Technical Information · issue 5 of 2009
New chain saws STIHL MS 171, MS 181, MS 211 MS 211 C
IssueTI 5/2009
Engine family 1139
Full text
Page 1 of 14
STIH)
Technical Information 05.2009
New chain saws STIHL MS 171, MS 181, MS 211 MS 211 C – Series 1139
Contents
1. Technical description
2. Specifications
3. Service accessories and special tools
4. Service notes
5. Spare parts
6. Repair times
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)m~ge 2 Technical Information 05.2009
Excellent power, reduced vibration and fuel efficient: 1. Technical description
these are the characteristic features distinguishing
the new STIHL chain saw models MS 171, MS 181, 1.1 2-cycle engine with stratified scavenging
MS 211 and MS 211 C.
A cushion of fuel-free air separates the unburned
The new STIHL 2-cycle engine with four-port fuel-air mixture from the exhaust gas. This cushion
technology and stratified scavenging ensures: of air is located in front of the unburned fuel-air
- Higher power levels and performance mixture. At the start of the exhaust and scavenging
cycle, fuel-free air enters from the transfer ports into
- Consistant torque over a wide speed range the combustion chamber and scavenges the
- Lower fuel consumption – up to 20 % as exhaust gas into the exhaust port. The fuel-free air
compared with conventional 2-stroke engines prevents the unburned fuel-air mixture from entering
the exhaust port, thus reducing scavenging losses
and fuel consumption.
The MS 171, MS 181, MS 211 and MS 211 C are
designed and built for:
1.1.1 Mechanical design
- Use around the farm, home and garden
- Thinning woods, trimming trees
- Preparing firewood
- Felling small trees
2
4
The air filter system with pre-separation
considerably extends the intervals between
changing the filter (filter life is roughly doubled as 1
compared with the MS 170, MS 180, MS 180 C and
further enhanced in comparison to the MS 210 and
MS 210 C).
The deluxe C-model MS 211 C is equipped with the
STIHL Easy2Start™ and quick chain adjuster
(QCA).
533TI001 KN
3
The fuel-air port (1) is separate from the fresh air
port (2). An integrally molded control slot (4) in the
piston skirt opens and closes the connection
between fresh air port (2) and transfer ports (3).
Piston
. MS 181, MS 211, MS 211 C:
two piston rings
MS 171: one piston ring
Crankshaft
. Five-part
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Technical Information 05.2009 Page 3
Carburetor The incoming air is swirled, so that the larger and
heavier dirt particles (black arrows) are hurled
. All position diaphragm carburetor with high
outwards.
speed semi-fixed jet, idle fixed jet and
premixture regulation. Pre-cleaned air (gray arrows) is guided inwards
. The setting range of the high speed adjusting through the pre-separator port to the air filter.
screw is restricted by a limiter cap (3/4 turn). This preliminary separation results in longer
intervals between filter cleaning or filter
. Accelerator pump for quick acceleration.
replacement.
Air filter
Ignition system
. Easy to service
. Microprocessor-controlled ignition system with
ignition timing adjustment for optimum . MS 171: Air filter with separate fleece
performance and torque. . MS 181, MS 211, MS 211 C:
One-part fleece filter with integrated sealing lip
Muffler Shutter for winter operation (MS 211, MS 211 C
. Single-chamber muffler, with spark-arresting only)
screen. The shutter located beside the spark plug should be
set to winter operation with the aid of a combination
wrench when working at temperatures below +50 °F
Clutch (+10 °C).
. Three shoe design In this setting, warm air from around the carburetor
is used in addition to the cold air, thus preventing the
. Light weight
carburetor from icing up.
1.2 Air filter system with pre-separation
2
533TI003 KN
533TI002 KN
1 = Winter operation
2 = Summer operation
At temperatures over +68 °F (+20 °C), the shutter
must be reset to summer operation, otherwise the
engine will malfunction due to overheating.
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)m~ge 4 Technical Information 05.2009
1.3 Anti-vibration system Quick chain adjuster
. Quick and easy tensioning of the saw chain
without tools
1.6 C-models with manual fuel pump
533TI004 KN
The new anti-vibration system with special springs –
on the handlebar with integrated overload protection
– ensures a low level of vibration.
533TI006 KN
1.4 Oil and fuel tank . Manual fuel pump for easy prime and to
comfortably start cold machines
2. Specifications
2.1 Power unit
MS 171
STIHL single cylinder two-stroke engine
533TI005 KN
Displacement: 1.84 cu. in (30.1 cm3)
Bore: 1.5 in (37 mm)
. Toolless caps for ease and comfort.
