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Technical Information · issue 16 of 2009

Fuel Hose Barb Connectors; Carburetor; Heat Shield; Fuel Pump; Filter Housing; Fuel Hose Between Carburetor and Fuel Pump; Summary

Models BT 120 C, BT 121, FS 120

IssueTI 16/2009

Part changes (3)

WasBecomesWhat the bulletin says
4134 121 0801 4134 121 0803 Left: Previous version with straight connector Right: New version with hose barb connector The previous end cover (1) 4134 121 0801 with straight connector (2) has been replaced by the new version (3) 4134 121 0803 with hose barb connector (4).
1129 007 1062 4128 007 1060 3 Carburetor Parts Kit Owing to the introduction of the new carburetors 1 3 with hose barb connector the previous carburetor parts kit 1129 007 1062 has been replaced by the new kit 4128 007 1060.
1129 129 0900 4134 121 4700 1129 129 0900 have been replaced by the new versions of the metering diaphragm (3) 4134 121 4700 and gasket (4) 4134 129 0901 to coincide with the introduction of the new carburetors with hose barb connector on the end cover.

Full text

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TI 16/2009 page 1
STIH)

Technical Information                                                               16.2009

  STIHL BT 120 C, 121 Earth Auger                               – Series 4313
  STIHL FS 350 Clearing Saw                                     – Series 4134
  STIHL FS 120, 200, 250 Brushcutters                           – Series 4134
  STIHL SP 200 Special Harvester                                – Series 4233
  STIHL HT 250 Pole Pruner                                      – Series 4134

  Contents
  1.   Fuel Hose Barb Connectors
  2.   Carburetor
  3.   Heat Shield
  4.   Fuel Pump
  5.   Filter Housing
  6.   Fuel Hose Between Carburetor and Fuel Pump
  7.   Summary

  1.      Fuel Hose Barb Connectors
  The above mentioned machines have been                  –   Carburetor, end cover, metering diaphragm,
  equipped for some time with hose barb connectors            gasket and carburetor parts kit, see chapter 2.
  for the fuel hoses. Straight connectors are no longer
                                                          –   Heat shield, see chapter 3.
  used for fuel hoses.
                                                          –   Fuel pump, see chapter 4.
  The following components and assemblies are
  affected by the change:                                 –   Filter housing, see chapter 5.
                                                          –   Fuel hose between carburetor and fuel pump,
                                                              see chapter 6.

  TI_16_2009_30_01_01.fm                                                                       englisch / English
)m~ge 2                                                                       Technical Information 16.2009

1.1      Interchangeability                             2.       Carburetor
Refer to the notes on interchangeability in the
following chapters regarding the individual                          2                      6
components and assemblies that have to be
replaced while servicing the fuel supply system.
                                                                                 4                      8
1.2      Service notes for hose barb connectors
To guarantee the tightness of the fuel system:
.     To avoid damaging hose barb connectors,

                                                                                                            250TI067 KN
      remove and install fuel hoses in line with the
      connector by hand where possible – do not use              1       3              5       7
      sharp-edged pliers, screwdrivers, etc. and do
      not cut open fuel hoses with a knife or similar   Left:     Previous carburetor with straight
      tools.                                                      connectors
                                                        Right:    New carburetor with hose barb
.     Do not re-use fuel hoses after removal. Always
                                                                  connectors
      replace with new hoses – fuel hoses may be
      over-stretched during removal.                    The previous carburetors (1) with straight
.     Install new fuel hoses dry or with the aid of     connectors (2, 3) on the end cover (4) and body
      OH 723 press fluid – 0781 957 9000. Other         have been replaced by the new versions (5) with
      press fluids are not approved and may result in   hose barb connectors (6, 7) on the end cover (8)
      damage to the fuel hoses.                         and carburetor body.

.     Coat the ends of the hose and connectors with
      OH 723 press fluid when installing new hoses
      onto the hose barb connectors.
                                                        Models BT 120 C, BT 121, FS 120
                                                        The previous C1Q-S82 carburetor with straight
Note on OH 723 press fluid                              connectors has been replaced by the new C1Q-
OH 723 press fluid produces a lubricating film which    S161 carburetor with hose barb connectors. For
simplifies assembly. The lubricant evaporates after     part numbers see chapter "7. Summary".
a short period – allowing for a tight fit.
Never use fuel, oil or grease as a lubricant for this
purpose. Fuel, oil and grease do not evaporate – the
                                                        Models FS 200, 250, 350, HT 250, SP 200
hose may loosen or become detached.
                                                        The previous C1Q-S83 carburetor with straight
                                                        connectors has been replaced by the new C1Q-
                                                        S162 carburetor with hose barb connectors. For
                                                        part numbers see chapter "7. Summary".

