Saito FG-57TS User manual

-1-
SAITOFG-57TSistheupdatedmodelexclusivelyforAcrobaticflightbasedonFG-57Twhichhasbeengottengoodreputations
frommanyscaleflyers.Thestandardequipmentssuchasstand-offmountandheatsinkmakeinstallationeasierandbringit
durabilityagainstheatduringyouractiveflight.Ofcourse,itsreliabilityandbeautifultwinsoundhavebeentakenfromFG-57T.
Specifications
Bore 󱔒36.0mmx2
Body:2,090g/Muffler:90g/Ignitionsystem:170gEnginemount:80g(20gx4）
Stroke 28.0mmx2 57.0cc
Disp.
Weight
Practicalspeed Approx.1,500-7,000rpm
D21”x23“~P10”x11”
MaxonGnd Approx.6,000~7,000rpm
Gas-engine50ccclass
Propeller Staticthrust Approx.6~8kgf(Dependonprop）
Applications
Fuel
Fuelconsumption
Batteryforignitionsystem
Standardaccessories
Enginemountset(Stand-off35mm)  4pcs
Ignitionsystem（w/sensor）   1set
Sparkplug[NGKCM-6]（Attachedtoengine） 2pcs
Mufflerset(2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
Regulargasoline：Oil＝20:1(Volumeratio)
Approx.35cc/min(Atfullthrottle6,500rpm)
*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
SAITO FG-57TS
4-Stroke Gasoline twin Engine Operating instructions
ThanksforbuyingSAITOFG-57TS4-strokegas-engine
exclusivelyformodelairplanes.
Inordertoavoidmisuse,pleasebesuretoreadwellthisinstruc-
tionmanualcarefully.Ifthereshouldbeanydeficiency,inconve-
nience,etc.concerningthemanufacture,ourcompanywill
repairthemwithresponsibility.
Anyfailureortroublecausedbyunnecessarydisassembly,
modification,orotherusesthanthoseprovidedintheinstruc-
tion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.
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.（Ref.chapter9）
◎
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.
1.Propeller
Dependingontheairframe,pleaseadoptthestandardsizein
thedataanduseareliableproductwhichis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.
*Propandfuelconsumption
Iftheloadislarge(thediameter&pitchofthepropislarge)forthe
enginecharacteristics,theair-fuelmixtureshouldberich.Thusthe
mainneedlehastobeopened.Thatis,eveniftherevolutionislow,
thefuelconsumptionishigh.Conversely,whentheloadissmalland
therevolutionishigh,thefuelconsumptionisloweredbecausethe
mainneedlecanbeclosed.
Inordertodecreasethefuelconsumptionandprolongtheenginelife,
apropellershouldbeusedwhoserevolutionismaximizedwhenthe
throttle-valveisfullyopened,whileusinganairframewhichenables
allflightswithabout90%oftheoutputofthepropeller.Inthiscase,
thethrottlevalvewillbefurtherthrottledduringhorizontalflight.On
thecontrary,anairframewhichcanonlydeliverperformanceinfully
openconditionwillsufferworseningfuelconsumptionandlife.
Fig.1
Outsidedimensions
60
4-
Ø 5.2
Ø
10
32.2 6
(85)
66
60
53
103
E.C
83 68.5
49.5
34
M10x1.25
103
E.C
78
(97)
96 38
159 217 3

