Operator's Manual

ServicingtheSparkPlug
ServiceInterval:Every100hours—Checkthespark
plug.
Ensurethattheairgapbetweenthecenterelectrode
andthesideelectrodeiscorrectbeforeinstallingthe
sparkplug.Useaspark-plugwrenchforremoving
andinstallingthesparkplugandagappingtool/feeler
gaugetocheckandadjusttheairgap.Installanew
sparkplugifnecessary.
Models68034and68035:UseaDENSO
U16FSR-UBoranNGKCR5HSBsparkplug.
Model68036:UseaDENSOW14EPR-UoranNGK
BP4ESsparkplug.
RemovingtheSparkPlug
1.Shutoffthemachineandletitcool.
2.Disconnectthewirefromthesparkplug(Figure
23).
g014506
Figure23
1.Sparkplug
2.Wire
3.Cleanaroundthesparkplug.
4.Useaspark-plugwrenchtoremovethespark
plugandthemetalwasher.
CheckingtheSparkPlug
1.Lookatthecenterofthesparkplug(Figure24).
Ifyouseelightbrownorgrayontheinsulator,
theengineisoperatingproperly.Ablackcoating
ontheinsulatorusuallymeansthattheair
cleanerisdirty.
Important:Donotcleanthesparkplug.
Alwaysreplacethesparkplugwhenithasa
blackcoating,wornelectrodes,anoilylm,
orcracks.
g023105
Figure24
1.Sideelectrode4.0.60to0.70mm(0.024to
0.028inch)gap(Models
68034and68035)
2.Centerelectrode5.0.70to0.80mm(0.028
to0.031inch)gap(Model
68036)
3.Insulator
2.Checkthegapbetweenthecenterandside
electrodes(Figure24).
3.Ifthegapisnotwithinthespeciedrange,do
thefollowing:
A.Ifthegapistoosmall,carefullybend
thesideelectrodeawayfromthecenter
electrodeuntilthegapbetweenthe
electrodesiscorrect.
B.Ifthegapistoolarge,carefullybendthe
sideelectrodetowardthecenterelectrode
untilthegapbetweentheelectrodesis
correct.
InstallingtheSparkPlug
1.Threadthesparkplugintothespark-plughole.
2.Tightenthesparkplugto27N∙m(20ft-lb).
Important:Ensurethatthesparkplugis
tightenedtothespeciedtorquevalue.A
loosesparkplugmaycausedamagetothe
cylinder,whileanovertightenedsparkplug
maycausedamagetothecylinder-head
threads.
3.Connectthewiretothesparkplug.
20