Saito FG-21 Instruction Manual

Φ32.0mm 26.0mm 20.9cc
15”x8“~16”x6”
・Filterwithweight[G36-154] ・DurabletubeforGasoline(1m)[G36-155] ・Aluminumspinnernut[100-30]
・Tappetadjustingkit[30-161] ・Digitaltachometer[G17-167]
Bore Body:690g/Muffler:83g/Ignitionsystem:100g/Enginemount:156gStroke Disp. Weight(Approx.）
RPMRange Approx.2,000-9,500rpm Maxonground Approx.8,000-9,000rpm
Propeller SP-1orSP-2Plug
Optionalparts
4-strokeglow100-110classApplications
Batteryforignitionsystem
Specifications
FG-21InstructionManual
2.Ignition
●Ignitionarrangement-Placethemainunitasfarfromother
electricaldevicesaspossible.
(1)Plugcord（meshedhightensioncord)
Inserttheplugcapoftheplugcorddeeplyintotheplug
attachedtothecylindertomakesureitwillnotcomeoff.
(2)Sensorcord
Connectwiththecordfromthesensorattachedtotheengine.
(3)Batterycord(black/redcord)
Useafullychargedbatterythathasadequatespec.(6-12V,more
than1000mAisrecommended).Betweenthebatteryandmain
unit,makesuretosetaheavydutyswitchwhosecapacityis
higherthan3A.
(4)Tachometercord
Connectthedigitaltachometer(Option).Otherwisetheconnec-
torisnormallyvacant.
※
Standard
accessories
6.Tappetadjustment
ThevalveclearanceshouldbecheckedandadjustedafterBreak-inandeveryafter2hourswhiletheengineiscold.Beforeadjusting
tappetgaps,tightenthescrewsaroundcylinderetc.
1.Removethesparkplugand
rockerarmcoversfromthe
cylinder.Thenturntheprop
CCWbyhandtoplacethe
pistonatTDCofcompression
stroke.
2.Loosenthelocknutand
adjustthegapbyhexagonal
wrenchuntilyougetthe
correctgap(belowpic)for
bothofintake&exhaust.
3.Oncethegapisset,tighten
thelocknutandattachthe
plugandcovers.
4.Turnthepropbyhandto
checkifthecompressionis
enough.Ifthegapislessthan
0,thevalveisalwaysopened
sightlyandlosecompression.
Thenadjustagain.
CorrectGap
Mustnotbeinserted
Closeto“0”withnolimit
Limitgauge
(0.1mm)
Loosenthelocknut
Adjustthegapturning
thesetscrew
TopDeadCenter
（bothvalvesareclosed)
Tightenthelocknut
tofixthesetscrew
・Enginemountset 1set ・Limitgauge(0.1t)fortappetadjustment 1pc ・Plugwrench  1pc
・Hexagonalwrench 1set ・Spannerfortappetadjustinglocknut 1pc ・Mufflerset  1set
・Ignitionsystem(w/sensor) 1set ・Sparkplug[SP-2](Attachedtotheengine) 1pc ・Anti-looseningnut 1pc
SwitchCapacity:3A〜
Sensor
Battery
Voltage:6-12V
Capacity:1,000mA〜:
Plugcap
(2)Sensorcord
(Black)
(1)Plugcord
Mainunit
(3)BatteryCord
(Red/Black)
(4)Tachometercord
(Brown/Red/Orange)
FuelTank
FuelLevel
ToOutsideoftheplane
Ventline
fuelsupplytocarburetor
Setthecenterofthecarb
slightlyabovethefuellevel
Fuelfillerline
Ventline
Gasoline-compatible
tankstopper
Gasoline-compatibletubing
Filterwithweight
Closeaspossible(within200mm)
Firewall
CCWtomake
rich
Main
Needle
Throttle
Fullopen
SAITOSEISAKUSHO,CO.,LTD. www.saito-mfg.com
22-7,3-chome,Tokagi,Ichikawa-shi,Chibaprefecture272-0024,JapanPhone:047-378-4156FAX:047-378-4155
Allspecificationsandmodelsaresubjecttochangewithoutnotice.
