Technical Information · issue 23 of 2008
New Brushcutters STIHL FS 56
IssueTI 23/2008
Full text
Page 1 of 12
STIH)
Technical Information 23.2008
New Brushcutters STIHL FS 56 – Series 4144
Contents
1. Technical description
2. Specifications
3. Cutting tools
4. Special Accessories
5. Servicing accessories
6. Spare parts
7. Servicing
The new lightweight brushcutters STIHL FS 56 C-E
and FS 56 RC-E have been designed for high
reliability, ruggedness and low maintenance.
The machine is available in a bicycle or pre-
assembled loop handle version.
The ergonomically designed controls, together with
the favorable power-to-weight ratio and easy
starting, make these machines easy to handle and
comfortable to use.
The range of application for the new brushcutters
will be the same as the FS 55.
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)m~ge 2 Technical Information 23.2008
1. Technical description 1.3 Engine with stratified scavenging
1.1 Function of stop switch and ignition 1.3.1 Mechanical Design
546TI000 KN
3
When the stop switch (1) is released, it returns to 2 4
the RUN position: The ignition is switched on – the
engine is ready for starting and can be started. If the 1
stop switch is pressed into the 0 position, the ignition
546TI002 KN
is switched off. Once the engine comes to a
complete stop, the ignition automatically resets so
the engine can be started.
Fresh mixture (1) and clean air (2) are fed into
different ports via the carburetor. Integrally molded
1.2 Choke lever control channels (3) on both sides of the piston skirt.
Open and close the connection between the clean
air port and the transfer port (4). No additional
components are required for controlling the clean
air.
An air cushion (air without fuel) separates the fresh
mixture (fuel-air mixture) and exhaust. The air
cushion is placed in front of the fresh mixture at the
beginning of the "exhaust and transfer" stroke. The
1 clean air flows from the transfer ports into the
combustion chamber purging the exhaust gases
546TI001 KN
and preventing the incoming fresh mixture from
exiting the exhaust port. This results in reduced
emissions through the reduction of fresh mixture
To start the engine, the choke lever (1) must be
losses and lower fuel consumption.
pressed and rotated to the Cold start g or Warm
start < position. Once the engine has been started
and the interlock lever and throttle trigger have been
engaged, the choke lever automatically returns to
the Run F position. Manual disengagement of the
choke lever will not be required.
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Technical Information 23.2008 Page 3
1.3.2 Carburetor
2 3
2 6 3 5
546TI003 KN
a) Full load, b) Idle c) Cold start d) Warm start
partial load
Full load and partial load Cold start
The air filter (1) divides the intake air into two During a cold start, the choke shutter is closed.
streams. The choke shutter (2) and throttle The throttle shutter is slightly open. The amount of
shutter (3) are open. The intake air flows above and air necessary for an optimal starting mixture is
below the choke and throttle shutters through the drawn in through the air bleed holes in the choke
carburetor (4). The fuel is drawn into the top part of shutter; the necessary amount of fuel is drawn in
the carburetor and flows through the venturi – where from the idle and main jet circuit.
the fresh mixture is formed. Warm start
The spacer flange (5) channels the fresh mixture
into the crankcase and the clean air into the transfer During a warm start, the choke and throttle shutters
ports. are opened to a defined angle so an ideal mixture of
air and fuel is fed to the engine for starting.
The baffle plate (6) in the carburetor, separates the
fresh mix and clean air paths from one another.
Idle
The choke shutter is open. The throttle shutter is
closed so far that only a small gap remains open at
the carburetor housing. A rich mixture is drawn in
through the idle circuit located at this gap. Air dilutes
the rich mixture into an optimal idle mixture which is
then drawn into the crankcase.
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)m~ge 4 Technical Information 23.2008
1.4 Loop handle
547TI001 KN
When the loop handle is secured flush against the
engine housing the recommended minimum
distance (A) between the handles should measure
approx. 7.9 in (200M). No additional aids are
required for setting the minimum distance.
