NGH GF30 Operation manual
1
GF304-StrokeRCGasolineEngines
Owner sOperatingInstructionManual
Dearcustomer:
ThankyouforpurchasingNGHGF304-strokegasolineengine.TheenginehasbeendevelopedbyNGHengineersto
offerallhobbyistsanew4-strokeengine.Youwillbedelightedwithstability,fueleconomy,energysaving,
environmentalprotection,lownoise,largetorqueoutputofyourNGHGF30.Wehopethatyouwillenjoywithyour
engine,andhavemanyfunandsafeflyingexperienceswithitsuse.
SafetyInstructionandWARNINGS!
Pleasereadthisinstructionmanualcarefullybeforeoperatingandbefamiliarwithfeaturesofthisproduct.Improper
operationmaycausedamageoftheproductsevenleadtopropertylossandpersonalinjury.
GF30engineisprecisionproductsmanufacturedbyNGHR&D.Itmustbeoperatedwithcaution.Theoperatorshall
masterknowledgeofinternalcombustionengineaswellasbasicmechanicalability.Thisproductisnotsuggestedfor
usebychildrenwithoutinstructedbyadults.Don tattemptdisassembly,usewithincompatiblecomponentsoraugment
productinanywaywithoutauthorizedapprovalbyourcompany.Itistoreadandfollowallinstructionsandwarnings
ofthismanualbeforeassembly,setuporusetoensureoperatecorrectlyandavoiddamageorseriousinjury.
AgeRecommendation:RCengineisnotatoy!Forbiddenforchildrenunder 15 years.
Theengineisdesignedforuseonamodelradiocontrolairplane.Ifitisusedforanypurpose,wewon'tberesponsible
foritsstabilityandsafety.
NGHortheirdealersaren tresponsibleforanyloss,injuryordamageresultingfromthemiss-useofRCengine.
Keepawayfromtherotatingpropellerareawhileoperatingtheengine.
Donotwearlooseclothingneartheengineorthepropeller.
Donotoperatetheenginenearloosematerialsuchasdirt,gravel,ropes,sand,etc.
Alwaysrunyourmodelengineinawell-ventilatedarea.Modelenginesproducepossiblyharmfulcarbonmonoxide
fumes.
Alwaysensurethatthepropellerissecurelyattachedtotheengineshaftandallretainingfastenersaretightened
properlybeforeeachflight.
Alwaysstandclearofandbehindthepropeller,ensurethefaceandbodyarefarawayfromthepropellerbladeafter
trajectory.Neverallowanyone,tobeinfrontofortothesidesofthepropellerwhenstartingorrunningtheengine.
Alwaysensurethatsmallpartsinthechildrencan ttouchplacetopreventchildrenfromswallowingparts;
Alwayscheckthepropellernuttightening.
Gasolineisextremelyflammable.Becarefulofanysparksfromelectricalcontactssuchasfuelpumps,battery
charger,etc.
Allowyourenginestopandcoolbeforetouchingorfueling.Therunningengineofthesurfacetemperatureishigh,
easytocauseburnsandotherpersonalinjury.
Besuretocheckwhethertherearelooseboltsbeforeflying.Wheninstallamuffler,themufflerinthethreadsofthe
screwintotheengineexhaust,untiltwistfixed,itisrecommendedtousescrewglue.
Ensuretheengineandmufflerinaircraftfairingenvironmentwithcoldair,makesuretheenginecooling.
ProductSpecifications:
Type：4-strokeaircooledgasolineengine（Onlyusedforfixed-wingaircraftmodel）
Bore：36mm Stroke：29.4mm
Volume：29.91cc Carburetor：WalbroWT962
MixOutput：2.68HP/9000rpm RPMRange：1600-8500rpm
Ignition：NGHAutomaticadvancingangleignition (RoHSandCECertified)
IgnitionPower：DC4.8V-8.4V 1000mAH Sparkplugtype：CM6
Fuel: 92#Unleadedgasoline+Fullysyntheticlubricants
(Non-4-strokelubricants) Mixratio：Gas:Oil=35:1
Recommendedpropeller：15x10、16×8-10、17x6-10
（Twoblades）
Weight：engine1160g、ignition105g、muffler100g
2
Carburetorsetupandadjustment:
NGH-GF30
four-stroke
gasoline
engine
used
Walbro
WT
carburetor
is
designed
for
NGH
unique.
