Stihl Br 420 C Manual

							30 English / USA
BR 340, BR 340 L, BR 420, BR 420 CDefinitions1. Nozzle, Straight
Aims and widens the spray or 
airstream.
2. Nozzle, Curved
Aims and widens the spray or 
airstream.
3. Blower Tube.
Directs spray or airstream.
4. Blower Tube.
Directs spray or airstream.
5. Control Handle.
Handle on the flexible hose to hold 
and direct the tube in the required 
direction.
6. Throttle Trigger.
Controls the speed of the engine.
7. Setting Lever.
Sets the trottle to various positions.
8. Stop Switch.
Stops engine
9. Pleated Hose.
For spraying, dusting or spreading 
in the desired direction.10. Harness.
For carrying the unit.
11. Backplate.
Helps protect the back of the user.
12. Back Padding.
Increases carrying comfort.
13. Air Filter Housing.
Covers the air filter element.
14. Antivibration Elements.
Elements designed to reduce the 
transmission of vibrations created 
by the engine to the operators back.
15. Spark Plug Boot.
Connects the spark plug to the 
ignition wire.
16. Muffler 
(with spark arresting screen).
Attenuates exhaust noises and 
diverts exhaust gases away from 
operator. The spark arresting 
screen is designed to reduce the 
risk of fire.
17. Carburetor Adjusting Screws.
For tuning carburetor.
18. Choke Knob.
Eases engine starting by enriching 
mixture.19. Starter Grip.
The grip of the pull starter, which is 
the device to start the engine.
20. Fuel Filler Cap.
For closing the fuel tank.
21. Fuel Tank.
For fuel and oil mixture. 
						

							31 BR 340, BR 340 L, BR 420, BR 420 CEnglish / USA
EPA:
The Emission Compliance Period 
referred to on the Emissions 
Compliance Label indicates the number 
of operating hours for which the engine 
has been shown to meet Federal 
emission requirements.
Category A = 300 hours, B = 125 hours, 
C = 50 hours
CARB: 
The Emission Compliance Period used 
on the CARB-Air Index Label indicates 
the terms: 
Extended = 300 hours, 
Intermediate = 125 hours, 
Moderate = 50 hours
BR 340, 340 L
BR 420, 420 CIgnition System
Fuel System
Rewind Starter
Specifications
Single cylinder two-stroke engine
Displacement: 2.74 ci 
(44.9 cm
3)
Bore: 1.61 in (41 mm)
Stroke: 1.34 in (34 mm)
Idle speed: 3,100 rpm
Single cylinder two-stroke engine
Displacement: 3.45 ci
(56.5 cm3)
Bore: 1.81 in (46 mm)
Stroke: 1.34 in (34 mm)
Idle speed: 3,100 rpmType: Electronic magneto ignition
Spark plug 
(suppressed):Bosch WSR 6 F
or
NGK BPMR 7 A;
Electrode gap: 0.02 in (0.5 mm)
Spark plug thread: M 14 x 1.25;
0.37 in (9.5 mm) 
long
Carburetor: All position diaphragm 
carburetor with integral fuel pump
Air filter: Paper element
Fuel tank capacity: 50 fl.oz. (1.5 l) 
Fuel mix: see chapter  
“Fuel”
Starter rope:  0.14 in dia. x 37.8 in 
(3.5 mm dia. x 960 mm)
1113 195 8200
Model Bystander noise  
per ANSI B 175.2-2000Air flow rate Air velocity Engine power Weight
dB(A) CFM (m
3/h) MPH (m/s) HP (kW) lbs (kg)
BR 340 73 688 (1170) 161 (72) 2.7 (2.0) 20.1 (9.1)
BR 340L 68 636 (1080) 146 (65) 1.9 (1.4) 20.3 (9.2)
BR 420 74 742 (1260) 174 (78) 3.5 (2.6) 20.1 (9.1)
BR 420 C 73 724 (1230) 172 (77) 3.3 (2.5) 20.5 (9.3) 
						

