Operator's Manual

ServicingtheSparkPlug
ServiceInterval:Every50hours—Checkthespark
plug.
Every100hours—Replacethesparkplug.
Ensurethattheairgapbetweenthecenterandside
electrodesiscorrectbeforeinstallingthesparkplug.
Useasparkplugwrenchforremovingandinstalling
thesparkplugandagappingtoolorfeelergaugeto
checkandadjusttheairgap.Installanewsparkplug
ifnecessary.
Type:Champion
®
RC12YCorAutolite
®
3924
AirGap:0.75mm(0.03inch)
RemovingtheSparkPlug
1.Parkthemachineonalevelsurface,disengage
theblade-controlswitch,andmovethe
motion-controlleversoutwardtothePARK
position.
2.Shutofftheengine,removethekey,andwait
forallmovingpartstostopbeforeleavingthe
operatingposition.
3.Cleantheareaaroundthebaseoftheplugto
keepdirtanddebrisoutoftheengine.
4.Removethesparkplug(Figure44).
g027478
Figure44
CheckingtheSparkPlug
Important:Donotcleanthesparkplug(s).
Alwaysreplacethesparkplug(s)whenithasa
blackcoating,wornelectrodes,anoilylm,or
cracks.
Ifyouseelightbrownorgrayontheinsulator,the
engineisoperatingproperly.Ablackcoatingonthe
insulatorusuallymeanstheaircleanerisdirty.
Setthegapto0.75mm(0.03inch).
g206628
Figure45
InstallingtheSparkPlug
g027480
Figure46
CleaningtheBlower
Housing
ServiceInterval:Every100hours/Yearly(whichever
comesrst)
Toensurepropercooling,ensurethatthegrass
screen,coolingns,andotherexternalsurfacesofthe
enginearekeptcleanatalltimes.
Cleanthecoolingnsandexternalsurfacesas
necessary.Makesurethatthecoolingshroudsare
installed.T orquetheblowerhousingscrewsto7.5
N∙m(5.5ft-lb).
Important:Operatingtheenginewithablocked
grassscreen,dirtyorpluggedcoolingns,and/or
coolingshroudsremoved,causesenginedamage
duetooverheating.
34