Stihl KA 120 User manual

STIHL KA 120, 250
Instruction Manual2 - 22

Contents
1 KombiAttachmentSystem............................2
2 Guide to Using this Manual.........................3
3 Safety Precautions and Working Techni‐
ques............................................................ 3
4 Approved Power Tool Attachments............ 7
5 Mounting the Bike Handle...........................7
6 Adjusting the Throttle Cable........................9
7 Fitting the Carrying Ring........................... 10
8 Fuel........................................................... 10
9 Fueling...................................................... 11
10 Starting / Stopping the Engine.................. 12
11 Operating Instructions...............................14
12 Cleaning the Air Filter............................... 14
13 Adjusting the Carburetor........................... 15
14 Spark Plug................................................ 15
15 Engine Running Behavior......................... 16
16 Replacing the Starter Rope and Rewind
Spring........................................................17
17 Storing the Machine.................................. 18
18 Inspections and Maintenance by Dealer...19
19 Maintenance and Care..............................19
20 Minimize Wear and Avoid Damage...........20
21 Main Parts.................................................21
22 Specifications............................................21
23 Maintenance and Repairs......................... 22
24 Disposal.................................................... 22
Dear Customer,
Thank you for choosing a quality engineered
STIHL product.
It has been built using modern production techni‐
ques and comprehensive quality assurance.
Every effort has been made to ensure your satis‐
faction and trouble-free use of the product.
Please contact your dealer or our sales company
if you have any queries concerning this product.
Your
Dr. Nikolas Stihl
1 KombiAttachmentSystem
.
.
.
.
002BA532 KN
+
+
In the STIHL KombiAttachmentSystem a number
of different KombiAttachmentEngines and attach‐
ments can be combined to produce a power tool.
In this instruction manual the functional unit
formed by the KombiAttachmentEngine and
attachment is referred to as the power tool.
Therefore, the separate instruction manuals for
the KombiAttachmentEngine and attachment
should be used together for the power tool.
Always read and and make sure you understand
both instruction manuals before using your
power tool for the first time and keep them in a
safe place for future reference.
In this instruction manual the KombiAttachmen‐
tEngine is also referred to as the basic power
tool.
The approved power tool models are listed in the
chapter on "Approved Basic Power Tools".
The approved power tool models are listed in the
chapter on "Approved Attachments".
English
2 0458-516-0121-B
© ANDREAS STIHL AG & Co. KG 2021
0458-516-0121-B. VA0.F21.
Printed on chlorine-free paper Printing inks contain vegetable oils, paper can be recycled.
Original Instruction Manual 0000006698_008_GB

2 Guide to Using this Manual
2.1 Pictograms
All the pictograms attached to the machine are
shown and explained in this manual.
2.2 Symbols in text
WARNING
Warning where there is a risk of an accident or
personal injury or serious damage to property.
NOTICE
Caution where there is a risk of damaging the
machine or its individual components.
2.3 Engineering improvements
STIHL's philosophy is to continually improve all
of its products. For this reason we may modify
the design, engineering and appearance of our
products periodically.
Therefore, some changes, modifications and
improvements may not be covered in this man‐
ual.
3 Safety Precautions and
Working Techniques
Special safety precautions must be
observed when working with a power
tool.
Always read and and make sure you
understand both instruction manuals
(KombiAttachmentEngine and power
tool attachment) before using your
power tool for the first time and keep
them in a safe place for future refer‐
ence. Non-observance of the safety
precautions may result in serious or
even fatal injury.
Observe all applicable local safety regulations,
standards and ordinances.
If you have not used this type of power tool
before: Have your dealer or other experienced
user show you how to operate your machine or
attend a special course in its operation.
Minors should never be allowed to use this prod‐
uct.
Keep bystanders, especially children, and ani‐
mals away from the work area.
When the power tool is not in use, shut it off so
that it does not endanger others. Secure it
against unauthorized use.
The user is responsible for avoiding injury to third
parties or damage to their property.
Lend or rent your machine only to persons who
are familiar with this model and its operation – do
not lend of rent your machine without the instruc‐
tion manuals of the KombiAttachmentEngine and
power tool attachment.
The use of noise emitting power tools may be
restricted to certain times by national or local
regulations.
To operate the power tool you must be rested, in
good physical condition and mental health.
If you have any condition that might be aggrava‐
ted by strenuous work, check with your doctor
before operating a power tool.
Persons with pacemakers only: The ignition sys‐
tem of your power tool produces an electromag‐
netic field of a very low intensity. This field may
interfere with some pacemakers. STIHL recom‐
mends that persons with pacemakers consult
their physician and the pacemaker manufacturer
to reduce any health risk.
Do not operate the power tool if you are under
the influence of any substance (drugs, alcohol)
which might impair vision, dexterity or judgment.
Use your power tool only for the applications
described in the instruction manual of the power
tool attachment you are using.
It must not be used for any other purpose
because of the increased risk of accidents and
damage to the machine. Never attempt to modify
your power tool in any way since this may result
in accidents or damage to the machine.
Do not operate the KombiAttachmentEngine
without a properly mounted power tool attach‐
ment since this may result in damage to the
machine.
Only mount attachments and accessories that
are explicitly approved for this power tool by
STIHL or are technically identical. It is important
that you read the chapter on "Approved Attach‐
ments". If you have any questions in this respect,
consult a servicing dealer. Use only high quality
tools and accessories in order to avoid the risk of
accidents and damage to the machine.
STIHL recommends the use of genuine STIHL
tools and accessories. They are specifically
2 Guide to Using this Manual English
0458-516-0121-B 3