							32 English / USA
BR 340, BR 340 L, BR 420, BR 420 C Contact your STIHL dealer for 
information regarding special 
accessories that may be available for 
your product.Users of this unit should carry out only 
the maintenance operations described 
in this manual. Other repair work may be 
performed only by authorized STIHL 
service shops.
Warranty claims following repairs can be 
accepted only if the repair has been 
performed by an authorized STIHL 
servicing dealer using original STIHL 
replacement parts.
Original STlHL parts can be identified by 
the STlHL part number, the 
STIHl
 
logo and, in some cases, by the STlHL 
parts symbol (. This symbol may 
appear alone on small parts.
Special Accessories Maintenance and Repairs  
						

							33 BR 340, BR 340 L, BR 420, BR 420 CEnglish / USA
Your Warranty Rights 
and ObligationsThe U.S. Environmental Protection 
Agency (EPA), the California Air 
Resources Board (CARB) and STIHL 
Incorporated are pleased to explain the 
Emission Control System Warranty on 
your model year 2000 and later 
equipment type engine. In California, 
new small off-road engines must be 
designed, built and equipped to meet the 
States stringent anti-smog standards. In 
other states, new 1997 and later model 
year small off-road equipment engines 
must be designed, built and equipped, at 
the time of sale, to meet the U.S. EPA 
regulations for small non road engines. 
The equipment engine must be free from 
defects in materials and workmanship 
which cause it to fail to conform with 
U.S. EPA standards for the first two 
years of engine use from the date of sale 
to the ultimate purchaser. 
STIHL Incorporated must warrant the 
emission control system on your small 
off-road engine for the period of time 
listed below provided there has been no 
abuse, neglect or improper maintenance 
of your small off-road equipment engine.
Your emission control system includes 
parts such as the carburetor and the 
ignition system. Also included may be 
hoses, and connectors and other 
emission related assemblies.Where a warrantable condition exists, 
STIHL Incorporated will repair your 
small off-road equipment engine at no 
cost to you, including diagnosis (if the 
diagnostic work is performed at an 
authorized dealer), parts, and labor.
Manufacturers Warranty 
Coverage:The small off-road equipment engines 
are warranted for two years in California. 
In other states, 1997 and later model 
year small off-road equipment engines 
are also warranted for two years. If any 
emission-related part on your engine is 
defective, the part will be repaired or 
replaced by STIHL Incorporated free of 
charge.Owners Warranty 
Responsibilities:As the small off-road equipment engine 
owner, you are responsible for the per-
formance of the required maintenance 
listed in your owners manual. STIHL 
Incorporated recommends that you 
retain all receipts covering maintenance 
on your small off-road equipment 
engine, but STIHL Incorporated cannot 
deny warranty solely for the lack of 
receipts or for your failure to ensure the 
performance of all scheduled 
maintenance.
Any replacement part or service that is 
equivalent in performance and durability 
may be used in non-warranty mainten-
ance or repairs, and shall not reduce the 
warranty obligations of the engine 
manufacturer.As the small off-road equipment engine 
owner, you should be aware, however, 
that STIHL Incorporated may deny you 
warranty coverage if your small off-road 
equipment engine or a part has failed 
due to abuse, neglect, improper 
maintenance or unapproved 
modifications.
You are responsible for presenting your 
small off-road equipment engine to a 
STIHL service center as soon as a 
problem exists. The warranty repairs will 
be completed in a reasonable amount of 
time, not to exceed 30 days.
If you have any questions regarding your 
warranty rights and responsibilities, 
please contact a STIHL customer 
service representative at
1-800-467-8445 or you can write to 
STIHL Inc., 536 Viking Drive,
P.O. Box 2015,
Virginia Beach, VA 23450-2015.
Coverage by STIHL IncorporatedSTIHL Incorporated warrants to the 
ultimate purchaser and each 
subsequent purchaser that your small 
off-road equipment engine will be 
designed, built and equipped, at the time 
of sale, to meet all applicable 
regulations. STIHL Incorporated also 
warrants to the initial purchaser and 
each subsequent purchaser that your 
engine is free from defects in materials 
and workmanship which cause the 
engine to fail to conform with applicable 
regulations for a period of two years.
STIHL Incorporated Federal and California
Emission Control Warranty Statement 
						

