Stihl BG 56 User manual

STIHL BG 56, 66, 86, SH 56, 86 Instruction Manual

Original Instruction ManualPrinted on chlorine-free paper
Printing inks contain vegetable oils, paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2020 0458-296-0121-E. VA5.F20. 0000008456_004_GB
BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
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 8
Assembling the Vacuum Shredder 10
Fuel 11
Fueling 12
Starting / Stopping the Engine 13
Cleaning the Air Filter 15
Adjusting the Carburetor 16
Spark Plug 17
Engine Running Behavior 18
Storing the Machine 18
Maintenance and Care 19
Minimize Wear and Avoid Damage 20
Main Parts 21
Specifications 22
Maintenance and Repairs 24
Disposal 24
EC Declaration of Conformity 24

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
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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, e.g. by trade organizations,
social insurance institutions, labor safety
authorities etc.
If you have not used this machine
before: Have your dealer or other
experienced user show you how to
handle your machine safely or attend a
specialist course.
Minors must never work with the
machine – except for young people over
the age of 16 who are being trained
under supervision.
Children, animals and bystanders must
not be allowed near the machine.
When the machine is not in use, put it in
a place where it does not endanger
others. Secure the machine against
unauthorized access.
The user is responsible for accidents or
risks involving third parties or their
property.
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 operating a power
tool.
It is important you read
and understand the User
Manual before commis-
sioning and keep it in a
safe place for future ref-
erence. Non-compliance
with the User Manual
may cause serious or
even fatal injury.

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
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The machine should only be provided or
loaned to people familiar with this model
and its operation. The instruction
manual should always be handed over
with the machine.
The use of noise emitting power tools
may be restricted to certain times by
national or local regulations.
Do not operate your machine if any of its
components are damaged.
Do not use a high-pressure washer to
clean the power tool. The solid jet of
water may damage parts of the unit.
Accessories and replacement 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 your dealer. Use only high
quality parts and accessories in order to
avoid the risk of accidents and damage
to the unit.
STIHL recommends the use of original
STIHL parts and accessories. They are
specifically designed to match the
product and meet your performance
requirements.
Never attempt to modify your power tool
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 fitness
To operate the power tool you must be
rested, in good physical condition and
mental health.
If you have any condition which may be
aggravated by strenuous work, check
with your doctor before operating a
power tool.
If you have a pacemaker: The ignition
system of your machine produces an
electromagnetic field of 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 tool.
Do not operate the power tool if you
have consumed alcohol or taken
medication, which may impair
responsiveness, or taken drugs.
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.
The vacuum shredder is designed for
picking up dry leaves and other
lightweight, loose and non-combustible
materials.
Do not blow-sweep or vacuum
hazardous materials.
Do not use the power tool for any other
purpose because of the increased risk of
accidents and damage to the power tool
itself. The product must not be modified
in any way - this may also lead to
accidents or damage to the unit.
Clothing and equipment
Wear proper protective clothing and
equipment.
Wear sturdy shoes with non-slip soles.
WARNING
Wear "personal" sound protection, e.g.
ear defenders.
STIHL can supply a comprehensive
range of personal protective equipment.
Transporting the machine
Always stop the engine.
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.
Avoid wearing any cloth-
ing, scarves, neckties or
jewelry which could get
into the air intake. Tie up
and confine long hair
above your shoulders.
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 snug fit.

