Saito FG-73R5 User manual

Φ29.0mm 22.0mm 72.7cc
22”x10”〜23”x10”
Bore
Mainbody:2,600g/Muffler:280g/Ignition:380g
Stroke Disp.
Weight(Approx.) RPMRange Approx.1,200-7,800rpmMaxonground Approx.6,500~7,500rpm
Propeller 1/4-32SP-1or
SP-2sparkplug
Plug
Optionalparts
2st-Gasoline50㏄classApplications
Batteryforignitionsystem Voltage:6-12V,greaterthan1,500mA
・Limitgauge(0.1t)fortappetadjustment 1pc ・Wrenchfortappetadjustinglocknut 1pc ・Plugwrench  1pc
・Sparkplug[SP-2](Attachedtotheengine) 5pcs ・Mufflerset   1set ・Anti-looseningnut  1pc
・Ignitionsystem(w/sensor)  1set ・Mufflerlocktie   2pcs ・Hexagonalwrench1.5mm 1pc
Specifications
FG-73R5InstructionManual
2.Ignition
●Placethemainunitasfarfromotherelectricaldevicesaspossible.
●PlacethetwoswitchesoftheignitionandtheRCreceiverasfarfrom
eachotheraspossible.
(1)Plugcord(meshedhightensioncord)
Inserttheplugcapof(1)Plugcorddeeplyontotheplugof#1cylinder
tomakesureitwillnotcomeoff.Theothercapsandplugsshouldbe
installedbythesameway.(Refertocylinder#onthereverseside)
(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
1500mAisrecommended).Betweenthebatteryandmainunit,make
suretoinstallaheavydutyswitchwhosecapacityishigherthan3A.
(4)Tachometercord(optional)
Connectthedigitaltachometer(Option)tothemainunit.Otherwisetheconnectorisnormallyvacant.
Standard
accessories
FuelTank FuelLevel
ToOutsideoftheplane
Ventline
Fuelsupplytocarburetor
Fuelfillerline
Ventline
Gasoline-compatible
tankstopper
Gasoline-compatibletubing
Filterwithweight
Setthecenterofthecarb
slightlyabovethefuellevel
Closeaspossible
Hollow
out
Firewall
Approx.30mm
1.Fuel
●Thefuelisa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.
・Filterwithweight[G36-154] ・Rubbertubeforgasoline(1m)[G36-155]
・Tappetadjustingkit[30-161] ・Digitaltachometer[G17-167]
3.Propeller
●RecommendedpropellerisMejzlik22”x10”whichbringsapprox.7,100rpm.(orFalcon22”x10”bringsapprox.6,800rpm).
●Useareliablepropwhichbringsmaximum6,500~7,500rpminconformitytoyourplane.
●Useawell-balancedprop.Neveruseapropthathasbeenscratchedordamagedevenifslightly.
●Neveruseexcessivelylightorheavyloadedprop.Theymaycauseenginefailure,bigaccident,oreveninjury.
●Asthepropelleriscompressedslightly,tightenthepropellernuteveryhourofoperation.
4.Break-inMOSTIMPORTANT!!
●Beforestartingtheengine,injectasuitableamount(approx.20〜30cc)ofengineoilintothelubricationnippleonthecrankcaseusinga
syringeorpumpwhileturningthepropellerbyhand.Afterthat,plugthisnipple.Asexcessisdischargedfromthebreathernipple,attacha
tubetothebreathernipple.
●Prop-recommendationforbreak-inprocess:Mejzlik22”x10”
●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.
●Beforestartingtheengine,openthemainneedleapprox.2turnsfromfullyclosed.
●Starttheengine(usingastarterisrecommendedforsafety).
●Runfor15~20secondsatlowspeedtowarmup.
●Openthrottlegraduallyuptofull.InthemeantimeturnthemainneedleCCW.Continuetoturnthe
mainneedleCCWtodropto3,000~4,000rpmkeepingthethrottleopenedfully.
●Runinthisveryrichconditionfor1literormoreoffuel.
●Now“initial”break-inisdone.
ver.Feb,2021
SwitchCapacity:3A〜
Sensor
Battery
Voltage:6-12V
Capacity:1,500mA〜
PlugCap
(2)Sensorcord
( 1)PlugCord
MainUnit
(3)BatteryCord
(4)TachometerCord
Throttle
Fullopen
CCWtomake
rich
Main
Needle
CW→Lean
CCW→Rich
CW→Lean
CCW→Rich
CCW→Rich
CW→Lean
Mainneedle Slow(Idle)Needle
(Adjustwith⊖screwdriver)
Slow
High
Throttlelever
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+1/2turnsCCWfromfullyclosed
●Slowneedle：Approx.7turnsCCWfromfullyclosed(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suddenlydecreasesafterpassingthepeak,instantlyturn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.
●IftheenginehesitatesforamomentorstallsbeforetheenginereachesmaxRPM,Itʼsbecausethemixtureistoolean.Thenturntheslow
needleCCWslightly.
●IftheengineisslowtoreachpeakRPM(fullthrottleset),itʼsbecausethemixtureistoorich.ThenturntheslowneedleCWslightly.
●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4~6clicks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.
