Stihl MS 500i User manual

2020-01
STIHL MS 500i Service Manual

Printed on chlorine-free paper Printing inks contain vegetable oils, paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2020 RA_004_2018_01_01. VA4.A20. 0000008112_006_GB
MS 500i 1
This service manual is protected by copyright. All rights reserved, especially the rights to reproduce, translate and process with electronic
systems.
Contents
1 About this Service Manual 3
1.1 Applicable Documentation 3
1.2 Symbols in Text 3
2 Safety During Repair Work 3
2.1 Protective gloves 3
2.2 Safety glasses 3
2.3 Replacement Parts 3
2.4 Screws 3
3 Preparations for Repair 3
3.1 Preparations 3
4 Troubleshooting Guide 4
4.1 Troubleshooting Guide 4
5 Spiked Bumper, Chain Catcher 5
5.1 Tools, Servicing Aids 5
5.2 Removing the Chain Catcher 5
5.3 Installing the Chain Catcher 5
5.4 Removing the Spiked Bumper 5
5.5 Installing the Spiked Bumper 5
6 Bar Mounting Studs 6
6.1 Tools, Servicing Aids 6
6.2 Removing the Bar Mounting Studs 6
6.3 Installing the Bar Mounting Studs 6
7 Filter Cover, Shroud 7
7.1 Tools, Servicing Aids 7
7.2 Removing the Twist Lock 7
7.3 Installing the Twist Lock 7
7.4 Removing the Stop Buffer 7
7.5 Installing the Stop Buffer 7
7.6 Removing the Shroud Lock 7
7.7 Installing the Shroud Lock 7
8 Decompression Valve 8
8.1 Tools, Servicing Aids 8
8.2 Removing the Decompression Valve 8
8.3 Installing the Decompression Valve 8
9 Handle 9
9.1 Tools, Servicing Aids 9
9.2 Removing the Handlebar 9
9.3 Installing the Handlebar 9
10 Rewind Starter 11
10.1 Tools, Servicing Aids 11
10.2 Removing the Rewind Starter 11
10.3 Relieving Tension of Rewind Spring 11
10.4 Removing the Starter Rope 12
10.5 Removing the Rope Rotor 12
10.6 Removing the Rewind Spring 12
10.7 Installing the rewind spring 12
10.8 Installing the Rope Rotor 13
10.9 Installing the Starter Rope 13
10.10 Tensioning the Rewind Spring. 14
10.11 Installing the Rewind Starter 14
11 Clutch 15
11.1 Tools, aids 15
11.2 Removing Clutch 15
11.3 Checking clutch drum 15
11.4 Disassembling clutch 16
11.5 Assembling clutch 16
11.6 Installing clutch 16
12 Chain Tensioner 17
12.1 Tools, Servicing Aids 17
12.2 Removing the Chain Tensioner 17
12.3 Installing the Chain Tensioner 17
13 Chain Brake 18
13.1 Tools, Servicing Aids 18
13.2 Removing the Brake Band, Spring and Lever 18
13.3 Installing the Brake Band, Spring and Lever 19
13.4 Testing the Chain Brake 20
14 Chain lubrication 21
14.1 Tools, Servicing Aids 21
14.2 Removing Oil Tank Vent Valve 21
14.3 Installing Oil Tank Vent Valve 22
14.4 Removing the Worm 22
14.5 Removing the Oil Pump 22
14.6 Removing the Hose 22
14.7 Removing Pickup Body from Oil Tank 22
14.8 Installing Pickup Body in Oil Tank 22
14.9 Installing the Hose 22
14.10 Installing the Oil Pump 22
14.11 Installing the Worm 23
15 Filter Base, Throttle Body 24
15.1 Tools, Servicing Aids 24
15.2 Removing the Filter Base 24
15.3 Installing the Filter Base 24
15.4 Removing the Throttle Body 24
15.5 Installing the Throttle Body 24
16 Throttle Control 25
16.1 Tools, Servicing Aids 25
16.2 Removing Trigger Lockout, Throttle Trigger
and Throttle Linkage 25
16.3 Installing Trigger Lockout, Throttle Trigger
and Throttle Linkage 26
17 Antivibration Elements 27
17.1 Tools, Servicing Aids 27
17.2 Removing the Antivibration Elements 27
17.3 Installing the Antivibration Elements 28