Piston stroke: 1.1 in (28 mm)
. Simple fill up provided by a large, easily- Power output according
accessible tank opening. to ISO 7293: 1.3 kW at 9,500 rpm
. Fuel level always visible through transparent Idle speed: 2,800 rpm
tank. Permissible max. speed
with bar and chain: 13,500 rpm
1.5 C-models with STIHL Easy2Start™ and
quick chain adjuster MS 181
STIHL Easy2Start™ STIHL single cylinder two-stroke engine
. For starting with less effort at a lower cranking
speed Displacement: 1.94 cu. in (31.8 cm3)
Bore: 1.6 in (38 mm)
. Smooth starting
Piston stroke: 1.1 in (28 mm)
Power output according
to ISO 7293: 1.5 kW at 9,500 rpm
Idle speed: 2,800 rpm
Permissible max. speed
with bar and chain: 13,500 rpm
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Technical Information 05.2009 Page 5
MS 211, MS 211 C 2.5 Weight
STIHL single cylinder two-stroke engine without fuel and cutting attachment:
MS 171 9.5 lbs (4.3 kg)
Displacement: 2.15 cu. in (35.2 cm3) MS 181 9.5 lbs (4.3 kg)
Bore: 1.7 in (40 mm) MS 211 9.5 lbs (4.3 kg)
Piston stroke: 1.1 in (28 mm) MS 211 C 10.1 lbs (4.6 kg)
Power output according
to ISO 7293: 1.7 kW at 9,500 rpm
Idle speed: 2,800 rpm
Permissible max. speed
with bar and chain: 13,500 rpm
2.2 Fuel system
Carburetor
All-position diaphragm carburetor with limiter cap
on the high speed adjusting screw and integral fuel
pump.
Standard limiter cap setting on the H screw
Low speed screw L: 1 turn open
High speed screw H: 3/4 turn open
(max. to stop)
Basic setting without limiter cap
Low speed screw L: 1 turn open
High speed screw H: 1 turn open
Fuel capacity
9.1 fl. oz (270 cm3)
2.3 Ignition system
Ignition module: Microprocessor-controlled
with ignition timing
Spark plug
(suppressed): NGK CMR 6H
Electrode gap: .020 in (0.5 mm)
2.4 Chain Lubrication
Oil pump: Speed-dependent,
fully-automatic pump with
rotary piston
Oil tank capacity: 8.8 fl. oz (260 cm3)
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)m~ge 6 Technical Information 05.2009
2.6 Recommended cutting attachments
Cutting attachment MS 171, MS 181
Guide bar: Reduced kickback STIHL guide bar (with green label)
Bar lengths: 12, 14, 16 in.
ROLLOMATIC ® E Mini: (30, 35, 40 cm)
Pitch: 3/8" P (9.32 mm)
Groove width: .043 in. (1.1 mm)
OILOMATIC ® Low kickback STIHL chain (with green label)
saw chains:
- STIHL PICCO™ Micro™ Mini Comfort 3
(61 PMMC3)
Pitch: 3/8"P (9.32 mm)
Groove width: .043 in. (1.1 mm)
Chain sprocket: Spur- or Rim sprocket
6-tooth for 3/8" P pitch
Cutting attachment MS 211, MS 211 C
Guide bar: Reduced kickback STIHL guide bar (with green label)
Bar lengths 12, 14, 16 in.
ROLLOMATIC ®: (30, 35, 40 cm)
Bar lengths 12, 14, 16 in.
ROLLOMATIC ® E Light: (30, 35, 40 cm)
Pitch: 3/8" P (9.32 mm)
Groove width: 0.050 in. (1,3 mm)
OILOMATIC® Low kickback STIHL chain (with green label)
saw chains:
- STIHL PICCO™ Micro™ Comfort 3
(63 PMC3)
Pitch: 3/8" P (9.32 mm)
Groove width: .050 in. (1,3 mm).
Chain sprocket: Spur- or Rim sprocket
6-tooth for 3/8" P pitch
7-tooth for 3/8“ P pitch
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Technical Information 05.2009 Page 7
3. Service accessories and
special tools
3.1 Service accessories
Part name Part No. Use
Set of carburetor parts 4229 007 1060 Repairing the carburetor
Grease 8 oz. (225 g) tube 0781 120 1111 Oil seals, oil pump drive, sprocket bearings, chain tensioner
Bearing and sliding surfaces for throttle trigger, brake lever
and trigger interlock
Standard commercially Cleaning crankshaft stub and cone on flywheel
available CFC and HFC-free
solvent-based degreasing
agent
Tube of sealant Dirko HT red 0783 830 2000 Engine pan, oil seals (outside diameter)
STIHL Press Fluid OH 723 0781 957 9000 Rubber elements, fuel hoses
Spare chain catcher 1139 650 7700 Repairing the integrally molded chain catcher on the chain
sprocket cover
Pan head self-tapping screw 9074 478 3025 Repairing the chain brake cover
IS-P4x16
Pan head self-tapping screw 9075 478 4115
IS-D5x16
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)m~ge 8 Technical Information 05.2009
3.2 Special tools
The following special tools are new.
