Stihl SR 430 User manual

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STIHL SR 430, 450 Instruction Manual
Notice d’emploi

GInstruction Manual
1 - 39
FNotice d’emploi
41 - 84

Original Instruction ManualPrinted on chlorine-free paper
Printing inks contain vegetable oils, paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2010 0458-454-8221-B. M0-2.B10.MET. 0000002505_003_GB
SR 430, SR 450
English
1
{
Contents
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.
Your
Hans Peter Stihl
Guide to Using this Manual 2
Safety Precautions and Working
Techniques 2
Assembling the Unit 9
Adjusting the Throttle Cable 11
Harness 11
Fuel 12
Fueling 13
Information Before You Start 14
Starting / Stopping the Engine 14
Operating Instructions 17
Calculating Required Quantity of
Solution 17
Metering Unit 18
Dusting and Spreading Mode 21
Filling the Container 23
Working 24
After Finishing Work 25
Storing the Machine 26
Replacing the Air Filter 26
Engine Management 27
Adjusting the Carburetor 27
Spark Plug 28
Engine Running Behavior 29
Replacing the Starter Rope and
Rewind Spring 29
Inspections and Maintenance by
Dealer 31
Maintenance and Care 32
Main Parts 34
Specifications 36
Special Accessories 37
Maintenance and Repairs 37
STIHL Limited Emission Control
Warranty Statement 37

SR 430, SR 450
English
2
Pictograms
All the pictograms attached to the
machine are shown and explained in this
manual.
Symbols in text
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 power tool
model before: Have your dealer or other
experienced user show you how to
operate your power tool or attend a
special course in its operation.
Minors should never be allowed to use a
power tool.
Keep bystanders, especially children,
and animals away from the work area.
When the power tool is not in use, shut if
off so that it does not endanger others.
Secure it against unauthorized use.
The user is responsible for avoiding
injury to third parties or damage to their
property.
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.
The use of noise emitting power tools
may be restricted to certain times by
national or local regulations.
Do not operate your sprayer if any of its
components are damaged. Pay special
attention to the tightness of the container
(no leaks).
Operate the unit only if it is complete and
properly assembled.
Do not use a pressure washer to clean
the unit. The solid jet of water may
damage parts of the unit.
Physical Condition
To operate the 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 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.
Applications
The sprayer is suitable for applying
fungicides, herbicides and pesticides at
ground level. Spraying overhead is
Guide to Using this Manual
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.
Safety Precautions and
Working Techniques
Special safety precau-
tions must be observed
when working with the
power tool.
It is important you read
and understand the
instruction manual before
using your power tool for
the first time and keep
the manual in a safe
place for future refer-
ence. Non-observance of
the safety precautions
may result in serious or
even fatal injury.

SR 430, SR 450
English
3
possible with units equipped with a
pressure pump. Typical areas of
application are in fruit, vegetable, wine
and crop growing, plantations, flower
growng, grassland and forestry.
Only use plant protection products that
are specifically approved for use in
sprayers/mistblowers.
Do not use your machine for any other
purpose because of the increased risk of
accidents and damage to the machine.
Never attempt to modify the unit in any
way since this may result in accidents or
damage to the unit.
Accessories and Spare Parts
Only use parts and accessories that are
explicity 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 your
model 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.
Clothing and Equipment
Wear proper protective clothing and
equipment when using, filling and
cleaning the sprayer. Follow the
chemical manufacturer's instructions
with respect to protective equipment.
Immediately change work clothes
contaminated with plant control
chemicals.
If you are spraying overhead, wear
impermeable head covering.
Do not wear sandals or go barefoot.
Breathing plant control chemicals may
endanger your health. Always wear a
suitable respirator to protect yourself
against health risks and allergic
reactions. Observe warnings in the
directions for use of the plant protection
product and all applicable local safety
regulations, standards and ordinances.
Handling of Chemicals
Read the instructions supplied with the
plant control chemical prior to use.
Follow the instructions with respect to
mixing, using, personal protection
equipment, storage and disposal.
Observe legal requirements for handling
plant control chemicals.
Plant control chemicals may contain
substances that are harmful to humans,
animals, plants and the environment –
risk or poisoning and risk of serious
or fatal injuries!
Plant control chemicals may be used
only by persons trained in their handling
and the appropriate first-aid measures.
Keep instructions or label of the plant
control chemical available at all times in
order to inform the doctor about the
chemical concerned in an emergency.
Clothing must be snug-fit-
ting but allow complete
freedom of movement.
For some chemicals it is
necessary to wear imper-
meable coveralls.
Avoid any clothing,
scarves, neckties, jewel-
lery 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 impermeable safety
boots with a non-slip sole
which are resistant to
plant control chemicals.
Wear safety glasses, res-
pirator and hearing
protection, e.g. earplugs
or ear muffs.
Wear impermeable
gloves resistant to plant
control chemicals.