designed to match the product and meet your
performance requirements.
Never attempt to modify your machine in any
way since this may increase the risk of personal
injury. STIHL excludes all liability for personal
injury and damage to property caused while
using unauthorized attachments.
Do not use a pressure washer to clean the unit.
The solid jet of water may damage parts of the
unit.
3.1 Clothing and Equipment
Wear proper protective clothing and equipment.
See also notes on "Clothing and Equipment" in
the instruction manual of the power tool attach‐
ment you are using.
3.2 Transporting the Power Tool
Always turn off the engine.
Transporting by vehicle: Properly secure your
power tool to prevent turnover, fuel spillage and
damage.
See also notes on "Transporting the Machine" in
the instruction manual of the power tool attach‐
ment you are using.
3.3 Fueling
Gasoline is an extremely flammable
fuel. Keep clear of naked flames. Do
not spill any fuel – do not smoke.
Always shut off the engine before refueling.
Do not fuel a hot engine – fuel may spill and
cause a fire.
Open the fuel cap carefully to allow any pressure
build-up in the tank to release slowly and avoid
fuel spillage.
Fuel your power tool only in well-ventilated
areas. If you spill fuel, wipe the machine immedi‐
ately – if fuel gets on your clothing, change
immediately.
Your power tool comes standard with either a
screw-type or bayonet-type fuel cap.
After fueling, tighten down the screw-
type fuel cap as securely as possible.
Insert the fuel cap with hinged grip
(bayonet-type cap) correctly in the
opening, turn it clockwise as far as
stop and fold the grip down.
This reduces the risk of unit vibrations causing
the fuel cap to loosen or come off and spill quan‐
tities of fuel.
To reduce the risk of serious or fatal burn inju‐
ries, check for fuel leakage. If fuel leakage is
found, do not start or run the engine until leak is
fixed.
3.4 Before Starting
Check that your power tool is properly assem‐
bled and in good condition – refer to appropriate
chapters in the instruction manuals.
–Check the fuel system for leaks, paying spe‐
cial attention to visible parts such as the tank
cap, hose connections and the manual fuel
pump (on machines so equipped). If there are
any leaks or damage, do not start the engine –
risk of fire. Have your machine repaired by a
servicing dealer before using it again.
–Use only an approved combination of cutting
attachment, deflector, handle and harness. All
parts must be assembled properly and
securely.
–The power tool attachment must be approved
for use with this KombiEngine.
–Slide control / stop switch must move easily to
STOP or 0.
–Smooth action of throttle trigger lockout and
throttle trigger – the throttle trigger must return
automatically to the idle position.
–Check that the spark plug boot is secure – a
loose boot may cause arcing that could ignite
combustible fumes and cause a fire.
–Never attempt to modify the controls or safety
devices in any way.
–Keep the handles dry and clean – free from oil
and dirt – for safe control of the power tool.
–Adjust the harness and handle(s) to suit your
height and reach.
To reduce the risk of accidents, do not operate
your power tool if it is damaged or not properly
assembled.
English 3 Safety Precautions and Working Techniques
4 0458-516-0121-B

If you use a shoulder strap or full harness: Prac‐
tice removing and putting down the machine as
you would in an emergency. To avoid damage,
do not throw the machine to the ground when
practicing.
See also notes on "Before Starting" in the
instruction manual of the power tool attachment
you are using.
3.5 Starting the Engine
Start the engine at least 3 meters from the fuel‐
ing spot, outdoors only.
Place the power tool on firm ground in an open
area. Make sure you have good balance and
secure footing. Hold the power tool securely. The
attachment must be clear of the ground and all
other obstructions because it may begin to run
when the engine starts.
To reduce the risk of injury, avoid contact with
the attachment.
Do not drop start the power tool – start the
engine as described in the instruction manual.
Note that the attachment continues to run for a
short period after you let go of the throttle trigger
– flywheel effect.
Check idle speed setting: The attachment must
be stationary when the engine is idling with the
throttle trigger released.
To reduce the risk of fire, keep hot exhaust
gases and hot muffler away from easily combus‐
tible materials (e.g. wood chips, bark, dry grass,
fuel).
See also notes on "Starting the Engine" in the
instruction manual of the power tool attachment
you are using.
3.6 Holding and Controlling the
Power Tool
Always hold the power tool firmly with both
hands on the handles. Make sure you always
have good balance and secure footing.
3.6.1 Models with bike handle
002BA055 KN
Right handle on control handle, left hand on left
handle.
3.6.2 Models with loop handle
002BA080 KN
Left hand on loop handle, right hand on control
handle, even if you are left-handed.
3.7 During Operation
In the event of impending danger or in an emer‐
gency, switch off the engine immediately by mov‐
ing the slide control / stop switch to STOP or 0.
The correct engine idle speed is important to
ensure that the attachment stops moving when
you let go of the throttle trigger. If the attachment
continues to run when the engine is idling, have
your dealer check your machine and make
proper adjustments or repairs. STIHL recom‐
mends an authorized STIHL servicing dealer.
Check and correct the idle speed setting regu‐
larly.
Be particularly alert and cautious when wearing
hearing protection because your ability to hear
warnings (shouts, alarms, etc.) is restricted.
To reduce the risk of accidents, take a break in
good time to avoid tiredness or exhaustion.
Work calmly and carefully – in daylight conditions
and only when visibility is good. Stay alert so as
not to endanger others.
3 Safety Precautions and Working Techniques English
0458-516-0121-B 5

