Maintenance
RemovingtheSparkPlug
1.DisengagethePTOandensuretheparkingbrake
isengaged.
2.Stoptheengine,removethekey,andwaitforall
movingpartstostopbeforeleavingtheoperating
position.
3.Disconnectthewirefromthesparkplug.
g027478
Figure55
Note:Duetothedeeprecessaroundthespark
plug,blowingoutthecavitywithcompressedair
isusuallythemosteffectivemethodforcleaning.
Thesparkplugismostaccessiblewhentheblower
housingisremovedforcleaning.
CheckingtheSparkPlug
1.Inspectthesparkplug
Note:Ifyouseelightbrownorgrayonthe
insulator,theengineisoperatingproperly.A
blackcoatingontheinsulatorusuallymeansthe
aircleanerisdirty.
Important:DoNotcleanthesparkplug(s).
Alwaysreplacethesparkplug(s)whenithas:
ablackcoating,wornelectrodes,anoilylm,
orcracks.
g027479
Figure56
1.Centerelectrode
insulator
3.Airgap(nottoscale)
2.Sideelectrode
2.Checkthegapbetweenthecenterandside
electrodes.
3.Setthegapto0.030inch(.76mm).
InstallingtheSparkPlug
1.Installthesparkplug.Makesurethattheairgap
issetcorrectly.
2.Tightenthesparkplugto18.5–22.1ft-lb(25–30
N-m).
g027960
Figure57
3.Pushthewireontothesparkplug.
CheckValveClearance
ServiceInterval:Every300hours—Check
valveclearance(Exmark
engine).
ContactanAuthorizedServiceDealer.
•Intake:.004–.006inches(.10–.15mm)
•Exhaust:.006–.008inches(.15–.20mm)
CheckandCleanCombustion
Chamber
ServiceInterval:Every300hours—Check
andcleancombustion
chamber(Exmarkengine).
ContactanAuthorizedServiceDealer.
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