Saito FG-11 User manual

SAITO FG-11
4-Stroke Gasoline Single Engine Operating instructions
FG-11isoneofthesmallestgas-engineamong4-strokegas-engineswhichisdesignedbasedonthelongseller-Glow
engine“FA-62”.Takingsamedevicessuchascarb,sparkplug,ignitionsystemfromexsitingsingle-gasenginessuchlike
“FG-21”“FG-17”“FG-14C”,durability,stability,andreliabilityaregivenaswell.
󱔒27.0mm
Body:465g/Muffler:50g/Ignitionsystem:100g/Enginemount:110gApprox.
19.0mm 10.9cc
Approx.2,000-9,500rpm
12”x8“~13”x8”
Approx.8,500~8,800rpm
APC13x7Approx.1.3~1.7kgf(Dependonprop）
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ThanksforbuyingSAITOFG-11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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,regula-
tions,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.Section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.
Specifications
Bore Stroke Disp.
Weight
Practicalspeed MaxonGnd
Propeller Staticthrust
Applications
Fuel
Fuelconsumption
Batteryforignitionsystem
Standardaccessories
4-strokeglow50-60class
Regulargasoline：Oil＝20:1(Volumeratio)
Approx.7cc/min(Atfullthrottle8,800rpm)
*Fuelflowvariesdependsuponpropload.Morefuelflowwithlargerloadandlessfuelflowwithsmallerload.
Voltage:6-8.4Vhigherthan1,000mAisrecommended
Enginemountset    1set
Ignitionsystem（w/sensor）   1set
Sparkplug[SAITOSP-1]（Attachedtoengine） 1pc
Mufflerset 1set
Limitgauge(0.1t)fortappetadjustment 1pc
Spannerfortappetadjustinglocknut  1pc
Hexagonalwrenchset   1set
Plugwrench     1pc
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.
(APC13ｘ7isrecommended)
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.
Outsidedimensions
Fig.1

Forthecapacity,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.)
*Thetankshouldbeplacedwithintherangeof200mmfromtheenginecentertothetankcenter.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.
5.Sparkplug
SAITOSP-1sparkplugisthestandardequipment.Dimensionsareasfollows;
Hexagonwidth:8mmScrewsize:UNEF1/4-32
Reach(withawasher):5.5mmSpark-gap:0.4-0.5mm
Forreplacement,pleasespecify“SAITOSP-1”.
Sinceourfourcycleengineusesamixedgasoline,pleasedecidethenumbersofflightsbyyourselfandcleanthesparkplug.
Pleasereplacewhenitisdegraded.(Considertheplugasconsumable).
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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]
・KlotzKL-200OriginalTechniplate
・DeluxeMaterialsPowerModel2T-S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
Gasoline-prooftube
（Option）
（Option）
Filterwithweight
Gasoline-proof
Pump
Fig.2
Fig.3 Centeroffueltank
Within200mm(closeaspossible)
Firewall
Enginecenter
Fueltank(100~150cc)
Gasoline-prooftube
Filterwithweight
Airinhalation
pipe
Fuelfeedingpipe
toCarbnipple
Rubbercapforgasoline-resistant
Fuellevel
above
Fuellevel
toOutsideof
thefuselage
Fig.4
Airinhalationpipe
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.