Use your machine only in the areas specified in
the instruction manual of the power tool attach‐
ment.
Your power tool produces toxic
exhaust fumes as soon as the engine
is running. These fumes may be col‐
orless and odorless and contain
unburned hydrocarbons and benzol.
Never run the engine indoors or in
poorly ventilated locations, even if
your model is equipped with a cata‐
lytic converter.
To reduce the risk of serious or fatal injury from
breathing toxic fumes, ensure proper ventilation
when working in trenches, hollows or other con‐
fined locations.
To reduce the risk of accidents, stop work imme‐
diately in the event of nausea, headache, visual
disturbances (e.g. reduced field of vision), prob‐
lems with hearing, dizziness, deterioration in abil‐
ity to concentrate. Apart from other possibilities,
these symptoms may be caused by an exces‐
sively high concentration of exhaust gases in the
work area.
Operate your power tool so that it produces a
minimum of noise and emissions – do not run the
engine unnecessarily, accelerate the engine only
when working.
To reduce the risk of fire, do not smoke while
operating or standing near your power tool. Note
that combustible fuel vapor may escape from the
fuel system.
The dusts, vapor and smoke produced during
operation may be dangerous to health. If the
work area is very dusty or smoky, wear a respira‐
tor.
If your power tool is subjected to unusually high
loads for which it was not designed (e.g. heavy
impact or a fall), always check that it is in good
condition before continuing work – see also
"Before Starting".
Check the fuel system in particular for leaks and
make sure the safety devices are working prop‐
erly. Do not continue operating your power tool if
it is damaged. In case of doubt, consult your
servicing dealer.
Do not operate your power tool in the starting
throttle position – engine speed cannot be con‐
trolled in this position.
Before leaving the power tool unattended: Shut
off the engine.
To reduce the risk of unintentional engine start
and injury, always shut off the engine and
remove the spark plug boot before changing the
attachment.
3.8 Vibrations
Prolonged use of the power tool may result in
vibration-induced circulation problems in the
hands (whitefinger disease).
No general recommendation can be given for the
length of usage because it depends on several
factors.
The period of usage is prolonged by:
–Hand protection (wearing warm gloves)
–Work breaks
The period of usage is shortened by:
–Any personal tendency to suffer from poor cir‐
culation (symptoms: frequently cold fingers,
tingling sensations).
–Low outside temperatures.
–The force with which the handles are held (a
tight grip restricts circulation).
Continual and regular users should monitor
closely the condition of their hands and fingers. If
any of the above symptoms appear (e.g. tingling
sensation in fingers), seek medical advice.
3.9 Maintenance and Repairs
Service the machine regularly. Do not attempt
any maintenance or repair work not described in
the instruction manual. Have all other work per‐
formed by a servicing dealer.
STIHL recommends that you have servicing and
repair work carried out exclusively by an author‐
ized STIHL servicing dealer. STIHL dealers are
regularly given the opportunity to attend training
courses and are supplied with the necessary
technical information.
Only use high-quality replacement parts in order
to avoid the risk of accidents and damage to the
machine. If you have any questions in this
respect, consult a servicing dealer.
STIHL recommends the use of genuine STIHL
replacement parts. They are specifically
designed to match your model and meet your
performance requirements.
To reduce the risk of injury, always shut off the
engine before carrying out any maintenance or
repairs or cleaning the machine. – Exception:
Carburetor and idle speed adjustments.
English 3 Safety Precautions and Working Techniques
6 0458-516-0121-B