MS 500i2
18 Fly wheel 30
18.1 Special Servicing Tools, Servicing Aids 30
18.2 Removing the Flywheel 30
18.3 Installing the Flywheel 30
19 Controller, Ignition Lead 32
19.1 Special Servicing Tools, Servicing Aids 32
19.2 Testing the Ignition System 32
19.3 Removing the Ignition Lead 32
19.4 Disassembling the Ignition Lead 33
19.5 Assembling the Ignition Lead 33
19.6 Installing the Ignition Lead 33
19.7 Removing the Controller 33
19.8 Installing the Controller 34
20 Fuel Hoses, Impulse Hose 35
20.1 Tools, Servicing Aids 35
20.2 Removing Fuel Suction Hose Outside the
Tank 35
20.3 Installing Fuel Suction Hose Outside the Tank 35
20.4 Removing Fuel Hose 35
20.5 Installing the Fuel Hose 36
20.6 Removing the Fuel Return Hose 36
20.7 Installing the Fuel Return Hose 36
20.8 Removing the Impulse Hose 36
20.9 Installing the Impulse Hose 37
21 Injection Pump, Stop Switch 39
21.1 Special Servicing Tools, Servicing Aids 39
21.2 Removing the Injection Pump 39
21.3 Removing the Stop Switch 39
21.4 Removing Cap and Spring from Injection
Pump 39
21.5 Removing the Injection Pump 39
21.6 Installing the Injection Pump 40
21.7 Installing Cap and Spring on Injection Pump 40
21.8 Installing the Stop Switch 40
21.9 Installing the Injection Pump 40
22 Generator, Sensor 41
22.1 Special Servicing Tools, Servicing Aids 41
22.2 Removing the Generator 41
22.3 Removing the Sensor 41
22.4 Installing the Sensor 42
22.5 Installing the Generator 42
23 Tank Housing 44
23.1 Tools, Servicing Aids 44
23.2 Removing Pickup Body from Fuel Tank 44
23.3 Installing Pickup Body In Fuel Tank 44
23.4 Removing Tank Vent from Fuel Tank 44
23.5 Installing Tank Vent in Fuel Tank 44
23.6 Removing Fuel Suction Hose Inside the Tank 45
23.7 Installing Fuel Suction Hose Inside the Tank 45
23.8 Removing Fuel Return Hose Grommet 45
23.9 Installing Fuel Return Hose Grommet 45
23.10 Removing the Tank Housing 45
23.11 Installing the Tank Housing 45
24 Stop Buffer, Grommets 47
24.1 Tools, Servicing Aids 47
24.2 Removing Grommet from Airflow Shroud 47
24.3 Installing Grommet in Airflow Shroud 47
24.4 Removing Grommets from Crankcase 47
24.5 Installing Grommets in Crankcase 47
24.6 Removing Crankcase Stop Buffers 47
24.7 Installing Crankcase Stop Buffers 48
25 Manifold, Injection Module 49
25.1 Tools, Servicing Aids 49
25.2 Removing the Airflow Shroud 49
25.3 Removing the Manifold 49
25.4 Installing the Manifold 50
25.5 Installing the Airflow Shroud 50
25.6 Removing the Contact Strip 50
25.7 Installing the Contact Strip 50
25.8 Removing the Injection Module 50
25.9 Installing the Injection Module 50
25.10 Removing the Injection Valve 51
25.11 Installing the Injection Valve 51
26 Muffler, Heat Shield 53
26.1 Tools, Servicing Aids 53
26.2 Removing Muffler and Heat Shield 53
26.3 Installing Muffler and Heat Shield 53
27 Cylinder, Piston 54
27.1 Tools, aids 54
27.2 Removing the cylinder 54
27.3 Removing the piston 55
27.4 Installing the piston 55
27.5 Installing cylinder 56
28 Crankcase, Crankshaft, Oil Seals 58
28.1 Tools, Servicing Aids 58
28.2 Removing Oil Seals 58
28.3 Installing the Oil Seals 59
28.4 Disassembling Crankcase and Removing
Crankshaft 60
28.5 Removing the Ball Bearings 61
28.6 Installing the Ball Bearings 61
28.7 Installing Crankshaft and Assembling
Crankcase 62
29 Tools, Servicing Aids 64
29.1 Tools, aids 64