-2-
Gasoline-prooftube
（Option）
（Option）
Filterwithweight
Gasoline-proof
Pump
Fig.2
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=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.2),andinthefueltankas
well(Fig.3).Withoutusingafilter,theperformanceofthecarburetorisnotdelivered,
resultinginfailures.
Usingoptionalpart“Filterwithweight”ishighlyrecommended.
4.Fueltankandpiping
Fuellevel
above
Fuellevel
toOutsideof
thefuselage
Fig.4
Airinhalationpipe
Fig.3 Centeroffueltank
Closeaspossible
Firewall
Stand-offmount
Fueltank(500~600cc)
Gasoline-prooftube
Filterwithweight
Airinhalation
pipe
Fuelfeedingpipe
toCarbnipple
Rubbercapforgasoline-resistant
Hollowoutreferringto
thecuttingsheet
Forthecapacity(about500cc-600cc),refertothedataandselectthebestofcommercialproduct.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.3)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performanceoftheenginedecreasesdramatically.)
*Whenperforminganacrobatwithalargechangeinfuellevelorthatrequiringanexcessivemovementofthrottle,thetank
mustbeplacedatapositionclosetotheengineasmuchaspossible.
*Whenprovide“Airinhalationpipe”asFig.3,arrangingthetubeabovethefuellevel(Fig.4)istheeffectivewayoffuelleakage
prevention.
*ThecarburetorofFG-57TS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.
5.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.)
6.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.
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.

-3-
Thefunctionofeachcord;
(1)Plugcord(meshedhightensioncord)
AsFig.5showstherearetwocordsavailablefortwocylinders.Whenyouputontheplugcap,insertittothepluguntilyou
canhearclickysoundtoavoidcomingoffduringflight.Andthenpulltheplugcaptomakesurethatitwonʼtcomeoff.
(2)Sensorcord(black/red/whitecord)
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.
Fig.5Ignitionsystem
(FG57T-153A)
Recommended battery
5cell-NiMH
2cell-LiPo
Voltage:6-9V
Capacity: 1,000mA 以上
Switch (not included)
Capacity: more than 3A
Plug cap
Plug cord
Main unit
Battery cord
Sensor cord
Sensor
Fig.6 Neutral
Position
Hand start
easy  area
Delay
Spark
timing
Advance
Spark timing
CCW
CW
Prop rotation
(CCW)
View from front
7.SensorpositionandPower/Startingeasiness;
TheignitionsensorcanbemovedtoCW(advancethesparktiming)orCCW(delaythetiming)asFig.6shows.
Atthefactorydefaultthesensorisfixedonthecenter(neutral)position.Thereasonisrelatedtothemethodsofenginestarting.
・Withanelectricstarter-Youcanstartwhereverthesensorisfixed.
Soyoucansetthesensorastherpmreachesmaximumspeed.
・Byhandflip(Manualstart)-Startingeasinessdependsonthesensorposition.
Thefactorydefaultissetasyoucanstartbyhandflipandalsogethighestrpminthatrangeaspossible.
Ifyouprefereasinessofhandstarting,movethesensortoCCWdirectiontodelaythesparktiming.Butthenthemaximumrpm
willslightlydecline.
Ifyoupreferpower(highestrpm),movethesensortoCWdirection.Butthenyoucan'tstartbyhandflipbutonlywithstarter.
Inadditionbythefeatureoftheignitionsystem,itheatsupwithenginerunning.Whenyourestarttheenginebyhandflip,you
shouldopenthethrottlevalveslightlywhileit'shot.Andit'sbettertoenlargethechokewithoutwettingtheplug.
Forsafetywerecommendtouseanelectricstarter.
Note：Ifthefuelremainsinthecarburetoraftertheflight,thecomponentsmadefromrubbersuchasadiaphragmwillbe
degradedmorerapidly.Whenyoustoptheengine,stopitwithfuelcutandseethatthefueldoesnotremaininthe
carburetor.
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.
8.Carburetor
Equippedwithasuitablecarburetorbytechnicalcooperationwith“Walbro”thatprovideshighlyreliablecarburetorsfor
othergas-engines.PleaserefertoFig.9andChapter13regardingadjustmentofthecarb.
9.Enginemounting,mufflerattachment,andbreather
wastedisposal(Fig.7)
FG-57TScanbeinstalledflexibleintheaxialdirectionby
varyingthelengthofstand-offmounts.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ormufflerlooseness.
Themufflersshouldbesecurelyinserteddeeplyintotheangleadapterfrom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usindthe
bracketincluded.
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.7
From
Breathernipple
Exhaust
Muffleroutlet
Aluminumpipe
Baffle
Cowling
Coolair
Firewall
Stand-off
mount
Adjustable
(Standard35mm)
Hollowout
minimumarea