Thefunctionofeachcord;
(1)Plugcord(meshedhightensioncord)
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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(6-8.4V,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(Brown/Red/Orangecord)
Optionalon-boardtachometercanbeattached.
8.Carburetor
Acarburetorwithapumpdevelopedexclusivelyforoursmall-sizefourcyclegasolineengineismounted,insteadofusing
mufflerpressure.Sincethecarburetorwithapumpintroducestheairfromtheairholeshowninthenextfigure,setit2mmor
moreapartfromthefirewallordrillaholeonthefirewall.
Whenadjustingthecarburetor,refertoFig.7.
Mainneedle:Toadjustthespeedatthetimeoffullopenofthethrottlevalve.
Slowneedle:Toadjustthespeedfromtheidlingtothemiddlespeed.
Turningeachneedleinclockwisedirection,thefuelwillbecomeleanerandtherotationspeedwillincrease.Turningitin
counterclockwisedirection,thefuelwillbecomericherandtherotationspeedwilldecrease.
Forthereference
Thefollowingdataforthe
needleadjustmentisiunder
theconditionofAPC13x7prop
andabout8800rpm.
Theengineisinstalledinthe
invertedposition.
Openingwidthoftheneedles
varydependingonthe
atmosphere,prop,installing
positionetc.
Mainneedle:
4/5~1turnopenfromfull
close
Slowneedle:
5~5+3/4turnclose
(1.7~2.0mm)fromthe
surfaceofthethrottlelever.
Adjustmentrangetendtobe
narrowasdisplacementis
smaller.
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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.
Sensor
Plugcap
(2)Sensorcord
(Black)
Fig.5Ignitionsystem
(G17-153)
(1)Plugcord
Mainunit
(3)BatteryCord
(Red/Black)
(4)Tachometercord
(Brown/Red/Orange)
Fig.6
NeutralPosition
Hand start
easy area
Delay
Sparktiming
Advance
Sparktiming
CCW
CW
Prop rotation
(CCW)
View from front
Recommendedbattery
5cell-NiMH
2cell-LiPo
Voltage:6-8.4V
Capacity:Morethan1,000mA
Switch(notincluded)
Capacity:Morethan3A
Note:Thecarburetorforthegasolineengineistheassemblyofverystrictanddelicateparts.Sopleasemakesuretousefilteredgasoline.
Moreover,DONOTdisassemblebyyourself.Ifthereʼreanytroublesregardingcarb,pleaseconsulttheshopfromwhichyouboughttheengine.
Thread into about 5~5+4/5 turns
(Approx.1.7~2.0mm from
the Reference plane)
Fig.7

-4-
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.)
(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)Openthemainneedle1turnfromfullclose.
(3)Powerontheignitionsystem.
(4)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.)
(5)Applythestartertothepropandactivateforabout5secondstostarttheengine.
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
From
Breathernipple
Exhaust
Muffleroutlet
Aluminumpipe
From
Breather
nipple
Tissue Small
case
Tooutside
fuselage
Baffle
Cowling
Coolair
9.Enginemounting,mufflerattachment,andbreatherwastedisposal
Invertedinstallationoftheengineisrecommendedforlubricationhowevernormalorsidemount-
ingarepossible.
Eitherway,makesuretouseSAITOstandardenginemountattached.Asagas-enginegeneratesmuch
heat,SAITOstandardmountisdesignedtoreleaseheateffectivelyandvibrationaswell.Anyother
mountwhichisnotenoughrobustandheatrelease,mightcausetroublesbyvibrationandheat.
Makethefirewallrobustenoughbecausethisparthastoendurevibrationandtorquecausedby
proprotation.However,atestbenchmadeofsteelthatdoesnʼtabsorbanyvibrationcanconcen-
tratevibrationontheengineandenginemountandthereispossibilitytobreaktheengine
mountinaworstcase.Especiallywithalowloadprop,enginetendtogeneratelargevibrationthat
isverydangerous.
Thereforepleaseuseawoodenbenchrobustenough,neveruseabenchmadeofsteel.
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andmuffler,thecowlingshouldbedevised.
Alsomaketheairflowoutletlargerthantheinlet.Buildingsomebafflesinsidethecowlingappropri-
atelywillenhancethecoolingefficiency.Insufficientcoolingmaycauseenginetroublesuchas
overheatormufflerlooseness.
Themufflershouldbesecurelytightenedupusingtwospanners.(Adhesives,suchasascrewlock
agent,areeffectiveagainstloosenessandleakage.)
Mufflerrightanglemanifold(Option)allowsmufflertosettothepositionasyoulike.Regardingthe
treatmentofthemuffler,pleaserefertoChapter14.
Forbreathertreatment,attachthegasolineprooftubetothebreathernippleandfixtheother
sideofthetubeonoutsideofthecowling.Fixathinaluminumpipetotheoutletofthetube
andbindittothemuffleroutlettodiffusethehotairtogetherwithexhaustgasintotheair.
Andoneoftheeffectivewayofdisposalistosetabrieffiltermadebyasmallcaseandatissue
insideastheFig.7shows.
(Pleasebenotedthatitmightbetoomuchtoaccumulateforthesmallcasedependingonsizeoftheengine.)
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immo-
bile.)
(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100-200cc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APC13”x7”(Approx8800rpm).
(8)Prepareanelectricstarter,alsoattachaspinner.(Thisisthestandardwayofstartingengine.)
(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thin(-)screwdriverforcarbadjustment.
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be
compressedsothatthenutsarerathereasytobeloosensopleaseconfirmcarefullythatthenutsaretightenedadequately.