MS 500i 3
1.1 Applicable Documentation
NPlease observe the following documentation in
addition to this service manual.
–Spare parts documentation
–TI bulletins
–Instruction manual
1.2 Symbols in Text
2.1 Protective gloves
Sharp or hot components can cause cuts or burns.
NIf sharp or hot components have to be handled during
a repair: Wear protective gloves.
2.2 Safety glasses
Particles and objects can be thrown into the air at high
speed during a repair. Thrown particles or objects can
cause eye injuries.
NIf there is a risk of particles being thrown during the
repair: Wear safety glasses.
2.3 Replacement Parts
If replacement parts not approved by STIHL are installed,
they may not fulfill the required function or deactivate
safety devices. This can result in serious or fatal injuries.
NSTIHL recommends the use of genuine STIHL
replacement parts.
2.4 Screws
Thread forming screws
Type P or DG screws form a permanent thread in the
material when installed for the first time. If the screw is not
re-installed in the existing thread, the security of the fixing
can no longer be guaranteed.
NHow to install type P or DG screws in an existing
thread:
–Place the screw in the hole.
–Turn the screw counterclockwise until it drops down
slightly.
The screw engages the existing thread.
–Tighten the screw to the specified torque.
Microencapsulated screws
The microencapsulation is only effective when the screw
is installed for the first time. If a microencapsulated screw
is re-used the screw joint may loosen in operation.
NReplace the microencapsulated screw.
NIf a microencapsulated screw is re-used, perform the
following steps:
–Clean tapped hole and screw thread.
–Coat screw thread with Loctite 242.
–Insert the screw and tighten it down to the specified
torque.
Aluminum screws
NDo not re-use screws.
NInsert screws in a crosswise pattern as far as stop.
NTighten down the screws in a crosswise pattern.
NTurn the screws another 90° in a crosswise pattern.
3.1 Preparations
NDrain the fuel tank into a container approved for fuels.
NRemove the chain and guide bar.
NClean the saw.
1 About this Service Manual
This symbol refers to a chapter in this service
manual.
A video is available for this chapter
This symbol shows the tightening torque for a
screw joint and the procedure after tightening.
In this example: Tightening torque 5 Nm. Then
rotate 1 full turn counterclockwise.
2 Safety During Repair Work
5 Nm
1
3 Preparations for Repair

MS 500i4
4.1 Troubleshooting Guide
Use the diagnostic software to directly access the detailed
troubleshootiing guide.
The guide describes symptoms and possible causes as
well as the following tests to locate the problem:
NTesting fuel system for leaks and correct operation.
NTesting engine for leaks.
NTesting fuel tank and tank vent for leaks.
NCalibrating the saw.
4 Troubleshooting Guide

MS 500i 5
5.1 Tools, Servicing Aids
–Socket, T27x125 – 0812 542 2104 or equivalent
–Torque wrench – 5910 890 0302 or equivalent
–Screwdriver, T27x200 – 5910 890 2415 or equivalent
–Open-end wrench, 8 mm
–Loctite 242 (medium-strength threadlocking
adhesive) – 0786 111 2101
5.2 Removing the Chain Catcher
NPreparations, @ 3.1.
NRemove the chain sprocket cover.
NTake out the screw (2).
NRemove the chain catcher (1).
5.3 Installing the Chain Catcher
NFit the chain catcher (1).
NIf the original screw (4) is re-used: Coat thread of
screw (2) with Loctite 242.
NInsert and tighten down the screw (2).
NFit the chain sprocket cover.
5.4 Removing the Spiked Bumper
NPreparations, @ 3.1.
NRemove the chain catcher, @ 5.2.
NHold nut (5) steady and take out the screw (3).
NRemove the spiked bumper (4).
5.5 Installing the Spiked Bumper
NPlace the spiked bumper (4) in position.
NInsert the screw (3).
NHold the nut (5) steady and tighten down the
screw (5).
NInstall the chain catcher, @ 5.3.
NFit the chain sprocket cover.
5 Spiked Bumper, Chain Catcher
4
1
3 M5x12 (8 Nm / 71 lbf. in.)
2 M5x16 (8 Nm / 71 lbf. in.)
5 M5
0000-GXX-5568-A0