							34 English / USA
BR 340, BR 340 L, BR 420, BR 420 CWarranty PeriodThe warranty periods will begin on the 
date the utility equipment engine is 
purchased by the initial purchaser and 
you have signed and sent back the 
warranty card to STIHL. If any emission 
related part on your engine is defective, 
the part will be replaced by STIHL 
Incorporated at no cost to the owner.
Any warranted part which is not 
scheduled for replacement as required 
maintenance, or which is scheduled only 
for regular inspection to the effect of 
repair or replace as necessary will be 
warranted for the warranty period.
Any warranted part which is scheduled 
for replacement as required mainten-
ance will be warranted for the period of 
time up to the first scheduled replace-
ment point for that part.DiagnosisYou, as the owner, shall not be charged 
for diagnostic labor which leads to the 
determination that a warranted part is 
defective. However, if you claim 
warranty for a component and the 
machine is tested as non-defective, 
STIHL Incorporated will charge you for 
the cost of the emission test.
Mechanical diagnostic work will be 
performed at an authorized STIHL 
servicing dealer. Emission test may be 
performed either at STIHL Incorporated 
or at any independent test laboratory. 
Warranty WorkSTIHL Incorporated shall remedy war-
ranty defects at any authorized STIHL 
servicing dealer or warranty station. Any 
such work shall be free of charge to the 
owner if it is determined that a warranted 
part is defective. Any manufacturer-
approved or equivalent replacement part 
may be used for any warranty 
maintenance or repairs on emission-
related parts and must be provided 
without charge to the owner. STIHL 
Incorporated is liable for damages to 
other engine components caused by the 
failure of a warranted part still under 
warranty.
The California Air Resources Boards 
Emission Warranty Parts List specifically 
defines the emission-related warranted 
parts. These warranted parts are:
Carburetor
Choke (Cold start enrichment system)
Intake manifold
Air filter 
Spark plug
Magneto or electronic ignition system 
(ignition module)
Catalytic converter (if applicable)
FastenersWhere to make a claim for 
Warranty Service Bring the product to any authorized 
STIHL servicing dealer and present the 
signed warranty card. 
Maintenance RequirementsThe maintenance instructions in this 
manual are based on the application of 
the recommended 2-stroke fuel-oil 
mixture (see also instruction Fuel). 
Deviations from this recommendation 
regarding quality and mixing ratio of fuel 
and oil may require shorter maintenance 
intervals.LimitationsThis Emission Control Systems War-
ranty shall not cover any of the following:
:repair or replacement required 
because of misuse, neglect or lack 
of required maintenance, 
:repairs improperly performed or 
replacements not conforming to 
STIHL Incorporated specifications 
that adversely affect performance 
and/or durability, and alterations or 
modifications not recommended or 
approved in writing by STIHL 
Incorporated, 
and
:replacement of parts and other 
services and adjustments 
necessary for required maintenance 
at and after the first scheduled 
replacement point. 
						

							35 BR 340, BR 340 L, BR 420, BR 420 CEnglish / USA
STIHL Registered TrademarksSTIHL
®
q
(
The color combination orange-grey 
(U.S. Registration #2,821,860)
4-MIX
®
AUTOCUT
®
EASYSTART
®
OILOMATIC
®
STIHL Cutquik
®
STIHL DUROMATIC
®
STIHL Farm Boss
®
STIHL Quickstop
®
STIHL ROLLOMATIC
®
STIHL WOOD BOSS
®
TIMBERSPORTS
®
YARD BOSS
®
Some of STIHL’s Common Law 
TrademarksBioPlus™
Easy2Start™
EasySpool™
ElastoStart™
Ematic /Stihl-E-Matic™
FixCut™
HT Plus™
IntelliCarb™
Master Control Lever™
Micro™
Pro Mark™
Quad Power™
Quiet Line™
STIHL Arctic™
STIHL Compact™
STIHL HomeScaper Series™
STIHL Interchangeable Attachment 
Series™
STIHL Magnum  /Stihl-Magnum™
STIHL MiniBoss™
STIHL MotoPlus 4™
STIHL Multi-Cut HomeScaper Series™
Stihl Outfitters™STIHL PICCO™
STIHL PolyCut™
STIHL PowerSweep™
STIHL Precision Series™
STIHL Protech™
STIHL RAPID™
STIHL SuperCut™
STIHL Territory™
TapAction™
TrimCut™
This listing of trademarks is subject to 
change.
Any unauthorized use of these 
trademarks without the express written 
consent of 
ANDREAS STIHL AG & Co. KG, 
Waiblingen is strictly prohibited.
Trademarks 
						

