Stihl FS 45 - Oil Seals

Oilsealstendtofailwhen
subjectedtoavacuum,i.e.the
sealinglipliftsawayfromthe
crankshaftduringthepiston’s
inductionstrokebecausethere
isnointernalcounterpressure.
Anadditionaltestcanbecarried
outwiththevacuumpumpto
detectthiskindoffault.
-Carryoutpreparations-
see5.3.1.
•
Connectthesuctionhoseof
vacuumpump00008503501
totestflangenipple.
•
Closeventscrew(1)on
pumpcylinder.
•
Operatelever(2)untilthe
gauge(3)indicatesavacuumof
0.5bar(7.25psi).
Note:Ifthevacuumreading
remainsconstant,orrisestono
morethan0.3bar(4.25psi)within
20seconds,itcanbeassumed
thattheoilsealsareingood
condition.
However,ifthepressurecontinues
torise(reducedvacuuminthe
crankcase),theoilsealsmustbe
replaced.
-Afterfinishingthetest,openthe
ventscrewanddisconnectthe
hose.
-Removethetestflange.
-Slackenoffthemufflerscrews.
-Removethesealingplateand
tightenscrewsto9.0Nm
(6.6lbf.ft)festziehen.
-Installthecarburetor-see9.2.2.
-Fittheshroud.
Itisnotnecessarytodisassemble
thecompleteenginetoreplacethe
oilseals.
Starterside:
-Removethestartercup-see7.4.
-Removetheenginehousing-
see4.1.
•
Applythepuller(1)
59108904400(withNo.3.1
jaws00008933706).
-Tensionthearms.
-Pullouttheoilseal.
Important:Takecarenotto
damagecrankshaftstub.
-Cleansealingsurfacewitha
standardsolvent-baseddegrea-
santcontainingnochlorinatedor
halogenatedhydrocarbons-
see11.2.
-Lubricatesealinglipsofoilseal
withgrease-see11.2.
5.3.3 VacuumTest 5.4 OilRings
VA
232RA038
1
VA
232RA037
1
2
3
VA
232RA035
12 FS45