Stihl 021

Online version - not for reprint
-Removethechainsprocket
cover.
•
Disengagethechainbrakeby
pullingthehandguardtoward
thefronthandle.
•
RemovetheE-clip(1).
•
Removethewasher(2).
-Removetherimsprocket,iffitted.
•
Pullofftheclutchdrum/chain
sprocket.
•
Taketheneedlecageoutofthe
sprocket.
-Cleanandinspecttheclutch
drum/chainsprocket.
Important:Iftherearenoticeable
wearmarksontheinsidediameter
oftheclutchdrum,checkitswall
thickness.Ifitislessthan80%of
theoriginalwallthickness,fita
newclutchdrum.
Note:Iftheclutchdrumhastobe
replaced,alsocheckthebrake
band-see4.4.2.
•
Iftheclutchdrum/chainsprocket
isstillserviceable,useNo.120
emerypaperoremerycloth
(grainsizeapprox.120µm)to
cleanandroughenitsfriction
surface.
Reassembleinthereverse
sequence.
-Cleanstubofcrankshaft.
Washneedlecageincleanwhite
spiritandlubricatewithgrease-
see11.2.
-Replacedamagedneedlecage.
-Rotateclutchdrum/chain
sprocketandapplyslight
pressureatthesamesameuntil
oilpumpdrivespringengages
properly.
-Ifrimsprocketwasfitted,re-
installitwiththecavitiesfacing
outward.
4. CLUTCH,CHAINDRIVE,CHAINBRAKE,CHAINTENSIONER
4.1 ClutchDrum/ChainSprocket
VA
143RA007
VA
170RA005
80%
100%
145RA006
!
VA
6 021,023,025