MS 500i6
6.1 Tools, Servicing Aids
–Combination wrench – 1129 890 3401
–Torque wrench – 5910 890 0312 or equivalent
–Stud puller, M8-7.5 – 5910 890 3000
–Stud puller, M8 – 5910 893 0501
–Loctite 270 (high-strength threadlocking adhesive) –
0786 111 2109
6.2 Removing the Bar Mounting Studs
NPreparations, @ 3.1.
NRemove the chain sprocket cover.
NUse stud puller 5910 893 0501 to remove the collar
stud (1).
6.3 Installing the Bar Mounting Studs
NCoat threads of collar studs (1) with Loctite 270.
NUse stud puller 5910 890 3000 to fit and tighten down
the collar studs (1).
NFit the chain sprocket cover.
6 Bar Mounting Studs
1 M8 (23 Nm / 204 lbf. in.)
1 M8 (23 Nm / 204 lbf. in.)
0000-GXX-5567-A0

MS 500i 7
7.1 Tools, Servicing Aids
–Screwdriver, 1.0x5.5x125
7.2 Removing the Twist Lock
NPreparations, @ 3.1.
NRemove the filter cover (2).
NUnlock the retaining tabs on the twist lock (1) and pull
the twist lock out of the filter cover (2).
7.3 Installing the Twist Lock
NPush the twist lock (1) in the filter cover (2).
NFit the filter cover (2).
7.4 Removing the Stop Buffer
NPreparations, @ 3.1.
NRemove the shroud (3).
NPull off the stop buffer (4).
7.5 Installing the Stop Buffer
NPush stop buffer (4) onto peg in shroud as far as the
stop.
NMount the shroud (3).
7.6 Removing the Shroud Lock
NPreparations, @ 3.1.
NRemove the filter cover (2).
NRemove the shroud (3).
NRemove grommet (5) with shroud lock (6) sideways.
NPush the shroud lock (6) out of the grommet (5).
7.7 Installing the Shroud Lock
NPush the shroud lock (6) into the grommet (5) so that
its base is properly seated in the grommet (5).
NPush grommet (5) with shroud lock (6) into the guide
in the cylinder as far as stop.
NMount the shroud (3).
NFit the filter cover (2), .
7 Filter Cover, Shroud
3
1
2
5
4
4
6
0000-GXX-5569-A0

MS 500i8
8.1 Tools, Servicing Aids
–Socket, 13 mm, long – 5910 893 2804 or equivalent
–Torque wrench – 5910 890 0312 or equivalent
8.2 Removing the Decompression Valve
NPreparations, @ 3.1.
NRemove the shroud.
NUnscrew the decompression valve (1).
8.3 Installing the Decompression Valve
NScrew decompression valve (1) into place by hand.
NTighten decompression valve (1) to specified torque.
NMount the shroud.
8 Decompression Valve
1
M10x1
(20 Nm /
177 lbf. in.)
0000-GXX-5570-A0