SR 430, SR 450
English
4
In an emergency, follow the chemical
manufacturer's instructions provided or
on the label.
Mixing the spray solution
Mix the plant protection product strictly
in accordance with the manufacturer's
instructions – incorrect mixtures may
produce toxic fumes or explosive
solutions.
–Never spray liquid plant control
chemicals undiluted.
–Prepare solution and fill the
container outdoors only or in well-
ventilated locations.
–Only prepare sufficient solution for
the job in hand so that nothing is left
over.
–Mix different chemicals only in
accordance with the manufacturer's
instructions – incorrect mixtures
may produce toxic fumes or
explosive solutions.
–Do not mix different plant protection
products unless such a mixture is
approved by the manufacturer.
Filling the Container
–Stand the power tool on a level
surface – do not fill the container
above the maximum mark.
–To reduce the risk of injury, do not
fill the unit while wearing it on your
back.
–Close the valve lever before filling.
–When filling from central water
supply, do not immerse the end of
the hose in the solution – sudden
low pressure in the system may
cause the solution to be sucked
back into the water supply.
–Before filling the container with
spray solution, carry out test run
with fresh water and check all parts
of the sprayer for leaks.
–After filling, fit the filler cap and
tighten it down firmly.
Using the unit
–Work only in the open or in very well
ventilated locations, e.g. open
greenhouses.
–Do not eat, drink or smoke while
working with plant control
chemicals.
–Never blow through nozzles or other
components by mouth.
–Avoid contact with plant control
chemicals – immediately change
clothing contaminated with plant
control chemical.
–Do not spray in windy conditions.
Unfavorable weather conditions may
result in an incorrect concentration of the
plant protection product. Overdosing
may damage plants and the
environment. Under-dosing may result
in unsuccessful plant treatment.
In order to reduce the risk of damage to
the environment and plants, do not
operate the sprayer if:
–in windy conditions
–at temperatures above 25°C in the
shade
–in direct sunlight
In order to reduce the risk of accidents
and damage to the power tool, never
operate the power tool with:
–flammable liquids
–viscous or sticky liquids
–caustic or corrosive chemicals
–liquids hotter than 50°C
Storage
–During work breaks, do not leave
the power tool in the hot sun or near
any heat source.
–Do not store spray solution in the
container for longer than one day.
–Store and transport spray solution
only in approved containers.
–Never store the spray solution in
containers intended for foods,
drinks or animal feed.
–Do not store spray solution with
foods, drinks or animal feed.
–Keep spray solution out of the reach
of children and animals.
–Store the unit empty and clean.
–Store the spray solution and unit in
a place secured against
unauthorized use.
–Store the spray solution and unit in
a dry place protected from frost.

