Stihl 171 Manual

STIH)
Technical Information
TI_27_2013_30_01_01.fm englisch / English
Chain saws STIHL MS 171, 181, 211 – Series 1139
Contents
1. Technical description
2. Handle frame
3. Starters
4. Muffler
5. Ignition module, wiring harness, contact spring
6. Carburetor, manifold, sleeve
7. Cylinder with piston (MS 211 only)
1. Technical description
To improve function, new components are
introduced for the chain saws MS 171, 181 and 211.
2. Handle frame
Handle frame for standard versions
The previous handle frame 1139 791 4900 is being
replaced by the new handle frame 1139 791 4903.
Handle frame for Easy2Start™ versions
The previous handle frame 1139 791 4901 is being
replaced by the new handle frame 1139 791 4904.
Both new handle frames differ from the previous
handle frames by a stub (2) that is in the opening on
the engine housing. The new handle frames and
stub (2) reduce the load on the AV spring (3), which
is why the retainer (1) 1139 790 8100 is no longer
installed on the new handle frames.
Left: previous handle frames:
Handle frame (Standard) 1139 791 4900
Handle frame (Easy2Start™)
1139 791 4901
Right: new handle frames:
Handle frame (Standard) 1139 791 4903
Handle frame (Easy2Start™)
1139 791 4904
3 3
2
533TI025 KN
1
27.2013

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Spare parts/service notes
The previous handle frames 1139 791 4900 and
1139 791 4901 are no longer available as spare
parts.
The new handle frames 1139 791 4903 and
1139 791 4904 can be used for machines with the
previous handle frames.
With the new handle frames, the retainer (1)
1139 790 8100 is no longer required.
The retainer 1139 790 8100 remains available as a
spare part for machines with the previous handle
frames.
2.1 Summary – handle frames
Item Part Name Previous New Rem.
1 Handle frame (Standard) 1139 791 4900 1139 791 4903 1) 3)
2 Handle frame (Easy2Start™) 1139 791 4901 1139 791 4904 1) 3)
3 Retainer 1139 790 8100 - - - 2)
Modification to be introduced : continuously
Remarks
1) Previous version of part no longer available from factory
2) Previous version of part remains available for older models
3) New version of part can also be used for older machines

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3. Starters
3.1 Easy2Start™ starter
The Easy2Start™ starter is converted from a
version with two pawls (1) to a version with one pawl
(2). The pawl does not change.
At the same time, the previous spring (3)
1128 195 3500 is replaced by the spring (4)
1118 195 3500.
Spare parts/service notes
The part number 1139 080 2103 for the
Easy2Start™ starter remains unchanged.
The previous spring 1128 195 3500 remains
available as a spare part.
3.2 Segment
The previous segment 1139 084 7800 is being
replaced by the new segment 1139 084 7802.
The new segment 1139 084 7802 has changed
geometrically and ensures a larger amount of
cooling air.
Spare parts/service notes
The new segment 1139 084 7802 can also be used
for previous versions.
The previous segment 1139 084 7800 is no longer
available as a spare part.
For MS 211 versions with a new "cylinder with piston
Ø 40 mm" 1139 020 1205, the previous segment
1139 084 7800 must not be used (see b7).
Left: previous Easy2Start™ starter
1139 080 2103 with two pawls (1) and
previous spring (3)
Right: new Easy2Start™ starter 1139 080 2103
with one pawl (2) and a different spring (4)
21
3
14
533TI029 KN
Left: previous segment 1139 084 7800
Right: new segment 1139 084 7802
533TI030 KN
1139 084 7800 1139 084 7802

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3.3 Summary – starters
Item Part Name Previous New Rem.
1 Fan housing with starter;
including Item 5
1139 080 2102 - - - 1)
2 Fan housing with starter;
including Item 6
- - - 1139 080 2102 3)
3 Fan housing with starter (Easy2Start™);
including Items 5, 7
1139 080 2103 - - - 1)
4 Fan housing with starter (Easy2Start™);
including Items 6, 8
- - - 1139 080 2103 3)
5 Segment 1139 084 7800 - - - 1)
6 Segment - - - 1139 084 7802 3)
7 Spring 1128 195 3500 - - - 2)
8 Spring - - - 1118 195 3500
Modification to be introduced : continuously
Remarks
1) Previous version of part no longer available from factory
2) Previous version of part remains available for older models
3) New version of part can also be used for older machines

