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Technical Information · issue 56 of 2001

New Models with Catalytic Converter

IssueTI 56/2001

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TI 56/2001 page 1
Technical Information

                                                                                                 56.2001
New Model BG 45 C, 55 C, 65 C, 85 C Blowers with Catalytic Converter – Series 4229
New Model SH 55 C, 85 C Shredder Vacuums with Catalytic Converter– Series 4229

Contents
1.   Catalytic Converter

2.   Service Note
3.   Repair Times
4.   Spare Parts

The time proven BG 45, 55, 65, 85 blowers and
SH 55, 85 shredder vacuums are now available in a

version with catalytic converter.

With the exception of the muffler, blower housing,
fan housing and heat shield, all parts are the same
                                                          1.1 fo Description of Operation
                                                          A metal carrier catalytic converter is used.
as those of the latest production versions without a
catalytic converter.

1.    Catalytic Converter
The catalytic converter integrated in the muffler is

designed to help reduce the amount of noxious
emissions in the exhaust gas by way of a chemical

reaction (after-burning). This chemical reaction is
initiated by the catalytic coating (noble metal) of the

                                                                                                               294TI001 KN
catalyzer carrier material. The main emissions that

occur are unburnt hydrocarbons, resulting from the
20 – 30% scavenging losses in the two-stroke
process, and carbon monoxide. After-burning the           This catalytic converter consists of the following

exhaust gases in the catalytic converter reduces          components:
hydrocarbon emissions by almost 50%.                      .     Honeycomb metal carrier with a catalytic
                                                                coating

                                                          .     Stainless steel housing

TI_56_2001_01_01_01.fm                                                                       englisch / english
)m~ge 2                                                                              Technical Information 56.2001

                                                                 Gasoline
                                                                 Use only brand-name gasoline with a minimum
                                                                 octane rating of 90. If the local regular gasoline has
                                                                 an octane rating of less than 90, use premium grade
                                                                 gasoline. Machines with a catalytic converter must
                                                                 always be run on a mixture of engine oil and
                                                                 unleaded gasoline.
                                                                 Engine Oil
                                                                 Use only STIHL 50:1 two-stroke engine oil for the
                                                                 fuel mix in models with a catalytic converter to take

                                                                 account of the special operating conditions.

                                                                 STIHL two-stroke engine oil guarantees good
                                                                 performance and reliability under high thermal
                                                                 loads. Furthermore, its low-ash combustion helps

                                                                 reduce the build-up of deposits in the catalytic
                                                                 converter. This aspect is very important to ensure a
                                                                 long catalyst service life.

                                                   294TI002 KN

A chemical reaction takes place when exhaust gas
                                                                 2.      fo
                                                                       Service Note
flows through the catalyzer and reduces the harmful              For servicing and repair procedures refer to the
emissions in the exhaust gas. Up to 50% of the                   service manuals for the series 4140 powerhead and
hydrocarbons (HC) are converted into water (H2O)                 series 4140 machine components.

and non-poisonous carbon dioxide (CO2). The                      These service manuals do not include the chapters
catalyzer is a component which initiates chemical                "Servicing the Carburetor", "Troubleshooting" or any
reactions without being consumed in the process.                 repairs involving standard procedures. Such
                                                                 procedures are contained in the Service Training

1.2   Maintenance and Repairs                                    System CD-ROMs “Carburetors“ and “Diagnosis“

The catalytic converter is maintenance-free                      and are available in separate handbooks, i.e.
providing the usual maintenance and care                         "Carburetors" and "Standard Repairs,
instructions are observed. Never attempt any                     Troubleshooting".

repairs on the catalytic converter.

1.3   Fuel                                                       3.    Repair Times

The two-stroke engine requires a mixture of
                                                                 The existing repair times tables also apply to model
gasoline and engine oil.
                                                                 versions with a catalytic converter.

The quality of the fuels and lubricants and the mix
ratio have a critical influence on the operation and
life of the engine.
                                                                 4.    Spare Parts

                                                                 The catalytic converter versions will be included in
                                                                 the existing spare parts documentation.

© 2001 Andreas STIHL AG & Co.                                    Technical Documentation
  Waiblingen                                                     D1/MTK-tr                                        7465

                                                                                                TI_56_2001_01_01_01.fm

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TI 56/2001 page 2

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