Stihl FS 45 User manual

Instruction ManualSTIHL FS 45
BA_U1_01_01.fm Seite 0 Montag, 3. November 2003 1:40 13

1FS 45
English
BA_SE_011_002_01_17.fmPrinted on chlorine-free paper.
Printing inks contain vegetable oils; paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2007 0458 232 0121 C. M3.6. H7. HFP.
STIHl
Contents
Guide to Using this Manual .............. 2
Safety Precautions and
Working Techniques ......................... 3
Approved Combinations of
Cutting Tool, Deflector,
Handle and Harness ....................... 13
Mounting the Loop Handle ............. 14
Mounting the Deflector ................... 15
Mounting Cutting Tools ................... 15
Fuel ................................................ 18
Fueling ............................................ 20
Starting / Stopping the Engine ........ 20
Operating Instructions .................... 23
Cleaning the Air Filter ..................... 23
Adjusting the Carburetor ................ 24
Catalytic Converter ......................... 26
Checking the Spark Plug ................ 26
Inspections and
Maintenance by Dealer .................. 27
Rewind Starter ................................ 27
Storing the Machine ........................ 28
Replacing the Nylon Line ............... 28
Replacing the Nylon Line ............... 30
Maintenance Chart ......................... 32
Minimize Wear and
Avoid Damage ................................ 33
Parts and Controls .......................... 34
Specifications ................................. 35
Special Accessories ....................... 36
Maintenance and Repairs ............... 36
Certificate of Conformity ................. 37
Quality Certification ........................ 38
Dear Customer,
Thank you for choosing a quality
engineered STIHL product.
This machine has been built using
modern production techniques and
comprehensive quality assurance.
Every effort has been made to ensure
your satisfaction and troublefree use
of the machine.
Please contact your dealer or our
sales company if you have any
queries concerning your machine.
Hans Peter Stihl

2
English
FS 45
Pictograms
All the pictograms attached to the
machine are shown and explained in
this manual.
The operating and handling instructions
are supported by illustrations.
Symbols in text
The individual steps or procedures
described in the manual may be marked
in different ways:
:A bullet marks a step or procedure
without direct reference to an
illustration.
A description of a step or procedure that
refers directly to an illustration may
contain item numbers that appear in the
illustration.
Example:
Loosen the screw (1)
Lever (2) ...
In addition to the operating instructions,
this manual may contain paragraphs
that require your special attention. Such
paragraphs are marked with the
symbols described below:
Warning where there is a risk of an
accident or personal injury or
serious damage to property.
Caution where there is a risk of
damaging the machine or its
individual components.
Note or hint which is not essential
for using the machine, but may
improve the operator’s under-
standing of the situation and result
in better use of the machine.
Note or hint on correct procedure in
order to avoid damage to the
environment.
Equipment and features
This instruction manual may refer to
several models with different
features. Components that are not
installed on all models and related
applications are marked with an
asterisk (*). Such components may
be available as special accessories
from your STIHL dealer.
Engineering improvements
STIHL’s philosophy is to continually
improve all of its products. As a result,
engineering changes and improvements
are made from time to time. If the
operating characteristics or the
appearance of your machine differ from
those described in this manual, please
contact your STIHL dealer for
assistance.
Therefore some changes, modifications
and improvements may not be covered
in this manual.
Guide to Using this Manual

3FS 45
English
Because a trimmer is a
high-speed, fast-cutting
power tool some special
safety precautions must
be observed in addition to
those that generally apply
when working with hand tools.
It is important that you
read and understand the
instruction manual before
using your power tool for
the first time. Keep it in a
safe place for later
reference. Non-observance of the
following safety precautions may cause
serious or even fatal injury.
Always observe local safety regulations,
standards and ordinances.
If you have never used this trimmer
model before:
Have your dealer or other experienced
user show you how to operate your
trimmer or attend a special course of
training in trimmer operation.
Minors should never be allowed to use a
trimmer.
Bystanders, especially children, and
animals should not be allowed in the
area where a trimmer is in use.
When the machine is not in use (work
break), shut it off so that it does not
endanger others and secure it against
unauthorized use.
The operator is responsible for avoiding
injury to third parties and damage to
their property.
Do not lend or rent your power tool
without the instruction manual. Be sure
that anyone using your power tool reads
and understands the information
contained in this manual.
You must be fit to work with a power tool.
Rested, healthy and in good physical
and mental condition
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 unit produces an
electromagnetic field of a very low
intensity. This field may interfere with
some pacemakers. To reduce health
risks of serious, STIHL recommends
that persons with pacemaker consult
their physician and the pacemaker
manufacturer before operating this tool.
Do not operate this power tool while
under the influence of any substance
(drugs, alcohol) which might impair
vision, dexterity or judgment.
Depending on the cutting tool fitted, use
your trimmer only for cutting grass, wild
growth and similar materials.
Do not use your trimmer for any other
purpose since it may result in accidents
or damage to the machine. Never
attempt to modify your power tool in any
way since this may also result in
accidents or damage to the machine.
Safety Precautions and
Working Techniques