SR 430, SR 450
English
5
Disposal
Never dispose of residual chemicals or
contaminated rinsing solutions in
waterways, drains, sewers, street
gutters or manholes.
–Dispose of residual solution and
used containers in accordance with
local waste disposal regulations.
Transporting the Unit
Always stop the engine.
Transporting in a vehicle:
–Properly secure your power tool to
prevent turnover, fuel spillage and
damage.
–The container must be empty and
clean.
Fueling
Always shut off the engine before
refueling.
Do not fuel a hot engine – fuel may spill
and cause a fire.
Always remove the power tool from your
back and put it on the ground before
refueling. Fuel the unit only when it is
standing securely on the ground.
Open the bayonet-type 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.
Bayonet fuel cap
Never use a tool to open or close the
bayonet-type fuel cap. This may
damage the cap and cause fuel leakage.
Close the bayonet-type fuel cap
carefully after refueling.
Before starting
Check that your power tool is properly
assembled and in good condition,
especially if it has been subjected to
unusually high loads for which it was not
designed (e.g. heavy impact or a fall).
–The setting lever must move easily
to STOP or 0
–Throttle trigger must move freely
and spring back to the idle position
when released.
–Check that the spark plug boot is
secure – a loose boot may cause
arcing that could ignite combustible
fumes and cause a fire.
–Check the fuel system for leaks.
–Check condition and tightness of
container, hose and metering unit.
–Check condition of harness straps
and replace damaged or worn
straps.
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.
For emergencies: Practise removing
and putting down the machine as you
would in an emergency. 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.
Your power tool is designed to be
operated by one person only. Do not
allow other persons in the work area –
even when starting.
Start the engine as described in the
instruction manual.
Place the unit on level ground, make
sure you have secure footing, hold the
unit securely.
If an assistant is required to put the
power tool on your back, make sure that
Gasoline is an
extremely flammable
fuel. Keep clear of naked
flames. Do not spill any
fuel – do not smoke.
Check for leakage. To
reduce the risk of seri-
ous of fatal burn
injuries, do not start or
run the engine until leak
is fixed.

SR 430, SR 450
English
6
–the engine is running at idle speed
–the assistant is not standing in the
area of the exhaust outlet and
breathing toxic fumes
–the valve lever and, on SR 450 only,
the metering lever is closed
–the assistant is not standing in the
area of the outlet nozzle
–the assistant must leave the work
area immediately after you have put
the power tool on your back.
Holding and Controlling the Power
Tool
Carry the unit on your back with both
harness straps – do not hang it over one
shoulder. Hold and control the blower
tube with your right hand on the control
handle – even if you are left-handed.
Walk slowly forwards as you work –
observe the nozzle outlet at all times –
do not walk backwards – risk of
stumbling.
Keep the power tool and container
upright. To avoid the risk of chemical
leaking from the container and causing
injury,do not bend forwards.
Dusting and spreading mode –
SR 450 only
The dusting and spreading mode can be
used for powder or dry granulate up to a
grain size of 5 mm.
Observe legal requirements for handling
the chemicals.
Observe the directions for use or the
label of the plant protection product.
Using the unit
Electrostatic charging with sparking can
occur when working with the dusting and
spreading attachment.
The risk is greatest
–in extremely dry weather conditions
–when using powdered products,
which create a highly concentrated
dust cloud.
To reduce the risk of accidents and
damage to the power tool, never operate
it with explosive or combustible
materials.
Do not apply sulphur or compounds
containing sulphur since they are highly
explosive and have a very low ignition
point.
To reduce the risk of sparking, explosion
or fire, make sure the discharge system
is completely and properly mounted to
the machine. It consists of a conductive
wire in the spray tube connected to a
metal chain. The metal chain must make
contact with a conductive surface to
dissipate electrostatic charges.
Do not operate your machine on a non-
conductive surface (e.g. plastic,
asphalt).
Never operate your machine with a
missing or damaged discharge system.
During Operation
0002BA002 KN
0002BA001 KN