The new machine is delivered with the loop handle
pre-assembled on the unit.
1.5 Gearhead
The gearhead is lubricated for life and will not
require additional lubrication by the end user.
If the gearhead is disassembled for repairs, it must
be relubricated by the servicing dealer.
1.6 STIHL Easy2StartTM
. for reduced cranking effort and lower cranking
speed
. Smooth starts
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Technical Information 23.2008 Page 5
2. Specifications
2.1 Engine
Single cylinder two-stroke engine
Displacement: 1.66 cu. in (27.2 cc)
Bore: 1.34 in (34 mm)
Stroke: 1.18 in (30 mm)
Engine power to ISO 8893: 1.08 bhp (0.8 kW)
Torque: 0.99 lbs.ft (1.35 Nm)
Idle speed: 2800 rpm (1/min)
Clutch engages at: 4200 rpm (1/min)
Cut-off speed
(Nominal value): 10000 rpm (1/min)
Starter mechanism: Dual pawl system
– Starter rope: Diameter 0.106 in, length 35.8 in
(Diameter 2.7 mm, length 910 mm)
– Pull-out reserve: 1.25 – 2.25 revolutions
2.2 Fuel system
Carburetor: all-position diaphragm carburetor with integral fuel pump.
Settings
High speed screw H (basic setting)
– without limiter cap for servicing dealers: 1 1/2 turns open
– with limiter cap for users: 3/4 turn counterclockwise (max. to stop)
Low speed screw L
(Standard setting): 3/4 turn counterclockwise
Idle speed screw LA: As required, cutting tool must not turn
Fuel tank capacity: 11.5 fl.oz (340 cc)
Fuel mixture: See instruction manual
Mix ratio: See instruction manual
2.3 Ignition system
Ignition module: with electronic magneto ignition
Spark plug
(suppressed): NGK CMR 6 H
Electrode gap: 0.020 in (0.5 mm)
2.4 Dimensions
Total length without cutting tool: 66.9 in (1700 mm)
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)m~ge 6 Technical Information 23.2008
2.5 Weight
Without cutting tool and deflector
Versions with Easy2Start™
FS 56 C-E1) 11.5 lbs (5.2 kg)
FS 56 RC-E 10.6 lbs (4.8 kg)
1) Version with bicycle handle
R = Loop handle
3. Cutting tools
The following cutting tools are approved: 1 2
Mowing heads
1 STIHL SuperCut™ 20-2 4002 710 2184
2 STIHL AUTOCUT® C 25-2 4002 710 2196 3 4, 5
®
3 STIHL AUTOCUT 25-2 4002 710 2191
4 STIHL TrimCut™ 30-2 4002 710 2193
5 STIHL TrimCut™ 31-2 4002 710 2156 6 7, 8
™
6 STIHL PolyCut 20-3 4002 710 2189
™
7 STIHL FixCut 25-2 4002 710 2131
9
8 STIHL FixCut™ 25-2 4002 710 2158
9 Deflector for mowing heads 4144 710 8114
Metal cutting tools
10 Grass cutting blade 230-4 4001 713 3801
11 Grass cutting blade 230-8 4001 713 3803
10 11
12 Deflector for grass cutting
blades 4144 710 8115
Mowing heads may be used on brushcutters with 12
deflector (9), bicycle and loop handle.
681TI166 KN
Grass cutting blades may only be used on
brushcutters with deflector (12), bicycle and loop
handle with barrier bar.
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Technical Information 23.2008 Page 7
4. Special Accessories
4.1 General
Part name Part No. Use
Harness 4130 710 9000
Full harness 4119 710 9001
Spool with nylon line See catalog for mowing heads STIHL SuperCut™ 20-2,
(Cutting AUTOCUT® C 25-2, AUTOCUT® 25-2
Attachments &
Accessories for
Brushcutters and
Trimmers).