4
English
FS 45
Only mount cutting tools or accessories
that are explicitly approved for this
power tool model by STIHL or are
technically identical. If you have any
questions in this respect, consult a
specialist dealer. To reduce the risk of
accidents or damage to the machine,
use only high quality tools and
replacement parts.
STIHL recommends the use of STIHL
original tools and accessories. The
characteristics of these components are
specifically designed to match your
machine and meet your performance
requirements.
The deflector on this trimmer cannot
protect the operator from all objects
thrown by the cutting tool (stones, glass,
wire, etc.). Such objects may ricochet
and then hit the operator.
Clothing and Equipment
Wear proper protective clothing and
equipment.
Clothing must be sturdy
but allow complete
freedom of movement.
Wear snug-fitting clothing,
e.g. an overall and jacket
combination, do not wear
a work coat.
Do not wear garments that could
become entangled with wood, scrub or
rotating parts of the machine. Avoid
loose-fitting jackets, scarves, neckties,
jewellery or anything that could get
caught on wood, brush or rotating parts
of the machine. Tie up and confine long
hair (e.g. with a hair net, cap, hard hat,
etc.).
Wear sturdy boots with
non-slip soles.
To reduce the risk of injury
to your eyes from thrown
objects, always wear
safety glasses and a
face shield.
Warning! A face shield alone does not
provide adequate eye protection.
Wear hearing protection (earplugs or ear
muffs).
Wear heavy-duty
gloves, preferably made
of leather.
STIHL offers a comprehensive range of
safety clothing and equipment.

5FS 45
English
Transporting the Unit
Always turn off the engine.
Carry the unit properly balanced by the
drive tube or loop handle.
Transporting in a vehicle:
Properly secure your unit to prevent
turnover, fuel spillage and damage.
Fueling
Gasoline is an
extremely flammable
fuel.
Do not smoke or bring any
fire or flame near the fuel,
avoid spilling fuel.
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 machine in well-ventilated
areas, outdoors only. Wipe off any
spilled fuel before starting and check for
leakage. Take care not to get fuel on
your clothing. If this happens, change
immediately.
Power tools come standard with either a
screw-type or bayonet-type fuel cap.
After fueling, tighten the
screw-type cap by hand
with as much force as
necessary.
Insert the fuel filler cap
with hinged grip (bayonet
type) 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 quantities of fuel.
To reduce the risk of serious or fatal
burn injuries, check for fuel leakage. If
fuel leakage is found, do not start or run
the engine until leak is fixed.
234BA001 KN