SR 430, SR 450
English
7
Do not direct the air blast towards
bystanders since the air flow can blow
small objects at great speed.
In the event of impending danger or in
an emergency, switch off the engine
immediately by moving the setting lever
to STOP or 0.
Throwing off power tool in an
emergency:
–Open the fastener on the hip belt
(special accessory).
–Slip the straps off your shoulders.
–Throw the power tool to the ground.
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.
Be particularly alert and cautious when
wearing hearing protection because
your ability to hear warnings (shouts,
alarms, etc.) is restricted.
To reduce the risk of accidents, take a
break in good time to avoid tiredness or
exhaustion.
Work calmly and carefully – in daylight
conditions and only when visibility is
good. Stay alert so as not to endanger
others.
Never work on a ladder or any other
insecure support.
When working in open ground and
gardens take special care to avoid
harming small animals.
To reduce the risk of electrocution,
never operate this power tool in the
vicinity of live wires or power cables.
Always clean the spray container and
hose system before changing to a
different plant protection product.
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.
Operate your power tool so that it
produces a minimum of noise and
emissions – do not run the engine
unnecessarily, accelerate the engine
only for cutting.
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". 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, have the
machine checked by your servicing
dealer.
After Finishing Work
Close the valve lever and, on SR 450
only, the metering lever.
Always shut off the engine before taking
the power tool off your back.
After finishing work, put the power tool
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).
Check all machine components for
leaks.
After finishing work, throughly clean the
power tool and wash your hands, face
and, if necessary, your clothes.
Keep other persons and animals away
from the areas that have been sprayed
and do not walk on them until the plant
protection chemical has dried.
Vibrations
Prolonged use of the power tool may
result in vibration-induced circulation
problems in the hands ("white finger
disease").
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 oper-
ate the power tool in
enclosed or poorly venti-
lated locations.

SR 430, SR 450
English
8
No general recommendation can be
given for the length of usage because it
depends on several factors.
The period of usage is prolonged by:
–Hand protection (wearing warm
gloves)
–Work breaks
The period of usage is shortened by:
–Any personal tendency to suffer
from poor circulation (symptoms:
frequently cold fingers, tingling
sensation)
–Low outside temperatures
–Amount of gripping force (holding
the power tool tightly restricts
circulation)
Users who use the machine periodically
or for long periods or users who
repeatedly experience corresponding
symptoms (e.g., tingling sensation in
fingers), should undergo a medical
examination.
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
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.
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 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.

SR 430, SR 450
English
9
The combination wrench and
screwdriver are in the supplied
accessory bag.
Fitting the pleated hose on the blower
tube
NSlide the wide hose clamp (1) onto
the blower tube (2) and line it up.
NPush the ring seal (3) (wide lip
facing left) onto the blower tube (2).
NPush the pleated hose (4) over the
ring seal (3).
NSlide the wide hose clamp (1) onto
the pleated hose (4).
NSecure the wide hose clamp (1) with
the screw (5) – the blower tube (2)
must still rotate.
Fitting the pleated hose on the elbow
– SR 430 only
NSlide the narrow hose clamp (6)
(bezel facing left) onto the elbow
and line it up.
NPush the pleated hose (4) over the
elbow (7).
NSlide the narrow hose clamp (6)
onto the pleated hose (4).
NSecure the hose clamp (6) with the
screw (8) from the side facing the
operator.
Fitting the antistatic system – SR 450
only
NAttach the antistatic wire (1) and
chain (2) to the blower housing with
screw (3).
Assembling the Unit
Hose and throttle cable, and the
metering unit's operating cable on
the SR 450, come connected
ready for use and must not be
kinked while assembling the
machine.
0002BA003 KN
12
2
4
3
0002BA004 KN
5
4
0002BA005 KN
1
2
7
6
0002BA006 KN
4
6
8
4
6
8
0002BA007 KN
31
2
0002BA054 KN