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4. Muffler
The previous mufflers are replaced by new mufflers.
The inner structure of the mufflers is changed.
Spare parts/service notes
The new mufflers can also be used for older
machines.
The previous mufflers are no longer available as a
spare part.
4.1 Summary – mufflers
Previous New
MS 171 1139 140 0601 1139 140 0610
MS 181, 211 1139 140 0603 1139 140 0608
Item Part Name Previous New Rem.
1 Muffler (MS 171) 1139 140 0601 1139 140 0610 1) 2)
2 Muffler (MS 181, 211) 1139 140 0603 1139 140 0608 1) 2)
Modification to be introduced : continuously
Remarks
1) Previous version of part no longer available from factory
2) New version of part can also be used for older machines

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5. Ignition module, wiring harness,
contact spring
5.1 Ignition module, wiring harness
5.1.1 Ignition module
The previous ignition module 1139 400 1307 is
being replaced by the new ignition module
1139 400 1311.
The terminal on the previous ignition module
1139 400 1307 is bent (1), whereas on the new
ignition module 1139 400 1311 it is straight (2).
5.1.2 Wiring harness
The previous wiring harness 1139 440 3000 is being
replaced by the new wiring harness 1139 440 3001.
The new wiring harness 1139 440 3001 differs from
the previous wiring harness 1139 440 3000 as
follows:
– The insulation is no longer needed on the
terminal connector of the short circuit wire (1)
– The shrink tube is no longer needed on the
terminal connectorof the ground wire (2)
5.1.3 Spare parts/service notes
The new ignition module 1139 400 1311 and new
wiring harness 1139 440 3001 must not be used for
machines with a previous ignition module
1139 400 1307 and previous wiring harness
1139 440 3000.
The previous ignition module 1139 400 1307 and
previous wiring harness 1139 440 3000 must not be
used for machines with a new ignition module
1139 400 1311 and new wiring harness
1139 440 3001.
The previous ignition module 1139 400 1307 and
previous wiring harness 1139 440 3000 remain
available as a spare part for older machines.
Left: previous ignition module 1139 400 1307
with bent terminal
Right: new ignition module 1139 400 1311 with
straight terminal
533TI027 KN
1 2
1139 400 1302 X 1139 400 1310 X
1139 400 1301 X
Top: previous wiring harness 1139 440 3000
Bottom: new wiring harness 1139 440 3001
12
533TI033 KN

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5.2 Contact spring
The previous contact spring (1) 1139 442 1600 is
replaced by the new contact spring (2)
1139 442 1601.
The new contact spring 1139 442 1601 has
changed geometrically and unlike the previous
contact spring 1139 442 1601, it is not heat treated.
The previous contact spring 1139 442 1600 is
brown-yellow, the new contact spring
1139 442 1601 is silver colored and is marked
"01A".
Spare parts/service notes
The new contact spring 1139 442 1601 can be used
for versions with a previous ignition module
1139 400 1307 and new ignition module
1139 400 1311.
The previous contact spring 1139 442 1600 must
not be used for versions with a new ignition module
1139 400 1311.
The previous contact spring 1139 442 1600 is no
longer available as a spare part.
5.3 Summary – ignition module, wiring harness, contact spring
Left: previous contact spring 1139 442 1600
Right: new contact spring 1139 442 1601
2
1
533TI035 KN
01A
Item Part Name Previous New Rem.
1 Ignition module 1139 400 1307 1139 400 1311 2)
2 Wiring harness 1139 440 3000 1139 440 3001 2)
3 Engine housing (Standard);
including Item 5
1139 020 3006 1139 020 3006
4 Engine housing (Easy2Start™);
including Item 5
1139 020 3007 1139 020 3007
5 Contact spring 1139 442 1600 1139 442 1601 1) 3)
Modification to be introduced : continuously
Remarks
1) Previous version of part no longer available from factory
2) Previous version of part remains available for older models
3) New version of part can also be used for older machines

