Technical Information · issue 24 of 2008
New STIHL KM 56 KombiMotor
IssueTI 24/2008
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STIH) Technical Information 24.2008 New STIHL KM 56 KombiMotor – Series 4144 Contents 1. Technical description 2. Specifications 3. KombiTools 4. Special accessories 5. Servicing accessories 6. Spare parts 7. Servicing TI_24_2008_30_01_02.fm englisch / English USA
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Page 2 Technical Information 24.2008
The new KombiMotor stands out by virtue of its 1. Technical description
modern appearance and exceptional ease of use.
The overall concept was designed for high reliability, 1.1 Function of stop switch and ignition
ruggedness and low maintenance requirements.
The ergonomically designed operating elements,
together with the favorable power-to-weight ratio 1
and easy starting, make these machines easy to
handle and comfortable to use.
The KombiMotor (abbreviation "KM") is available
with a loop handle and Easy2Start!™ as the
KM 56 RC. When the loop handle is used with a
barrier bar, all KombiTools can be connected to the
546TI000 KN
KombiMotor without restrictions.
The following KombiTools are currently available:
FS-KM, FSB-KM, HL-KM 0°, HL-KM 135°,
When the stop switch (1) is not actuated, it remains
FH-KM 135°, BG-KM, HT-KM, BF-KM, FCB-KM,
in the position Run: The ignition is on – the engine
FCS-KM, KB-KM and KW-KM, as well as the HT
is ready for starting and can be started. If the stop
Shaft Extension and HT/HL CFK Shaft Extension.
switch is pressed into the position 0, the ignition is
The KombiTools can be ordered individually. switched off. Once the engine comes to a complete
By swapping the KombiTools, it is possible to cover stop, the ignition automatically resets so the engine
a broad range of applications and uses. can be started.
The multi-purpose STIHL KombiSystem is highly
versatile: Customers can choose which KombiTool 1.2 Choke lever
they want supplied as original equipment with their
KombiMotor.
KombiMotor and KombiTool can be easily
transported and stored in minimum space.
1
546TI001 KN
To start the engine, the choke lever (1) must be
pressed and rotated to the position Cold start g or
Warm start <. Once the engine has been started
and the interlock lever and throttle trigger have been
engaged, the choke lever automatically returns to
the position Run F. It will not be necessary to move
the choke lever to the position Run F by hand.
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Technical Information 24.2008 Page 3
1.3 Loop handle 1.5 Engine with stratified scavenging
1.5.1 Mechanical Design
A
547TI001 KN
When the loop handle is secured flush against the
engine housing, the recommended minimum 3
distance (A) between the loop handle and controls 2 4
is ensured by the design of the loop handle. The
distance is approx. 7.9 in (200 mm). No additional 1
aids are required for setting the minimum distance.
546TI002 KN
The new machine is delivered with the loop handle
pre-assembled on the unit. The barrier bar mounts
with just one screw, so the KombiMotor can be used
with all KombiTools. Fresh mixture (1) and clean air (2) are fed into
The barrier bar must be mounted before delivery of different ports via the carburetor. Integrally molded
the KombiMotor. 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
1.4 Versions with STIHL Easy2Start™ components are required for controlling the clean
air.
. for reduced cranking effort and lower cranking
speed An air cushion (air without fuel) separates the fresh
mixture (fuel-air mixture) and exhaust. The air
. smooth starts cushion is placed in front of the fresh mixture. At the
beginning of the "exhaust and transfer" stroke, air
without fuel flows from the transfer ports into the
combustion chamber purging the exhaust gases
and preventing the incoming fresh mixture from
exiting the exhaust port. This results in reduced
emissions through the reduction of fresh mixture
losses and lower fuel consumption.
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1.5.2 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.
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.