1
3
2
4
533TI021 KN
Item Part name Part No. Use
1 Installing tool 10; 5910 890 2210 Fitting hookless snap rings in piston
including: Item 2
2 Sleeve 5910 893 1707 Fitting hookless snap rings in piston
(supplements the previous installing tool, 10)
3 Locking strip 0000 893 5904 Blocking the crankshaft, see section 4.8
4 Flange 1139 893 2500 Leakage testing
5 Installing tool 1123 890 2202 Installing / removing the oil pump
6 Conversion kit 1139 007 1002 Installing / removing the oil pump
(for converting the present installing tool 1123 890 2201)
The existing special tools are listed in the Service Manual STIHL MS 171, MS 181, MS 211,
MS 211 C.
3.3 Special accessories for the user
Item Part name Part No. Use
1 Quick tensioner kit 1139 007 1000 For retrofitting the quick chain adjuster on the MS 171,
MS 181 and MS 211. The conversion is described in
Supplement 0457 798 0000
2 Starter grip 0000 190 3402 For more comfort during starting (not for C-models)
ElastoStart™
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Technical Information 05.2009 Page 9
4. Service notes 4.2 Maintenance / repair
All safety regulations and safety instructions in the
Instruction Manual must be observed if the chain
saw has to be started up during servicing.
4.1 Carburetor Adjustment
533TI009 KN
1
The limiter cap for the high speed adjusting screw
must be removed when replacing a damaged
adjusting screw or when cleaning the carburetor.
. Remove limiter cap with
service tool 5910 890 4501 (1).
Used caps must not be reused, as they are
The high speed adjusting screw H can only be damaged when removed.
adjusted by the user within a range of 270°
(3/4 turn). Adjustment after maintenance / repair
The carburetor has been adjusted for optimum . Check air filter – clean or replace if necessary.
performance and fuel efficiency.
. Check spark arresting screen – clean or replace
Fine adjustments are still possible to adapt to if necessary.
changes in elevation (mountains, sea-level).
. Check the chain tension.
4.1.1 Mechanical design
6
5
1
2
3
533TI008 KN
4
. Low speed adjusting screw L (1)
. High speed adjusting screw H (2)
. Limiter cap (3)
. Idle speed adjusting screw (4)
. Limit Stop (5)
. Choke shutter (6)
The limiter cap (3) is fitted over the knurled head of
the adjusting screw (2). The limit stop (5) on the
carburetor housing serves as a limiter.
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4.2.1 Basic setting without limiter cap 4.2.2 Securing the limiter cap
533TI012 KN
. Starting from the closed position of the adjusting Used caps must not be reused, as they are
screw: damaged when removed.
. Fit a new limiter cap (1) for the high speed
H = Open 1 turn
adjusting screw H and line it up with the rich limit
L = Open 1 turn
stop (arrow)
a
Set the recommended speeds within a tolerance
range of +/– 200 rpm.
1. Set idle speed to 3,400 rpm with adjusting
screw (LA).
2. Turn the low speed screw (L) clockwise or
counterclockwise to set the highest speed. 533TI011 KN
If this speed is greater than 3,700 rpm, stop and
repeat step 1.
. Press the limiter cap until it snaps into place.
3. Set the speed to 3,400 rpm again with idle
speed adjusting screw (LA). Do not press the limiter cap fully home on the
carburetor housing, otherwise it will be damaged:
Minimum distance a = .040 in (1 mm)
4. Set the speed to 2,800 rpm with low speed
screw (L).
If the setting is too lean, the engine may be
damaged by overheating and a shortage of
lubricant.
5. Continue with "Securing the limiter cap".
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Technical Information 05.2009 Page 11
4.2.3 Standard setting with limiter cap 4.4 Chain catcher
The limiter cap must not be removed when making
the standard setting.
533TI020 KN
533TI010 KN
The chain catcher (1) is integrally molded onto the
chain sprocket cover. Replace damaged or broken
chain catchers.
. Turn the high speed screw (H) counterclockwise
as far as possible (max. 3/4 turn) . File down the chain catcher (1)
. Turn the low speed screw (L) clockwise until it is
lightly seated, then back off 1 turn
4.3 Accelerator pump
533TI015 KN
2 3 4
. Fit a replacement chain catcher (2)
1139 650 7700 with countersunk screw
M6x14 (3) 9062 319 1270 and lock nut
533TI013 KN
M6-10 (4) 9214 320 0900
1 4 2 3
The carburetor is equipped with an accelerator
pump.