							36 English / USA
BR 340, BR 340 L, BR 420, BR 420 C 
						

							37
BR 340, BR 340 L, BR 420, BR 420 C español / EE.UU
BA_SE_003_004_31_09.fm
Impreso en papel sin cloro.
Las tintas contienen aceites vegetales,el papel es reciclable.
© ANDREAS STIHL AG & Co. KG, 2005 
0458 373 3021 B
. M2. L5.  CP . Prin ted  in US A 
STIHlContenidoGuía para el uso de este manual  ...  38
Precauciones de seguridad  ............  39
Armado del soplador  ......................  48
Combustible ...................................  50
Llenado de 
combustible ....................................  51
Información previa
al arranque  .....................................  52
Arranque / parada del motor ...........  52
Instrucciones de manej o ................  55
Limpieza del filtro de  aire  ...............  55
Manejo del motor  ............................  56
Ajuste del carburador  .....................  56
Convertidor catalítico  ......................  58
Revisión de la bujía  ........................  58
Chispero en silenciador  ..................  59
Sustitución de la cuerda de 
arranque y resorte de rebobinado  ..  60
Almacenamiento de la máquina  .....  63
Tabla de mantenimiento  .................  64
Piezas y controles  ..........................  65
Especificaciones .... .........................  67
Accesorios especiales  ....................  68
Mantenimiento y 
reparaciones ...................................  68
Declaración de garantía de 
STIHL Incorporated sobre sistemas 
de control de emisiones según 
normas Federales y del Estado 
de California  ...................................  69
Marcas comerciales ........................  71 Permita que solamente las personas 
que comprenden la materia tratada en 
este manual manejen su soplador. 
Para obtener el rendimiento y satisfac-
ción máximos del soplador STIHL, es 
importante leer y comprender las ins-
trucciones de mantenimiento y las pre-
cauciones de seguri
dad antes de usarlo. 
Comuníquese con el concesionario o 
distribuidor de STIHL si no se entiende 
alguna de las instrucciones dadas en el 
presente manual.
!
Advertencia
Dado que el soplador es una herra-
mienta de corte motorizada de gran 
velocidad, es necesario tomar medidas 
especiales de seguridad para reducir el 
riesgo de lesiones. 
El uso descuidado o inadecuado de 
cualquier máquina puede causar lesio-
nes graves.
La filosofía de STIHL es mejorar conti-
nuamente todos su productos. Como 
resultado de ello, periódicamente se 
introducen cambios de diseño y mejo-
ras. Si las caracter ísticas de funciona-
miento o la apariencia de su soplador 
difieren de las descritas en este manual, 
comuníquese con el concesionario 
STIHL para obtener la información y 
ayuda que requiera. 
						

							38 español / EE.UU
BR 340, BR 340 L, BR 420, BR 420 CPictogramasTodos los pictogramas que se 
encuentran en la máquina se muestran 
y explican en este manual.
Las instrucciones de uso y manipulación 
vienen acompañadas de ilustraciones.Símbolos en el textoLos pasos individuales o procedimientos 
descritos en el manual pueden estar 
señalados en diferentes maneras:
:Un punto identifica un paso o 
procedimiento sin referencia directa 
a una ilustración. 
Una descripción de un paso o 
procedimiento que se refiere 
directamente a una ilustración puede 
tener números de referencia que 
aparecen en la ilustración.
 Ejemplo:
Suelte el tornillo (1) 
Palanca (2) ...Además de las instrucciones de uso, en 
este manual pueden encontrarse 
párrafos a los que usted debe prestar 
atención especial. Tales párrafos están 
marcados con los símbolos que se 
describen a continuación.
Advertencia donde existe el riesgo 
de un accidente o lesiones 
personales o daños graves a la 
propiedad.
Precaución donde existe el riesgo 
de dañar la máquina o los 
componentes individuales.
Nota o sugerencia que no es 
esencial para el uso de la máquina, 
pero puede ayudar al operador a 
comprender mejor la situación y 
mejorar su manera de manejar la 
máquina.
Nota o sugerencia sobre el 
procedimiento correcto con el fin de 
evitar dañar el medio ambiente.
Equipo y característicasEste manual de instrucciones 
puede describir varios modelos con 
diferentes características. Los 
componentes que no se encuentran 
instalados en todos los modelos y 
las aplicaciones correspondientes 
están marcados con un asterisco 
(*). Esos componentes pueden ser 
ofrecidos como accesorios 
especiales por el concesionario 
STIHL.
Mejoramientos técnicosLa filosofía de STIHL es mejorar 
continuamente todos su productos. 
Como resultado de ello, periódicamente 
se introducen cambios de diseño y 
mejoras. Si las características de 
funcionamiento o la apariencia de su 
máquina difieren de las descritas en 
este manual, comuníquese con el 
concesionario STIHL para obtener la 
ayuda que requiera.
Por lo tanto, es posible que algunos 
cambios, modificaciones y 
mejoramientos no hayan sido descritos 
en este manual.
Guía para el uso de este 
manual 
						