It
has
the
perfect
stability
of
idle
speed
and
acceleration
sensitivity.
It's
better
to
remove
fuel
from
the
carburetor
after
a
set
of
fl
ight
to
avoid
carburetor
rubber
components
deteriorating
over
time,
which
may
lead
to
engine
performance
failure.
Methods:
Start
engine
without
connecting
the
fuel
pipe
until
all
fuel
oil
in
the
carburetor
exhausted.
SetupCarburetor:
①—Choke：Closeitbeforethefirststarttheengine,andquicklyrotatingpropeller,thefueloilsuctionwithinthetank
intothecarburetor,whenyoustarttheengineshouldbeopenit.
②—Thethrottlecontrolarm：Infinitelyadjustable-speeddevice,controltheturningspeedoftheengine.
③—Nozzle：Connecttheoiltankandsupplythefueltoengine.
④—Highspeedneedle(H).：Afterfullyopenthethrottlecontrolarm ②,adjustthehighspeedneedlecangetthebest
highspeed.
⑤—Idlingspeedneedle(L)：Put ②returntotheinitialposition,adjusttheidlingspeedneedlecanobtainsatisfactory
lowspeed.
⑥—Idlemixtureadjustmentscrew：Adjustingthefuelandairmixingratioatidle,itactuallycontroltheinitial
positionof ②,adjust ⑥and ⑤willobtainthebetteridlingspeed.
Theinitialsetupofthecarburetorisfactorysettings,theenginefirststartdon tneedtoadjust.
Thefactorysettingstatus:
④—Highspeedneedle,Fullyclosed(clockwise)beforeexiting(anticlockwise)1.25-1.5rings；
⑤—Idlespeedneedle,Fullyclosed(clockwise)beforeexiting(anticlockwise)1.5-1.75rings；
⑥—Idlemixtureadjustmentscrew,Thethrottlecontrolarmattheotherendofthelimitpawlnearthescrewconeabout
0.6mm.
AdjustCarburetor:
Whentheenginerunning,youwanttoadjustthecarburetor,pleaseadjustitbasedonfactorySettings:
Intheprocessofadjustingthecarburetor,pleaseuseahigh-qualitytachometertodetermineyouradjustedresults,the
tachometeryouneedtobuyone.
Firstadjustthehighspeedneedle:Engineruntimewillbeturnedonatfullthrottleposition,adjustthehighneedleand
watchthechangeofthetachometer,maketheenginerpmreachthemaxperminute.Engineworkinastablehighspeed
(pleasenote:donotlettheenginerunboundaryforalongtime,thisisabigdamageforengine).
Adjusttheidlespeedneedle:Thethrottlereturntotheidleposition,adjusttheidlespeedneedleandwatchthechange
ofthetachometer.Lettheengineruninastablestateofidlespeed(Advice17x8woodenpropelleridlespeedat
1800rpm).
Whennecessarytheidlemixtureadjustmentscrewjointadjustmentstoensuretheengineidlespeedstability,smooth
acceleration;Iftheengineisidlingstartdifficult(ExcludeCDIignitionpowershortage,excessivefuelcombustion
chamber,sparkplugproblemsandsoon).Thisshowsthatair-fuelratio(A/F)islowatidling,pleaseadjustidlemixture
adjustmentscrew,increaseairratio,oradjustidlingneedletoreducetheamountoffuel,A/Fratiotoachieve
appropriateproportion.(Tip:Thelargerenginepropeller,themoreperfectloweridlespeedyouwillget.)