-4-
10.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500-600cc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thereʼrenoleakageatalltheconnections.)
(6)Forfuel,prepareamixedgasolinewithavolumeratioof“gasoline:oil”=“20:1”orricherthanthat.
(7)Prepareawellbalanced22”x10”carbon-madeprop(Mejzlikisrecommended).
*Propattachment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.
(10)Prepareafuelpumpforgasoline.(Besuretoattachafiltertotheintakeport.Itisavailableasanoption.)
(11)Inordertocheckdischargeofthebreather,attachaheat-proofandgasoline-prooftransparenttube.
(12)Prepareabatteryfortheelectricstarterandthebarforcarbadjustment&choking(standardaccessory).
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.
Note:Pleasetightenupthepropregularlyatleastonceintenflights.Especiallyforawoodenprop,ittendstocompressedso
thatthenutsarerathereasytobeloosensopleaseconfirmcarefullythatthenutsaretightenedadequately.
11.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)AsshowninFig.8,passthechokebar(withM3.5threadonitstip)thoroughtheholeinthecowling.Thenturnthebarto
insertintotheM3.5internalthreadatthecenterofthethrottlelever.
(3)FullyclosethethrottleandpullthechokebarandfixitwithacliporclampasshowninFig.8sothatitmaynotgobackto
thepreviousposition.


(4)Graspthepropbyhandandturnittotheforwarddirection(CCW)forseveraltimes,untilthecarburetorgenerates
hissing-likesounds.
(5)Afterhearingthissoundforabout5times,quicklyflickthepropbycrankingitsome10times.Thenchokingiscompleted.
(6)Removethechokebar.
(7)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.)
(8)Flickthepropquicklyandenginewillstart.Iftheenginedoesnʼtstart,repeatthechokingprocedure(1)to(7).
*Afterstarting,runtheenginefor10to20sectofillupinsidethecarbwithfuelenoughbeforeopeningthethrottle.
12.Break-in
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11andrunitfor10secinlowspeed.
Fig.8
Chokebar
Temporary
fixedbyclip
Throttlelever
M3.5threadfor
Chokebar
Slowneedle
Throttlevalve
(Movetotheleft)
Cowling
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turnopenfromfullclose
SDVforSlowneedle：
4.5turnopenfromfullclose
Throttlelever
Slowneedle
CCW
torichCW tolean
Mainneedle
CCW
torichCW tolean
Fig.9

-5-
(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.
(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14andadjustthecarburetorreferringtoChapter13.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.
13.Adjustmentofcarburetor
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.
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1,500~1,800rpmatidlingatfactorydefault.
(1)Afterfillingupthefueltank,starttheengineasdescribedinChapter11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1,500rpm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.
Atipforcarbadjustmentistosettheslowneedleslightlyleanaslongastheenginedoesnʼtstopwhenopenthethrottle
valvequicklyfromlowtohigh.
Forthemainneedle,richconditionasfarasitdoesnʼtaffecttotheflightisaknacktoincreasetheenginelife.
Thebesttunevariesdependingonmanyfactorssuchasweather,qualityoftheoil,prop,andsoon.
Duringyourflights,pleaseperformfine-tunesothatlow-middle-highspeedmatchesbestwiththeairplane.
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immidiately.
14.Normaloperation,maintenance,andadditionalinformation
(1)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(Fig.10).Toperformitfirst,eithercylinderisOK.
(a)Removetheplugandrockercoversfromthe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)Oncheckingthegap,securelytighten(butnotexcessively)thelocknut.
(e)Dothesameadjustmentfortheother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.
(2)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.
(3)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.
(4)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.
Tappetadjustment
Fig.10
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.

