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Technical Information · issue 4 of 1998

Carburetor; starter mechanism; tank housing; choke

IssueTI 4/1998
From serial 38 430 817, 38 434 327

Part changes (1)

WasBecomesWhat the bulletin says
4223 120 0600 4223 120 0650 Carburetor HS 279 B HS 274 HS 279 The original carburetor 4223 120 0600 (type HS 274) is replaced by version 4223 120 0650 (type HS 279 B).

Full text

Page 1 of 4

TI 4/1998 page 1
Technical Information

                                                                                                       04.98

Cut-off machines STIHL TS 400 – type 4223

Contents

1. Carburetor HS 279 B (no high speed adjusting screw, fixed jet),
   grommet, throttle control, shroud, choke lever

2. Carburetor HS 274
3. Starter mechanism (steel shaft, rope rotor, starter rope dia. 4.5 mm)
4. Tank housing (enlarged scope of supply)

Compliance with EPA regulations (see TI 27.97) is achieved with the modifications described below.
The factory applies the label shown below to all machines that conform to the latest standard.
               Andreas Stihl IMPORTANT ENGINE INFORMATION
 ENGINE FAMILY: A8XS.     R ; Type:    ; DISPL.:   CC;M.D.:
 THIS ENGINE CONFORMS TO U.S. EPA PHASE 1 EMISSION REGULATIONS

                                                                               000TI013 KN

 FOR ULGE´s. REFER TO OWNER´S MANUAL FOR MAINTENANCE
 SPECIFICATIONS AND ADJUSTMENT.                    967 34

1. Carburetor HS 279 B
                                                                   HS 274                         HS 279
The original carburetor 4223 120 0600
(type HS 274) is replaced by version

4223 120 0650 (type HS 279 B).                                     H       L                           L
The new carburetor does not have a high speed
adjusting screw (H screw).

The carburetor is set at the factory to provide an                  LA                            LA
optimum fuel-air mixture under all operating
conditions. It ensures that the machine will run
                                                                                                               338TI012 KN

smoothly, be fuel efficient, operate reliably and
produce low emissions.

1.1 Standard setting
• Check the air filter and clean or replace it if
    necessary
• Check the spark arresting screen and clean or
    replace it if necessary
• Carefully screw the low speed screw (L) down
    onto its seat.
    Then open it one turn counterclockwise (L = 1)                                            L
• Set engine speed to 2,500 rpm with the idle
    speed screw (LA).                                                                        LA
                                                                                                                338TI013 KN

! Use a tachometer.
)MQKVU=J=O

1.2 Fuel (mixing ratio)

The EPA permit was obtained with a fuel-oil mixing ratio of 50:1. See all TI 27.97!

1.3 Federal Emission Control Systems Utility Engines
See TI 27.97!

1.4 Grommet, throttle control, shroud, choke lever

Following introduction of the new carburetor, the
grommet (1) with three openings (for H, L, LA) is
replaced by version 4223 123 7501 (2) with two
openings (for L and LA) to guide the carburetor

screwdriver.

The grommet is no longer available. The replace-
ment shroud can still be used for both old and new
machines.

The throttle control (throttle trigger, throttle trigger
interlock) and choke lever have also been

                                                                                                                338TI014 KN
modified. The choke lever has been given a new

part number and is included in the new replace-                              1                     2
ment carburetor.

Supply of spare parts                                                  fo
To simplify replacement of the shroud, it is now also available as a complete assembly including all the
individual parts for throttle control (see Summary).

1.5 Summary

Item        Part name                                      Original              New                   Remarks
                                                           version               version

            Carburetor HS 274;                               4223 120 0600        ---                      1)

  1         Carburetor HS 279 B;                             ---                  4223 120 0650            2)
            including Items 2 to 8 and 13:
  2         Inlet control lever                              1110 121 5000        1124 121 5000            3)
  3         Low speed adjusting screw                        4223 122 6800        4221 122 6801            4)

  4         High speed adjusting screw                       4223 122 6700        ---                      3)
  5         Throttle shaft with lever                        4223 120 7100        4223 120 7101            3)

  6         Throttle lever                                   4223 123 7300        4223 121 3500            3)
  7         Fixed jet 0.64                                   4205 121 5600        ---                      3)
  8         Fixed jet 0.73                                   ---                  4223 121 5602
            Other parts see section 2

