8/3/2019 STIHLCARBSETTINGS

1/1

CarburetorSettingsforaStihlChainsawSCREW(H)CAUTION!Adjustmentofthehighspeedadjustingscrew(H)notonlyaffectsthepoweroutputbutalsothemaximumoff-loadenginespeed.Ifthesettingistoolean(screwturnedtoofarclockwise),themaximumpermissibleenginespeedwillbeexceeded.Thiscancauseenginedamage,broughtaboutbylackoflubricationandoverheatinginparticular.Correctionstothesettingofthehighspeedadjustingscrewmay

becarriedoutonlyifanaccuratetachometerisavailabletocheckthemaximumenginespeedof13,000rpm(withbarandcorrectlytensionedchain).Whentheengineistestedatthefactorythecarburetorissettoobtainaslightlyrichermixturetoensurethatthecylinderboreandthebearingsreceiveadditionallubricationduringthebreak-inperiod.Thissettingshouldbeleftasitisforthefirstthreetankfillings.Thehighspeedadjustingscrewmaythenbeturnednomorethan1/4turnclockwise(leanermixture).Caution:Theenginesmaximumpermissiblerpmmustnotbeexceeded!Notethatevenslightalterationsontheadjustingscrewshaveanoticeableeffectontheenginesrunningbehavior.Onlycarryoutcarburetoradjustmentsaftercleaningtheairfilterandwarminguptheengine.Ifyouhavenomeansofcheckingthemaximumenginespeed,donotsetthehighspeedadjustingscrew(H)anyleanerbyturningit(clockwise)beyondthebasicsetting

below!SafeBasicSettingForScrews(H)&(L)CarefullyscrewthetwoadjustingScrews(H)&(L)downontotheirseats(clockwise).Then:Highspeedadjustingscrew(H):backoff1completeturnLowspeedadjustingscrew(L):backoff1completeturnBasicSettingForScrew(LA)Turnidlespeedadjustingscrew(LA)untilthechainstops.Thenturncounter-clockwiseonequarterofaturn.FineTuningScrew(L)Erraticidlingbehavior;pooraccelerationIdlesettingtoolean;turnlowspeedadjustingscrew(L)counterclockwiseuntilenginerunsandacceleratessmoothly.Nowreadjustscrew(LA).ExhaustsmokesatidlespeedIdlespeedsettingtoorich;turnlowspeedadjustingscrew(L)clockwiseuntil

enginespeeddrops.Thenturnscrewbackonequarterturnandcheckthatenginestillacceleratessmoothlywhenyouopenthethrottle.Nowreadjustscrew(LA).StihlChainsawTroubleshootingGuide1.CompressionTestCanyouliftthesawoffthegroundwiththepullrope?2.FuelTest-Removeairfilterandcoverandspraystarterfluidinthecarburetorandtrytostart.Usea50:1fuelmixturewithpremiumfuel3.SparkTestRemovesparkplugcleanwithsolvent&wirebrush.Reconnectplugwireandletplughangclosetoengineblock(awayfromanygas)pullstarterropeandlookforspark,dimlightingmakesiteasiertosee.Ifnosparkreplaceplugandtryagain.Checkoff/onswitchandwirecomingfromcoil.Ifstillnosparkreplacecoil.(Oldersawscleanandadjustpointsfirst)4.Sawrunsonstarterfluid(seereplyfromDavidbelow)notongasintank.Checkgastankforoldgas,emptyoldgaslookforsyr

upgunkinthebottomofthetank,ifpresentcleanandrinseseveraltimesuntilclean(Iusecarburetorcleaner&gasandanybrushthatcanreachinandnotmel

t)Trytostartwithfreshgasmix.Ifitdoesntstartcheckandreplacefuellineandpick-up.Ifitstilldoesntstartremovecarburetorandcheckmanifoldboot(tubebetweencarburetorandengine)replaceifneededandtrytostart.Ifitstilldoesntstartremovecarburetor,disassembleandcleancarburetor,youmayhavetodisassembleandsoakinsolventovernighttrynottogetsolventorcarburetorcleanerongaskets.Checkgaskets,diaphragmgasketshouldbesmoothandpuffynotwrinkledorwiltedifindoubtreplace.Carburetorkitsarearound$8-$15andincludeallgaskets,needleandspring.Reassemble(makingsureallgasketsarepositionedproperly)andtrytostartifitstilldoesntstartreplacecarburetor.