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Technical Information 16.2009                                                                                Page 3

Interchangeability                                          2.1           Changes to Individual Parts of
                                                                          Carburetor
The new carburetors may be installed in previous
machine versions only in conjunction with a new
heat shield 4134 122 1801 (see chapter 3.) and a
new fuel hose to the fuel pump (see chapter 6.). For
this reason the new replacement carburetors are
supplied from the factory together with a heat shield
                                                                      1                      2
(see chapters 3. and "7. Summary").
Previous carburetors can be combined with the new                     3                      4
fuel pump if a fuel hose of the right length is used
(see chapters 5. and 6.).
                                                                      5                      6

                                                                                                                      256TI068 KN
Previous carburetors can be combined with a new
filter housing if a fuel hose of the right length is used
because the new filter housing supplied from the
factory comes with a new fuel pump (see chapters            The following individual parts of the carburetor were
4., 5. and 6.).                                             modified in connection with the engineering change
                                                            described above:
The new heat shield can be installed with the
previous versions of the carburetors.                       –     End cover (1, 2), see 2.1.1
                                                            –     Metering diaphragm (3, 4), see 2.1.2

Parts Availability                                          –     Gasket (5, 6), see 2.1.2

The previous versions of the carburetors are no             –     Carburetor parts kit, see 2.1.3
longer available from the factory. Only the new
carburetors with hose barb connector, including the
new heat shield, will be supplied as replacements.
                                                            2.1.1         End Cover
Service Note
Apart from using a new hose to the fuel pump when
installing a new carburetor with hose barb connector
for the first time, the molded hose 4128 358 0800 to
the pickup body may also be replaced if needed.                 2                           4
The new carburetor is supplied with instructions for
installing the heat shield and the fuel hose.                     1                         3
Observe the service notes on hose barb connectors
(see chapter 1.2).
                                                                                                                      256TI069 KN

                                                            Left:          Previous version with straight connector
                                                            Right:         New version with hose barb connector
                                                            The previous end cover (1) 4134 121 0801 with
                                                            straight connector (2) has been replaced by the new
                                                            version (3) 4134 121 0803 with hose barb
                                                            connector (4).

TI_16_2009_30_01_01.fm
)m~ge 4                                                                                   Technical Information 16.2009

Parts Availability                                                  Parts Availability
The previous end cover (1) 4134 121 0801 remains                    The previous versions of the metering
available for machines with the previous carburetor.                diaphragm (1) 4129 121 4700 and gasket (2)
                                                                    1129 129 0900 remain available for machines with
                                                                    the previous carburetor.
Service Note
The previous end cover (1) 4134 121 0801 may
                                                                    Service Note
only be installed in machines with the previous
carburetor. The previous carburetor can be                          The previous versions of the metering
identified by the straight connector (2) on the end                 diaphragm (1) 4129 121 4700 and gasket (2)
cover (1).                                                          1129 129 0900 may only be installed in machines
The new end cover (3) 4134 121 0801 may only be                     with the previous carburetor. The previous
installed in machines with the new carburetor. The                  carburetor can be identified by the straight
new carburetor can be identified by the hose barb                   connector on the end cover.
connector (4) on the end cover (3). Observe the                     The new versions of the metering diaphragm (3)
service notes on hose barb connectors (see chapter                  4134 121 4700 and gasket (4) 4134 129 0901 may
1.2).                                                               only be installed in machines with the new
                                                                    carburetor. The new carburetor can be identified by
                                                                    the hose barb connector on the end cover. Observe
                                                                    the service notes on hose barb connectors (see
                                                                    chapter 1.2).
2.1.2    Metering Diaphragm, Gasket

                                                                    2.1.3   Carburetor Parts Kit
                                                                    Owing to the introduction of the new carburetors
    1                       3                                       with hose barb connector the previous carburetor
                                                                    parts kit 1129 007 1062 has been replaced by the
                                                                    new kit 4128 007 1060. The difference between the
   2                        4                                       new and previous carburetor parts kits is the new
                                                                    metering diaphragm 4134 121 4700 and the new
                                                      256TI070 KN

                                                                    gasket 4134 129 0901.

Left:     Previous versions                                         Parts Availability
Right:    New versions                                              The previous carburetor parts kit 1129 007 1062
The previous versions of the metering                               remains available for machines with the previous
diaphragm (1) 4129 121 4700 and gasket (2)                          carburetors and for other models.
1129 129 0900 have been replaced by the new
versions of the metering diaphragm (3)
4134 121 4700 and gasket (4) 4134 129 0901 to
coincide with the introduction of the new carburetors
with hose barb connector on the end cover.

