NGH GF30 - Maintenance and Installation Procedures; Fuel Tank Connection; Valve Clearance Adjustment; Engine Installation Guidelines

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.