Note:
●Asitusesoil-mixedfuel,theplanemaysometimesgetdirtyfromtheexhaust.
●Useareliableandwell-balancedprop.Otherwiseitmaycauseanabnormalvibrationandcouldresultinaseriousaccident.
●Duringoperation,allenginescrewscanloosenduetometalheatexpansion.Checkandtightenoccasionally.
●Whentheexhaustvalvegetsdullbycarbonorsludgeespeciallyincoldatmosphere,removetherockercoverandapplysomeanti-rust
spraytotheexhaustvalvetohelpthevalvetomovesmoothly.
●Payattentiontothesurroundingssoasnottodisturbothersbynoiseandexhaust.
●Alwayskeepspectatorsstandbehindtheenginewhenoperatingtheengine.
●Asexhaustsmokeisharmful,becarefulnottobreatheinorotherwiseexposeyourselftoitsharmfuleffects.
●Payattentionnottotouchtherotatingpropellerwhenstartingengine,andmovetorearsideoftheaircraftoncetheengineisstarted.
●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.
Warranty:
●Ifthereisanydeficiencyfromthefactoryconcerningmanufacture,pleaseconsultwiththeshopordistributoryouboughtfrom.Our
companywillberesponsibleforrepair.However,anyfailureortroublecausedbyunnecessarydisassembly,modification,orotheruses
thanthoseprovidedintheinstructionmanualisnotsubjecttowarranty.
●Ignitionsystemissubjecttothewarrantyonlyforinitialfailure.Oncethesystemhasbeenactivatedsuccessfully,itwillnolongerbesubject
towarranty.
ver.March,2022
1.Fuel
●Thefuelismixtureofregulargasolineorhigh-octanegasolineandhigh-quality2-strokeengineoil.
●[Exampleofoilrecommendation]
・KlotzKL-200OriginalTechniplate・DeluxeMaterialsPowerModel2T-S・ENEOSRACINGSPECPRO-2T(SAITOSTANDARD)etc.
Ifsuchoilsarenotavailableinyourcountry,thenpleaseasktheofficialSAITOdistributorinyourcountryforanalternative. 
NEVERuse“cheapoil”designedforutilityenginesforbrushcutter,lawnmower,orchainsawetc.
●Besuretousethemixture“gasoline:oil=15~20:1”byvolumeratio.(Ex.1000mlofgasolineshouldbemixedwithmorethan50mlofoil).
●Duringthebreak-inprocess,use15:1mixedfueltoensurethebestlubricationforinitialrunning.
●Anydamagecausedbythefuelused,inwhichtheoilratioislowerthan20:1willnotbecoveredbywarranty.
●Donotusegasolinecontainingethanol.Itmaycausenotonlypowerlossbutalsocorrosioninsidetheengine.
3.Propeller
●RecommendedpropellerisAPC15x8~16x6whichbringsapprox.9,000rpm.Largersizeorgreaterpitchcancauseenginebrokendueto
overload.
●Useawell-balancedone.Neverusethepropellerthathasbeenscratchedordamagedevenifslightly.
●Asthepropelleriscompressedslightly,tightenthepropellernuteveryhourofoperation.
4.Break-inMOSTIMPORTANT!!
●Prop-recommendation:APC16”x6”.
●Use15:1fuel:oilratioforbreak-in.
●Nevermakethefuelmixtureleanduringbreak-in.Itcouldcauseseizureevenduringidlingor
low-speedrunning.
●Checkthattheslowneedleissettothereferenceposition.(Depth0.9~1.1mmfromthesurfaceof
thethrottlelever.)
●Beforestartingtheengine,openthemainneedleApprox.1+1/2turnsfromfullyclosed.