Do not turn the engine over on the starter with
the spark plug boot or spark plug removed
unless the slide control / stop switch is on STOP
or 0 since there is otherwise a risk of fire from
uncontained sparking.
To reduce the risk of fire, do not service or store
your machine near open flames.
Check the fuel filler cap for leaks at regular inter‐
vals.
Use only a spark plug of the type approved by
STIHL and make sure it is in good condition –
see "Specifications".
Inspect the ignition lead (insulation in good con‐
dition, secure connection).
Check the condition of the muffler.
To reduce the risk of fire and damage to hearing,
do not operate your machine if the muffler is
damaged or missing.
Do not touch a hot muffler since burn injury will
result.
Vibration behavior is influenced by the condition
of the AV elements – check the AV elements at
regular intervals.
4 Approved Power Tool
Attachments
The following STIHL attachments may be moun‐
ted to the basic power tool:
FS
(B)
FS
(A)
BF
228BA071 KN
Interchangeable
Attachment
Application
FS (A) 1) Brushcutter with mowing
head
FS (B) 1) 2) Brushcutter with metal
cutting attachment
BF Cultivator with pick tines
5 Mounting the Bike Handle
5.1 Mounting Bike Handle with
Swiveling Handle Support
The machine is supplied with the swiveling han‐
dle support already mounted on the shaft. To
mount the handlebar it is necessary to remove
the clamp moldings.
5.1.1 Removing the Clamp Moldings
► Hold the lower clamp (1) and upper clamp (2)
firmly together.
► Release the wing screw (3) – the clamps are
loose once the wing screw has been released.
They are pushed apart by the two
springs (4 and 5).
► Pull out the wing screw – the washer (6)
remains on the wing screw.
► Separate the clamp moldings – the
springs (4 and 5) remain in the lower clamp.
1) Use shoulder strap
2) Barrier bar required on loop handle
4 Approved Power Tool Attachments English
0458-516-0121-B 7

5.1.2 Securing the Handlebar
1
7
A
250BA046 KN
► Place the handlebar (7) in the lower clamp (1)
so that distance A is no more than 15 cm
(6 in).
► Place the upper clamp in position and hold
both clamp moldings together.
► Push the wing screw through the two clamps
as far as stop – hold all parts together and
secure them.
002BA234 KN
8
► Place the secured assembly on the handle
support (8) with the wing screw at the side
nearest the engine.
► Push the wing screw into the handle support
as far as stop and then screw it down – but do
not finally tighten yet.
► Line up the handlebar at a right angle to the
drive tube – check distance A again.
► Tighten down the wing screw firmly.
5.1.3 Mounting the Control Handle
► Take out the screw (9) – the nut (10) remains
in the control handle (11).
► Push the control handle onto the handlebar (7)
until the holes (13) line up – the throttle trig‐
ger (12) must point towards the gearbox.
► Insert the screw (9) and tighten it down firmly.
English 5 Mounting the Bike Handle
8 0458-516-0121-B

5.1.4 Fitting the Throttle Cable
NOTICE
Do not kink the throttle cable or lay it in tight radii
– make sure the throttle trigger moves freely.
15 14
14
15
15
250BA002
► Position the throttle cable retainer (15) and
throttle cable (14) against the drive tube.
► Close the throttle cable retainer (15). The
retainer (15) snaps into place.
5.1.5 Adjusting the Throttle Cable
► Check adjustment of throttle cable – see chap‐
ter on "Adjusting the Throttle Cable".
5.1.6 Swiveling the Handlebar
Transport position
3
7
90°
002BA650
► Loosen the wing screw (3) and unscrew it until
the handlebar (7) can be rotated.
► Rotate the handlebar 90° counterclockwise
and then swing the handles down.
► Tighten down the wing screw (3) firmly.
Working position
► Reverse the sequence described above to
swing the handles up and turn the handlebar
clockwise.
6 Adjusting the Throttle
Cable
A properly adjusted throttle cable is the precondi‐
tion for correct operation in the full throttle, start‐
ing throttle and idle positions.
Adjust the throttle cable only after the unit is fully
assembled – the control handle must be in the
normal operating position.
6 Adjusting the Throttle Cable English
0458-516-0121-B 9

002BA163 KN
► Use a suitable tool to push the slide to the end
of the slot (see illustration).
STOP
249BA017 KN
1
2
► Press down the throttle trigger lockout (1) and
squeeze the throttle trigger (2) (full throttle) –
this sets the throttle cable correctly.
7 Fitting the Carrying Ring
The carrying ring comes standard with the
machine or is available as a special accessory.
002BA142 KN
1
2
1
For position of carrying ring see "Main Parts".
► Place the clamp (1) against the drive tube with
the tapped hole on the left (viewed from
engine).
► Squeeze the two ends of the clamp together
and hold in that position.
► Insert the M6x14 screw (2).
► Line up the carrying ring.
► Tighten down the screw firmly.
8 Fuel
Your engine requires a mixture of gasoline and
engine oil.
WARNING
For health reasons, avoid direct skin contact with
gasoline and avoid inhaling gasoline vapor.
8.1 STIHL MotoMix
STIHL recommends the use of STIHL MotoMix.
This ready-to-use fuel mix contains no benzol or
lead, has a high octane rating and ensures that
you always use the right mix ratio.
STIHL MotoMix uses STIHL HP Ultra two-stroke
engine oil for an extra long engine life.
MotoMix is not available in all markets.
8.2 Mixing Fuel
NOTICE
Unsuitable fuels or lubricants or mix ratios other
than those specified may result in serious dam‐
age to the engine. Poor quality gasoline or
engine oil may damage the engine, sealing rings,
hoses and the fuel tank.
8.2.1 Gasoline
Use only high-quality brand-name gasoline with
a minimum octane rating of 90 – leaded or unlea‐
ded.
Gasoline with an ethanol content of more than
10% can cause running problems in engines with
a manually adjustable carburetor and should not
be used in such engines.
Engines equipped with M-Tronic deliver full
power when run on gasoline with an ethanol con‐
tent of up to 25% (E25).
8.2.2 Engine Oil
If you mix the fuel yourself, use only STIHL two-
stroke engine oil or another high-performance
English 7 Fitting the Carrying Ring
10 0458-516-0121-B

