Stihl Hs81 Hs86 Service Manual

STIH)

STIHL HS 81, 86

2005-10

Contents

1.

2.

Foreword Safety

3

Specifications

5

3.1 3.2 3.3 3.4

Power unit Fuel system Ignition system Tightening torques

5 5 5 6

4.

Troubleshooting

8

4.1 4.2 4.3 4.4 4.5 4.6

Clutch Cutting attachment Rewind starter Ignition system Carburetor Engine

8 9 10 11 12 14

5.

Cutting attachment

15

5.1

Removal and installation, trimmer versions 15 Removal and installation, cutter versions 18 Disassembly of cutting attachment HS 81 20 Disassembly of cutting attachment HS 86 22 Disassembly HS 81 T/ HS 86 T, adjustment set for blade clearance 25

5.3 5.4 5.5

6.

Gear

6.1

Gear wheel, trimmer versions Gear wheel, cutter versions Drive pinion Bearing Gear housing Grease gearbox

6.2 6.3 6.3.1 6.4 6.5 7.

Clutch

7.1

Removal and installation Clutch drum, trimmer versions Clutch drum cutter versions

7.2 7.3

Engine

8.1

8.6 8.6.1 8.6.2 8.7

Muffler, spark arresting screen Leakage testing Preparations Vacuum test Pressure test Oil seals Complete engine Removal and installation Engine housing Crankshaft Removal Installation Ball bearing, crankcase Piston Removal Installation Piston rings

9.

Ignition system

9.1 9.1.1

Ignition module 54 Removal and installation 54 Ignition timing 55 Testing the ignition module 56 Spark plug terminal / ignition lead 57 Flywheel 58 Short circuit wire 59 Testing 59 Removal and installation, engine side 59 Removal and installation, handle side, HS 81 61 Removal and installation, handle side, HS 86 63 Troubleshooting chart, ignition system 65

4

3.

5.2

8.

26

8.2 8.2.1 8.2.2 8.2.3 8.3 8.4 8.4.1 8.4.2 8.5 8.5.1 8.5.2 8.5.3

9.2 9.3 9.4 9.5 9.6 9.6.1 9.6.2 9.6.3 9.6.4

26 9.7 28 29 30 31 31 32

36 37 38 38 39 40 41 41 42 43 43 45

54

Rewind starter

68

10.1 10.2 10.3 10.4 10.5

General Pawls Rope rotor Starter rope / grip Tensioning the rewind spring Replacing the rewind spring Starter rope guide bushing

68 68 69 70

10.6 34 10.7

11.

Anti-vibration system, repair

74

11.1

Rear anti-vibration buffer, cutter versions 74 11.2 Front anti-vibration buffer, cutter versions 75 11.3 Springs 76 11.4 Handle frame HS 81 77 11.4.1 Handlebar HS 81 77 11.5 Handle frame HS 86 78 11.6 Exhaust pipe 79 12.

Operating levers

79

12.1 49 50 50 51 53

10.

32

35

36

70

Throttle trigger / throttle trigger interlock HS 81 79 12.2 Twist lock HS 81 81 12.3 Starting throttle lock HS 81 82 12.4 Handle mouldings HS 81 82 12.5 Throttle trigger / throttle trigger interlock HS 86 84 12.5.1 Slide control 85 12.5.2 Handle mouldings HS 86 86 13.

Fuel system

13.1 13.2 13.3 13.3.1

Air filter 87 Filter housing 88 Carburetor 89 Removal and installation 89 Choke lever 90 Leakage testing 90 Servicing the carburetor 91 Metering diaphragm / hand pump 91 Inlet needle 92 Fixed jet 93 Pump diaphragm 94 Adjusting screws 95 Carburetor adjustment 96 Basic setting 96 Standard setting 97 Spacer flange, removal and installation 98 Tank vent 99 Check 99 Removal and installation 100

13.3.2 13.3.3 13.4 13.4.1 13.4.2 13.4.3 13.4.4 13.4.5 13.5 13.5.1 13.5.2 13.6 13.7 13.7.1 13.7.2

87

71 73

q Š ANDREAS STIHL AG & Co. KG, 2005

HS 81, HS 86

1

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Contents

13.8 13.8.1 13.8.2 13.8.3 13.8.4

Fuel intake Pick-up body Fuel hoses Fuel filler cap Fuel tank, removal and installation

104

14.