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Technical Information 16.2009                                                                                   Page 5

Service Note                                                      Interchangeability
The previous carburetor parts kit 1129 007 1062                   The new heat shield may be installed in the previous
may only be installed in machines with the previous               version of the machines.
carburetor. The previous carburetor can be                        The previous heat shield may not be used in
identified by the straight connector on the end cover.            machines with carburetors that have hose barb
The new carburetor parts kit 4128 007 1060 may                    connectors.
only be installed in machines with the new
                                                                  A new carburetor with hose barb connector must be
carburetor. The new carburetor can be identified by
                                                                  installed with a new heat shield.
the hose barb connector on the end cover. Observe
the service notes on hose barb connectors (see
chapter 1.2).                                                     Service Note
                                                                  If a new carburetor is installed in the previous
                                                                  version of the machine, a new heat shield must be
                                                                  installed with it.
3.       Heat Shield
                                                                  Parts Availability
                                      1                           In view of the conditions for ensuring the
                                                                  interchangeability of the new heat shield in earlier
                                                                  machines -
                                                                  .    only the new heat shields will be supplied from
                                                                       the factory in future.
                                                                  .    the new heat shield will always be supplied
                                 2                                     along with carburetors with hose barb
                                                                       connectors.
                                                    250TI071 KN

Left:     Previous heat shield
Right:    New heat shield                                         4.       Fuel Pump
The introduction of the hose barb connectors (1) on
the carburetor body changes the position of the
hose to the pickup body. The new connector (2)
between the carburetor body and hose is at an
angle of 90°. For this reason the heat shield was
modified and now has a large cut-out for the hose
(see illustration).                                                    1                     4

                                                                           2            3        5             6
                                                                                                                         256TI037 KN

                                                                  Left:         Previous fuel pump with straight
                                                                                connectors
                                                                  Right:        New fuel pump with hose barb
                                                                                connectors

TI_16_2009_30_01_01.fm
)m~ge 6                                                                      Technical Information 16.2009

The previous fuel pump (1) 4130 350 6200 with            5.       Filter Housing
straight connectors (2, 3) has been replaced by the
new version (4) 0000 350 6201 with hose barb
connectors (5, 6). Furthermore, the geometry of the
snap hooks (arrows) on the new fuel pump (4)
differs from the previous version (1).
The filter housing has been modified to suit the new          1                     2
geometry of the fuel pump, see chapter 5.
The straight connectors (2, 3) of the previous fuel
pump (1) are in line with one another, while the hose
barb connectors (5, 6) of the new fuel pump (4) are

                                                                                                             256TI072 KN
offset.

Parts Availability                                       Left:        Previous filter housing
                                                                      4134 140 2800
The previous fuel pump (1) 4130 350 6200 remains
                                                         Right:       New filter housing 4134 140 2801
available for older machines with the previous filter
housing.                                                 The previous version of the filter housing (1) will be
For reasons of interchangeability in previous            replaced by the new version (2) to coincide with the
machine versions the new fuel pump is supplied           introduction of the new fuel pump 0000 350 6201
with the new filter housing, see chapter 5.              (see chapter 4). The difference between the new
                                                         filter housing (2) and the previous version (1) is the
                                                         modified contour and index (arrows) of the seat for
Service Note                                             the fuel pump.
The previous fuel pump (1) 4130 350 6200 may
only be installed in machines with the previous filter   Interchangeability
housing (see chapter 5).
                                                         The new filter housing 4134 140 2801 can only be
The new fuel pump (4) 0000 350 6201 may only be          installed in previous machine versions in
installed in machines with the new filter housing, see   combination with the new fuel pump
chapter 5.                                               0000 350 6201.
When installing a fuel pump, note the length of the      The new filter housing can be replaced as a
hose to the carburetor for the previous and the new      separate item only in new machine versions.
version, see chapter 6.
                                                         The length of the fuel hose between the carburetor
                                                         and fuel pump depends on the type of connector on
                                                         the carburetor. For this reason check the length of
                                                         the hose to the carburetor when fitting the new filter
                                                         housing, see also chapter 6.

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Technical Information 16.2009                                                                          Page 7

Parts Availability                                      The instruction sheet supplied with the 'filter housing
                                                        set' 4134 140 2850 has been amended accordingly.
In order to guarantee interchangeability on older
machines, the new filter housing and the new fuel
pump 4130 350 6201 are available from the factory
in a 'filter housing set' 4134 140 2850.
The previous filter housing 4134 140 2800 is no         6.       Fuel Hose Between Carburetor
longer available as a replacement part.
                                                                 and Fuel Pump
Filter housing 4134 140 2801 is also available as a
separate item from the factory for new machine
versions.