engine oil in accordance with JASO FB, JASO
FC, JASO FD, ISO-L-EGB, ISO-L-EGC or ISO-L-
EGD.
STIHL specifies STIHL HP Ultra two-stroke
engine oil or an equivalent high-performance
engine oil in order to maintain emission limits
over the machine’s service life.
8.2.3 Mix Ratio
STIHL 50:1 two-stroke engine oil: 50 parts gaso‐
line to 1 part oil
8.2.4 Examples
Gasoline STIHL engine oil 50:1
Liters Liters (ml)
1 0.02 (20)
5 0.10 (100)
10 0.20 (200)
15 0.30 (300)
20 0.40 (400)
25 0.50 (500)
► Use a canister approved for storing fuel. Pour
oil into canister first, then add gasoline and
mix thoroughly.
8.3 Storing Fuel
Store fuel only in approved safety-type fuel can‐
isters in a dry, cool and safe location protected
from light and the sun.
Fuel mix ages – only mix sufficient fuel for a few
weeks work. Do not store fuel mix for longer than
30 days. Exposure to light, the sun, low or high
temperatures can quickly make the fuel mix
unusable.
STIHL MotoMix may be stored for up to 2 years
without any problems.
► Thoroughly shake the mixture in the canister
before fueling your machine.
WARNING
Pressure may build up in the canister – open it
carefully.
► Clean the fuel tank and canister from time to
time.
Dispose of remaining fuel and cleaning fluid
properly in accordance with local regulations and
environmental requirements.
9 Fueling
9.1 Preparations
256BA060 KN
► Before fueling, clean the filler cap and the area
around it to ensure that no dirt falls into the
tank.
► Position the machine so that the filler cap is
facing up.
9.2 Filling Up with Fuel
Take care not to spill fuel while fueling and do
not overfill the tank. STIHL recommends you use
the STIHL filler nozzle for fuel (special acces‐
sory).
► Open the filler cap.
► Fill up with fuel.
► Close the filler cap.
9 Fueling English
0458-516-0121-B 11

WARNING
After fueling, tighten down the filler cap as
securely as possible by hand.
9.3 Changing the Fuel Pickup Body
250BA051 KN
Change the fuel pickup body every year:
► Drain the fuel tank.
► Use a hook to pull the fuel pickup body out of
the tank and take it off the hose.
► Push the new pickup body into the hose.
► Place the pickup body in the tank.
10 Starting / Stopping the
Engine
10.1 Controls
3
STOP
56
4
7
002BA182 KN
1
2
START
STOP-
1 Throttle trigger lockout
2 Throttle trigger
3 Slide control
10.1.1 Positions of slide control
4 STOP-0 – engine off – ignition is switched off
5F – normal run position – the engine is running
or can start
6 START – ignition is switched on – the engine
can start
10.1.2 Symbol on slide control
7h – stop symbol and arrow. To stop the
engine, push the slide control in the direction
of the arrow on the stop symbol (h) to
STOP-0.
10.2 Starting
► Press down the trigger lockout lever and
squeeze the throttle trigger
► and hold them in that position.
► Move the slide control to START and hold it
there.
English 10 Starting / Stopping the Engine
12 0458-516-0121-B