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6. Carburetor, manifold, sleeve
6.1 Technical description
The chain saws STIHL MS 171, 181 and 211 will be
fitted with a new carburetor as standard.
The new carburetors differ from previous
carburetors by a modified low speed adjusting
screw, high speed adjusting screw (MS 211 only)
and throttle shutter.
Together with the new carburetors, a new sleeve
and new manifold are introduced.
6.2 Overview of carburetor
The chain saws MS 181 and MS 211 are being fitted
with common carburetor versions.
The previous carburetors remain available as a
spare part for older machines.
6.3 Carburetor adjustment
The basic setting for servicing and the standard
setting for the new carburetors is the same as the
previous carburetors.
6.4 Manifold
6.4.1 MS 171, 181
The previous manifold 1139 140 2501 is being
replaced by the new manifold 1139 140 2502.
The new manifold 1139 140 2502 is marked by a
conical groove on the fuel mix duct (see arrow).
The cross-section of the clean air duct on the
manifold has been increased.
Spare parts
The new manifold 1139 140 2502 can also be used
for versions with a previous manifold
1139 140 2501.
The previous manifold 1139 140 2501 is no longer
available as a spare part.
For the new carburetors, the new manifold
1139 140 2502 is required.
Service notes
When making repairs, if the previous manifold
1139 140 2501 is replaced by the new manifold
1139 140 2502, coat the previous sleeve
1139 141 1801 with press fluid before inserting into
the manifold.
Previous New
MS 171 C1Q-S238 –
1139 120 0615
C1Q-S270 –
1139 120 0619
MS 181 C1Q-S239 –
1139 120 0616 C1Q-S269 –
1139 120 0613
MS 211 C1Q-S241 –
1139 120 0618
MS 211 C1Q-S240 –
1139 120 0617
C1Q-S268 –
1139 120 0612
Left: previous manifold 1139 140 2501
Right: new manifold 1139 140 2502
XXXX XXX XXXX
XXXX XXX XXXX
533TI032 KN
1139 140 2501-X 1139 140 2502-X

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6.4.2 MS 211
To adapt to the modified geometry of the intake
ports of the new cylinder (see b7), the previous
manifold 1139 140 2500 is replaced by the new
manifold 1139 140 2502.
The new manifold 1139 140 2502 is marked by a
conical groove on the fuel mix duct (see arrow).
Spare parts/service notes
The new manifold 1139 140 2502 cannot be used
for versions with a previous cylinder.
The previous manifold 1139 140 2500 cannot be
used for versions with a new cylinder.
The previous manifold 1139 140 2500 remains
available as a spare part.
For the new carburetors, the new manifold
1139 140 2502 is required.
6.5 Sleeve
The previous sleeve 1139 141 1801 is replaced by
the new sleeve 1139 141 1802.
The new sleeve (1) 1139 141 1802 is conical and is
secured to the new carburetors.
Spare parts/service notes
The new sleeve 1139 141 1802 can only be used in
conjunction with the new carburetors.
The new carburetors are supplied as spare parts
with the new sleeve 1139 141 1802.
The previous sleeve 1139 141 1801 remains
available as a spare part for versions with the
previous carburetor.
Left: previous manifold 1139 140 2500
Right: new manifold 1139 140 2502
XXXX XXX XXXX
XXXX XXX XXXX
533TI034 KN
1139 140 2500-X 1139 140 2502-X
Left: previous sleeve 1139 141 1801
Right: new sleeve 1139 141 1802
533TI026 KN
533TI031 KN
1

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6.6 Summary – carburetor, manifold, sleeve
6.6.1 MS 171
6.6.2 MS 181
Item Part Name Previous New Rem.
1 Carburetor C1Q-S238;
including Item 3, 7
1139 120 0615 - - - 1)
2 Carburetor C1Q-S270;
including Items 4, 6, 8
- - - 1139 120 0619 2)
3 Low speed screw 1139 122 6803 - - - 1)
4 Low speed screw - - - 1139 122 6805 2)
5 Sleeve 1139 141 1801 - - - 1)
6 Sleeve - - - 1139 141 1802 2)
7 Throttle shutter 1139 121 3300 - - - 1)
8 Throttle shutter - - - 1139 121 3302 2)
9 Manifold 1139 140 2501 1139 140 2502 3)
Modification to be introduced : continuously
Remarks
1) Previous version of part remains available for older models
2) New version of part cannot be used for older machines
3) New version of part can also be used for older machines
Item Part Name Previous New Rem.
1 Carburetor C1Q-S239;
including Items 3, 7
1139 120 0616 - - - 1)
2 Carburetor C1Q-S269;
including Items 4, 6, 8
- - - 1139 120 0613 2)
3 Low speed screw 1139 122 6803 - - - 1)
4 Low speed screw - - - 1139 122 6804 2)
5 Sleeve 1139 141 1801 - - - 1)
6 Sleeve - - - 1139 141 1802 2)
7 Throttle shutter 1139 121 3300 - - - 1)
8 Throttle shutter - - - 1139 121 3302 2)
9 Manifold 1139 140 2501 1139 140 2502 3)
Modification to be introduced : continuously
Remarks
1) Previous version of part remains available for older models
2) New version of part cannot be used for older machines
3) New version of part can also be used for older machines