MS 500i 9
9.1 Tools, Servicing Aids
–Socket, T27x125 – 0812 542 2104 or equivalent
–Torque wrench – 5910 890 0302 or equivalent
–Screwdriver, T27x200 – 5910 890 2415 or equivalent
9.2 Removing the Handlebar
NPreparations, @ 3.1.
NTake out the screws (5).
NTake out the screw (3).
NTake out the screws (1).
NRemove the handlebar (2) from the guide (7).
NEase the handle housing (8) away from the
crankcase (arrow) and hold it there.
NPull the handlebar (2) off the screw bosses on
handlebar mount (9).
NRemove the handlebar (2) forwards, over the hand
guard.
NPull off the bushing (10).
NTake out the screw (4).
9.3 Installing the Handlebar
NInsert and tighten down the screw (4).
NPush bushing (10) onto the screw (4) so that it snaps
into place.
NFit the handlebar (2) over the hand guard from the
front.
9 Handle
2
9
7
8
6
1 P6x32.5
(6 Nm /
53 lbf. in.)
3M5x20
(6 Nm / 53 lbf. in.)
10
M6x26
(8 Nm /
71 lbf. in.)
4
5
P6x32.5
(6 Nm / 53 lbf. in.)
0000-GXX-5573-A0
9
2
8
0000-GXX-3541-A0

MS 500i10
NEase the handle housing (8) away from the
crankcase (arrow) and hold it there.
NPush holes in handlebar (2) onto the screw bosses on
the handlebar mount (9) (arrows).
NPlace the handlebar (2) in the guide (7).
NInsert and tighten down the screws (1).
NInsert and tighten down the screws (5).
NInsert and tighten down the screw (3).
9
2
8
0000-GXX-3492-A0

MS 500i 11
10.1 Tools, Servicing Aids
–Socket, T27x125 – 0812 542 2104 or equivalent
–Torque wrench – 5910 890 0302 or equivalent
–Screwdriver, T27x200 – 5910 890 2415 or equivalent
–Pin punch, 2 mm
–STIHL multipurpose grease – 0781 120 1110
–STIHL gear grease – 0781 417 1315
10.2 Removing the Rewind Starter
NPreparations, @ 3.1.
NTake out the screw (1).
NTake out the screws (2).
NRemove the fan housing (3) with rewind starter (4 -
12).
10.3 Relieving Tension of Rewind Spring
WARNING
The rewind spring can pop out and cause serious eye and
hand injuries.
Wear safety glasses and work gloves.
NRemove the rewind starter, @ 10.2.
NGrip the segment (6) by the lug and pull it out of the
fan housing (3).
NIf the segment (6) is stuck: Use 2 mm pin punch to
drive out the pins (arrows) in the segment.
NRemove the segment (6).
NPull out the starter grip (4) about 10 cm (4 in).
NHold the rope rotor (8) steady.
NTake three turns of the rope off the rotor (8).
NPull out the starter grip (4) until the starter rope (5) is
under tension.
NLet go of the rope rotor (8) and guide the starter rope
(5) back into the housing until the rewind spring (7) is
no longer under tension.
10 Rewind Starter
5
4
3
7
8
9
11
6
2 M5x20 (6 Nm / 53 lbf. in.)
10
1 M5x20
(6 Nm /
53 lbf. in.)
0000-GXX-5571-A0
3
6
0000-GXX-5580-A0

MS 500i12
10.4 Removing the Starter Rope
WARNING
The rewind spring can pop out and cause serious eye and
hand injuries.
Wear safety glasses and work gloves.
NRemove the rewind starter, @ 10.2.
NRelieve tension of rewind spring, @ 10.3.
NUnwind the starter rope (5) from the rope rotor (8).
NPull about 10 cm (4 in) length of starter rope (5) out of
the rotor (8).
NUndo the knot (12).
NPry the nipple (13) out of the grip (4).
NPull out the starter rope (5).
10.5 Removing the Rope Rotor
WARNING
The rewind spring can pop out and cause serious eye and
hand injuries.
Wear safety glasses and work gloves.
NRemove the rewind starter, @ 10.2.
NRelieve tension of rewind spring, @ 10.3.
NRemove the starter rope, @ 10.4.
NRemove the spring (11).
NRemove the pawls (10).
NRemove the washer (9).
NPull off the rope rotor (8). The rewind spring (7) may
pop out and unwind.
10.6 Removing the Rewind Spring
WARNING
The rewind spring can pop out and cause serious eye and
hand injuries.
Wear safety glasses and work gloves.
NRemove the rewind starter, @ 10.2.
NRelieve tension of rewind spring, @ 10.3.
NRemove the rope rotor, @ 10.5.
NTake out the rewind spring (7). The rewind spring (7)
may pop out and unwind.
10.7 Installing the rewind spring
Installing new rewind spring
NWear safety glasses and work gloves.
NLubricate the rewind spring (7) in the frame with a few
drops of special lubricant before installing.
NFit the rewind spring (7) with frame (14) in position so
that the anchor loop engages the lug (15).
NApply punch to holes in frame (15) and push the
rewind spring (7) into the fan housing (3) (arrows).
NRemove the frame (14). The rewind spring (7) may
pop out and unwind.
NPush the rewind spring (7) fully into its seat in the fan
housing (3).
NCoat the rewind spring (7) with special lubricant.
NInstall the rope rotor, @ 10.8.
Installing unwound rewind spring
NWear safety glasses and work gloves.
5
13
12 8
4
0000-GXX-5581-A0
15
7
14
0000-GXX-5585-A0

