Note:Duetothedeeprecessaroundthespark
plug,blowingoutthecavitywithcompressedair
isusuallythemosteffectivemethodforcleaning.
Thesparkplugismostaccessiblewhentheblower
housingisremovedforcleaning.
3.Removethesparkplugandmetalwasher.
Figure28
1.Sparkplugandwirelocation
CheckingtheSparkPlug
ServiceInterval:Every200hours—Checksparkplug
conditionandgap.
Every2years—Checksparkplug
conditionandgap.
1.Lookatthecenterofthesparkplug(Figure29).
Ifyouseelightbrownorgrayontheinsulator,the
engineisoperatingproperly.Ablackcoatingonthe
insulatorusuallymeanstheaircleanerisdirty.
Important:Nevercleanthesparkplug.Always
replacethesparkplugwhenithasablack
coating,wornelectrodes,anoilylm,orcracks.
2.Checkthegapbetweenthecenterandsideelectrodes
(Figure29).Bendthesideelectrode(Figure29)if
thegapisnotcorrect.
Figure29
1.Centerelectrodeinsulator3.Airgap(nottoscale)
2.Sideelectrode
InstallingtheSparkPlug
ServiceInterval:Every500hours—Replacethespark
plug.
1.Installthesparkplug.Makesurethattheairgapis
setcorrectly.
2.Tightenthesparkplugto30ft-lb(41N-m).
3.Pushthewireontothesparkplug(Figure28).
CleaningtheBlowerHousing
ServiceInterval:Beforeeachuseordaily—Checkair
intakeandcoolingareas(cleanas
necessary).
Every100hours—Cleantheblower
housing(moreoftenunderextremely
dusty,dirtyconditions).
Toensurepropercooling,makesurethegrassscreen,
coolingns,andotherexternalsurfacesoftheengine
arekeptcleanatalltimes.
Removetheblowerhousingandanyothercooling
shrouds.Cleanthecoolingnsandexternalsurfacesas
necessary.Makesurethecoolingshroudsarereinstalled.
Torquetheblowerhousingscrewsto5.5ft-lb(7.5N-m).
Important:Operatingtheenginewithablocked
grassscreen,dirtyorpluggedcoolingns,and/or
coolingshroudsremoved,willcauseenginedamage
duetooverheating.
27