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
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Transporting in a vehicle:
–Secure the machine against
overturning, damage and fuel
spillage
Refueling
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.
Only refuel the machine in a well
ventilated place. If you spill fuel, wipe the
machine immediately – if fuel gets on
your clothing, change immediately.
This helps reduce the risk of unit
vibrations causing an incorrectly
tightened fuel cap to loosen or come off
and spill quantities of fuel.
Before starting
Check that your machine is properly
assembled and in good condition – refer
to appropriate chapters in the instruction
manual:
–Check the fuel system for leaks,
especially the visible parts, e. g.,
fuel cap, hose connections, manual
fuel pump (only in machines with a
manual fuel pump). In case of
leakage and damage, do not start
the engine – risk of fire! Have the
machine serviced by a dealer
before using it
–Throttle trigger must move freely
and spring back by itself to the idle
position
–Setting lever/switch must move
easily to STOP or 0
–Keep the handles dry and clean –
free from oil and dirt – this is
important for safe control of the
machine
–The blower tubes must be properly
assembled.
–Check that the spark plug boot is
secure – a loose boot may cause
sparking that could ignite
combustible fumes and cause a fire!
–Check the condition of blower wheel
and blower housing.
Wear of the blower housing (cracks,
nicks, chips) may result in an increased
risk of injury from thrown foreign objects.
If the blower housing is damaged,
consult your dealer – STIHL
recommends you contact a STIHL
servicing dealer.
Never attempt to modify the controls or
safety devices
To reduce the risk of accidents and
personal injury, 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 user
manual.
Place the machine on level ground only,
ensure that you have a secure footing
and hold the machine securely.
As soon as the engine starts, the
increasing air flow may eject objects
(e.g. stones).
While working
In the event of impending danger or in
an emergency, switch off the engine
immediately by moving the setting lever
/ switch to STOP or 0.
Your power tool is designed to be
operated by one person only. Do not
allow other persons in the work area.
Gasoline is extremely
flammable – keep it
away from naked flames
– do not spill any fuel – no
smoking.
Check for fuel leakage!
Never start the engine if
fuel has been spilled or is
leaking – Fatal burns may
result!
After fueling, tighten
down the screw-type fuel
cap as securely as
possible.

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
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This distance must also be maintained in
relation to objects (vehicles, window
panes) – risk of property damage!
When blow-sweeping and vacuum
shredding (in open ground and
gardens), watch out for small animals to
avoid harming them.
Never leave a running machine
unattended.
Take special care in slippery conditions
– damp, snow, ice, on slopes or uneven
ground.
Watch out for obstacles: Be careful of
refuse, tree stumps, roots and ditches
which could cause you to trip or stumble.
Do not work on a ladder or in unstable
locations.
Be particularly alert and cautious when
wearing hearing protection because
your ability to hear warnings (shouts,
alarms, etc.) is restricted.
Work calmly and carefully – in daylight
conditions and only when visibility is
good. Proceed with caution, do not put
others in danger.
Take breaks when you start getting tired
or feeling fatigue – risk of accidents!
Mufflers with catalytic converters can
become especially hot.
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.
Stop work immediately if you start
suffering from nausea, headaches,
impaired vision (e.g. your field of vision
gets smaller), impaired hearing,
dizziness, or impaired concentration –
these symptoms may possibly be the
result of too-high exhaust gas
concentration – Risk of accidents!
To reduce the risk of fire, do not smoke
while operating or standing near your
power tool. Combustible fuel vapor may
escape from the fuel system.
Always wear a dust mask if dust is
generated.
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.
After work, place the machine on a level,
non-flammable surface. Do not place the
machine near easily flammable
materials (e.g. wood chips, bark, dry
grass, fuel) – risk of fire!
Never attempt to insert objects into the
impeller housing through the intake
screen or the nozzle. They may be
expelled at very high speed by the
blower – risk of injury.
If there is a noticeable change in running
behavior (e.g. higher vibrations), stop
work and rectify the cause of the
problem.
If the machine was exposed to a load 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 in
particular that the fuel system has no
leaks and the safety equipment is fully
operative. Do not continue operating
your power tool if it is damaged. In case
of doubt, contact a dealer.
Using the blower
The blower is designed for one-handed
operation. The operator must carry the
blower with his right hand on the control
handle.
To reduce the risk
of injury from
thrown objects, do
not allow any other
persons within 5
meters of your
own position.
Do not direct the air blast
towards bystanders or
animals since the air flow
can blow small objects at
great speed – risk of
injury.
Your power tool produces
toxic exhaust fumes as
soon as the engine is
running. These gases
may be odorless and
invisible and may contain
unburned hydrocarbons
and benzene. Never run
the engine indoors or in
poorly ventilated loca-
tions, even if your model
is equipped with a cata-
lytic converter.
295BA052 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
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Always hold the power tool firmly in your
hand.
When blow-sweeping in open terrain
and in gardens, look out for small
animals.
Work only slowly, moving in a forwards
direction – always observe the discharge
area of the blower tube – do not move
backwards – risk of tripping!
WARNING
Operate the machine only with the
blower tube completely mounted – risk
of injury!
The round nozzle is particularly suitable
for use on uneven surfaces (e.g. fields
and lawns).
The flat nozzle (either included with unit
or available as special accessory)
produces a broad and powerful
airstream at ground level. It can be
aimed and controlled very accurately.
This nozzle is highly effective for blow-
sweeping sawdust, leaves, grass
cuttings, etc. on flat surfaces.
Using the Vacuum Attachment
For specific assembling instructions,
see appropriate chapter in this User
Manual.
The vacuum attachment is designed for
two-handed operation. Hold and operate
the unit with your right hand on the
control handle and your left hand on the
assist handle.
Wear the harness of the catcher bag
hanging from one shoulder. Practice
setting down the unit together with the
catcher bag to remove the unit quickly
from your body in case of emergency –
risk of injury!
WARNING
To reduce the risk of injury, operate your
power tool only with a properly mounted
suction tube and closed catcher bag.
NOTICE
Vacuuming abrasive material (such as
grit, stone chips, etc.) causes the
impeller wheel and impeller housing to
wear at a rapid rate. This results in a
considerable loss of suction power. In
such a case you should contact your
dealer. STIHL recommends you have
this work done by a STIHL servicing
dealer.
Take particular care when vacuuming
wet leaves since they may block the
blower wheel and elbow.
To clear a blockage in the machine:
–Switch off the machine.
–Remove the elbow and suction tube
– see "Assembling the Vacuum
Shredder".
–Clean the elbow and blower
housing.
When vacuuming in open terrain and in
gardens, look out for small animals.
295BA053 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
7
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.
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.
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:
–Keeping your hands warm
–Work breaks
The period of usage is shortened by:
–Any personal tendency to suffer
from poor circulation (symptoms:
frequently cold fingers, itching).
–Low outside temperatures.
–Gripping force (a tight grip hinders
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.
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 performed by a
servicing dealer.
STIHL recommends that you have
servicing and repair work carried out
exclusively by an authorized STIHL
servicing dealer. STIHL dealers are
To reduce the risk of per-
sonal injury from fire,
never attempt to pick up
hot or burning sub-
stances (e.g. smoldering
ashes, glowing
cigarettes).
To reduce the risk of fatal
injury from fire or explo-
sion, never attempt to
pick up combustible fluids
(e.g. gasoline) or materi-
als soaked in
combustible fluids.
Switch off the engine
before opening the intake
screen. The shield must
always be closed and
secured when the suction
tube is not mounted to
reduce the risk of injury
from contact with rotating
components. This can
also result in damage to
the engine.

