Stihl BG 50 User manual

{
STIHL BG 50 Instruction Manual
Notice d’emploi

GInstruction Manual
1 - 23
FNotice d’emploi
24 - 49

Original Instruction ManualPrinted on chlorine-free paper
Printing inks contain vegetable oils, paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2018 0458-425-8221-C. VA2.H18. 0000007163_006_GB
BG 50
English
1
{This instruction manual is protected by copyright. All rights reserved, especially the rights to reproduce, translate and process
with electronic systems.
Contents
Dear Customer,
Thank you for choosing a quality
engineered STIHL product.
It has been built using modern
production techniques and
comprehensive quality assurance.
Every effort has been made to ensure
your satisfaction 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
Guide to Using this Manual 2
Safety Precautions and Working
Techniques 2
Assembling the Blower 7
Fuel 8
Fueling 9
Starting / Stopping the Engine 10
Cleaning the Air Filter 13
Engine Management 14
Adjusting the Carburetor 14
Spark Plug 15
Engine Running Behavior 16
Storing the Machine 17
Inspections and Maintenance by
Dealer 17
Maintenance and Care 18
Main Parts 19
Specifications 20
Maintenance and Repairs 21
Disposal 21
STIHL Limited Emission Control
Warranty Statement 22

BG 50
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Pictograms
The meanings of the pictograms
attached to the machine are explained in
this manual.
Depending on the model concerned, the
following pictograms may be attached to
your machine.
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.
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 manual.
Observe all applicable local safety
regulations, standards and ordinances.
If you have not used this model before:
Have your dealer or other experienced
user show you how it is operated or
attend a special course in its operation.
Minors should never be allowed to use
this product.
Keep bystanders, especially children,
and animals away from the work area.
When the power tool is not in use, put it
in a place where 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.
Do not lend or rent your power tool
without the instruction manual. Be sure
that anyone using it understands the
information contained in this manual.
Guide to Using this Manual
Fuel tank; fuel mixture of
gasoline and engine oil
Operate manual fuel
pump
Safety Precautions and
Working Techniques
Special safety precau-
tions must be observed
when working with a
power tool.
It is important that you
read the instruction man-
ual before first use and
keep it in a safe place for
future reference. Non-
observance of the
instruction manual may
result in serious or even
fatal injury.

BG 50
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In some countries the operation of noise
emitting power tools is restricted by local
regulations. Observe country-specific
requirements and regulations.
Do not use a pressure washer to clean
your power tool. The solid jet of water
may damage parts of the power tool.
Accessories and Spare Parts
Only use parts and accessories that are
explicitly approved for this power tool by
STIHL or are technically identical. If you
have any questions in this respect,
consult a servicing dealer. Use only high
quality parts and accessories in order to
avoid the risk of accidents and damage
to the machine.
STIHL recommends the use of genuine
STIHL replacement parts. They are
specifically 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.
Physical Condition
To operate this power tool you must be
rested, in good physical condition and
mental health. If you have any condition
that might be aggravated by strenuous
work, check with your doctor before
operating a power tool.
Persons with pacemakers only: The
ignition system of your power tool
produces an electromagnetic field of a
very low intensity. This field may
interfere with some pacemakers. To
reduce health risks, STIHL recommends
that persons with pacemakers consult
their physician and the pacemaker
manufacturer before operating this
power tool.
Do not operate the power tool if you are
under the influence of any substance
(drugs, alcohol) which might impair
vision, dexterity or judgment.
Intended Use
The blower is designed for blow-
sweeping leaves, grass, paper and
similar materials, e.g. in gardens, sports
stadiums, car parks and driveways. It is
also suitable for blow-sweeping forest
paths.
Do not use your power tool for any other
purpose because of the increased risk of
accidents.
Do not operate or store your power tool
at temperatures below -10°C – exposure
to low temperatures may damage
machine components.
Personal Protective Equipment
Wear proper protective clothing and
equipment.
Avoid any clothing, scarves, neckties,
jewellery or anything that could get into
the air intake. Tie up and confine long
hair (e.g. with a hair net, cap, hard hat,
etc.).
Wear sturdy shoes with non-slip soles.
WARNING
Wear hearing protection, e.g. earplugs
or ear muffs.
Transporting the Power Tool
Always stop the engine.
Transporting in a vehicle:
–Properly secure your power tool to
prevent turnover, fuel spillage and
damage.
Fueling
Always shut off the engine before
refueling.
Do not fuel a hot engine – fuel may spill
and cause a fire.
Clothing must be sturdy
but allow complete free-
dom of movement. Wear
snug-fitting clothing, an
overall and jacket combi-
nation, do not wear a
work coat.
To reduce the risk of eye
injuries, wear close-fit-
ting safety glasses in
accordance with Euro-
pean Standard EN 166.
Make sure the safety
glasses are a comforta-
ble and snug fit.
Gasoline is an extremely
flammable fuel. Keep
clear of naked flames. Do
not spill any fuel – do not
smoke.