In the carburetor, there is a baffle plate (6) that
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 hole 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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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
– Pull-out reserve: (Diameter 2.7 mm, length 910 mm)
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)
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2.4 Weight and dimensions
Overall length Weight
KombiMotor, with Easy2Start™ without KombiTool without KombiTool, without fuel
KM 56 RC: 33.1 in (840 mm) 9.5 in (4.3 kg)
R = Loop handle
Overall length Weight
KombiTools without KombiMotor without KombiMotor
FS-KM: 37.0 in (940 mm) 2.6 lbs (1.2 kg) 1)
FSB-KM: 30.3 in (770 mm) 1.6 lbs (0.7 kg) 1)
HL-KM 135°: 63.0 in (1600 mm) 5.7 lbs (2.6 kg)
HL-KM 0°: 45.7 in (1160 mm) 4.0 lbs (1.8 kg)
FH-KM 135°: 52.4 in (1330 mm) 5.3 lbs (2.4 kg)
BG-KM: 35.0 in (890 mm) 4.0 lbs (1.8 kg)
HT-KM: 49.6 in (1260 mm) 4.2 lbs (1.8 kg) 2)
BF-KM: 39.4 in (1000 mm) 9.0 lbs (4.1 kg) 3)
FCB-KM: 36.2 in (920 mm) 4.9 lbs (2.2 kg) 4)
FCS-KM: 39.4 in (1000 mm) 5.7 lbs (2.6 kg) 4)
KB-KM: 49.2 in (1250 mm) 14.1 lbs (6.4 kg) 3)
KW-KM: 49.2 in (1250 mm) 16.3 lbs (7.4 kg) 3)
1)
Without cutting attachment, without deflector
2)
Without bar and chain
3) With deflector
4) With cutting attachment and deflector
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3. KombiTools
3.1 KombiTools
The following KombiTools are available: FH-KM
KombiTools Intended use
FS-KM Trimmer with mowing head
1
FS-KM Trimmer with grass cutting blade
FS-KM HT-KM 2
FSB-KM Trimmer with curved shaft and
mowing head
HL-KM 135° Hedge trimmer, adjustable BG-KM
HL-KM 0° Hedge trimmer
FSB-KM
FH-KM 135° Power Scythe, adjustable FS-KM FCB-KM FCS-KM
BG-KM Blower
HT-KM Pole pruner
BF-KM Soil cultivator
KB-KM KW-KM
FCB-KM Edger BF-KM
FCS-KM Edger
KB-KM Bristle brush
470TI004 KN
KW-KM STIHL PowerSweep™
1 Extension drive tube, approved for use on
HT-KM only
2 Carbon Extension drive tube, approved for use
on HT-KM, HL-KM 0° and HL-KM 135°
Information regarding loop handle with barrier bar –
see b 1.3
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3.2 Cutting attachments for FS-KM
The following cutting attachments are approved for
FS-KM:
Mowing heads
1 STIHL SuperCut™ 20-2 4002 710 2184
1 2
2 STIHL AUTOCUT® C 25-2 4002 710 2196
3 STIHL AUTOCUT® 25-2 4002 710 2191
4 STIHL TrimCut™ 30-2 4002 710 2193
3 4, 5 5 STIHL TrimCut™ 31-2 4002 710 2156
6 STIHL PolyCut™ 20-3 4002 710 2189
7 STIHL FixCut™ 25-2 4001 710 2131
6 7, 8 8 STIHL FixCut™ 25-2 4002 710 2158
Metal cutting tools
9 10 9 Grass cutting blade 230-4 4001 713 3801
10 Grass cutting blade 230-8 4001 713 3803
681TI168 KN
All cutting attachments listed must be used with
approved deflectors (see catalog "Cutting
Attachments & Accessories for Brushcutters and
Trimmers").
3.3 Cutting attachments for FSB-KM
The following cutting attachments are approved for Mowing heads
FSB-KM:
1 STIHL AUTOCUT® 11-2 4004 710 2192
2 STIHL PolyCut™ 5-3 4004 710 2180
All cutting attachments listed must be used with
approved deflectors (see catalog "Cutting
Attachments & Accessories for Brushcutters and
Trimmers").
1 2
002TI034 BL
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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 Nylon 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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5. Servicing accessories
5.1 Special tools
The following new special tools are required for the KM 56 RC:
8
a
5910 893
1708 A
1
2
901TI065 KN
The sleeve (1) of installing tool 5910 890 2208 has Flange (2) 5910 850 4200 replaces previous flange
a new camfer angle (a) of 20 degrees. The previous 1128 850 4200. The new flange has an additional
sleeve had a camfer angle of 45 degrees. The new recess at the sealing surface facing the spacer
sleeve 5910 893 1708 replaces previous sleeve flange.