► Now release the throttle trigger, slide control
and trigger lockout in that order. This is the
starting throttle position.
250BA018 KN
9
8
► Set the choke knob (8) to:
gif the engine is cold
efor warm start – also use this position if the
engine has been running but is still cold.
► Press the manual fuel pump bulb (9) at least
five times – even if the bulb is filled with fuel.
10.2.1 Cranking
002BA038 KN
002BA040 KN
► Place the power tool on the ground so that it
rests on the machine support:
To reduce the risk of injury, check that the
attachment is not touching the ground or any
other obstacles – see also "Starting / Stopping
the Engine" in the instruction manual of the
attachment you are using.
► Make sure you have a firm footing, either
standing, stooping or kneeling.
► Hold the unit firmly on the ground with your left
hand and press down – do not touch the throt‐
tle trigger, lockout lever or slide control.
NOTICE
Do not stand or kneel on the drive tube.
002BA072 KN
► Hold the starter grip with your right hand.
► Pull the starter grip slowly until you feel it
engage and then give it a brisk strong pull.
NOTICE
Do not pull out the starter rope all the way – it
might otherwise break.
► Do not let the starter grip snap back. Guide it
slowly back into the housing so that the starter
rope can rewind properly.
► Continue cranking.
10.2.2 When engine begins to fire
►Turn the choke knob to e.
► Continue cranking until the engine runs.
10.2.3 As soon as the engine runs
► Blip the throttle trigger immediately. The slide
control moves to the normal run position F –
and the engine settles down to idle speed.
WARNING
Make sure the carburetor is correctly adjusted.
The working tool must not rotate when the
engine is idling.
Your machine is now ready for operation.
10.3 Stopping the Engine
► Push the slide control in the direction of the
arrow on the stop symbol (h) to STOP-0.
10.4 At very low outside tempera‐
tures
As soon as the engine runs:
10 Starting / Stopping the Engine English
0458-516-0121-B 13

► Blip the throttle trigger to disengage the start‐
ing throttle position. The slide control moves to
the normal run position F – and the engine set‐
tles down to idle speed.
► Open the throttle slightly.
► Warm up the engine for a short period.
10.5 If engine does not start
10.5.1 Choke knob
If you did not turn the choke knob to e quickly
enough after the engine began to fire, the com‐
bustion chamber is flooded.
►Turn the choke knob to e.
► Select the starting throttle position.
► Start the engine by pulling the starter rope
briskly – 10 to 20 pulls may be necessary.
If the engine still does not start
► Push the slide control in the direction of the
arrow on the stop symbol (h) to STOP-0.
► Remove the spark plug – see "Spark Plug".
► Dry the spark plug.
► Open the throttle wide.
► Crank the engine several times with the starter
to clear the combustion chamber.
► Refit the spark plug – see "Spark Plug".
► Move the slide control to START.
►Set the choke knob to e – even if the engine
is cold.
► Start the engine.
10.5.2 Throttle cable adjustment
► Check adjustment of throttle cable – see chap‐
ter on "Adjusting the Throttle Cable".
10.5.3 Fuel tank run until completely dry
Recommendation: Carry out the following steps
irrespective of the engine's operating condition
before the tank was run dry.
►Turn the choke knob to g.
► Go to section on "Starting" and re-start the
engine as described for a cold engine.
11 Operating Instructions
11.1 During break-in period
A factory-new machine should not be run at high
revs (full throttle off load) for the first three tank
fillings. This avoids unnecessary high loads dur‐
ing the break-in period. As all moving parts have
to bed in during the break-in period, the frictional
resistances in the engine are greater during this
period. The engine develops its maximum power
after about 5 to 15 tank fillings.
11.2 During Operation
After a long period of full throttle operation, allow
the engine to run for a short while at idle speed
so that engine heat can be dissipated by the flow
of cooling air. This protects engine-mounted
components (ignition, carburetor) from thermal
overload.
11.3 After Finishing Work
Storing for a short period: Wait for the engine to
cool down. Empty the fuel tank and keep the
machine in a dry place, well away from sources
of ignition, until you need it again. For longer out-
of-service periods – see "Storing the Machine".
12 Cleaning the Air Filter
12.1 If there is a noticeable loss of
engine power
250BA071 KN
►Turn the choke knob to g.
► Press in the tab (1) and remove the filter
cover (2).
► Clean away loose dirt from around the filter (3)
and inside the filter cover.
► Remove and check the filter element – replace
it if is dirty or damaged.
► Install the filter element in the filter cover.
► Refit the filter cover.
English 11 Operating Instructions
14 0458-516-0121-B

13 Adjusting the Carburetor
13.1 General Information
The carburetor comes from the factory with a
standard setting.
This setting provides an optimum fuel-air mixture
under most operating conditions.
13.2 Preparations
► Shut off the engine.
► Mount the attachment.
► Check the air filter and replace if necessary.
► Check that the throttle cable is properly adjus‐
ted – readjust if necessary – see chapter on
"Adjusting the Throttle Cable".
13.3 Carry out the standard setting.
–High speed screw (H) = 3/4
–Low speed screw (L) = 3/4
255BA006 KN
HL
► Turn high speed screw (H) counterclockwise
as far as stop (no more than 3/4 turn).
► Turn the low speed screw (L) carefully clock‐
wise as far as stop, then turn it back 3/4 turn.
13.4 Adjust idle speed
► Carry out the standard setting.
► Start and warm up the engine.
255BA007 KN
LA
13.4.1 Engine stops while idling
► Turn the idle speed screw (LA) clockwise until
the engine runs smoothly – the attachment
must not run.
13.4.2 Attachment runs when engine is idling
► Turn the idle speed screw (LA) counterclock‐
wise until the attachment stops moving and
then turn the screw another 1/2 to 1 full turn in
the same direction.
WARNING
If the attachment continues to run when the
engine is idling, have your machine checked and
repaired by your servicing dealer.
13.4.3 Erratic idling behavior, poor accelera‐
tion (despite correction to setting of LA
screw).
Idle setting is too lean
► Turn the low speed screw (L) counterclock‐
wise, no further than stop, until the engine
runs and accelerates smoothly.
13.4.4 Erratic idling behavior
Idle setting is too rich
► Turn the low speed screw (L) clockwise, no
further than stop, until the engine runs and
accelerates smoothly.
It is usually necessary to change the setting of
the idle speed screw (LA) after every correction
to the low speed screw (L).
13.5 Fine Tuning for Operation at
High Altitude
A slight correction of the setting may be neces‐
sary if engine does not run satisfactorily:
► Carry out the standard setting.
► Warm up the engine.
► Turn high speed screw (H) slightly clockwise
(leaner) – no further than stop.
NOTICE
After returning from high altitude, reset the car‐
buretor to the standard setting.
If the setting is too lean there is a risk of engine
damage due to insufficient lubrication and over‐
heating.
14 Spark Plug
► If the engine is down on power, difficult to start
or runs poorly at idle speed, first check the
spark plug.
13 Adjusting the Carburetor English
0458-516-0121-B 15