							39 BR 340, BR 340 L, BR 420, BR 420 Cespañol / EE.UU
Advertencia !
El uso de cualquier 
soplador puede ser peli-
groso. Es importante 
que usted lea, com-
prenda bien y respete las siguientes 
medidas de seguridad.
!
Advertencia !
Vuelva a leer el manual 
del usuario y las ins-
trucciones de seguridad 
periódicamente.
No preste ni alquile nunca la máquina 
sin entregar el manual del usuario.
Asegúrese que todas las personas que 
utilicen la máquina lean y comprendan 
la información contenida en este 
manual.
!
Advertencia !
El uso descuidado o inadecuado de 
cualquier máquina puede causar lesio-
nes graves. Pida a su concesionario 
STIHL que le enseñe el manejo del 
soplador. Respete todas las disposicio-
nes, reglamentos y normas de seguri-
dad locales del caso.
!
Advertencia !
Nunca permita a los niños que usen un 
soplador. No se debe permitir la proximi-
dad de otros, especialmente niños y ani-
males, donde se esté utilizando la 
maquina.La mayoría de las medidas de seguridad 
y avisos contenidos en este manual se 
refieren al uso de todos los sopladores 
de STIHL. Los distintos modelos pueden 
contar con piezas y controles diferentes.
Vea la sección correspondiente de su 
manual del usuario para tener una des-
cripción de los controles y la función de 
cada componente de su modelo de 
máquina.
El uso seguro de un soplador atañe a
1. el operador
2. el soplador
3. el uso del soplador.
EL OPERADORCondición física
Usted debe estar en buenas condicio-
nes físicas y psíquicas y no encontrarse 
bajo la influencia de ninguna sustancia 
(drogas, alcohol, etc.) que le pueda res-
tar visibilidad, destreza o juicio. No 
maneje el soplador cuando está fati-
gado.
Esté alerta. Si se cansa durante el 
manejo de la máquina, tómese un des-
canso. El cansancio puede provocar 
una pérdida del control. El uso de cual-
quier soplador es fatigoso.  Si usted 
padece de alguna dolencia que pueda 
ser 
agravada por la fatiga,
 consulte a su 
médico antes de utilizar la máquina.El soplador STIHL viene equipado con 
un sistema antivibración (AV). El sis-
tema AV ha sido diseñado para reducir 
la transmisión de las vibraciones produ-
cidas por el motor al cuerpo del opera-
dor. Se recomienda el uso del sistema 
AV a aquellas personas que utilizan 
sopladores en forma constante y regu-
lar.
Mantenga el sistema AV en buen 
estado. Un soplador con componentes 
flojos o con amortiguadores AV dañados 
o desgastados también tendrá tenden-
cia a tener niveles más altos de vibra-
ción.
!
Advertencia !
El sistema de encendido de la máquina 
produce un campo electromagnético de 
intensidad muy baja. El mismo puede 
interferir con algunos tipos de marcapa-
sos. Para reducir el riesgo de lesiones 
graves o mortales, las personas porta-
doras de marcapasos deben consultar a 
sus médicos y al fabricante del marca-
pasos antes de usar esta máquina.
Precauciones de seguridad