MS 500i 13
NFit anchor loop of rewind spring (7) over the lug (15).
NFit the rewind spring (7) in the housing clockwise,
holding it in place at the same time.
NPush the rewind spring (7) fully into its seat in the fan
housing (3).
NCoat the rewind spring (7) with special lubricant.
NInstall the rope rotor, @ 10.8.
10.8 Installing the Rope Rotor
WARNING
The rewind spring can pop out and cause serious eye and
hand injuries.
Wear safety glasses and work gloves.
NCoat the starter post (16) with special lubricant.
NPush the rope rotor (8) onto the starter post (16) so
that the loop (arrow) of the rewind spring (7) engages
the recess in the rotor (8).
NFit the washer (9).
NFit the pawls (10).
NLubricate pegs (17) on pawls with multipurpose
grease.
NFit the spring clip (11) so that its loops (arrows) are
around the pegs (17).
NInstall the starter rope,@ 10.9.
10.9 Installing the Starter Rope
NInstall the rope rotor, @ 10.8.
WARNING
The rewind spring can pop out and cause serious eye and
hand injuries.
Wear safety glasses and work gloves.
NThread the starter rope (5) through the grip (4).
NPress the nipple (13) into the grip (4) as far as stop.
NThread the starter rope (5) through the bushing (18).
NThread the starter rope (5) through the rope rotor (8).
NSecure the end of the rope (5) with a simple overhand
knot.
NPush the rope (5) into the recess (arrow).
15
7
0000-GXX-5586-A0
16
78
0000-GXX-5587-A0
10
10
17 17
11
9
0000-GXX-3495-A0
85
5
413
8
18
0000-GXX-5582-A0

MS 500i14
NWind the starter rope (5) onto the rope rotor (8).
NTension the rewind spring, @ 10.10.
10.10 Tensioning the Rewind Spring.
WARNING
The rewind spring can pop out and cause serious eye and
hand injuries.
Wear safety glasses and work gloves.
NPull out a short length of starter rope (5) between the
rope rotor (8) and bushing (18).
NUse the starter rope (5) to rotate the rope rotor six full
turns clockwise.
NHold the rope rotor (8) steady.
The rewind spring (7) is now pre-tensioned. Rotating the
starter rope (5) and rope rotor (8) causes the rope to
become twisted.
NPull out the twisted rope (5) with the starter grip (4)
and straighten it out.
NKeep the starter rope (5) under tension and allow it to
slowly rewind onto the rope rotor (8).
The starter grip (4) should sit firmly in the rope guide
bushing (18).
NIf the starter grip (4) is too loose, rotate the rope rotor
(8) one more turn to increase tension of rewind spring
(7).
NPull starter grip (4) out to full length and check how
much further the rope rotor (8) can be turned.
It must be possible to turn the rotor (8) another half turn.
NIf the rope rotor (8) cannot be turned any further: Hold
the rotor (8) steady and take one turn of the rope off
the rotor (8).
NPosition retaining lugs (arrows) of segment (6) in
recesses in fan housing (3).
NPush the pins of the segment (6) into the holes in the
fan housing (3) so that they snap into position.
10.11 Installing the Rewind Starter
NFit the fan housing (3) with the rewind starter (4 - 12).
NInsert and tighten down the screws (2) firmly.
NInsert and tighten down the screw (1) firmly.
58
18
0000-GXX-5583-A0
3
6
0000-GXX-5584-A0