(2)Next,intheconditionof(1),fullyopenthethrottlevalve,turnbackthemainneedletomaketheair-fuelmixtureveryrichin
therangewheretheenginedoesnotstall(about4,000rpm).Operateinthisconditionwith2(ormore)tanks.(Conductthis
stepcheckingthedensityoftheexhaustandthebreatherʼswasteoil(inky-blackwasteoil)).
(3)Next,afterfillingupthetank,re-starttheengine.Withthethrottlevalvefullyopened,throttlethemainneedleandoperate
theengineforonetankat7500‒8,000rpm.
(4)Next,afterfillingupthetank,re-starttheengine.Withthethrottlevalvefullyopened,turnthemainneedlefromtherichto
thepeaksseveraltimes.Whenthepeakbecomestable,openthethrottlevalvefromlowspeedtohighspeedseveraltimes
tochecktheresponse.Andgraduallyelongatethetimeofhigh-speedoperation.Conductthisoperationforonetank.
(5)Whentherevolutionisstabilizedatpeak,theground-levelbreak-iniscompleted.Afteradjustingthetappetgapinthe
mannerofsection“14”,adjustthecarburetoraccordingtothefollowingsection.Therunning-iniscompletedbyperforming
some20flightsinalittlerichcondition.Subsequently,theflightshouldbeperformedinsucharichconditionasfarasnotto
influencetheflight.
13.Adjustmentofcarburetor
Theprincipalmethodofadjustmentisthesameasthatforourglowengine.
Inprinciple,acarburetorisadjustedbyfirstachievingpeak(thehighestrevolution)withthemainneedleandthensetidling
(lowspeedrevolution)withthethrottlevalveandtheslowneedle.(Unlessthepeakiscertainlyachieved,idlingadjustmentwill
bedifficultandnotstabilized.)
(1)Afterfillingupthefueltank,starttheengineinthemannerofSection“11”andthenfullyopenthethrottlevalvewiththe
throttlestick.
(2)Byturningthemainneedledependingonthetachometerandtheexhaustsound,achievepeakcarefully.
*Asforadjustingthemainneedleinthecaseofactualflight,settingthepeakintheperpendicularattitudewithapropeller
intheupwarddirectionisrecommendedifitʼspossible.Inthatadjusting,itʼllberichenoughinthehorizontalattitudeso
itʼsmoresimilartotheconditionduringtheactualflight.
(3)Next,closethethrottlevalveuntiltheengineoperatesstablywithanidlingrotationofaround2000-2500rpm,adjusting
theslowneedlewiththe(-)screwdriverandthethrottlevalvecarefully.
*Sincetherichnessleveloftheair-fuelmixturevariescorrespondingtothenatureoftheairframe,pleaseadjustitdepending
ontheuserʼsskill.
Generally,inascaleflightinwhichthestabilityofalow-speedzoneisconsideredasimportantandtheengineisoperated
slowly,adjusttheair-fuelmixturetoberelativelylean.Inanacrobaticflightinwhichtheearlystand-upfromalowspeedis
consideredasimportant,adjusttheair-fuelmixturetobeslightlyrich.
(4)Aftertheidlingisset,getthethrottlevalveslowlyfullyopened.Iftherevolutionbecomessloworgoesupsuddenly,adjust
carefullyuntilitchangeslinearlyfromidlingtopeak,byfine-tuningwiththeslowneedle.
(5)Aftertheaboveadjustmentiscompleted,openthethrottlevalvefromidlingtopeakquickly.Iftherevolutiondoesnot
achievepeakimmediatelybutgetdelayedasthethrottlevalveisfullyopened,fine-tunethemainneedleandperformthe
sameprocessfromidlingtopeakquickly.Repeatthiscarefullyuntiltheresponseimproves.
*Thekeytomaketheenginelastforlonglifeisoperatingwiththeslightlyrichconditionasfarasitdoesnʼteffecttotheflight.
Adjustmentisneededdependingontheengineattachmentdirection,thepropeller,thefuel,theplug,theclimatecondition,
etc.Duringflights,pleasefine-tunesothatlowspeed,mediumspeed,andhighspeedmatchbestwiththeairframe.
14.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.
(2)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.
(3)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.
(4)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highqualityoil.
(5)ChargethebatteryfortheignitionsystemandRCdevicefully.(Sincetheignitionsystemgenerateshightension,becareful
ofelectricalshock.)
(6)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.
(7)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.
(8)BecauseallofSAITOgas-enginesuseoil-fuelmixture,theretendtobecarbonbuildupinside
themufflerasshowninthepicture.Itcausessomeproblemsontheexhaustoutletand
consequentlyreducesthepower.Thereforecleaning/removingcarboneveryabout50flights
isrecommended.Usingapartscleaningsprayiseffectiveway.Actually,itdependsonthe
qualityoftheoilsowhenyoufeelthepowerloss,pleasecheckinsidethemuffler.
Inthecaseofthepicturewhichhadbeendonemorethan70flights,byremovingthecarbon
buildup,thesmoothnessoftheengineimproveddramatically.
-5-
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:Overclosingthemainneedleisverydangerousbecauseitmaycauseknockingandpropellernutloosening.Then,
turnthemainneedleCCWimmediatelytomakeitrichalittle.