Replacement blades (pack of 12) 4111 007 1001 for mowing head STIHL PolyCut™ 20-3
Transport guard 4119 790 3906 for grass cutting blades
4.2 Mowing line for mowing heads
Line diameter / color Use
0.095 in (2.4 mm) / orange STIHL SuperCut™ 20-2, AUTOCUT® C 25-2, AUTOCUT® 25-2,
TrimCut™ 30-2, TrimCut™ 31-2, STIHL PolyCut™ 20-3,
FixCut™ 25-2
0.105 in (2.7 mm) / red AUTOCUT® 25-2, TrimCut™ 30-2, TrimCut™ 31-2,
STIHL PolyCut™ 20-3, FixCut™ 25-2
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)m~ge 8 Technical Information 23.2008
5. Servicing accessories
5.1 Special tools
The following new special tools are required for the FS 56:
8
a
5910 893
1708 A
1
2
901TI065 KN
The sleeve (1) of installing tool 5910 890 2208 has The puller (3) has a 3/8" thread and may only be
a new camfer angle (a) of 20 degrees. The previous used for Series 4144 and 4140. This puller cannot
sleeve had a camfer angle of 45 degrees. The new be used with metric threads because thread
sleeve 5910 893 1708 replaces previous sleeve damage will occur.
5910 893 1703.
The existing special tools are listed in the service
Recommendation: Retrofit special tool manual for STIHL FS 56.
5910 890 2208 with new sleeve 5910 893 1708 and
update existing stocks of special tool 5910 890 2208
with new sleeve 5910 893 1708.
Flange (2) 5910 850 4200 replaces previous flange
1128 850 4200. The new flange has an additional
recess at the sealing surface side.
Item Part name Part No. Use
1 Sleeve 5910 893 1708 Installing hookless snap rings in pistons
(supplement to installing tool
5910 890 2208)
2 Flange 5910 850 4200 Engine leakage test
3 Puller 5910 893 0800 Removing the flywheel
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Technical Information 23.2008 Page 9
5.2 Aids
Part name Part No. Use
Starter rope 35.8 in (910 mm) 4137 195 8200 Rewind starter
ElastoStart™ (special accessory) 0000 190 3403 Starter mechanism (handle with rope)
– Starter rope 35.8 in (910 mm) 4137 195 8200
Set of carburetor parts 4241 007 1002 Carburetor Zama C1M-S145
Carburetor Zama C1M-S146 (only for
California)
STIHL gear lubricant for Drive shaft in drive tube
hedge trimmers
– 3 oz (80 g) tube 0781 120 1109
– 8 oz (225 g) tube 0781 120 1110
NEW:
STIHL fitting paste Paste contains molybdenum sulfide and
– Tube 1.8 oz (50 g) 0781 130 1014 graphite; use for lubrication between crankshaft
stub and clutch drum
STIHL special oil Rewind spring in rewind starter
– 3.4 fl oz (100 ml) bottle 0781 417 1315 bearing bore in rope rotor
Standard solvent-based degreaser not Cleaning the crankshaft stub and cone on the
containing any chlorinated or flywheel (see TI 25.2005)
halogenated hydrocarbons
6. Spare parts
Separate spare parts documentation will be
available for the FS 56 at market launch.
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)m~ge 10 Technical Information 23.2008
7. Servicing
The safety instructions in the instruction manual
must be observed if the machine is started during
servicing.
7.1 Service manuals
The following manuals can be used for repairs to the
FS 56:
For engine, controls and drive shaft of the FS 56 For gearhead
(powerhead 4144) of the FS 56
Service manual Service manual Service manual
Powerhead 4144 Components 4144 CombiTools
0455 938 0123 0455 545 0123 0455 227 0123
7.2 Tightening torques 7.4 Maintenance and Repairs
The tightening torques are specified in the service
manual. 7.4.1 Barbed connectors on the carburetor
7.3 First use after long periods of storage
If the machine has been stored for a period of
several months and at temperatures below 5 °C (40
degrees) press the manual fuel pump several times
in order to purge the carburetor, wait a few minutes,
then start the engine.