► Fit a new spark plug after about 100 operating
hours – or sooner if the electrodes are badly
eroded. Install only suppressed spark plugs of
the type approved by STIHL – see "Specifica‐
tions".
14.1 Removing the Spark Plug
► Turn off the engine.
250BA054 KN
► Pull off the spark plug boot (1).
► Unscrew the spark plug.
14.2 Checking the Spark Plug
000BA039 KN
A
► Clean dirty spark plug.
► Check electrode gap (A) and readjust if neces‐
sary – see "Specifications".
► Rectify the problems which have caused foul‐
ing of the spark plug.
Possible causes are:
–Too much oil in fuel mix.
–Dirty air filter.
–Unfavorable running conditions.
1
000BA045 KN
WARNING
Arcing may occur if the adapter nut (1) is loose
or missing. Working in an easily combustible or
explosive atmosphere may cause a fire or an
explosion. This can result result in serious inju‐
ries or damage to property.
► Use resistor type spark plugs with a properly
tightened adapter nut.
14.3 Installing the Spark Plug
2
002BA446 KN
1
► Screw the spark plug (2) into the cylinder and
fit the boot (1) (press it down firmly).
15 Engine Running Behavior
If engine running behavior is unsatisfactory even
though the air filter is clean and the carburetor
and throttle cable are properly adjusted, the
cause may be the muffler.
Have the muffler checked by a servicing dealer
for contamination (carbonization).
STIHL recommends that you have servicing and
repair work carried out exclusively by an author‐
ized STIHL servicing dealer.
English 15 Engine Running Behavior
16 0458-516-0121-B

16 Replacing the Starter Rope
and Rewind Spring
16.1 Removing the Fan Housing
1
1
1
1
256BA075 KN
► Take out the screws (1).
► Remove the fan housing.
16.2 Replacing the Starter Rope
32
4
256BA032 KN
► Remove the spring clip (2).
► Carefully remove the rope rotor with
washer (3) and pawl (4).
WARNING
The rewind spring may pop out and uncoil during
this operation – take care to avoid the risk of
injury.
6
5
256BA033 KN
► Pry the cap (5) out of the grip.
► Remove the remaining rope from the rotor and
starter grip.
► Tie a simple overhand knot in the new rope
and then thread it through the top of the grip
and the rope bushing (6).
► Refit the cap in the grip.
256BA034 KN
► Thread the rope through the rotor and secure
it with a simple overhand knot.
► Coat the rope rotor bearing bore with non-res‐
inous oil.
► Slip the rotor over the starter post – turn it
back and forth to engage the anchor loop of
the rewind spring.
16 Replacing the Starter Rope and Rewind Spring English
0458-516-0121-B 17

