-9
41
42-2
32-5
110
23
31-6
22
32-4
69
120
01
40-3
19
31-7
129
15
27-220
33
28-2
28-3
28-1
27-1
49
99-1
99-5
99-7
35
37-1128
32-1
31-3
78-2
No. Item Qty
01 Cylinder 3
06 Piston 3
07 Pistonpin 3
08 Pistonpinretainer 6
09 Pistonring 3
10 Masterrod 1
11 Linkrod 2
12 Linkpin&Retainer&Washer 2ea.
12-1,-2,-3
14 Cylinderscrewset １set
14-1,-2,-3,-4
15 Crankcase 1
17 RearcoverA 1
18 RearcoverB 1
19 Breathernipple 1
20 Frontballbearing 1
22 Rearballbearing 1
23 Crankshaft 1
Tapercollet&Driveflange
27-1,-2
Propwasher&Nut
28-1,-2,-3
Crankcasescrewset
31-1,-2,-3,-4,-5,-6,-7
33 Camgearhousing 3
35 Camgear 3
36 Camgearshaft 3
Steelwasherset
37-1,-2
38 Tappet 6
39 Pushrod 6
Pushrodcover&Rubberseal
40-1,-2,-3
41 Rockerarm 6
1set
1set
1set
1set
1set
28
31
37
40
27
Enginegasketset
32-1,-2,-3-1,-3-2,-4,-5,-8,-9 1set32
SAITOFG-84R3PartsList(1/2)
Rockerarmscrew&Nut
42-1,-2
43 Rockerarmpin 6
44 Rockerarmbracket(left) 3
45 Rockerarmbracket(right) 3
46 Valveset(In&Ex) 6
1set42
Valvespring&Keeper&Retainer
47-1,-2,48 1set47

121
-1
-4
82-1
-9
82-1
31-4
82-1
-8
12-3
95-3
17
18
-2
-5
31-1
95-195-2
88
-2
10
32-3
12-2
95-482-182-1
-3
-7
82-1
82-1
-1
82-1
-6
93
11
82-1
12-1
32-331-2
No. Item Qty
48 Valveretainer(Cotter) 6
49 6
3
3
１set
2set
1
3
3
1
1
1
1set
SAITOFG-84R3PartsList(2/2)
69 Intakepipe
78 Flexibleexhaustpipe
78-1,-2,-3
88 Throttlelever 1
Enginemountset
95-1,-2,-3,-4
Mufflerbracketset
99-1,-5,-7
110 Antilooseningnut
120 Sparkplug(NGKCM-6)
121 Masterrodplug
128 Heatsink
129 Lubricationadopter
152 Screwpin(Fordriveflangesetting)
Electronicignitionsystem
153-1,-2,-3,-4
153
99
95
Carburetorcomplete
82-1-1,-1-2,-1-3,-1-4,-1-5,-1-6
-1-7,-1-8,-1-9,88,93
1set82-1
Rockerarmcover
153
-2
153
-4
153
-3
153
-1