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
8
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.
Do not turn the engine over on the
starter with the spark plug boot or spark
plug removed since there is otherwise a
risk of fire from uncontained sparking.
Do not service or store your machine
near open flames.
Check the fuel filler cap for leaks at
regular intervals.
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 condition, 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.
Shut off the engine before rectifying
problems. Mounting the Blower Tube
NLine up the arrows (1).
NPosition the union nut so that the
symbol ‚ is in line with the arrows.
NPush the blower tube (2) into the fan
housing stub (3) as far as stop.
NPush the union nut (4) over the fan
housing stub as far as stop.
NRotate the union nut (4) in direction
of arrow until symbol ƒ is in line
with the arrows – union nut snaps
audibly into position.
Assembling the Blower
1
3
296BA016 KN
296BA017 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
9
BG 56, BG 86, SH 56, SH 86
NPush nozzle (5) onto blower
tube (2) as far as lug (6),
position (a) (long) or position (b)
(short), and rotate nozzle in
direction of arrow to lock in position.
BG 66
NLine up the arrows (1).
NPosition the union nut so that the
symbol ‚ is in line with the arrows.
NPush the blower tube (2) into the fan
housing stub (3) as far as stop.
NPush the union nut (4) over the fan
housing stub as far as stop.
NRotate the union nut (4) in direction
of arrow until symbol ƒ is in line
with the arrows – union nut snaps
audibly into position.
NPush nozzle (5) in position (a) onto
the blower tube (2) as far as lug (6)
and rotate in direction of arrow to
lock in position.
Removing the Blower Tube
NShut down the engine.
NInsert a suitable tool through the
opening in the union nut to press
down the tab.
NRotate the union nut in the direction
of the arrow as far as the stop.
NRemove the blower tube.
ab
5
6
2
296BA031 KN
1
296BA018 KN
3
296BA019 KN
a
65
2
296BA032 KN
296BA020 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
10
Mounting the Elbow
NPush the elbow (1) into the catcher
bag (2) as far as the mark (smaller
arrow).
NTighten strap (3) on catcher bag
and press down the tab (4).
NOTICE
Make sure the zipper on the catcher bag
is closed.
NLine up the arrows (5).
NPosition the union nut so that the
symbol ‚ is in line with the arrows.
NPush the elbow into the recess in
the fan housing stub (6) as far as
stop.
NPush the union nut (7) over the fan
housing stub as far as stop.
NRotate the union nut (7) in direction
of arrow until symbol ƒ is in line
with the arrows – union nut snaps
audibly into position.
Assembling the Suction Tube
NLine up the arrows on the suction
tube and extension tube. Push
together and lock in position.
Mounting the Suction Tube
NShut down the engine.
NInsert screwdriver in the tab (1) and
press down to disengage the intake
screen (2) and then open the intake
screen.
NLine up the arrows (3).
NPosition union nut (5) so that the
opening lines up with the arrows (3).
NPush the suction tube into the fan
housing stub (4) as far as stop.
NPush the union nut (5) over the fan
housing stub.
Assembling the Vacuum
Shredder
4
295BA058 KN
3
2
1
5
296BA021 KN
6
8
296BA022 KN
295BA080 KN
1
2
269BA030 KN
4
3
296BA023 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
11
NRotate union nut (5) in direction of
arrow until it snaps audibly into
position.
NContinue turning the union nut in
direction of arrow and tighten it
down firmly.
Removing the Elbow
NShut down the engine.
NInsert a suitable tool through the
opening in the union nut to press
down the tab.
NRotate the union nut in the direction
of the arrow as far as the stop.
NRemove the elbow.
Removing the Suction Tube
NShut down the engine.
NRotate the union nut in the direction
of the arrow as far as the stop.
NInsert a suitable tool through the
opening in the union nut to press
down the tab.
NContinue turning the union nut in the
direction of the arrow as far as the
next stop.
NRemove the suction tube.
NClose the intake screen and lock it
in position.
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.
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.
Mixing Fuel
NOTICE
Unsuitable fuels or lubricants or mix
ratios other than those specified may
result in serious damage to the engine.
Poor quality gasoline or engine oil may
damage the engine, sealing rings, hoses
and the fuel tank.
Gasoline
Use only high-quality brand-name
gasoline with a minimum octane rating
of 90 – leaded or unleaded.
296BA033 KN
296BA024 KN
296BA025 KN
Fuel

