ServicingtheSparkPlug(s)
ServiceInterval:Every100hoursoryearly,
whichevercomesrst—Replaceor
cleanandgapthesparkplug.
Ensurethattheairgapbetweenthecenterandside
electrodesiscorrectbeforeinstallingthesparkplug.
Useasparkplugwrenchforremovingandinstalling
thesparkplugandagappingtoolorfeelergaugeto
checkandadjusttheairgap.Installanewsparkplug
ifnecessary.
TypeofSparkPlug:BriggsandStratton491055
AirGap:0.75mm(0.03inch)
RemovingtheSparkPlug(s)
1.Parkthemachineonalevelsurface,disengage
theblade-controlswitch(PTO),andengagethe
parkingbrake.
2.Shutofftheengine,removethekey,andwait
forallmovingpartstostopbeforeleavingthe
operatingposition.
3.Cleantheareaaroundthebaseoftheplugto
keepdirtanddebrisoutoftheengine.
4.Locateandremovethesparkplug(s)asshown
inFigure49.
g009922
g027478
Figure49
CheckingtheSparkPlug(s)
Important:Donotcleanthesparkplug(s).
Alwaysreplacethesparkplug(s)whenithasa
blackcoating,wornelectrodes,anoilylm,or
cracks.
Ifyouseelightbrownorgrayontheinsulator,the
engineisoperatingproperly.Ablackcoatingonthe
insulatorusuallymeanstheaircleanerisdirty.
Setthegapto0.75mm(0.03inch).
g206628
Figure50
InstallingtheSparkPlug(s)
g027661
Figure51
43