BG 50
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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 immediately – if fuel gets on
your clothing, change immediately.
This reduces the risk of unit vibrations
causing the fuel cap to loosen or come
off and spill quantities of fuel.
Before Starting
Check that your power tool is properly
assembled and in good condition – refer
to appropriate chapters in the instruction
manual.
–Check the fuel system for leaks,
paying special 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.
–Throttle trigger must move freely
and spring back to the idle position
when released.
–Stop switch must move easily to 0
–Check that the spark plug boot is
secure – a loose boot may cause
arcing that could ignite combustible
fumes and cause a fire.
–Check condition of blower wheel
and blower housing – see chapter
on "Using the Unit".
–A worn blower housing (cracks,
nicks, chips) may result in an
increased risk of injury from thrown
foreign objects.
–If either the blower wheel or blower
housing is damaged, consult your
dealer – STIHL recommends you
contact a STIHL servicing dealer.
–Never attempt to modify the controls
or safety devices in any way.
To reduce the risk of accidents, do not
operate your power tool if it is not
properly assembled and in good
condition.
Starting the Engine
Start the engine at least 3 meters from
the fueling spot, outdoors only.
Your power tool is designed to be
operated by one person only. Do not
allow other persons in the work area –
even when starting.
Do not drop start the power tool – start
the engine as described in the
instruction manual.
Place the power tool on level ground,
make sure you have secure footing, hold
the power tool securely.
As soon as the engine starts, the air flow
may throw small objects (e.g. stones) in
your direction.
During Operation
In the event of impending danger or in
an emergency, switch off the engine
immediately by moving the stop switch
to 0.
Never leave a running machine
unattended.
Take special care in slippery conditions,
on slopes or uneven ground.
Watch out for obstacles such as tree
stumps, roots and ditches which could
cause you to trip or stumble.
Never work on a ladder or any other
insecure support.
Be particularly alert and cautious when
wearing hearing protection because
your ability to hear warnings (shouts,
alarms, etc.) is restricted.
Check for leakage. To
reduce the risk of serious
of fatal burn injuries, do
not start or run the engine
until leak is fixed.
After fueling, tighten
down the screw-type fuel
cap as securely as
possible.
Do not direct the air
blast towards bystand-
ers or animals since
the air flow can blow
small objects at great
speed.
To reduce the risk
of injury from
thrown objects, do
not allow any other
persons within a
radius of 5 meters
of your own
position.