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
12
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 content of up to 25% (E25).
Engine Oil
If you mix the fuel yourself, use only
STIHL two-stroke engine oil or another
high-performance 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.
Mix Ratio
STIHL 50:1 two-stroke engine oil: 50
parts gasoline to 1 part oil
Examples
NUse a canister approved for storing
fuel. Pour oil into canister first, then
add gasoline and mix thoroughly.
Storing Fuel
Store fuel only in approved safety-type
fuel canisters 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.
NThoroughly shake the mixture in the
canister before fueling your
machine.
WARNING
Pressure may build up in the canister –
open it carefully.
NClean 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.
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
filler cap is facing up.
STIHL recommends you use the STIHL
filler nozzle for fuel (special accessory).
Fill up with fuel
Take care not to spill fuel while fueling
and do not overfill the tank.
Gasoline STIHL engine oil 50:1
Liters Liters (ml)
10.02(20)
5 0.10 (100)
10 0.20 (200)
15 0.30 (300)
20 0.40 (400)
25 0.50 (500)
Fueling
295BA064 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
13
NOpen the filler cap.
NFill up with fuel
NClosing the cap
WARNING
After fueling, tighten down the filler cap
as securely as possible.
Changing the fuel pickup body
Change the fuel pick up body every
year.
NDrain the fuel tank.
NUse a hook to pull the fuel pickup
body out of the tank and take it off
the hose.
NPush the new pickup body into the
hose.
NPlace the pickup body in the tank.
Starting the Engine
NObserve safety precautions.
NPress the manual fuel pump
bulb (1) at least five times – even if
the bulb is filled with fuel.
Adjusting the setting lever
Only on BG 66 C, BG 86, SH 86
NTo start, move the setting lever to
the run position F
The setting lever (2) allows the throttle
trigger (3) to be locked in any required
position during operation.
Adjusting the choke knob
If the engine is cold
NTurn the choke knob to g
If the engine is warm
NTurn the choke knob to <
Also use this setting if the engine has
been running but is still cold.
295BA065 KN
Starting / Stopping the
Engine
1
296BA009 KN
295BA069 KN
296BA007 KN
3
295BA067 KN
295BA068 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
14
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 right
hand on the housing and press
down.
NHold the starter grip with your left
hand.
Version with ErgoStart
NPull the starter grip steadily.
Version without ErgoStart
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.
As Soon as Engine Runs
NBlip the throttle trigger (3) – the
choke knob moves to the run
position F – the engine returns to idle
speed.
Stopping the Engine
BG 56, BG 66, SH 56
NMove the stop switch to 0 – the
engine stops – the stop switch
springs back to the on position.
BG 66 C, BG 86, SH 86
NMove the setting lever to 0 – the
engine stops – the setting lever
springs back to the on position.
Other Hints on Starting
If the engine stops in position g or
during acceleration
NMove the choke lever to < and
continue cranking until the engine
runs.
296BA006 KN
296BA008 KN
3
296BA008 KN
295BA072 KN
295BA073 KN