The pump piston (1) is located in the bore (2) behind
the throttle shaft (3) and is held in idle position by
the compression spring (4).
When opening the throttle shutter, fuel is also sent
through the main nozzle into the venturi providing
fast acceleration.
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)m~ge 12 Technical Information 05.2009
4.5 Chain brake cover 4.6 Rewind starter
The chain brake cover has two integrally molded The hand guard must be pried outward in order to
domes which must be replaced by screws when remove the rewind starter.
damaged or broken.
1
533TI016 KN
1
. Remove the domes completely and drill two
holes in the chain brake cover
. If any debris remains in the engine housing, it
533TI017 KN
must be pressed inwards and removed 1 1
. Position A: 11/64" (4.5 mm) hole, insert pan
head self-tapping screw IS-P4x16 . Remove the screws (1) from the rewind starter
(9074 478 3025)
. While pryng the hand guard outwards with
. Position B: 7/32" (5.5 mm) hole, insert pan head a combination wrench (2) lift it off the bushing
self-tapping screw IS-D5x16 (9075 478 4115) on the fan housing
4.7 Conversion kit
The existing installing tool 1123 890 2201 (for
installation / removal of the oil pump) can be
modified with the conversion kit 1139 007 1002 for
servicing the MS 171, MS 181, MS 211 and
MS 211 C.
Conversion of the installing tool is described in
Supplement 0457 360 0047.
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Technical Information 05.2009 Page 13
4.8 Block crankshaft 4.10 Location of the serial number
533TI019 KN
The serial number is located on the engine housing,
below the muffler.
533TI018 KN
4.11 Service Manual
Servicing and repair work is described in the
The new locking strip 0000 893 5904 is used to Service Manual MS 171, MS 181, MS 211 and
block the crankshaft. MS 211 C.
Only this locking strip should be used to avoid
damaging the piston.
. The locking strip must make contact with the
5. Spare parts
opposite cylinder wall when inserted. Separate spare parts lists are available for the new
. Move the piston upwards, holding the locking machines.
strip firmly at the same time. The flexible locking
strip assumes an optimum position in relation to
the piston head and cylinder head.
. Position of the locking strip as illustrated.
All other positions may result in damage to the
piston.
4.9 Oil seal
The oil seal 9639 003 1585 (with rigid housing) can
be installed when the engine pan is separated from
the cylinder during servicing.
Only the oil seal 9638 003 1581 (with flexible
housing) may be pressed in when the cylinder and
engine pan are still assembled.
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)m~ge 14 Technical Information 05.2009
6. Repair times The repair times are specified in minutes.
The repair times are specified for trained specialist Type of repair MS 171
personnel and a fully equipped customer service MS 181
repair shop. MS 211
MS 211 C
1 Replace crankcase, crankcase 120
gasket or re-seal crankcase.
Includes air leak test.
2 Replace engine housing or cylinder 120
shroud.
3 Replace crankshaft main 120
bearing(s). Includes air leak test.
4 Replace crankshaft seal(s). 60
Includes air leak test.
5 Perform engine air leak test. 30
6 Replace cylinder and/or piston. 110
Includes air leak test and repair of
components causing failure.
7 Replace ignition module or 30
flywheel. Includes stop circuit test.
8 Replace fuel tank line, tank vent, or 25
fuel pick-up body.
9 Replace intake manifold or intake 45
flange, including leak test.
10 Repair or replace carburetor. 35
Includes fuel system testing.
11 Replace fuel tank housing. 120
12 Replace oil pick-up/delivery line. 30
Includes oil output test.
13 Replace oil pump and/or drive 25
gear. Includes oil output test.
14 Replace rear handle frame or 20
handle housing.
15 Repair or replace rewind starter. 20
16 Repair or replace clutch, clutch 20
shoes or clutch springs.
17 Repair chain brake, including 25
check for proper function.
18 Replace muffler. 20
19 Replace air filter or filter housing. 15
22 Repair or replace stop switch. 20
Includes circuit testing.
40 Miscellaneous repairs and other 15
repairs not listed.
45 Handling allowance only-no labor. 10
50 No labor. 0
© ANDREAS STIHL AG & Co. KG, 2009 Technical Documentation
D1/MTK-ke
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Extracted from the manufacturer's 2012 service catalogue. Most of these PDFs embed fonts with a shifted character map, so the text above was recovered rather than copied — read it as a faithful but imperfect transcription, and treat the page image above each block as the authority where the two disagree — the figures exist only there, because they are vector drawings that text extraction cannot keep.