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5
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.
When blow-sweeping (in open ground
and gardens), watch out for small
animals to avoid harming them.
After finishing work, put the unit down on
a level, non-flammable surface. To
reduce the risk of fire, do not put it down
near easily combustible materials (e.g.
wood chips, bark, dry grass, fuel).
To reduce the risk of serious or fatal
injury from breathing toxic fumes,
ensure proper ventilation when working
in trenches, hollows or other confined
locations.
To reduce the risk of accidents, stop
work immediately in the event of
nausea, headache, visual disturbances
(e.g. reduced field of vision), problems
with hearing, dizziness, deterioration in
ability to concentrate. Apart from other
possibilities, these symptoms may be
caused by an excessively high
concentration of exhaust gases in the
work area.
The dust that occurs during operation
may be harmful to health. If dust levels
are very high, wear a suitable respirator.
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.
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 Work". Check the fuel
system in particular for leaks and make
sure the safety devices are working
properly. Do not continue operating your
power tool if it is damaged. In case of
doubt, consult your servicing dealer.
Using the Blower
Your blower is designed for one-handed
operation. It must be carried by the
control handle in the right hand.
Always hold the power tool firmly in your
hand.
Watch out for small animals when using
the blower on open ground, in yards and
gardens.
Walk slowly forwards as you work –
observe the nozzle outlet at all times –
do not walk backwards – risk of
stumbling.
WARNING
To reduce the risk of injury, operate the
unit only with a properly mounted blower
tube.
Working Technique
To minimize blowing time, use a rake
and broom to loosen dirt particles before
you start blowing.
Recommended working technique to
minimize air pollution:
–If necessary, dampen the surface to
be cleaned in order to avoid creating
too much dust.
–Do not blow particles in the direction
of bystanders, in particular in the
direction of children, pets, open
windows or freshly washed
vehicles. Take special care in such
situations.
–Remove the blow-swept debris in
rubbish bins – do not blow it onto the
neighbor's land.
Your power tool produces
toxic exhaust fumes as
soon as the engine is
running. These fumes
may be colorless and
odorless and contain
unburned hydrocarbons
and benzol. Never run
the engine indoors or in
poorly ventilated loca-
tions, even if your model
is equipped with a cata-
lytic converter.
0075BA001 KN

BG 50
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6
Recommended working technique to
minimize noise:
–Operate your power tool at
reasonable times only – not early in
the morning, late at night or during
midday rest periods when people
could be disturbed. Observe local
rest periods.
–Operate blowers at the lowest
engine speed necessary to
accomplish the task.
–Check your blower before starting
work. Pay special attention to the
muffler, air intakes and air filter.
MAINTENANCE, REPAIR AND
STORAGE
WARNING
Use only identical STIHL replacement
parts for maintenance and repair. Use of
non-STIHL parts may cause serious or
fatal injury.
Strictly follow the maintenance and
repair instructions in the appropriate
section in this instruction manual.
Please refer to the maintenance chart in
this instruction manual.
WARNING
Always stop the engine and make sure
that the fan is stopped before doing any
maintenance or repair work or cleaning
the power tool. Do not attempt any
maintenance or repair work not
described in this instruction manual.
Have such work performed by your
STIHL servicing dealer only.
Do not clean your machine with a
pressure washer. The solid jet of water
may damage parts of the machine.
WARNING
Use the specified spark plug and make
sure it and the ignition lead are always
clean and in good condition. Always
press spark plug boot snugly onto spark
plug terminal of the proper size. A loose
connection between spark plug terminal
and the ignition wire connector in the
boot may create arcing that could ignite
combustible fumes and cause a fire.
Keep spark plug clean, and make sure
ignition lead is in good condition. Do not
use a spark plug with a detachable SAE
adapter terminal. Arcing may occur that
could ignite combustible fumes and
cause a fire. This can result in serious
injuries or damage to property.
WARNING
Never test the ignition system with the
boot removed from the spark plug or
with a removed spark plug, since
uncontained sparking may cause a fire.
WARNING
Do not operate your power tool if the
muffler is damaged, missing or modified.
An improperly maintained muffler will
increase the risk of fire and hearing loss.
Your muffler is equipped with a spark-
arresting screen to reduce the risk of
fire; never operate your power tool if the
screen is missing, damaged or clogged.
Remember that the risk of a brush or
forest fire is greater in hot or dry
weather.
In California, it is a violation of § 4442 or
§ 4443 of the Public Resources Code to
use or operate gasoline-powered tools
on forest-covered, brush-covered or
grass-covered land unless the engine’s
exhaust system is equipped with a
complying spark arrester that is
maintained in effective working order.
The owner/operator of this product is
responsible for properly maintaining the
spark arrester. Other states or
governmental entities/agencies, such as
the U.S. Forest Service, may have
similar requirements. Contact your local
fire agency or forest service for the laws
or regulations relating to fire protection
requirements.
Tighten all nuts, bolts and screws except
the carburetor adjustment screws after
each use.
For maintenance items please also refer
to the maintenance chart in this
instruction manual.
Store the power tool in a dry and high or
locked location out of reach of children.
Before storing for longer than a few
days, always empty the fuel tank. See
chapter "Storing the machine" in this
instruction manual.
Store fuel in an approved and properly
labeled safety-type canister only. Take
care when handling gasoline! For health
and safety reasons, avoid direct contact
with the skin and avoid inhaling fuel
vapor!
Maintenance, replacement, or repair of
the emission control devices and
systems may be performed by any
nonroad engine repair establishment or
individual. However, if you make a
warranty claim for a component which