SR 430, SR 450
English
10
Fitting the pleated hose on the elbow
– SR 450 only
NPush the antistatic wire (9) into the
pleated hose (4).
NSlide the narrow hose clamp (6)
(bezel facing left) onto the elbow
and line it up.
NPush the antistatic wire (9) between
the ends of the narrow hose
clamp (6).
NPush the pleated hose (4) over the
elbow (7).
NSlide the narrow hose clamp (6)
onto the pleated hose (4).
NSecure the hose clamp (6) with the
screw (8) from the side facing the
operator – make sure the antistatic
wire is positioned in the notch.
Adjusting and securing the control
handle
NPut the machine on your back and
adjust the harness – see "Harness".
NSlide the control handle (1) along
the tube to the most comfortable
position – distance between nozzle
outlet (2) and the control handle (1)
must be at least 500 mm (a).
NSecure the control handle (1) with
the screw (3).
NUse the retainer (4) to secure the
hose and throttle cable, and
metering unit's operating cable on
the SR 450, to the 6th pleat (arrow)
on the pleated hose.
9
0002BA008 KN
4
9
6
0002BA009 KN
746
8
4
6
8
0002BA010 KN
a
1
0002BA011 KN
2
0002BA058 KN
1
3
4
0002BA012 KN

SR 430, SR 450
English
11
It may be necessary to correct the
adjustment of the throttle cable after
assembling the machine or after a
prolonged period of operation.
Adjust the throttle cable only when the
unit is completely and properly
assembled.
NSet throttle trigger to the full throttle
position – as far as stop.
NCarefully rotate the screw in the
throttle trigger in the direction of the
arrow until you feel initial resistance.
Then rotate it another full turn.
Adjusting the harness
NPull the ends of the straps
downward to tighten the harness.
NAdjust the harness so that the
backplate fits snugly and securely
against your back.
Loosening the harness
NLift the tabs of the sliding adjusters.
Disconnecting harness from
backplate
NPull the ring (1) out of the slot.
Adjusting the Throttle
Cable
0002BA013 KN
Harness
373BA003 KN
373BA004 KN
0002BA055 KN
1

SR 430, SR 450
English
12
This engine is certified to operate on
unleaded gasoline and with the mix ratio
50:1.
Your engine requires a mixture of high-
quality premium gasoline and high-
quality two-stroke air-cooled engine oil.
Use premium branded unleaded
gasoline with a minimum octane rating
of 89 RON.
Note: Models equipped with a catalytic
converter require unleaded gasoline. A
few tankfuls of leaded gasoline can
reduce the efficiency of the catalytic
converter by more than 50%.
Fuel with a lower octane rating may
result in preignition (causing "pinging")
which is accompanied by an increase in
engine temperature. This, in turn,
increases the risk of the 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 as
well. This could cause running problems
or even damage the engine. For this
reason it is essential that you use only
high-quality fuels!
Fuels with different percentages of
ethanol are being offered. Ethanol can
affect the running behaviour of the
engine and increase the risk of lean
seizure.
Use only STIHL two-stroke engine oil or
equivalent high-quality two-stroke air-
cooled engine oils for mixing.
We recommend STIHL 50:1 two-stroke
engine oil since it is specially formulated
for use in STIHL engines.
Do not use BIA or TCW (two-stroke
water cooled) mix oils!
Use only STIHL 50:1 heavy-duty
engine oil or an equivalent quality two-
stroke engine oil for the fuel mix in
models equipped with a catalytic
converter.
Take care when handling gasoline.
Avoid direct contact with the skin and
avoid inhaling fuel vapour.
The canister should be kept tightly
closed in order to avoid any moisture
getting into the mixture.
The fuel tank and the canister in which
fuel mix is stored should be cleaned
from time to time.
Fuel mix ratio
Only mix sufficient fuel for a few days
work, not to exceed 3 months of storage.
Store in approved safety fuel-canisters
only. When mixing, pour oil into the
canister first, and then add gasoline.
Dispose of empty mixing-oil canisters
only at authorized disposal locations.
Fuel
Examples
Gasoline Oil (STIHL 50:1 or equiva-
lent high-quality oils)
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)