6
English
FS 45
Before Starting
Check that your power tool is properly
assembled and in good condition – refer
to appropriate chapters in the owner’s
manual:
– Check that the combination of
cutting tool, deflector, handle and
harness is approved and all parts
are properly assembled.
To reduce the risk of injury, never
use metal cutting tools.
– Slide control / stop switch must
move easily to STOP or 0
– Smooth action of throttle trigger and
throttle trigger interlock (if fitted) –
throttle trigger must return
automatically to idle position.
– Check that spark plug boot is secure
– a loose boot may cause arcing
that could ignite combustible fumes
and cause a fire.
– Cutting tool: Check for correct and
secure assembly and good
condition.
– Check protective devices (e.g.
deflector) for damage and wear.
Replace any damaged parts. Do not
continue operating your trimmer if
the deflector is damaged.
– Never attempt to modify the controls
or safety devices.
– Keep the handles dry and clean,
free from oil and dirt, for safe
control.
– Adjust the harness and handle(s) to
suit your height and reach.
To reduce the risk of accidents, operate
your power tool only if it is in good
working order.
Be prepared for an emergency when
wearing a harness: Practise quickly
setting down the unit. To avoid damage,
do not throw the machine to the ground
when practising.
Starting the Engine
Start the engine at least 3 meters from
the fueling spot, outdoors only.
Place the unit on firm ground in an open
area. Make sure you have good balance
and secure footing. Hold the unit
securely. The cutting tool must be clear
of the ground and all other obstructions
because it may begin to rotate when the
engine starts.
Your trimmer is a one-person unit. To
reduce the risk of injury from thrown
objects, do not allow other persons
within a radius of 15 meters of your own
position, even when starting.
To reduce the risk of
injury, avoid contact with
the cutting tool.
Do not drop start the power tool. The
correct starting procedure is described
in your instruction manual.

7FS 45
English
Note that the cutting tool
continues to rotate for a
short period after you let
go of the throttle trigger
(flywheel effect).
Check idle speed: The cutting tool must
not rotate 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 combustible materials (e.g.
wood chips, bark, dry grass, fuel).
Holding and Controlling the Unit
Always hold the unit firmly with both
hands on the handles. Make sure you
always have good balance and secure
footing.
Left hand on the loop handle, right hand
on the control handle.
During Operation
In the event of imminent danger or in an
emergency, switch off the engine
immediately – move the slide control /
stop switch to 0or d.
In order to reduce the risk of injury to
bystanders from thrown objects, always
keep bystanders 15 meters away from
your own position.
To reduce the risk of damage to
property, also maintain this distance
from other objects (vehicles, windows).
Make sure the idle speed setting is
correct. The cutting tool must not rotate
when the engine is idling with the throttle
trigger released.
Check and correct the idle speed setting
at regular intervals. If the cutting tool still
rotates, have your dealer check your
trimmer and make proper adjustments
or repairs.
002BA056 KN
15m (50ft)

8
English
FS 45
Take special care in slippery conditions
– damp, snow, on slopes, uneven
ground, etc.
Watch out for obstacles such as tree
stumps and roots which could cause you
to trip or stumble.
Make sure you always have firm and
secure footing.
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 at all times so as not to
endanger others.
Your power tool produces
toxic exhaust fumes as
soon as the engine is
running. These fumes
may be colorless and
odorless. Never run the
engine indoors or in poorly ventilated
locations, even if your model is equipped
with a catalytic converter.
To reduce the risk of serious of fatal
injury from breathing toxic fumes,
ensure proper ventilation when working
in trenches, hollows or other confined
locations.
Operate your power tool so that it
produces a minimum of noise and
emissions – do not run engine
unnecessarily, accelerate the engine
only for trimming.
To reduce 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 dust, vapor and smoke created
during operation may be damaging to
health. Wear a suitable respirator in very
dusty or smoky conditions.
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 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, have the
machine checked by your servicing
dealer.
Do not operate your power tool with the
starting throttle lock engaged as you do
not have control of the engine speed in
this position.
.
To reduce the risk
of personal injury
from thrown
objects, never
operate the unit
without the proper deflector for the type
of cutting tool being used.
Before starting work,
inspect the area for
stones, glass, pieces of
metal or other solid
objects which could
damage the cutting tool or
be thrown and cause damage to
property (e.g. parked vehicles,
windows).