BG 50
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7
has not been serviced or maintained
properly or if nonapproved replacement
parts were used, STIHL may deny
coverage.
For any maintenance please refer to the
maintenance chart and to the warranty
statement near the end of the instruction
manual.
Mounting the Blower Tube
NPush the blower tube (1) with lug (2)
into the fan housing stub (3) and
rotate it in the direction of the arrow
to lock in position.
Removing the Blower Tube
NUse a suitable tool to lift the tab (6)
on the fan housing stub (3).
NRotate the blower tube in the
direction of the arrow and then pull it
out.
Assembling the Blower
3
2
295BA003 KN
1
6
295BA005 KN
3

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8
This engine is certified to operate on
unleaded gasoline and the STIHL two-
stroke engine oil at a mix ratio of 50:1.
Your engine requires a mixture of high-
quality gasoline and two-stroke air
cooled engine oil.
Use mid-grade unleaded gasoline with a
minimum octane rating of 89 ((R+M)/2)
and no more than 10% ethanol content.
NOTICE
Fuel with an octane rating below 89 may
increase engine temperatures. This, in
turn, increases the risk of piston seizure
and damage to the engine.
The chemical composition of the fuel is
also important. Some fuel additives not
only detrimentally affect elastomers
(carburetor diaphragms, oil seals, fuel
lines, etc.), but magnesium castings and
catalytic converters as well. This could
cause running problems or damage the
engine. For this reason STIHL
recommends that you use only quality
unleaded gasoline!
NOTICE
Gasoline with an ethanol content of
more than 10% can cause running
problems and major damage in engines
and should not be used.
For further details, see
www.STIHLusa.com/ethanol
The ethanol content in gasoline affects
engine speed – it may be necessary to
readjust the carburetor if you use fuels
with various ethanol contents.
WARNING
To reduce the risk of personal injury
from loss of control and/or contact with
the running cutting tool, do not use your
unit with an incorrect idle adjustment. At
correct idle speed, the cutting tool
should not move.
If your machine’s idle speed is
incorrectly adjusted, have your
authorized STIHL servicing dealer
check your machine and make the
proper adjustments and repairs.
The idle speed and maximum speed of
the engine change if you switch from a
fuel with a certain ethanol content to a
fuel with a much higher or lower ethanol
content.
This problem can be avoided by always
using fuel with the same ethanol
content.
To ensure the maximum performance of
your STIHL engine, use a high quality 2-
cycle engine oil. To help your engine run
cleaner and reduce harmful carbon
deposits, STIHL recommends using
STIHL HP Ultra 2-cycle engine oil or ask
your dealer for an equivalent fully
synthetic 2-cycle engine oil.
To meet the requirements of EPA and
CARB we recommend to use STIHL HP
Ultra oil.
STIHL MotoMix
STIHL recommends the use of STIHL
MotoMix. STIHL MotoMix has a high
octane rating and ensures that you
always use the right gasoline/oil mix
ratio.
STIHL MotoMix uses STIHL HP Ultra
two-stroke engine oil suited for high
performance engines.
For further details, see
www.STIHLusa.com/ethanol
If not using MotoMix, use only STIHL
two-stroke engine oil or equivalent high-
quality two-stroke engine oils that are
designed for use in air cooled two-cycle
engines.
The use of non-seasonal gasoline
blends may increase the potential for
pressure to build in the fuel tank during
operation. For example, using a winter
blend during the summer will increase
pressure in the fuel tank. Always use
gasoline blends appropriate to the
season, altitude and other
environmental factors.
Do not use BIA or TCW rated (two-
stroke water cooled) mix oils or other
mix oils that state they are for use in both
water cooled and air cooled engines
(e.g., outboard motors, snowmobiles,
chain saws, mopeds, etc.).
WARNING
Take care when handling gasoline.
Avoid direct contact with the skin and
avoid inhaling fuel vapor. When filling at
the pump, first remove the container
from your vehicle and place the
container on the ground before filling. To
Fuel