Recommendation: Before storing the machine for
546TI009 KN
an extended period, always run the engine until the
carburetor is dry, otherwise the carburetor
diaphragms may malfunction – see "Storing the
machine" in the instruction manual. The carburetor has two barbed connectors (arrows)
on which the fuel hoses are seated. In order to
ensure there are no leaks in the fuel system, it is
important to follow the steps listed below:
. Install and remove fuel hoses, by hand
whenever possible, in order to avoid damage to
the barbed connector – sharp-edged pliers,
screwdrivers, etc., must not be used – nor
should fuel hoses be cut open with a knife or
similar implement.
. Do not reuse fuel hoses after disassembly,
always replace them with new hoses – fuel
hoses may be over-extended when removed.
. Install new fuel hoses dry or with the aid of press
fluid OH 723 – 0781 957 9000. Other press
fluids are not permitted and may lead to fuel
hose damage.
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Technical Information 23.2008 Page 11
. When using press fluid OH 723, apply press 7.4.2 Installing the clutch drum
fluid to the ends of the hose and connectors
prior to installation.
1
Notes regarding press fluid OH 723
Press fluid OH 723 produces a lubricant film to aid
in assembly. The lubricant evaporates after a short
time allowing for a tight fit.
Never use fuel, oil or grease as a lubricant. Fuel, oil
and grease does not evaporate and may allow the
hose to slip from the connector.
546TI010 KN
For installation of the clutch drum (1), the crankshaft
stub (arrow) must be lubricated with the new fitting
paste 0781 130 1014.
a 2
546TI011 KN
Coat the crankshaft stub (2) with fitting paste in area
a = 0.4 in (10 mm).
Notes regarding fitting paste: If fitting paste is not
applied to the crankshaft stub or the carburetor is
improperly adjusted, the cutting tool may rotate
when the machine is idling.
The fitting paste can also be used with the previous
models FS 45, FS 55 and KM 55.
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)m~ge 12 Technical Information 23.2008
7.5 Serial number
Code Type of Repair FS 56
RC-E
FS 56
C-E
6 Replace cylinder and/or piston.
Includes air leak test and repair
of components causing failure. 50
7 Replace ignition module or
flywheel. Includes stop circuit
test. 30
546TI005 KN
8 Replace fuel tank line, tank
vent, or fuel pick-up body. 20
9 Replace intake manifold or
The serial number is located in two places on the intake flange. 20
underside of the engine housing – as shown in the
10 Repair or replace carburetor.
illustration.
Includes fuel system testing. 30
11 Repair throttle control. 20
7.6 Repair times 12 Repair or replace rewind starter. 15
The specified repair times apply for trained and 13 Repair or replace clutch, clutch
qualified personnel as well as for properly equipped shoes or clutch springs. 30
repair shops. 14 Replace muffler. 15
15 Replace air filter or filter
The repair times are specified in minutes.
housing. 15
This table for the FS 56 can be added to the STIHL 16 Repair or replace stop switch.
repair times table. Includes circuit testing. 25
17 Replace clutch housing. 20
18 Replace drive shaft and/or drive
tube. 30
Code Type of Repair FS 56 19 Replace bearing liner in drive
RC-E tube. 20
FS 56
20 Replace limit stop or deflector. 15
C-E
21 Repair gearbox assembly or
2 Replace crankcase, crankcase arbor shaft assembly. 15
gasket or re-seal crankcase.
22 Replace fuel tank. 20
Includes air leak test. 50
26 Replace gears and/or bearings
3 Replace crankshaft main
in gearbox. 30
bearing(s). Includes air leak
test. 50 40 Miscellaneous repairs and other
repairs not listed. 15
4 Replace crankshaft seal(s).
Includes air leak test. 50 45 Handling allowance only-no
labor. 10
5 Perform engine air leak test. 30
50 No labor. 0
© ANDREAS STIHL AG & Co. KG, 2008 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.