MS 500i 15
11.1 Tools, aids
–Screwdriver - 0000 890 2300
–Locking strip - 0000 893 5904
–Torque wrench – 5910 890 0312 or equivalent tool
–Screwdriver T27x200 – 5910 890 2415 or equivalent
tool
–Assembly hook - 5910 890 2800
–Socket DIN3124-S19x12.5L – 5910 893 5613 or
equivalent tool
–Flex ratchet wrench
11.2 Removing Clutch
NPrepare for repair, @ 3.1.
NRelease chain brake.
NRemove chain sprocket cover.
NRemove circlip (1).
NRemove washer (2).
NRemove rim sprocket (3).
NRemove clutch drum (4).
NRemove needle cage (5).
NRemove shroud.
NRemove the spark plug.
NSlide locking strip 0000 893 5904 through the spark
plug hole and hold.
NTurn clutch (6) as far as possible clockwise by hand.
The piston is blocked.
NUnscrew clutch (6) clockwise.
NPull locking strip 0000 893 5904 out of the spark plug
hole.
NRemove the washer (7).
11.3 Checking clutch drum
NRemove the clutch drum, @ 11.2.
NExamine the clutch drum (4) for signs of wear.
If distinct wear marks are visible on the inner diameter of
the clutch drum (4):
NMeasure wall thickness a.
11 Clutch
54
32
1
7
M12x1 LH 6
(50 Nm / 37 lbf. ft.)
8
11
10 9
0000-GXX-5574-A0
4
b
100%
a
0000-GXX-3505-A0

MS 500i16
If wall thickness a is less than 80% of wall thickness b:
NReplace clutch drum (4).
11.4 Disassembling clutch
NRemove the clutch, @ 11.2.
NUse hook 5910 890 2800 to remove the clutch springs
(10).
NRemove centrifugal weights (8) from carrier (11).
NRemove the holder (9) from the carrier (11).
11.5 Assembling clutch
NSlide the holder (9) onto the centrifugal weights (8).
NSlide the centrifugal weights (8) together with the
holder (9) onto the carrier (11).
NHook clutch springs (10) onto the side with the
hexagon (arrow) using the hook 5910 890 2800.
11.6 Installing clutch
NAssembling clutch, @ 11.5.
NSlide washer (7) onto the crankshaft (8) so that the
marking “TOP” is visible.
NSlide locking strip 0000 893 5904 through the spark
plug hole and hold.
NTurn clutch (6) as far as possible anticlockwise by
hand on the crankshaft.
The piston is blocked.
NTighten clutch (6) counterclockwise.
NPull locking strip 0000 893 5904 out of the spark plug
hole.
NInstall the spark plug.
NPosition the spark plug boot (2) so that the tab (arrow)
is located in the recesses of the air guide shroud.
NInstall shroud.
NSlide on the needle cage (5).
NSlide on the clutch drum (4) so that the spigot (arrow)
of the worm sits in the groove (arrow) of the clutch
drum (4).
NSlide on rim sprocket (3).
NSlide on the washer (2).
NInstall the circlip (1).
NAttach the chain sprocket cover.
NEngage chain brake.
NCalibrate the chain saw, @ 4.
The control unit is optimally adjusted to the mechanical
and mechatronic components.
10
0000-GXX-3542-A0
9
8
11
0000-GXX-3543
10
0000-GXX-3506-A0
0000-GXX-5610-A0
4
0000-GXX-5588-A0