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
（Thestatebothvalvesareclosed) Tightenthelocknut
tofixthesetscrew
6.Tappetadjustment
Thevalveclearanceshouldbecheckedandadjustedafterbreak-inandeverytimeaftertwohourswhiletheengineiscold.Beforeadjusting
tappetgaps,tightenthescrewsaroundcylindersetc.
1.Removethesparkplugand
rockerarmcoversof#1
cylinder.Thenturntheprop
CCWbyhandtoplacethe
pistonatTDCofcompres-
sionstroke.
2.Loosenthelocknutand
adjustthegapbyhexago-
nal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.Dothesame
adjustmentforthe#3-#5-#2
-#4cylindersinorder.
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slightlyandwilllose
compression.Thenadjustagain.
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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.
※
※IfyouuseLi-Po,werecommendthespeclessthan2,500mAcapacityand
lessthan30Cdischargerate

Item
Cylinder
Piston
Piston pin
Piston pin retainer
Piston ring
Master rod
Linked conrod
Link pin
Cylinder screw set
14-1,-2
Crankcase
Rear bearing housing
Rear cover A
Rear cover B
Breather nipple
Front ball bearing
Rear ball bearing
Crankshaft
Taper collet & Drive flange
27-1,-2
Prop washer & Nut
28-1,-2
Crankcase screw set
31-1,-2,-3,-4,-5,-6,-7,-8
Engine gasket set
32-1,-2,-3,-4,-5,-6,-8
Cam gear housing
Cam gear
Cam gear shaft
Steel washer set
Tappet
Pushrod
Pushrod cover & Rubber seal
40-1,-2,-3
Rocker arm
Rocker arm screw & Nut
42-1,-2
Rocker arm pin
Valve (In & Ex)
No.
01
06
07
08
09
10
11
12-1L
14
15
16
17
18
19
20
22
23
27
28
31
32
33
35
36
37
38
39
40
41
42
43
46
Qty
5
5
5
10
5
1
4
4
5set
1
1
1
1
1
1
1
1
1ea
1ea
1set
1set
5
5
5
5set
10
10
10ea
10
10ea
10
5set
Item
Valve spring & Retainer
47-1,-2,48
Cotter (Valve retainer)
Rocker arm cover
Counter gear & Thrust washer
52-1,-2,-3
Counter gear shaft
53-1,-2
Intake pipe
Muffler complete
78-1,-2,-3,-4,-5,-6,-7
Carburetor complete
82-1-1,-1-2,-1-3,-1-4,-1-5,-1-7,-1-8,-1-9,-1-13,
-1-14,-1-15,-1-16,-1-17,-1-18,-1-19,-1-20,-1-21,
-1-22,-1-23,-1-24,-1-25,-1-26,-1-27,-1-28,-1-29,
-1-31,31-6,85,88B,89,90-1,91-1,131
Main needle valve
85,90-1
Throttle lever
88B,90-1
Slow needle
Carburetor screw & spring set
82-1-7,-1-8,-1-13,-1-16,-1-17,-1-26,-1-28,
90-1,31-6
Carburetor gasket set
91-1,82-1-9,-1-14,-1-18,-1-20,-1-22,-1-31
Engine mount set
Anti loosening nut
Spark plug (SP-2)
Link pin retainer plate
Throttle valve extension adapter / set screw
Muffler right angle adapter / nut
Screw pin
Electronic ignition system
153-1,-2,-3,-4
Pump assembly
82-1-17,-1-18,-1-19,-1-20,-1-21,-1-22,-1-23,
-1-24,-1-25,-1-26
Insulator joint for carburetor
Initial lube nipple
No.
47
48
49
52
53
69
78
82-1
85
88B
89
90
91
95
110
120
121
131
140
152
153
160
170
175
Qty
10ea
10
10
5ea
5ea
5
1set
1set
1
1
1
1set
1set
1set
1
5
1
1
5
1
1set
1set
1
1
外形寸法図
Outside dimension
󱔘230
#1
#2
#3
#4
#5
Prop direction
41
182
73
9686
M10×1.25
110
3050
80
28-1 27-228-2 27-1 20
19
37
36
35
32-1
33
31-3
38
40-3
40-1
39
40-2
41
42-1
43
42-2
47-1
47-2
48
32-2
49
14-2
46
32-8
01
14-1
140
16
22 23
32-6
32-5 69
090708
11
12-1L
121 31-7 32-3 17
18 31-8 95
32-4
06
31-2 82-1
10
31-1
120
152110 31-4
31-5
175 53-2
53-1 52-1
-2
15 52-3
170
78-7 78-1 78-5 78-2 78-4 78-3 78-6
153-2 153-3
153-4
153-1
153
90-1
90-1
90-1
88B
131
82-1
-9
89
82-1
-16
82-1
-5
82-1
-2
82-1
-14 82-1 -3 82-1 -4 85
90-1
82-1
-29
31-6
82-1
-7 82-1
-8
82-1
-27
82-1
-27
82-1
-28
82-1
-13
82-1
-15
82-1
-1
82-1
-31
82-1
-17 82-1
-18 82-1
-24 82-1
-19 82-1
-25 82-1 -20 82-1 -24 82-1
-21 82-1
-25 82-1
-22 82-1
-23 82-1
-26
91-1
82-1
4-󱔘5.2
Cylinder ID number #
(View from front)
Firing order : #1-#3-#5-#2-#4
シリンダー番号#
（前方から見て）
点火順序: #1-#3-#5-#2-#4