32
4
256BA032 KN
► Fit the pawl (4).
► Fit the washer (3).
► Push the spring clip (2) into position – it must
point counterclockwise as shown and engage
the pawl's peg.
16.3 Tension the rewind spring.
427BA016 KN
► Make a loop in the unwound starter rope and
use it to turn the rope rotor six full revolutions
counterclockwise.
► Hold the rope rotor steady.
► Pull out and straighten the twisted rope.
► Release the rope rotor.
► Slowly release the starter rope so that it winds
onto the rotor.
The starter grip must sit firmly in the rope bush‐
ing. If the grip droops to one side: Add one more
turn on the rope rotor to increase spring tension.
NOTICE
When the starter rope is fully extended it must
still be possible to rotate the rotor another one
and a half turns. If this is not the case, the spring
is overtensioned and could break.
► Take one turn of the rope off the rotor.
► Install the fan housing.
16.4 Replacing a Broken Rewind
Spring
► Remove the rope rotor as described in
"Replacing the Starter Rope".
WARNING
The bits of the spring may still be under tension
and could fly apart when you remove the rope
rotor and spring housing. To reduce the risk of
injury, Wear a face shield and work gloves.
7
7
271BA053 KN
► Take out the screws (7).
► Remove the spring housing and pieces of
spring.
► Lubricate the new, ready-to-fit replacement
spring in the new spring housing with a few
drops of resin-free oil.
► Place the replacement spring with spring
housing in position – bottom plate facing up.
If the spring pops out and uncoils, refit it in the
clockwise direction, starting outside and working
inwards.
► Fit the screws.
► Refit the rope rotor as described in "Replacing
the Starter Rope".
► Tension the rewind spring.
► Install the fan housing.
17 Storing the Machine
For periods of about 3 months or longer
► Drain and clean the fuel tank in a well ventila‐
ted area.
► Dispose of fuel properly in accordance with
local environmental requirements.
► Run the engine until the carburetor is dry – this
helps prevent the carburetor diaphragms stick‐
ing together.
► Thoroughly clean the machine.
► Check the air filter and replace the element if
necessary.
► Remove, clean and inspect the attachment.
Coat metal parts of interchangeable attach‐
ment with corrosion inhibiting oil.
► Store the machine in a dry and secure location
– out of the reach of children and other unau‐
thorized persons.
English 17 Storing the Machine
18 0458-516-0121-B

18 Inspections and Mainte‐
nance by Dealer
18.1 Maintenance Work
STIHL recommends that you have servicing and
repair work carried out exclusively by an author‐
ized STIHL servicing dealer.
18.2 Antivibration Element
250BA066 KN
A vibration-absorbing rubber element is installed
between the powerhead and the drive tube.
Have it checked if there are signs of wear or a
noticeable increase in vibration levels.
19 Maintenance and Care
The following intervals apply for normal operating
conditions. The specified intervals must be short‐
ened accordingly when working for longer than nor‐
mal or under difficult cutting conditions (extensive
dust, etc.).
Before starting work
At the end of work and/or daily
Whenever tank is refilled
Weekly
Monthly
Annually
If faulty
If damaged
As required
Complete machine Visual inspection (condi‐
tion, leaks)
X X
Clean X
Control handle Function test X X
Air filter Clean X X
replace X
Manual fuel pump check X
Have repaired by a spe‐
cialist dealer1)
X
Fuel pickup body in fuel
tank
check X
replace X X X
Fuel tank Clean X X
Carburetor Check idle adjustment –
the attachment must not
move
X X
Set idle speed X
Spark plug Adjust electrode gap X
18 Inspections and Maintenance by Dealer English
0458-516-0121-B 19

The following intervals apply for normal operating
conditions. The specified intervals must be short‐
ened accordingly when working for longer than nor‐
mal or under difficult cutting conditions (extensive
dust, etc.).
Before starting work
At the end of work and/or daily
Whenever tank is refilled
Weekly
Monthly
Annually
If faulty
If damaged
As required
Replace after every 100
hours of operation
Cooling air intakes Visual inspection X
Clean X
All accessible screws,
nuts and bolts (not
adjusting screws)
Tighten X
Anti-vibration elements check X X X
Have replaced by serv‐
icing dealer1)
X
Safety information label replace X
1)STIHL recommends STIHL dealers
20 Minimize Wear and Avoid
Damage
Observing the instructions in this manual helps
reduce the risk of unnecessary wear and dam‐
age to the power tool.
The power tool must be operated, maintained
and stored with the due care and attention
described in this owner's manual.
The user is responsible for all damage caused by
non-observance of the safety precautions, oper‐
ating and maintenance instructions in this man‐
ual. This includes in particular:
–Alterations or modifications to the product not
approved by STIHL.
–Using tools or accessories which are neither
approved or suitable for the product or are of a
poor quality.
–Using the product for purposes for which it
was not designed.
–Using the product for sports or competitive
events.
–Consequential damage caused by continuing
to use the product with defective components.
20.1 Maintenance Work
All the operations described in the "Maintenance
Chart" must be performed on a regular basis. If
these maintenance operations cannot be per‐
formed by the owner, they should be performed
by a servicing dealer.
STIHL recommends that you have servicing and
repair work carried out exclusively by an author‐
ized STIHL servicing dealer. STIHL dealers are
regularly given the opportunity to attend training
courses and are supplied with the necessary
technical information.
If these maintenance operations are not carried
out as specified, the user assumes responsibility
for any damage that may occur. Among other
parts, this includes:
–Damage to the engine due to neglect or defi‐
cient maintenance (e.g. air and fuel filters),
incorrect carburetor adjustment or inadequate
cleaning of cooling air inlets (intake ports, cyl‐
inder fins).
–Corrosion and other consequential damage
resulting from improper storage.
–Damage to the machine resulting from the use
of poor quality replacement parts.
20.2 Parts Subject to Wear and Tear
Some parts of the power tool are subject to nor‐
mal wear and tear even during regular operation
in accordance with instructions and, depending
on the type and duration of use, have to be
English 20 Minimize Wear and Avoid Damage
20 0458-516-0121-B