BG 50
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9
reduce the risk of sparks from static
discharge and resulting fire and/or
explosion, do not fill fuel containers that
are sitting in or on a vehicle or trailer.
The container should be kept tightly
closed in order to limit the amount of
moisture that gets into the mixture.
The machine's fuel tank should be
cleaned as necessary.
Fuel mix ages
If not using MotoMix, only mix sufficient
fuel for a few days of work, not to exceed
30 days of storage. Store in approved
fuel-containers only. When mixing, pour
oil into the container first, and then add
gasoline. Close the container and shake
it by hand to ensure proper mix of oil and
gasoline.
WARNING
Shaking fuel can cause pressure to build
in the fuel container. To reduce the risk
of fire and severe personal injury or
property damage from fuel spraying,
allow the fuel container to sit for several
minutes before opening. Open the
container slowly to release any residual
pressures. Never open the fuel
container in the vicinity of any ignition
source. Read and follow all warnings
and instructions that accompany your
fuel container.
Dispose of empty mixing-oil containers
only at authorized disposal locations.
Preparations
NBefore fueling, clean the filler cap
and the area around it to ensure that
no dirt falls into the tank.
NPosition the machine so that the
tank cap faces up.
STIHL recommends you use the STIHL
filler nozzle for fuel (special accessory).
Filling Up with Fuel
Take care not to spill fuel while fueling
and do not overfill the tank.
Gaso-
line
Oil (STIHL 50:1 or equiva-
lent high-quality oils)
US gal. US fl.oz.
12.6
2 1/2 6.4
512.8
Fueling
295BA033 KN

BG 50
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10
NOpen the cap.
NFill up with fuel.
NClose the cap.
WARNING
After fueling, tighten down the filler cap
as securely as possible by hand.
The blower may be equipped with
different carburetors.
Version A
Version B
Starting the Engine – Version A
NObserve safety precautions.
NPress the fuel pump bulb at least
five times – even if the bulb is
already filled with fuel.
NMove the stop switch (1) to the run
position I
Setting the choke lever
If the engine is cold
NMove the choke lever (3) to g
NPull the throttle trigger (2) and hold it
there.
NCrank engine until it begins to fire.
Starting / Stopping the
Engine
0000-GXX-2854-A00000-GXX-2855-A0
0075BA003 KN
2
1
0075BA002 KN
3
0000-GXX-0616-A0

