Stihl 021 Service & Repair Manual

Online version - not for reprint
1. SafetyPrecautions1
2. Introduction 2
3. Specifications 3
3.1 Engine 3
3.2 FuelSystem 3
3.3 IgnitionSystem 4
3.4 CuttingAttachment 4
3.5 SpecialAccessories 4
3.5.1 ForUser 4
3.5.2 ForService 4
3.6 TighteningTorques 5
4. Clutch,ChainDrive,
ChainBrakeand
ChainTensioner 6
4.1 ClutchDrum/
ChainSprocket 6
4.2 ChainCatcher 7
4.3 Clutch 7
4.4 ChainBrake 8
4.4.1 CheckingFunction 8
4.4.2 Disassembly 8
4.4.3 Assembly 10
4.5 FrontChainTensioner12
4.6 SideChainTensioner12
5. Engine 13
5.1 ExhaustMuffler/Spark
ArrestingScreen 13
5.2 LeakingTest 14
5.2.1 Preparations 14
5.2.2 PressureTest 15
5.2.3 VacuumTest 15
5.3 OilSeals 16
5.4 Removingand
Installing 18
5.5 Cylinder 18
5.6 Piston 20
5.7 PistonRings 22
5.8 Crankshaft 22
5.9 ConnectingRod
(021uptoSerialNo.
X34944402) 23
5.10 DecompressionValve24
6. IgnitionSystem 24
6.1 SparkPlugBoot 24
6.2 IgnitionLead 25
6.3 IgnitionModule 25
6.3.1 IgnitionTiming 26
6.3.2 Removingand
Installing 26
6.4 Flywheel 27
7. RewindStarter 28
7.1 RoutineMaintenance 28
7.2 RewindSpring 28
7.2.1 Replacing 28
7.2.2 Tensioning 29
8. AVHandleSystem/
HandleHousing 30
8.1 AnnularBuffers 30
8.2 FrontHandle 31
8.3 HandleHousing 31
8.4 SwitchShaft 33
8.5 ContactSpring 34
8.6 ThrottleTrigger/
InterlockLever 34
9. ChainLubrication 36
9.1 PickupBody36
9.2 Connector/
SuctionHose 36
9.3 VentValve 37
9.4 Worm 38
9.5 OilPump 38
10. FuelSystem 39
10.1 AirFilter 39
10.2 Carburetor 41
10.2.1LeakageTest 41
10.2.2Removingand
Installing 42
10.2.3Adjustment(except
023LandUSA) 43
10.2.4Adjustment
(023LandUSA) 44
10.3 TankVent 45
10.4 PickupBody 46
10.5 SuctionHose 46
10.6 ManualFuelPump 47
10.6.1FuelHoses 47
10.7 FuelTank 48
11. SpecialServicing
ToolsandAids 50
11.1 SpecialServicingTools50
11.2 ServicingAids 52
1. SAFETY
PRECAUTIONS
Ifthechainsawisstartedupinthe
courseofrepairsormaintenance
work,observealllocalandcountry-
specificsafetyregulationsaswell
asthesafetyprecautionsand
warningsintheowner’smanual.
Gasolineisanextremelyflamm-
ablefuelandcanbeexplosivein
certainconditions.
Improperhandlingmayresultin
burnsorotherseriousinjuries.
Warning!Donotsmokeorbring
anyfireorflamenearthefuel.All
workwithfuelmustbeperformed
outdoorsonly.Spilledfuelmustbe
wipedawayimmediately.
Washhandsthoroughlyafter
everycontactwithwasteoil.
Donotpourwasteoildownthe
drainorallowittosoakintothe
ground.
Collectwasteoilandtakeittoan
officialdisposalsiteforenviron-
ment-friendlydisposal.
©2000 AndreasStihlAG&Co.,Waiblingen
021,023,025
CONTENTS
021,023,025 1

Stihl 021 Specifications

General

Brand	Stihl
Model	021
Category	Chainsaw
Language	English