Whentheenginehighspeedandidlespeedadjustmentiscompleted,trytoruntheengineaccelerationperformance.
Firstlettheenginetorun10secondsatidlingandthequicklymovethethrottlecontrolarmatfullthrottleposition,
therewillbethefollowingthreesituations:
A.Enginespeedisresponsiveandsmoothtransitiontothehighestspeed,instructionsfortheadjustmentoftheengineis
verygood.
B.Engineaccelerationhasacoughperformance,graduallytransitiontothehighestspeed,illustratetheidlespeed
needlesetrelativelyrichoil,theidlespeedneedletomakeasmalladjustment(clockwiserotation),andthentryagain,
trytoacceleratethereactionconstantadjustmentuntiltheenginereachesyourrequest.
C.Rapidthrottlewhentheenginesuddenlystoppedrunning,thisshowsthattheidlespeedneedlesetrelativelyleanoil,
theidlespeedneedletomakeasmalladjustment(anticlockwiserotation),andthentryagain,trytoacceleratethe
reactionconstantadjustmentuntiltheenginereachesyourrequirements.
3
TheFuelTankConnecting
Fueltankconnectiondiagram
Valveclearanceadjustment:
After
approximately
2
hours
flight,
valve
clearance
adjustment
may
be
necessary.
Before
adjusting
valve
clearance
,
should
check
valvebodytomovefreely,noclampingstagnationphenomenon.
Duetothethermalexpansionofmetalmaterials,valveclearance Valveclearanceadjustmentdiagram
adjustmentshouldbecarriedoutafterenginehascooledcompletely.
Adjustthevalvesmustbeintheengine scompressionstroke(Intake
andexhaustvalvesinafullyclosedposition).Whenadjustmentis
completed,makesureyoutightenthehexagonalnut.
Howtoadjustthevalveclearance:
Removetherockerarmcover;revolvethepropellerslowlybyhandandalignwithTDCmark.Meanwhilethemarker
onthecamshaftisdirectlybelow.Inthisposition,takeasmallsheet(thickness0.06-0.1mm)intobetweenrockerand
valve.Withahexagonalwrenchadjustment,afterthat,tightenthehexnut(notethehexagonalnutshouldnotbe
screwedtootight),asshowninthefigurebelow.
Thevalveclearanceisthemostimportantfactorinthemaintenanceoffour-strokeengines,andoperationwithan
excessclearancewilldegradeperformance.Inparticular,alargegapaggravatesabrasionofthetappetwillmadethe
camincreasestheunusualsound;asmallgap(ornogap)isalsoinfluencetheperformanceoftheengine,sothatthe
valvedoesnotclosetightlyresultingthecompressionstrokeairleaks.
Engineinstallation:
NGH-GF304-strokeengineneedtouserailbracketmountonasuitableRCaircraft.Itcaneffectivelyreducethehigh
frequencyvibrationoffour-strokeenginerunningatahighspeed.Asshownbelow:
Notice: PleasemakesuretoinstallafirewallonthebackofRCaircraftusingmetalflatwasherorratchetnuttoprevent
thepawlboltintoplywood.Besuretocheckbeforeyouflyifthereareloosebolts.
4
Startingtheengine:
1.Accordingtheengineconnectionmethod,installtheengineonRCairplaneandlockpropellers.
Madethecarburetorinitialsetupandconnectthesparkplug,electronicignitionandsensors,putthefuelintotheoil
tank,connectthepowerandradiocontrolequipment.
2.Powerofftheelectronicigniteratthistimeandclosethecarburetorchoke.Rapidlyrotatingthepropellerofthe
engineandmakethefuelinthetanksuckedintocarburetor,pleasepayattentiontothesuctionofthefuelshouldnot
betoomuch,otherwisewilldrownthesparkplug,theenginestartdifficult.
3.Pleaseopenthecarburetorthrottleairinlet,powerontheelectronicigniter,thenstarttheengineusingthemotor
starter,theenginewillbegintowork,thefanswilladjustthecarburetoraccordingtoyourownneed.Accordingto
theabovestepstoadjustthecarburetoradjustment
Warning: Makesureallbystanders,especiallychildren,atleast15mawayfromrotatingengine.