SR 430, SR 450
English
13
Preparations
NBefore fueling, clean the bayonet-
type fuel cap and the area around it
to ensure that no dirt falls into the
tank.
NPosition the machine so that the fuel
cap is facing up.
Opening the bayonet-type fuel cap
NPress the bayonet-type fuel cap
down as far as stop, turn it
counterclockwise (about 1/8 turn)
and remove.
Filling up with fuel
Take care not to spill fuel while fueling
and do not overfill the tank. STIHL
recommends you use the STIHL filler
nozzle for fuel (special accessory).
Closing the bayonet-type fuel cap
NPlace the cap on the tank opening
and turn it slips into position.
NPress the fuel cap down by hand as
far as stop and turn it clockwise
(about 1/8 turn) until it engages.
Change the fuel pickup 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.
Fueling
Never use a tool to open or close
the bayonet-type fuel cap. This
may damage the cap and cause
fuel leakage.
0002BA014 KN
2.
1.
0002BA015 KN
2.
1.
0002BA016 KN

SR 430, SR 450
English
14
Control handle
1Setting lever
2Throttle trigger
3Throttle trigger interlock 1)
Functions of setting lever
Run position F
Engine runs or is ready to start. Throttle
trigger (2) can be moved to any position.
Stop position 0
Ignition is interrupted, engine stops. The
setting lever (1) is not locked in this
position. It springs back to the run
position. The ignition is switched on
again.
Throttle trigger limiter position 1)
Travel of throttle trigger can be limited in
two stages:
a1/3 throttle
b2/3 throttle
To disengage the travel limiter,
Nreturn the setting lever (1) to the run
position F.
Throttle lock 1)
The throttle trigger (2) can be locked in
two positions:
aFull throttle
bHalf throttle
To disengage the lock,
Nreturn the setting lever (1) to the run
position F.
Before starting
NClose valve lever (1) for solution
feed.
Additionally on SR 450:
NClose the metering lever (2) for
dusting and spreading mode.
Starting the engine
NObserve safety precautions.
Information Before You
Start
With the engine stopped and
before starting, check the air
intakes between the backplate
and powerhead for blockages and
clean if necessary.
1
0002BA017 KN
23
1) Not in all versions, country-specific
0002BA053 KN
a
b
0002BA059 KN
a
2
b
Starting / Stopping the
Engine
Start your unit on a clean, dust-
free surface only to ensure that no
dust is sucked in.
0002BA060 KN
1
0002BA052 KN
2

SR 430, SR 450
English
15
NThe setting lever must be on F
NPress the fuel pump bulb (3) at least
eight times – even if the bulb is filled
with fuel.
Cold engine (cold start)
NPress in the choke knob (4) and turn
it to c.
Warm engine (warm start)
NPress in the choke knob (4) and turn
it to o.
Also use this setting if the engine has
been running but is still cold.
Cranking
NPlace the unit securely on the
ground and make sure that
bystanders are well clear of the
nozzle outlet.
NMake sure you have a firm footing:
Hold the unit with your left hand on
the housing and put one foot against
the base plate to prevent it slipping.
NPull the starter grip slowly with your
right hand until you feel it engage
and then give it a brisk strong pull.
Do not pull out the starter rope to full
length – 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.
NContinue cranking until the engine
runs.
0002BA019 KN
0002BA020 KN
HLA
L
4
0002BA021 KN
4
0002BA022 KN
0002BA023 KN

SR 430, SR 450
English
16
As soon as the engine runs
NPull the throttle trigger – the choke
knob (4) automatically returns to the
run position (e).
At very low outside temperatures:
NOpen throttle slightly – warm up the
engine for a short period.
Shut off the engine
NMove the setting lever in the
direction of 0– the engine stops –
the setting lever springs back to the
on position.
Other hints on starting
Engine stalls in cold start position c
or under acceleration
NMove the choke knob to oand
continue cranking until the engine
runs.
Engine does not start in warm start
position o
NMove the choke knob to cand
continue cranking until the engine
runs.
If the engine does not start
NCheck that all settings are correct.
NCheck that there is fuel in the tank
and refuel if necessary.
NCheck that the spark plug boot is
properly connected.
NRepeat the starting procedure.
Fuel tank run until completely dry
NAfter refueling, press the fuel pump
bulb at least eight times – even if the
bulb is filled with fuel.
NSet the choke knob according to
engine temperature.
NStart the engine.
4
0002BA024 KN
0002BA025 KN