BG 50
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11
NMove the choke lever (3) to f.
NPull the throttle trigger (2) and hold it
there.
NContinue cranking until the engine
runs.
NWait 10 seconds, then move the
choke lever (3) to e.
If the engine is warm
Also use this setting if the engine has
been running but is still cold.
NMove the choke lever (3) to f.
NPull the throttle trigger (2) and hold it
there.
NContinue cranking until the engine
runs.
NWait 10 seconds, then move the
choke lever (3) to e.
Cranking
NPlace the unit on the ground so that
it is secure.
NMake sure you have a firm footing:
Hold the unit firmly with your left
hand on the housing and press
down.
NHold the starter grip with your right
hand.
NPull 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.
NDo not let the starter grip snap back.
Guide it slowly back into the housing
so that the starter rope can rewind
properly.
Starting the Engine – Version B
NObserve safety precautions.
NPress the fuel pump bulb at least
five times – even if the bulb is
already filled with fuel.
NMove the stop switch (1) to the run
position I
Setting the choke lever
If the engine is cold
NMove the choke lever (3) to g
0000-GXX-0617-A0
3
295BA016 KN
0075BA003 KN
2
1
0075BA002 KN
3
0000-GXX-2832 A0

BG 50
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12
NPull the throttle trigger (2) and hold it
there.
NCrank engine until it begins to fire.
NSet the choke lever (3) to e.
NPull the throttle trigger (2) and hold it
there.
NContinue cranking until the engine
runs.
If the engine is warm
Also use this setting if the engine has
been running but is still cold.
NSet the choke lever (3) to e.
NPull the throttle trigger (2) and hold it
there.
NContinue cranking until the engine
runs.
Cranking
NPlace the unit on the ground so that
it is secure.
NMake sure you have a firm footing:
Hold the unit firmly with your left
hand on the housing and press
down.
NHold the starter grip with your right
hand.
NPull 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.
NDo not let the starter grip snap back.
Guide it slowly back into the housing
so that the starter rope can rewind
properly.
Stopping the Engine
NMove the stop switch to 0
Other Hints on Starting
If the engine stops during warm-up or
acceleration
NRepeat the starting procedure – see
"If the engine is cold".
If engine does not start
NMake sure all settings are correct
(choke shutter, stop switch in run
position I).
NRepeat the starting procedure.
If the engine still does not start
NMove the stop switch to 0
NRemove the spark plug – see
"Spark Plug".
NDry the spark plug.
NCrank the engine several times with
the starter to clear the combustion
chamber.
NRefit the spark plug – see "Spark
Plug".
NMove the stop switch to I
Nset the choke lever to e – even if
the engine is cold.
NPull the throttle trigger (2) and hold it
there.
NNow start the engine.
295BA016 KN

BG 50
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13
If fuel tank has been run completely dry
and then refueled
NPress the fuel pump bulb at least
five times – even if the bulb is
already filled with fuel.
NSet the choke lever according to
engine temperature.
NNow start the engine.
If there is a noticeable loss of engine
power
NMove the choke lever to g
NSqueeze the tabs (1) together.
NSwing the filter cover (2) open and
take it away.
NClean away loose dirt from around
the filter.
NTake the filter (3) out of the filter
housing (4).
NInstall a new filter. Temporary
measure: wash the filter.
Replace any damaged parts.
NFit the filter (3) in the filter
housing (4).
NFit the filter cover (2) so that it snaps
into position.
0075BA003 KN
Cleaning the Air Filter
0075BA005 KN
1
2
4
0075BA006 KN
3
2

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14
Exhaust emissions are controlled by the
design of the engine and components
(e.g. carburation, ignition, timing and
valve or port timing).
General Information
The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
Preparations
NShut off the engine.
NCheck the air filter and clean or
replace if necessary.
NCheck the spark arresting screen
(not in all models, country-specific)
in the muffler and clean or replace if
necessary.
Standard Setting
NTurn high speed screw (H)
counterclockwise as far as stop (no
more than 3/4 turn).
NTurn the low speed screw (L)
clockwise as far as stop, then turn it
back 3/4 turn.
Adjusting Idle Speed
NCarry out the standard setting.
NStart and warm up the engine.
Engine Management Adjusting the Carburetor
295BA085 KN