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
15
If engine does not start
NMake sure all settings are correct
(choke knob, setting lever in run
position F).
NRepeat the starting procedure.
If fuel tank has been run completely dry
and then refueled
NPress the manual fuel pump
bulb (1) at least five times – even if
the bulb is filled with fuel.
NNow start the engine.
Dirty air filters reduce engine power,
increase fuel consumption and make
starting more difficult.
Different Air Filters
Different models are equipped with
different air filters. The models can be
identified by the filter housing and the air
filter itself.
Version with Flat Filter Material
NTurn the filter cover lock (1)
counterclockwise to the vertical
position.
NRemove the filter cover (2).
NClean away loose dirt from around
the filter.
NPull off the retainer (3) and take the
air filter element (4) out of the filter
housing (5).
NReplace the filter element. As a
temporary measure you can knock it
out on the palm of your hand or blow
it out with compressed air – do not
wash.
Replace any damaged parts.
Installing the filter element
NFit the filter (4) in the filter
housing (5) and push the
retainer (3) into position.
NRefit the filter cover (2) and turn the
filter cover lock clockwise to the
horizontal position.
1
296BA009 KN
Cleaning the Air Filter
1
295BA074 KN
2
3
295BA075 KN
2
5

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
16
Version with Pleated Filter Material
NUnscrew the filter cover lock (1)
counterclockwise.
NRemove the filter cover (2).
NClean away loose dirt from around
the filter.
NTake the air filter (3) out of the filter
housing (4).
Cleaning the air filter
NCarefully knock the filter out on the
palm of your hand or blow it clear
with compressed air from the inside
outwards.
In case of stubborn dirt or sticky filter
fabric
NWash the air filter in STIHL special
cleaner (special accessory) or a
clean, non-flammable solution (e.g.
warm soapy water). Rinse the filter
from the inside outwards under a jet
of water – do not use a pressure
washer.
NDry the filter – do not expose to high
temperatures.
Place the filter in position.
NInstall the filter element in the filter
housing.
NFit the filter cover and tighten the
filter cover lock clockwise.
The carburetor has been set at the
factory to provide an optimum fuel-air
mixture under most operating
conditions.
Adjusting Idle Speed
Engine stops while idling
NTurn the idle speed screw (LA)
clockwise until the engine runs
smoothly.
1
296BA026 KN
22
296BA027 KN
3
4
Adjusting the Carburetor
0000-GXX-7919-A0

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
17
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.
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).
Spark Plug
1
296BA015 KN
000BA039 KN
A
1
000BA045 KN
3
002BA178 KN
2

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
18
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.
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.
Engine Running Behavior Storing the Machine