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6.6.3 MS 211
Item Part Name Previous New Rem.
1 Carburetor C1Q-S240;
including Items 5, 9, 11
1139 120 0617 - - - 1)
2 Carburetor C1Q-S268;
including Items 6, 8, 10, 12
- - - 1139 120 0612 2)
3 Carburetor C1Q-S241;
including Items 5, 9, 11
1139 120 0618 - - - 1)
4 Carburetor C1Q-S269;
including Items 6, 8, 10, 12
- - - 1139 120 0613 2)
5 Low speed screw 1139 122 6803 - - - 1)
6 Low speed screw - - - 1139 122 6804 2)
7 Sleeve 1139 141 1801 - - - 1)
8 Sleeve - - - 1139 141 1802 2)
9 Throttle shutter 1139 121 3300 - - - 1)
10 Throttle shutter - - - 1139 121 3302 2)
11 High speed screw 1139 122 6700 - - - 1)
12 High speed screw - - - 4244 122 6700 2)
13 Manifold 1139 140 2500 1139 140 2502 1) 2)
Modification to be introduced : continuously
Remarks
1) Previous version of part remains available for older models
2) New version of part cannot be used for older machines

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7. Cylinder with piston (MS 211 only)
All versions of the chain saw MS 211 will be fitted
with a new cylinder.
Difference
The new cylinder has a side cover and modified ribs.
7.1 Spare parts
For versions of the chain saw MS 211 with the new
cylinder, in deviation from the versions with the
previous cylinder, the following new spare parts are
required:
– Cylinder with piston Ø 40 mm 1139 020 1205
– Piston Ø 40 mm 1139 030 2007
– Piston ring Ø 40 mm 1139 034 3000
– Carburetor C1Q-S120C – 1139 120 0612
– see b6
– Carburetor C1Q-S269 – 1139 120 0613
– see b6
– Sleeve 1139 141 1802 – see b6
– Manifold 1139 140 2502 – see b6
– Ignition module 1139 400 1311 – see b5
– Contact spring 1139 442 1601 – see b5
– Wiring harness 1139 440 3001 – see b5
– Segment 1139 084 7802 – see b3.2
– Oil seal 9639 951 1584 – see b7.2
7.2 Service notes – oil seal
Repairs on disassembled crankcase
For versions of the chain saw MS 211 with new
"Cylinder with piston Ø 40 mm" 1139 020 1205, the
temperature-resistant oil seal 9639 951 1584 with
rigid housing is required.
For versions of the chain saw MS 211 with previous
"Cylinder with piston Ø 40 mm" 1139 020 1202, the
oil seal 9639 003 1585 with rigid housing continues
to be required.
Repairs on disassembled crankcase
For versions of the chain saw MS 211 with new
"Cylinder with piston Ø 40 mm" 1139 020 1205
and for versions with previous "Cylinder with piston
Ø 40 mm" 1139 020 1202, the oil seal
9638 003 1581 with flexible housing is required.
Left: previous "Cylinder with piston Ø 40 mm"
1139 020 1202
Right: new "Cylinder with piston Ø 40 mm"
1139 020 1205 with side cover (1) and
modified ribs
1
533TI028 KN

Technical Information 27.2013 Page 13
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7.3 Summary – cylinder with piston (MS 211 only)
© ANDREAS STIHL AG & Co. KG, 2013
Item Part Name Previous New Rem.
1 Cylinder with piston Ø 40 mm;
including Items 3, 5, 7
1139 020 1202 - - - 1)
2 Cylinder with piston Ø 40 mm;
including Items 4, 6, 8
- - - 1139 020 1205
3 Piston Ø 40 mm; including Item 5 1139 030 2001 - - - 1)
4 Piston Ø 40 mm; including Item 6 - - - 1139 030 2007
5 Piston ring Ø 40 mm 1123 034 3005 - - - 1)
6 Piston ring Ø 40 mm - - - 1139 034 3000
7 Oil seal DIN3760-AS15x25x5; 9639 003 1585 - - - 1)
8 Oil seal DIN3760-AS15x25x5 - - - 9639 951 1584
9 Manifold 1139 140 2500 1139 140 2502 1)
10 Ignition module 1139 400 1307 1139 400 1311 1)
11 Wiring harness 1139 440 3000 1139 440 3001 1)
12 Contact spring 1139 442 1600 1139 442 1601 2)
13 Carburetor C1Q-S240 1139 120 0617 - - - 1)
14 Carburetor C1Q-S268;
including Item 18
- - - 1139 120 0612
15 Carburetor C1Q-S241 1139 120 0618 - - - 1)
16 Carburetor C1Q-S269;
including Item 18
- - - 1139 120 0613
17 Sleeve 1139 141 1801 - - - 1)
18 Sleeve - - - 1139 141 1802
19 Segment 1139 084 7800 - - -
20 Segment - - - 1139 084 7802 2)
Modification to be introduced : continuously
Remarks
1) Previous version of part remains available for machines with the previous cylinder
2) New version of part can also be used for older machines