9FS 45
English
Special care must be taken when
working in difficult, over-grown terrain.
When cutting high scrub, under bushes
and hedges: Keep cutting tool at a
minimum height of 15 cm to avoid
harming small animals (e.g.
hedgehogs).
Always shut off the engine before
leaving the unit unattended.
Check the cutting tool at regular short
intervals. If behavior of cutting tool
changes, check it immediately:
– Turn off the engine. Hold the unit
firmly and press the cutting tool into
the ground to bring it to a standstill.
– Check condition and tightness –
look for cracks.
– Replace damaged cutting tools
immediately, even if they have only
superficial cracks.
Clean grass and weeds off the cutting
tool mounting at regular intervals. If the
cutting tool or deflector becomes
clogged or stuck, always turn off the
engine and make sure the cutting tool
has stopped before cleaning.
To reduce the risk of unintentional
engine start and injury, always shut off
the engine and remove the spark plug
boot before replacing the cutting tool.
Never repair damaged or cracked
cutting tools by welding, straightening or
modifying the shape (out of balance).
This may cause parts of the cutting tool
to come off, hit the operator or
bystanders at high speed and result in
serious or fatal injuries.
When using mowing heads
Use the approved deflector with a
properly mounted line limiting blade to
ensure the nylon lines are trimmed to the
correct length.
To reduce the risk of injury, always shut
off the engine before adjusting length of
nylon line on manually adjustable
mowing heads.
Using the unit with over-long nylon
cutting lines increases the load on the
engine and reduces its operating speed.
This causes the clutch to slip
continuously and results in overheating
and damage to important components
(e.g. clutch, polymer housing
components). There is also a risk of
injury from the cutting tool rotating while
the engine is idling.

10
English
FS 45
Vibrations
Prolonged use of the unit 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)
– 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, seek medical advice.
Maintenance and repairs
The machine must be serviced regularly.
Do not attempt any maintenance or
repair work not described in your
Owner’s Manual. All other work should
be carried out by a servicing dealer.
STIHL recommends that maintenance
and repair work be carried out only by
authorized STIHL dealers. STIHL
dealers receive regular training and are
supplied with technical information.
Use only high-quality replacement parts,
in order to avoid the risk of accidents or
damage to the machine. Contact a
dealer if in doubt.
STIHL recommends the use of genuine
STIHL spare parts. Such parts have
been optimized for the machine and the
user's requirements.
Before starting any maintenance or
repair work and before cleaning the
machine, always stop the engine and
disconnect the spark plug boot to
avoid all risk of injury if the engine
starts up inadvertently. – Exception:
adjustment of carburetor and idle speed.
Do not service or store the machine near
a naked light – risk of fire due to the
fuel.
Check fuel cap regularly for tightness.
Use only the spark plugs approved by
STIHL – see Specifications.
Inspect ignition lead (insulation in good
condition, secure connection).
To reduce the risk of fire due to ignition
outside the cylinder, move the slide
control / stop switch to STOP or 0before
turning the engine over on the starter
with the spark plug boot removed or the
spark plug unscrewed.
Check that the muffler is in perfect
working condition.
Do not use the machine if the muffler is
damaged or missing – risk of fire! –
Hearing damage!
Do not touch the hot muffler – risk of
burns!
The condition of the anti-vibration
buffers influences the machine's
vibrations – they must be examined
regularly.

11FS 45
English
Cutting Tools and Deflectors
For safety reasons only the
combinations of cutting tool,
deflector, handle and harness
approved in your specific power
tool’s instruction manual may be
mounted.
Only mowing heads may be used on
loop-handled trimmers with a curved
drive tube.
Symbols on Deflectors
An arrow on the deflector shows the
correct direction of rotation of the cutting
tools:
Nylon Line Cutting Head
Nylon line achieves soft cut for edging
and trimming around trees and fence
posts – less risk of damaging tree bark.
To reduce the risk of serious
injury, never use wire or metal-
reinforced line or other material in
place of the nylon cutting line.
STIHL FixCut
Check the wear marks
To avoid the risk of injury from tool
breakage and parts being thrown in your
direction, do not use the mowing head
if the raised moldings (1) on its base are
worn as shown in the illustration. Install
a new mowing head.
000BA015 KN

12
English
FS 45
Mowing Head with Polymer
Blades – STIHL PolyCut 6-3
For mowing unobstructed edges of
meadows (without posts, fences, trees
or similar obstacles).
Observe maintenance instructions for
PolyCut mowing head.
Observe the wear limit marks
Wear limit marks are integrated in the
base of the PolyCut.
Do not continue using the PolyCut if one
of the circular holes (1; arrow) becomes
visible or if the projecting rim (2; arrow)
has worn away. Install a new mowing
head.
If the wear limit marks are ignored,
there is a risk of the cutting tool
shattering and flying parts injuring
the operator or bystanders.
To reduce the risk of accidents from
shattered blades, avoid contact with
stones, metal and similar solid objects.
Check PolyCut blades for cracks at
regular intervals. If a crack is found on
one blades, always replace all blades.
1
002BA073 KN
2
002BA074 KN