●Starttheengine(usingastarterisrecommendedforsafety).
●Soonafterstarting,Openthrottlegraduallyuptofull.InthemeantimeturnthemainneedleCCW.
ContinuetoturnthemainneedleCCWuntiltheRPMdeclines(toapprox4-5,000rpm)keeping
thethrottleopenedfully.
●Runinthisveryrichconditionfor1literoffuel.
●Now“initial”break-inisdone.
Slow High
Throttlelever
CCW→Rich
CC→Lean
Mainneedle
Slow(Idle)Needle
(Adjustwith⊖screwdriver)
CW→Lean
CCW→Rich
Approx.
0.9~1.1mm
SlowNeedle
5.Adjustmentofcarburetorafterinitialbreak-in.
◇Needlereferenceposition(Setafterinitialbreak-in)
●Starttheengineafteradjustingtheneedletothefollowingreferencevalue.
●Mainneedle：Approx.1+1/3~1+1/2turnsCCWfromfullyclosed
●Slowneedle：Approx.2+1/2~3turnsCW(Approx.0.9~1.1mm)fromthesurfaceofthethrottlelever.(Thenthrottlevalveshouldbefully
closed)
●Actually,thebestpositionoftheneedlesvarydependingontheprop,
temperature,humidityandsoon.Pleaseadjustasnecessaryafter
observingtheengineperformanceduringflight.
◇Peakadjustment
●Afterstartingtheengine,warmupforapprox.30secondsatlowspeed.
●Achievethepeakatfullthrottle.
→TurnthemainneedleCWgraduallytothepositionwheretheRPMis
greatest(thepeak).ContinuingtoturntheneedleCWpastthepeak
couldleadtoseizuresoturnitslowlyandcarefully.IftheRPMsudden-
lydecreasesafterpassingthepeak,instantlyreturnthemainneedle
CCWtoagainincreasetheRPM.Otherwiseitcoulddamagetheengine
seriously.
●OnceachievingpeakRPM,returnthethrottletolowspeed.Makeanoteofthepositionofmainneedleatthepeakatthattime.(Howmany
turnsyoudidCWbasedonthereferencevalue.)
◇SlowneedleAdjustment
●AfterachievingpeakRPM,nextisslowneedleadjustment.OpenthethrottlefromlowRPMtofullthrottlequickly.
●TurntheslowneedleCCWslightlyiftheenginehesitatesforamomentorstallsbeforetheenginereachesmaxRPMbecausethemixtureis
toolean.
●TurntheslowneedleCWslightlyiftheengineisslowtoreachpeakRPM(fullthrottleset)becausethemixtureistoorich.
●AdjusttheslowneedleasaboveuntiltheRPMfollowsthethrottlemovementsmoothly.Theimportantpointistoadjusttheslowneedle
AFTERthemainneedlehasbeenadjustedtoitspeak.
●Nowbreak-inatgroundlevelisdone.Adjusttappetsbythemethoddescribedlater.
◇Pre-flight/Flightadjustment
●Whentheslowneedleadjustmentisdone,checktheresponsebyrevvingupfromlowspeedtofullthrottlequicklyseveraltimes.
●OpenthethrottlefullyandturnthemainneedleCCWapprox.60〜90degreesfromthepeakposition.Thisistomakethefuelmixturericher
intheairwheretheRPMgethigherthanontheground.
●Afteralladjustmentsaremade,flyyouraircraftandfinetunetheengineaccordingtothesituation.Basicallytuningshouldbedonewiththe
mainneedle.Readjustmentoftheslowneedleisrarelyneededifthefirstadjustmentoftheslowneedlehasbeendonesuccessfully.
Voltage:6-12V,greaterthan1,000mA
※IfyouuseLi-Po,werecommendthespeclessthan2,500mAcapacityand
lessthan30Cdischargerate

Saito FG-21 Specifications

General

Brand	Saito
Model	FG-21
Category	Engine
Language	English