                                                                                  1
5.1      Service Note

5.1.1    Interim Version of Filter Housing
         4134 140 2850
The interim version of the filter housing was

                                                                                                             250TI073 KN
supplied with 2 fuel hoses of different lengths.
Lengths of fuel hoses:
–     68 mm for machines with carburetors with          A change in the length of the fuel hose (1) between
      straight connectors and the new fuel pump         the carburetor and fuel pump became necessary
      4130 350 6201 with hose barb connector.           when the hose barb connectors were introduced.
                                                        The length of the hose was changed in 2 stages.
–     65 mm for machines with carburetors with hose
      barb connectors and the new fuel pump
      4130 350 6201 with hose barb connector.
                                                        6.1      Interim Solution
An instruction sheet showing the correct use of the
                                                        Length of fuel hose (1; see also explanation under
hoses was supplied with the filter housing, see also
                                                        5.1.1):
chapter 6.
                                                        –     The 65 mm hose is for machines with hose barb
                                                              connectors on the new carburetor and new fuel
                                                              pump or straight connector on the previous fuel
5.1.2    New Version of Filter Housing
                                                              pump.
         4134 140 2850
Tests have shown that hoses of different lengths are    –     The 68 mm hose is intended for machines with
not necessary when installing a new filter housing            carburetors with straight connectors and the
4134 140 2850 (with new fuel pump). A fuel hose               new fuel pump with hose barb connector.
with a length of 67 mm is suitable in combination       For a temporary period machines with hose barb
with different types of connectors, see 6.2. For this   connectors were equipped with a 65 mm fuel hose
reason hoses are no longer supplied with the new        on the production line.
filter housing.

TI_16_2009_30_01_01.fm
)m~ge 8                                                                         Technical Information 16.2009

6.2        New Solution                                   6.4         Service Note
Length of fuel hose (1; see also explanation under        As described in 6.2, a 67 mm hose can be used for
5.1.2):                                                   previous and new versions of the carburetors and/or
                                                          machines. It is also possible to simply follow the
–       The 67 mm hose is suitable for all combinations
                                                          notes in the instruction sheet which is supplied with
        of straight and hose barb connectors.
                                                          the different versions of the filter housing
This hose has been used for some time in                  4134 140 2850.
production and in parts support.

6.3        Parts Availability
Only the 1 m fuel hose 0000 930 2802 is supplied
as a replacement from the factory. The hose
lengths necessary for installation must be cut from
the replacement hose. This information is noted in
the parts list.

7.         Summary
Item        Part Name                                           Previous             New             Rem.
            BT 120 C, BT 121, FS 120
    1       C1Q-S82 carburetor                                  4134 120 0603        ---             1)
            including items 5, 7 and 8:
    2       C1Q-S161 carburetor                                 ---                  4134 120 0652
            including items 5, 7, 8 and 9:

            FS 200, 250, 350, HT 250, SP 200
    3       C1Q-S83 carburetor                                  4134 120 0604        ---             1)
            including items 5, 7 and 8:
    4       C1Q-S162 carburetor                                 ---                  4134 120 0653
            including items 5, 7, 8 and 9:

            All models
    5       End cover                                           4134 121 0801        4134 121 0803   2)
    6       Carburetor parts kit;                               1129 007 1062        4128 007 1060   2) 3)
            including items 7, 8:
    7       Metering diaphragm                                  4129 121 4700        4134 121 4700   2) 3)
    8       Gasket                                              1129 129 0900        4134 129 0901   2) 3)
            all other parts as before

 9          Heat shield                                         4134 122 1800        4134 122 1801   4)
10          Filter housing                                      ---                  4134 140 2850
            including items 11, 12:
11          Filter housing                                      4134 140 2800        4134 140 2801   1)
12          Fuel pump                                           4130 350 6200        0000 350 6201   2) 3)
13          Hose, 68 mm (earlier)                               -*-                  ---             5)

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Technical Information 16.2009                                                                          Page 9

Item    Part Name                                               Previous          New             Rem.
14      Hose, 67 mm                                             -*-               -*-             5)
15      Hose, 65 mm (interim)                                   ---               -*-             5)
16      Hose, 1 m                                               0000 930 2802     0000 930 2802   6)

Modification to be introduced : in progress
Remarks
1) Previous version of part no longer available from factory
2) Previous version of part remains available for older models
3) Previous version of part remains available for other models
4) Previous version of part will be supplied from factory only as long as existing stocks last
5) Part not available as replacement, it has to be cut to length from item 16
6) Replacement for items 13 to 15

© ANDREAS STIHL AG & Co. KG, 2009                           Technical Documentation
                                                            D1/MTK-na

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