13FS 45
English
Cutting Tools
1STIHL AutoCut C 5-2 mowing head
2STIHL AutoCut 5-2 mowing head
3STIHL PolyCut 6-3 mowing head
4STIHL FixCut 5-2 mowing head
Deflector
5Deflector with line limiting blade for
mowing heads only (see “Mounting
the Deflector”)
Handle
6Loop handle
Harness/Shoulder Strap
7Shoulder strap may be used
Equipment
The complete trimmer includes:
– Cutting tool
– Deflector
– Handle
– Shoulder strap (special accessory)
Approved Combinations
Depending on the cutting tool you intend
to use, select the correct combination
from the table below.
For safety reasons only those
versions of the cutting tools,
deflectors, handles and harnesses/
straps shown in the table may be
used. Other combinations are not
permitted because of the risk of
accidents.
Only mowing heads (1, 2, 3, 4) may be
used on loop-handled trimmers with a
curved drive tube.
To reduce the risk of accidents and
injury, avoid contact with the rotating
cutting tool.
Approved Combinations of Cutting Tool, Deflector, Handle
and Harness
Cutting Tools Deflector Handle Shoulder Strap
681FK028 KN
3
002BA000 KN
4
Schnur/LINE 2
681FK213 KN
Schnur/LINE 1
1
25
6
0
02BA125 KN
7

14
English
FS 45
:Place friction liner in the loop
handle.
:Fit the loop handle (1) on the drive
tube approx. 20 cm (A) forward of
the control handle (2).
:Slide spacer (3) – if available – as
far as possible into loop handle.
:Insert screw (4) in loop handle and
through spacer until the hexagon
head rests in the socket head of the
loop handle.
:Fit the washer (5).
:Fit and tighten down the wingnut (6).
Adjusting loop handle to most
comfortable position:
:Unscrew wingnut (6).
:Turn or move loop handle (1) along
drive tube as required.
:Retighten wingnut (6).
Mounting the Loop Handle
223BA017 KN
223BA018 KN
4
65
232BA027 KN
1
2
3
A

15FS 45
English
:Push the deflector (1) over the
clamp (2).
:Insert nut (3) in the hex recess in the
deflector.
:Make sure the holes line up.
:Fit screw (4) and tighten it down
firmly.
Preparations
:Lay your trimmer on its back with
the loop handle and shroud pointing
down and the output shaft facing up.
Thrust Plate
The thrust plate is shipped with the
Polycut 6-3 and FixCut 5-2. It is only
required for these mowing heads.
AutoCut 5-2 mowing head
AutoCut C 5-2 mowing head
:Pull the thrust plate (1) (if fitted) off
the shaft (2).
STIHL PolyCut 6-3 mowing head,
STIHL FixCut 5-2 mowing head
:Slip the thrust plate (1) over the
shaft (2) and engage hexagon
recess (3) on external hexagon (4).
Mounting the Deflector
1
2
232BA066 KN
4
232BA067 KN
3
Mounting Cutting Tools
232BA026 KN
232BA033 KN
1
2
3
4

16
English
FS 45
Mounting the Mowing Head
Keep instruction sheet for mowing
head in a safe place.
Assembling STIHL AutoCut 5-2
:Fit the spring (1) in the head (2).
All other steps are described in the
instruction sheet provided with the
mowing head.
:Wind the nylon lines (3) onto the
spool (4).
:Thread the ends of the nylon lines
through the sleeves and place the
spool in the head.
STIHL AutoCut 5-2
:Push the mowing head (2) over the
shaft (5) and engage the hex recess
(7) on the external hexagon (6).
:Place the cap (8) on the head – turn
it clockwise as far as stop and then
tighten it down firmly.
STIHL AutoCut C 5-2
:Push the mowing head (2) over the
shaft – as with the AutoCut 5-2.
:Screw the spool (9) into the head
until the two arrows are in alignment
(see illustration) – secure the spool
in this position.
:Push the cap (8) into the spool as
far as stop, turning it clockwise at
the same time.
:Turn cap as far as stop and tighten
it down by hand.
1
232BA054 KN
23
4
3
7
5
2
232BA053 KN
6
8
9
681BA018 KN
Schnur/LINE 2
Schnur/LINE 1
2
8