(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(Fig.10).
(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.
*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)Occasionallytightenthepropnutandexhaustnut(whileitishot).
(11)Pleasenoticethatourguaranteewillnotcoveranybreakageortroubleontheengine
causedbyuserʼsdisassemblingormodification.
(12)Takeanextremecareforsafetywhenoperatingtheengineorflyingthemodelairplanenottobotherothers.
(13)Anengineforamodelairplaneisnotatoy.Handleitwithanextremecare.
(14)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[G36-154]  ・Neoprenetubeforgasoline(1m)[G36-155]
・SparkplugSP-1[G20-120]  ・Aluminumspinnernut[50-30]
・Tappetadjustingkit[30-161]  ・Digitaltachometer[G17-168]
Tappetadjustment
Fig.9
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.
-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

153
153-1
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153-2
SAITOFG-11PartsList
No. Description Q'ty No. Description Q'ty
01 Cylinder 1 Valveset(In&Ex)
06 Piston 1 46-1,-2
07 Pistonpin 1 Valvespring&Keeper&Retainer
08 Pistonpinretainer 2 47-1,-2,48
09 Pistonring 1 48 Valveretainer(Cotter) 2
10 Connectingrod 1 49 Rockerarmcover 2
Cylinderscrewset 69 Intakemanifold(Intakepipe) 1
14-1,-2 74 Muffler 1
15 Crankcase 1 Mufflermanifoldset
17 Rearcover(Backplate) 1 75-1,80
19 Breathernipple 1 80 Mufflernut 2
20 Frontballbearing 1 82-1 Carburetorcomplete 1set
22 Rearballbearing 1 Carburetorbodyassembly
23 Crankshaft 1 82-1-1,-1-2,-1-3,-1-4,-1-7,-1-8,-1-13,-1-14
Tapercollet&Driveflange -1-15,-1-27,-1-28,32-5,91-1
27-1,-2 85 Fullthrottleneedle 1
Propwasher&Nut Throttlebarrelassembly
28-1,-2 82-1-5,-1-9,88B,89
Crankcasescrewset Throttlelever
31-1,-2,-3 88B,90-1
Enginegasketset 89 Idleneedle 1
32-1,-2,-3,-4,-5,-6,-8 Carburetorscrew&springset
33 Camgearhousing 1 82-1-7,-1-8,-1-13,-1-16,-1-26,-1-28,90-1
35 Camgear 1 Carburetorgasketset
36A Camgearshaft 1 32-4,-5,-6,82-1-9,-1-14,-1-18,-1-20,-1-22,91-1
37 Steelwasherset 1set Enginemountset
38 Tappet 1 95-1,-2,-3,-4,-5,-6
39 Pushrod 1 110 Antilooseningnut 1
Pushrodcover&Rubberseal 152 Screw-pin(Fordriveflangesetting) 1
40-1,-2,-3 Electronicignitionsystem
41 Rockerarm 1 153-1,-2,-3,-4,-5
Rockerarmscrew&Nut Pumpassembly
42-1,42-2 82-1-17,-1-18,-1-19,-1-20,-1-21,-1-22,-1-23
43 Rockerarmpin 2 -1-24,-1-25,-1-26
14
27
28
31
32
40
42
1set
1ea.
1ea.
1set
1set
2ea.
2ea.
95
153
1set
87
88B
90
1
91
46
1set
47
2ea.
160
1set
1set
1set
1set
1set
1set
1set
75
83-1