BG 50
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15
Engine stops while idling
NTurn the idle speed screw (LA)
clockwise until the engine runs
smoothly – then back it off a 1/4 turn
from that position.
Erratic idling behavior, poor acceleration
(despite correction to setting of LA
screw).
Idle setting is too lean
NTurn the low speed screw (L)
carefully counterclockwise, no
further than stop, until the engine
runs smoothly and accelerates well.
Erratic idling behavior, engine speed
drops when swinging the machine
Idle setting is too rich
NTurn the low speed screw (L) slowly
clockwise 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).
Fine Tuning for Operation at High
Altitude
A slight correction of the setting may be
necessary if the engine does not run
satisfactorily:
NCarry out the standard setting.
NWarm up the engine.
NTurn high speed screw (H) slightly
clockwise (leaner) – no further than
stop.
NOTICE
After returning from high altitude, reset
the carburetor to the standard setting.
If the setting is too lean there is a risk of
engine damage due to insufficient
lubrication and overheating.
NIf the engine is down on power,
difficult to start or runs poorly at idle
speed, first check the spark plug.
NFit 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
"Specifications".
Removing the Spark Plug
NPull off the spark plug boot (1).
NUnscrew the spark plug.
295BA086 KN
Spark Plug
1
295BA083 KN

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16
Checking the Spark Plug
NClean dirty spark plug.
NCheck electrode gap (A) and
readjust if necessary – see
"Specifications".
NRectify the problems which have
caused fouling of the spark plug.
Possible causes are:
–Too much oil in fuel mix.
–Dirty air filter.
–Unfavorable running conditions.
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 injuries or
damage to property.
NUse resistor type spark plugs with a
properly tightened adapter nut.
Installing the Spark Plug
NScrew the spark plug (3) into the
cylinder and fit the boot (2) (press it
down firmly).
If engine running behavior is
unsatisfactory even though the air filter
is clean and the carburetor is properly
adjusted, the cause may be the muffler.
Have the muffler checked for
contamination (carbonization) by your
servicing dealer.
STIHL recommends that you have
servicing and repair work carried out
exclusively by an authorized STIHL
servicing dealer.
000BA039 KN
A
1
000BA045 KN
3
000BA050 KN
2
Engine Running Behavior

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For periods of 3 months or longer
NDrain and clean the fuel tank in a
well ventilated area.
NDispose of fuel properly in
accordance with local
environmental requirements.
NRun the engine until the carburetor
is dry – this helps prevent the
carburetor diaphragms sticking
together.
NThoroughly clean the machine – pay
special attention to the cylinder fins
and air filter.
NStore the machine in a dry, high or
locked location, – out of the reach of
children and other unauthorized
persons.
Spark arresting screen in muffler
NIf the engine is down on power,
check the spark arresting screen in
the muffler.
STIHL recommends that you have
servicing and repair work carried out
exclusively by an authorized STIHL
servicing dealer.
Storing the Machine Inspections and Maintenance
by Dealer

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Maintenance and Care
The following intervals apply to normal operating conditions only. If your daily working
time is longer or operating conditions are difficult (very dusty work area, etc.), shorten
the specified intervals accordingly.
before starting work after finishing work or daily after each refueling stop weekly monthly every 12 months if problem if damaged as required
Complete machine
Visual inspection (condition, wear,
leaks) xx
Clean x
Control handle Check operation xx
Air filter Clean xx
Replace xx
Manual fuel pump Check X
Have repaired by servicing dealer1) X
Pickup body in fuel tank Check x
Have replaced by dealer1) xxx
Fuel tank Clean xx
Carburetor Check idle setting xx
Readjust idle x
Spark plug Readjust electrode gap x
Replace after 100 operating hours
Spark arrestor in muffler Check x
Have replaced by dealer1) xx
Cooling inlets Clean x
All accessible screws and nuts (not adjust-
ing screws) Retighten x
Safety labels Replace x
1) STIHL recommends an authorized STIHL servicing dealer.