(5)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.
(6)ChargethebatteryfortheignitionsystemandRCdevicefully.(Sincetheignitionsystemgenerateshightension,becareful
ofelectricalshock.)
(7)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timeofascentshouldbeaproperpeakoftheengineduringflight.
(8)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.
(9)Occasionallytightenthepropnutandexhaustnut(whileitishot).
(10)Pleasenoticethatourguaranteewillnotcoveranybreakageortroubleontheengine
causedbyuserʼsdisassemblingormodification.
(11)Takeanextremecareforsafetywhenoperatingtheengineorflyingthemodelairplanenottobotherothers.
(12)Anengineforamodelairplaneisnotatoy.Handleitwithanextremecare.
(13)Notesforpurchasingparts:
Pleasegiveorderstotheshopyoupurchasedfromwithasheetwithenginename,partnameornuber,andmarking
(alphabetonthelowerfaceofrearcover).
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]  ・Smokingexhaustpipe(pair)[57T-167]
-6-
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

No. ItemQty No. Qty
01 Cylinder(Left) 1 Rockerarmscrew&Nut
02 Cylinder(Right) 1 42-1,-2
06 Piston 2 43 Rockerarmpin 4
07 Pistonpin 2 44 Rockerarmbracket(left） 2
08 Pistonpinretainer 4 45 Rockerarmbracket(right) 2
09 Pistonring 2 46 Valveset(In&Ex) 4
10 Connectingrod 2 Valvespring&Keeper&Retainer
13 Connectingrodscrew 4 47-1,-2,48
Cylinderscrewset 48 Valveretainer(Cotter) 4
14-1,-2,-3,-4 49 Rockerarmcover 4
15 Crankcase 1 69 Intakepipe(Left) 1
17 Rearcover(Backplate) 1 70 Intakepipe(Right) 1
19 Breathernipple 1 73 Flexiblemuffler 2
20 Frontballbearing 1 80 Mufflernut 4
21 Mainballbearing 1 Carburetorcomplete
22 Rearballbearing 1 82-1-1,-1-2,-1-3,-1-6,-1-7,-1-8,
-1-9,-1-10,-1-11,-1-12,88,93
23 Crankshaft 1 Carburetorbodyassembly
Tapercollet&Driveflange 82-1-1,-1-2,-1-3,88
27-1,-2 88 Throttlelever 1
Propwasher&Nut Carburetorscrew&springset
28-1,-2,-3 82-1-9,-1-10,-1-11,-1-12
Crankcasescrewset Carburetorgasketset
31-1,-2,-3,-4 82-1-6,-1-7,-1-8
Enginegasketset 93 Intakevelocitystack(airfunnel) 1
32-1,-2,-3,-4,-8,-9 Enginemountset
33-1 Camgearhousing(Left) 1 95-1,-2,-3,-4,-5
33-2 Camgearhousing(Right) 1 Mufflerbracketset
34 Camgear(Left) 1 99-1,-2,-3,-4,-5,-6,-7,-8
35 Camgear(Right) 1 110 Antilooseningnut 1
36 Camgearshaft 1 120 Sparkplug(NGK CM-6） 2
Steelwasherset 140 Mufflerrightangleadapter 2
37-1,-2 152 Screw-pin(Fordriveflangesetting) 1
38 Tappet 4 Electronicignitionsystem
39 Pushrod 4 153-1,-2,-3,-4
Pushrodcover&Rubberseal Intakemanifoldassembly
40-1,-2,-3 164-1,-2,-3,-4,-5,-6,-7
41 Rockerarm 4
1set
1set
1set
1set
1set
1set
1set
1set
1set
1set
1set
1set
1set
1set
1set
1set
42
47
1set
91
90
83-1
82-1
164
153
99
95
31
32
37
40
14
27
28
SAITOFG-57TSPartsList
153
153-1
153-2
153-4
153-3