5910 893 1703. The puller (3) has a 3/8" thread and may only be
Recommendation: Retrofit special tool used for Series 4144 and 4140. This puller cannot
5910 890 2208 with new sleeve 5910 893 1708 and be used with metric threads because thread
update existing stocks of special tool 5910 890 2208 damage will occur.
with the new sleeve 5910 893 1708.
The existing special tools are listed in the service
manual for STIHL KM 56 RC.
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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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
– 1.8 oz (50 g) tube 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 KM 56 RC when it is launched on the market.
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
within the KombiSystem:
For KombiMotor KM 56 RC (powerhead 4144) For the KombiTools
Service manual Service manual Service manual
Powerhead 4144 Components 4144 KombiTools
0455 938 0123 0455 545 0123 0455 227 0123
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7.2 Tightening torques . When using press fluid OH 723, apply press
The tightening torques are specified in the service fluid to the ends of the hose and connectors
manual. prior to installation.
Notes regarding press fluid OH 723
Press fluid OH 723 produces a lubricant film to aid
7.3 First use after long periods of storage
in assembly. The lubricant evaporates after a short
In isolated cases, problems may be experienced time allowing for a tight fit.
with starting when the machine is stored over a
Never use fuel, oil or grease as a lubricant. Fuel, oil
period of several months and at temperatures under
and grease does not evaporate and may allow the
(40 degrees) 5 °C.
hose to slip from the connector.
In this case, press the manual fuel pump several
times in order to purge the carburetor. Afterwards,
wait a few minutes, then start the engine.
Recommendation: Before storing the machine for
an extended period, always run the engine until the
carburetor is dry, otherwise the carburetor
diaphragms may stick together – see also "Storing
the machine" in the owner's manual.
7.4 Maintenance and Repairs
7.4.1 Barbed connectors on the carburetor
546TI009 KN
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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7.4.2 Installing the clutch drum 7.5 Serial number
546TI005 KN
546TI010 KN
For installation of the clutch drum (1), the crankshaft The serial number is located in two places on the
stub (arrow) must be lubricated with the new fitting underside of the engine housing – as shown in the
paste 0781 130 1014. illustration.
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.
If the cutting tool turns when the machine is idling,
check for proper carburetor adjustment and verify
fitting paste has been applied to the crankshaft stub.
The fitting paste can also be used with the previous
models FS 45, FS 55 and KM 55.
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7.6 Repair times
Code Type of Repair KM 56 RC
The specified repair times apply for trained and
9 Replace intake manifold or
qualified personnel as well as for properly equipped
intake flange. 20
repair shops.
10 Repair or replace carburetor.
The repair times are specified in minutes. Includes fuel system testing. 30
This table for the KM 56 RC can be added to the 11 Repair throttle control. 20
STIHL repair times table. 12 Repair or replace rewind starter. 15
13 Repair or replace clutch, clutch
shoes or clutch springs. 30
Code Type of Repair KM 56 RC 14 Replace muffler. 15
2 Replace crankcase, crankcase 15 Replace air filter or filter
gasket or re-seal crankcase. housing. 15
Includes air leak test. 50 16 Repair or replace stop switch.
3 Replace crankshaft main Includes circuit testing. 25
bearing(s). Includes air leak 17 Replace clutch housing. 20
test. 50
18 Replace outer drive tube. 30
4 Replace crankshaft seal(s).
19 Replace shaft coupler or gear
Includes air leak test. 50
box. 15
5 Perform engine air leak test. 30
21 Replace drive shaft. 15
6 Replace cylinder and/or piston.
22 Replace fuel tank. 20
Includes air leak test and repair
of components causing failure. 50 40 Miscellaneous repairs and other
repairs not listed. 15
7 Replace ignition module or
flywheel. Includes stop circuit 45 Handling allowance only-no
test. 30 labor. 10
8 Replace fuel tank line, tank 50 No labor. 0
vent, or fuel pick-up body. 20
© ANDREAS STIHL AG & Co. KG, 2008 Technical Documentation
D1/MTK-ke
TI_24_2008_30_01_02.fm 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.