EngineBreak-in:
Pleaseusehighqualitysyntheticoils,gasolineandmachineoilwithmixingratio35:1.NGHisrecommendedtouse
smallersizepropellersatfirstbreak-inandfollow-upabout10timesinflight.Keepmediumspeedrunningfor15
minutes(nomorethan4000rpm)afterstartedengine,thenhighspeedrunning(6500rpm)for3minutes,atlastmedium
speedrunningfor5minutes,highspeedrunningfor3minutes,reciprocating3-5timescompletebreak-in.Breakingin
enginecarefullywillincreaseitslife.Pleasemakesuretheenginegotthecompletebreak-inbeforeyouusethelarger
loadpropeller.
Enginecooling:
Ifenginebeinginstalledinthefairing,theremustbeenoughairbeingpulledintocooltheengine,andit'snecessaryto
assureenoughairflowinginthefaring.
Referencedata:Outletareashouldbe3-5timesbiggerthantheentranceareatoensureadequatecooling.
EngineFailureRemoval:
Iftheengineisdifficulttostart,oridlespeedorunstableinhighspeed.Pleasecheck:whethertheelectriccircuitandoil
lineofengineistrouble,whethertheengineleaksair,whethertheelectronicignitionworksoritspowersupplyis
adequate,whetherthesparkplugflameout.Ifnecessary,replacewithanewsparkplug.
Ruleoutenginefailure:
Iftheengineisdifficulttostart,oridlespeedorunstableinhighspeed.Pleasecheck:whethertheelectriccircuitandoil
lineofengineistrouble,checkiftheengineleaksair,oriftheelectronicignitionworks,orifitspowersupplyis
adequate,orifthesparkplugflameoutorifthecapisstickitsrightposition.Ifnecessary,replacewithanewspark
plug.
EngineMaintenance:
Toreducethefuelconsumption,extendengine slife,pleaseadjusttheengine shighestspeedandmakeenginerunin
theoutputmaximumspeedof90%oncethegaspedalfullopened.Iftheloadislarge(Propeller sdiameterandscrew
pitcharebig),thefuelmustbeadequate.Iftheloadissmall,thespeedwillbehighwhilethefuelconsumptionwillbe
less;Pleasemakesuretoemptythecarburetoraftereachflight,otherwiseit llcausetherubberofcarburetoragingto
affecttheengineperformance;Pleasecleanthecarbondepositiononthesparkplugandkeepthegapfrom0.7mmto
0.8mmbetweentheelectrodes;Ifit sdifficulttostarttheengine,idlespeedunstableorwhenhighspeedoperation
flameout,pleasereplacethesparkplugs;Pleasecleantheenginesurfaceafterusedeachtime,itcanmaketheengine
getbettercooling;Thecarburetormaybeblockedseriouslyifyouusedifferentbrandsortypesoflubricatingoil
together,youneedselectabetterfuelfilter;Iftheenginelowspeedworkforalongtime,canleadtosparkplugcarbon
deposition;Regularlycheckthefuelsystem,makesuredonotleakfuel,donotleakair.
EngineGuarantee:
IftheNGHenginehasperformancedefectscausedbythedefectsofprocess,materialandmanufacturing,wecertify
that:ChangeforfreewithinoneyearandGuaranteewithintwoyearssincethedateyoupurchased.Pleasenotethe
guaranteeisonlyfortheoriginalpurchaser,notincluding:Normalwearforengine;damagecausedbythefailureof
maintenance;damageforengineoverspeedoperationcausedbyusingsmallpropeller;Bearingrust;Crash;Use
inappropriatefuel;Damagecausedbyforeignbodies;Damagecausedbyunreasonableinstallationoroperating
environment;Damagecausedbyimproperdismantle;Damagecausedbyanymodification.
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