17FS 45
English
STIHL PolyCut 6-3
:Fit the thrust plate on the shaft.
:Insert the nut (10) in the mowing
head.
:Screw the mowing head (11)
clockwise onto the shaft (5) as far
stop.
:Block the shaft
:Tighten down the mowing head
firmly
Remove the stop pin
Blocking the shaft
:Insert a suitable tool (12) through
the holes (13) in the deflector and
thrust plate – turn the thrust plate
back and forth if necessary.
:Tighten down the mowing head
firmly.
Remove the tool used to block the
shaft.
STIHL FixCut 5-2
:Slip the thrust plate (2) over the
shaft.
:Place the mowing head on the
thrust plate (2).
The thrust plate’s collar (arrow)
must engage the hole in the mowing
head.
:Push the thrust washer (3) over the
shaft (1) so that it locates against
the base.
:Block the shaft. Fit the nut (4) on the
shaft and tighten it down firmly with
the combination wrench (5).
Remove the tool used to block the
shaft.
11
5
681BA019 KN
10
3
1
2
4
232BA074 KN
5

18
English
FS 45
Adjusting Nylon Line
AutoCut
:Hold the rotating cutting head
horizontal to the ground – tap it on
the ground – about 3cmof fresh
line is advanced.
:The blade (1) on the deflector (2)
trims surplus line to the correct
length. Avoid tapping the head more
than once at a time.
Line feed operates only if both lines
still have a minimum length of
2.5 cm.
Removing the Mowing Head
AutoCut
:Hold the mowing head steady
and unscrew the cap
counterclockwise.
PolyCut
:Block the shaft.
:Unscrew the mowing head
counterclockwise.
FixCut
:Block the shaft.
:Use the combination wrench to
unscrew the mounting nut clockwise
from the shaft.
If the mounting nut turns too freely,
fit a new one.
Replacing Nylon Line / Polymer
Blades
AutoCut
See chapter on “Replacing Nylon Line”.
PolyCut, FixCut
Follow the instructions supplied with the
mowing head.
Your engine requires a mixture of
gasoline and engine oil.
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 is specially
formulated for use in STlHL engines
and guarantees a long engine life.
MotoMix is not available in all markets.
Mixing Fuel
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.
1
232BA007 KN
2
Fuel

19FS 45
English
Gasoline
Use only high-quality brand-name
gasoline with a minimum octane rating
of 90 – leaded or unleaded.
If your machine is equipped with a
catalytic converter, you must use
unleaded gasoline.
A few tankfuls of leaded gasoline
will greatly reduce the efficiency of
the catalytic converter.
Engine Oil
Use only quality two-stroke engine oil.
We recommend STIHL two-stroke
engine oil since it is specially
formulated for use in STlHL engines
and guarantees a long engine life.
If STIHL two-stroke engine oil is not
available, use only quality two-stroke oil
designed for use in air cooled engines.
Do not use oils designed for water
cooled engines or engines with a
separate lubricating system (e.g.
conventional four-stroke engines).
Use only STIHL 50:1 two-stroke
engine oil for the fuel mix in models with
a catalytic converter.
Mix Ratio
STIHL 50:1 two-stroke engine oil:
50 parts gasoline to 1 part oil
Other high-quality two-stroke engine
oils:
25 parts gasoline to 1 part oil
Examples
:Use a canister approved for storing
fuel. Pour oil into the 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 3 months.
Exposure to light, the sun, low or high
temperatures can quickly make the fuel
mix unusable.
:Thoroughly shake the mixture in the
canister before fueling your
machine.
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 environment requirements.
Gaso-
line
STIHL
engine oil
50:1
Other high-
quality two-
stroke engine
oils:
25:1
Liters Liters (cc) Liters (cc)
1 0.02 (20) 0.04 (40)
5 0.10 (100) 0.20 (200)
10 0.20 (200) 0.40 (400)
15 0.30 (300) 0.60 (600)
20 0.40 (400) 0.80 (800)
25 0.50 (500) 1.00 (1000)