SR 430, SR 450
English
17
During break-in period
A factory-new machine should not be
run at high revs (full throttle off load) for
the first three tank fillings. This avoids
unnecessary high loads during the
break-in period. As all moving parts
have to bed in during the break-in
period, the frictional resistances in the
engine are greater during this period.
The engine develops its maximum
power after about 5 to 15 tank fillings.
During Operation
After a long period of full throttle
operation, allow the engine to run for a
short while at idle speed so that engine
heat can be dissipated by the flow of
cooling air. This protects engine-
mounted components (ignition,
carburetor) from thermal overload.
After Finishing Work
Storing for a short period: Wait for the
engine to cool down. Empty the fuel tank
and keep the machine in a dry place,
well away from sources of ignition, until
you need it again. For longer out-of-
service perionds – see "Storing the
Machine".
Determining surface area (m2)
In the case of ground crops, simply
multiply the length of the field by its
width.
The surface area of high-growing plants
is calculated approximately by
measuring the length of the rows and the
average height of the foliage. The result
is multiplied by the number of rows and
then by two if both sides have to be
treated.
The surface area in hectares is obtained
by dividing the number of square meters
by 10,000.
Example:
A field 120 meters long and 30 meters
wide has to be treated with a pesticide.
Area:
120 m x 30 m = 3,600 m2
3,600 / 10,000 = 0.36 ha
Determining quantity of active
ingredient
Refer to the instructions supplied with
the active ingredient to determine:
–Required quantity of active
ingredient for 1 hectare (ha).
–Concentration of active ingredient
(mix ratio).
Multiply the required quantity of active
ingredient for 1 hectare by the area
determined in hectares. The result is the
quantity of active ingredient required for
the area to be treated.
Example:
According to the maker’s instructions,
0.4 liters of active ingredient are
required per hectare to obtain a
concentration of 0.1%.
Quantity of active ingredient:
0.4 (l/ha) x 0.36 (ha) = 0.144 l
Determining quantity of solution
The quantity of solution required is
calculated as follows:
TW= Quantity of active ingredient in l
K= Concentration in %
TW= Required quantity of solution in l
Example:
The calculated quantity of active
ingredient is 0.144 liters. According to
the maker’s instructions, the
concentration is 0.1%.
Quantity of solution:
Determining walking speed
Carry out a trial run with the machine
fueled and the container filled with
water. Operate the spray tube (swing it
Operating Instructions Calculating Required
Quantity of Solution
TWx 100 = TB
K
0.144 l x 100 = 144 l
0,1 %

SR 430, SR 450
English
18
back and forth) as for the real run
described below. Determine the
distance walked in one minute.
Also use the trial run to check the
selected working width. The best
working width for low-growing crops is
4–5 m. Mark the working width with
stakes.
Dividing the distance walked in meters
by the time in minutes gives you the
walking speed in meters per minute
(m/min).
Example:
The distance covered in one minute is
10 meters.
Walking speed:
Determining discharge rate
The setting of the metering unit is
calculated as follows:
Va= Quantity of solution
vb= Walking speed
Va= Discharge rate
b= Working width
A = Area
Example:
The values determined above and a
working width of 4 meters require the
following setting on the metering unit:
Hectares (ha) have to be converted into
m2(ha x 10,000 = m2).
To adjust the required discharge rate
see "Metering Unit".
Valve lever
Solution feed is started and stopped with
the valve lever (1).
NPosition A (valve lever vertical, up)
– open
NPosition B (valve lever horizontal,
down) – closed
Metering knobs
The scope of supply includes metering
knobs which allow a wide range of
different discharge rates.
10 m = 10 m/min
1min
Va(l) x vb(m/min) x b(m) = Vc(l/min)
A (m2)
144 l x 10 (m/min) x 4m = 1.6 l/min
3,600 m2Metering Unit
1
0002BA061 KN
A
B
1