Special tools

105

15.

Servicing accessories

107

2

101 101 102 103

HS 81, HS 86

Foreword

This service manual contains a detailed description of all the typical repair work required for this power tool.

The illustrated spare parts lists should also be consulted when carrying out repairs, for they show the installed position and sequence of assembly for the individual parts.

The latest edition of the respective parts lists should always be used when determining the part numbers of the required replacement parts.

Faults in the machine may be due to several causes. Refer to the chapter "Troubleshooting" and the "STIHL Service Training System" for troubleshooting procedures for all function groups.

Refer to the "Technical Information" bulletins for engineering changes which have been introduced since publication of this service manual.

Technical information bulletins supplement the parts list and service manual until a new edition is published.

The special tools mentioned in the text are listed in the chapter "Special tools" in this manual. The tools can also be identified in the manual "STIHL special tools" on the basis of their part number. This manual lists all the tools supplied by STIHL. The following graphic symbols are used in the text and illustrations in order to make this manual easier to use and understand: In the text: : = Activity to be carried out as shown in the picture above the text. – = Activity to be carried out but not shown in the picture above the text.

2 1 3

4 1

442RA000 TG

1.

Repairs can be carried out more easily by mounting the power tool on the assembly stand (3) 5910 890 3100. The clamping plate (2) 5910 894 2102 is secured to the assembly stand with two screws (1) for this purpose.

The third screw hole (4) allows the clamping plate to be secured horizontally as well.

A Pointer (short arrow)

The power tool is secured by means of the three DG screws from the fan housing (arrows) on the fan side of the machine.

aDirection of movement (long arrow)

The fan housing must first be removed.

b 4.2 = Reference to another chapter, in this case to chapter 4.2

It is also possible to secure the power unit on the clutch side after removal.

In the illustrations:

442RA001TG

Service manuals and technical information bulletins should always be on hand wherever professional repairs are carried out. They must not be passed on to third parties.

Secure the power unit to the smaller recess in the clamping plate with the three DG screws (arrows) from the screw connection between gear housing and crankcase.

HS 81, HS 86

3

2.

Always use original STIHL replacement parts.

Original STIHL parts can be identified by the STIHL part number, the STIH) logo and the STIHL parts symbol ( This symbol may appear alone on small parts.

Safety

Specific national safety regulations and the safety instructions in the instruction manual must be observed if the power tool has to be started up during repairs or maintenance work.

Petrol is highly inflammable and may explode under certain conditions.

Incorrect handling may result in severe burns and other serious injuries.

Always wear suitable gloves if parts are heated for assembly / disassembly.

Keep away from sources of heat, sparks and naked flames. Fuel may only be handled out of doors.

Spilled fuel must be wiped away immediately.

4

HS 81, HS 86

3.

3.1

Specifications

Power unit HS 81

Displacement: Bore: Piston stroke: Power output to ISO 7293: Max. permissible speed: Idle speed: Clutch: Clutch engages at: Crankcase leakage test at gauge pressure: under vacuum:

3.2

22.7 cmÂł 22.7 cmÂł 34 mm 34 mm 25 mm 25 mm 0.7 kW (1.0 HP) 0.7 kW (1.0 HP) at 7000 rpm at 7000 rpm 9100 rpm 9100 rpm 2800 rpm 2800 rpm Centrifugal clutch without linings 4000 rpm 4000 rpm 0.5 bar 0.5 bar

Fuel system Carburetor leakage test at gauge pressure: Operation of tank vent at gauge pressure: Fuel:

3.3

HS 86

0.8 bar 0.3 bar As specified in the instruction manual

Ignition system Air gap between ignition module and fanwheel: Spark plug (suppressed): Electrode gap:

HS 81, HS 86

0.15 ... 0.40 mm Bosch USR 7AC 0.5 mm

5

3.4

Tightening torques

DG screws are used in thermoplastic and alloyed materials. These screws cut a thread in the material when they are screwed in for the first time. The material is permanently deformed. The screws can be removed and refitted as often as desired. The strength of the screw connection is not impaired if the specified tightening torque is maintained.

It is therefore essential to use a torque wrench.