MS 500i 17
12.1 Tools, Servicing Aids
–Screwdriver – 0000 890 2300 or equivalent
–Socket, T27x125 – 0812 542 2104 or equivalent
–Torque wrench – 5910 890 0302 or equivalent
–Screwdriver, T27x200 – 5910 890 2415 or equivalent
–STIHL multipurpose grease – 0781 120 1110
12.2 Removing the Chain Tensioner
NPreparations, @ 3.1.
NRemove the chain sprocket cover.
NTake out the screw (1).
NRemove the side plate (2).
NTurn spur gear (6) clockwise until the tensioner slide
(9) butts against the right end of the slot and exposes
the screw (4).
NTake out the screw (4).
NPull out the spur gear (6) together with the cover plate
(5) and retainer (3).
NPry the retainer (3) off the cover plate (5).
NRemove the cover plate (5) from the spur gear (6).
NPull out the sealing ring (7).
NPull out the tensioner slide (9) together with the
adjusting screw (8).
NRemove the thrust pad (10).
NUnscrew the adjusting screw (8) from the tensioner
slide (9).
12.3 Installing the Chain Tensioner
NCoat teeth of adjusting screw (8) with multipurpose
grease.
NScrew the adjusting screw (8) a few turns into the
tensioner slide (9).
NFit the thrust pad (10) on the end of the adjusting
screw (8).
NFit the tensioner slide (9) together with the adjusting
screw (8).
NLubricate sealing ring (7) with multipurpose grease.
NFit the sealing ring (7) in the recess in the spur gear
(6).
NCoat teeth of spur gear (6) with multipurpose grease.
NSlide the cover plate (5) onto the spur gear (6).
NPush the retainer (3) onto the spur gear (6).
NFit the spur gear (6) together with the cover plate (5)
and retainer (3) in position.
NInsert and tighten down the screw (4).
NPlace the side plate (2) in position.
NInsert and tighten down the screw (1).
NFit the chain sprocket cover.
12 Chain Tensioner
10
9
8
3
2
5
6
7
M4x8 (2 Nm / 18 lbf. in.) 4
1 M4x8
(2 Nm /
18 lbf. in.)
0000-GXX-5575-A0

MS 500i18
13.1 Tools, Servicing Aids
–Screwdriver – 0000 890 2300 or equivalent
–Socket, T27x125 – 0812 542 2104 or equivalent
–Assembly tool – 1117 890 0900
–Combination wrench – 1142 890 3400
–Torque wrench – 5910 890 0302 or equivalent
–Screwdriver, T27x200 – 5910 890 2415 or equivalent
–Hook – 5910 890 2800
–Flat nose side cutting pliers
–STIHL multipurpose grease – 0781 120 1110
–Loctite 242 (medium-strength threadlocking
adhesive) – 0786 111 2101
13.2 Removing the Brake Band, Spring and Lever
NPreparations, @ 3.1.
NRemove the chain sprocket cover.
NRemove the clutch drum, @ 11.2.
NTake out the screw (1).
NRemove the side plate (2).
NTake out the screws (3).
NRemove the cover (4).
NEngage the chain brake.
NTake out the screw (5).
NPull the brake band (6) out of its seat.
NUnhook the brake band (6) from the lever (13).
NInstall a new brake band (6) if:
–there are noticeable signs of wear on the inside
diameter
–the remaining thickness is less than 0.6 mm
(0.0024 in).
NUse hook 5910 890 2800 to disconnect short end of
brake spring (8).
NUnhook the brake spring (8) from the lever (13).
NPull the protective tube (7) off the brake spring (8).
NIf the turns of the brake spring (8) are not tightly
against one another, install a new spring.
NRemove the E-clip (12).
NTake out the screw (14).
NRemove the hand guard (15) with brake lever (13).
NPull the lever (13) out of the hand guard (15).
NDisconnect and remove the torsion spring (11) from
the lever (9).
NRemove the E-clip (10).
NRemove the lever (9).
13 Chain Brake
9
15
6
4 2
8
7
13 12 11
10
M4x12 (3 Nm / 27 lbf. in.) 53
M4x12
(2.5 Nm / 22 lbf. in.)
3 M4x12 (2.5 Nm / 22 lbf. in.)
14 M5x20
(6 Nm /
53 lbf. in.)
1
M4x8
(2 Nm / 18 lbf. in.)
0000-GXX-5576-A0