Fastener

Thread size

For component

Screw

P 6x18

Screw

M 8x 1 Li M 5x30

Screw

P 4x16

Screw

D 5x20

Screw

D 5X20

Screw Screw Nut

P 6x18 M 5x21 M5

Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw

M 6x18 D 5x24 D 5x24 P 6x18 P 6x19 P 5x18 D 4x18 D 5x24 D 5x20 P 6x18 M 5x25 M 5x25 M 8x 1 LI D 5x20 P 3.5x9 D 5x24 P 6x18 M 8x1 P 6x18 D 4x18 M14x1.25

Stop / handle frame / tank (HS 81R, HS 86R) Drive pinion / hub (trimmer versions) Control handle / lock nut (with washer) (HS 86) Control handle / outer / inner handle moulding (HS 86) Spring / stop buffer / gear housing (HS 81R, HS 86R) Spring / gear housing (HS 81T, HS 86T) Spring / handle frame Filter cover / filter housing Filter housing / carburetor / spacer flange Clutch shoe / carrier Gearbox cover / gear housing Gear housing / crankcase Handle frame / fuel tank Handlebar / handle frame (HS 81) Handle mouldings (HS 81) Retainer / rubber buffer / gear housing Crankcase drive side / ignition side Fan housing / crankcase, fan side Fan housing / engine housing Blade / lock nut (with washer) Blade / reinforcement / lock nut Carrier / crankshaft Engine housing / gear housing Detent spring / slide control (HS 86) Muffler / cylinder Screw / handle frame Flywheel / crankshaft Strut / handle frame Exhaust pipe / gear housing Exhaust pipe / muffler

Screw Collar screw Screw Screw Nut Screw Screw

6

Tightening torque Remarks (Nm) 4.0 15.0 3.0 1.3 6.0 6.0 4.0 3.5 4.0 12.0 9.0 9.0 4.0 4.0 4.0 4.5 9.0 6.0 6.0 8.0 8.0 25.0 6.0 1.1 9.0 4.0 25.0 4.0 4.5 10.0

HS 81, HS 86

Screw Screw Screw Screw Screw

M11x 8 M 5x30 M 10x 1 D 4x18 D 5x45 D 5x24

Screw plug / gearbox cover Reinforcement / guide / gear housing Spark plug Ignition module / cylinder Spacer flange / cylinder Cylinder / crankcase

6.0 9.0 9.0 4.0 6.0 9.0

Remarks: 1) Loctite 243 medium strength 2) Loctite 270 normal strength 3) Loctite 272 high strength up to 250 °C 4) Connection between crankshaft and flywheel must be degreased and oil-free

Screwdriver speed: Plastoform screws max. 600 rpm, DG screws max. 500 rpm When inserting the DG and P-type screws in an existing thread: Insert the DG or P-type screw in the hole and turn it anticlockwise until it gently drops into the hole in axial direction. Turn the screw in clockwise and tighten with the specified torque.

This ensures that the screw engages the existing thread and does not cut a new thread, thus preserving the strength of the screw connection.

An impact wrench must not be used to unscrew or tighten the screw connections!

Screws with and without locking serration must not be confused.

HS 81, HS 86

7

4.

4.1

Troubleshooting Clutch

Condition

Cause

Remedy

Blades stop under load at full throttle

Clutch shoes badly worn

Install new clutch shoes or clutch

Clutch drum badly worn

Install new clutch drum

Blades deformed

Replace blade

Engine idle speed too high

Adjust idle speed screw LA (anticlockwise)

Blades run at idle speed

Clutch springs stretched or fatigued Replace clutch springs or install new clutch Clutch spring hooks broken Loud noises

8

Replace clutch springs

Clutch springs stretched or fatigued Replace all clutch springs Ball bearing of drive pinion damaged

Replace ball bearing

Clutch shoe retainer broken

Install new clutch

Clutch shoes and carrier worn

Install new clutch

Gearbox is dry

Examine gear for signs of damage and lubricate

HS 81, HS 86

4.2

Cutting attachment

Condition

Cause

Remedy

Blades move stiffly

Blades run dry

Clean running surface of blades and coat with resin solvent

Guide screws over-tightened (version with adjustable blade clearance)

Adjust blade clearance

Spacer sleeves missing or create too little space

Examine sleeves, install or replace if necessary

HS 81, HS 86

9

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• Thank you very much for reading the preview of the manual.

• You can download the complete manual from: www.heydownloads.com by clicking the link below

• Please note: If there is no response to CLICKING the link, please download this PDF first and then click on it.

CLICK HERE TO

DOWNLOAD THE COMPLETE MANUAL