 9          Shroud, complete; including Item 10:             ---                  4223 080 1603
10          Shroud, complete; including Item 11:             4223 080 1600        4223 080 1600            5)

11          Grommet                                          4223 123 7500        ---                      3)
12          Grommet                                          ---                  4223 123 7501
13          Choke lever                                      4223 121 6100        4223 121 6101            4)

Modification to be introduced continuously
Remarks
1) Part is no longer required as a spare part (see section 2 for individual parts)
2) Part is now a general spare part (also for machines without EPA permit)
3) Original version of part remains available for older machines
4) Original version of part is no longer available from factory (see section 2)
5) Only modified version of part (without grommet) is available from factory
)MQKVU=J=P

2. Carburetor HS 274                                                               1
                                                                                   4
Until the EPA carburetor is introduced,
the new version of carburetor 4223 120 0600                            2
will be installed in machines from serial number
X 38 434 327 onwards (in two stages).
The type designation will initially be changed from
HS 274 B to HS 274 C and then to HS 274 D with
implementation of the second stage.

                                                                                                             338TI015 GM
The modifications serve to improve the running at
                                                                                                      3
part throttle operation (first stage) and to ensure
standardization with other series and carburetor
types (second stage).

Modifications*:                                       (first stage):       (second stage)
                            HS 274 B                  HS 274 C             HS 274 D
1 Control spring            1124 122 3000             1106 122 3005        1124 122 3000

2 Fixed jet                 4223 121 5600             4205 121 5600        4205 121 5600
3 Low speed adjusting screw 4223 122 6800             4223 122 6800        4221 122 6801
4 Valve jet                 4221 121 5400             4221 121 5400        4223 121 5400

* New part numbers are highlighted in bold type

Service notes
Note the carburetor type designation!                        fo
Only the parts specified above may be installed in carburetor type HS 274 C (except for the low speed
adjusting screw 4223 122 6800 which is no longer available).
Except for the 0.64 fixed jet (4205 121 5600), spare parts for carburetor HS 274 D can also be used for
carburetor type HS 274 B (refer also to the spare parts list).

Supply of spare parts
The (EPA) carburetor HS 279 B must be used as a spare part, even in older machines,
when replacing the complete carburetor. The new choke lever is included with this carburetor

(see section 1).

Summary

Item        Part name                                 Original                New                   Remarks
                                                      version                 version

  1         Carburetor HS 274 B;                      4223 120 0600          ---                     1)

            including Items 2 to 5:
  2         Control spring                            1124 122 3000          ---                     2)
  3         Fixed jet 0.69                            4223 121 5600          ---                     2)
  4         Low speed adjusting screw                 4223 122 6800          ---                     1)

  5         Valve jet                                 4221 121 5400          ---                     2)
  6         Carburetor HS 274 C;                      ---                    4223 120 0600           1)
            including Items 4, 5, 7, 8:

  7         Control spring                            ---                    1106 122 3005           2)
  8         Fixed jet 0.64                            ---                    4205 121 5600           2)
  9         Carburetor HS 274 D;                      ---                    4223 120 0600           1)
            including Items 2, 8, 10, 11:
10          Low speed adjusting screw                 ---                    4221 122 6801           2)
11          Valve jet                                 ---                    4223 121 5400           2)

Modification to be introduced (HS 274 C) from serial No. X 38 434 327 onwards
Remarks
1) Part is no longer required as a spare part (see "Service notes", "Supply of spare parts" and section 1)
2) Part is still available
)MQKVU=J=Q

3. Starter mechanism

A starter cover with injection-moulded steel shaft, a larger rope rotor and a starter rope with 4.5 mm diameter
is installed in machines from serial No. X 38 430 817 onwards in order to improve operation of the machine.

Summary

Item        Part name                                 Original                  New                    Remarks
                                                      version                   version

            Starter cover with starter mechanism;     4223 190 0400            4223 190 0401           1)
            including Items 1 to 5:
  1         Starter cover; including Item 2:          4223 190 0410            4223 190 0411           1)

  2         Groove-headed screw                       4223 084 5600            ---                     2)

  3         Rope rotor                                4223 190 1000            4223 190 1001           1)
  4         "ElastoStart" handle; including Item 5:   1128 190 3400            1122 190 3400           2)
  5         Starter rope, dia. 3.5 mm                 1128 190 2900            ---                     2)

  5         Starter rope, dia. 4.5 mm                 ---                      1122 190 2900
            Starter rope, dia. 3.5 mm / set of 28     0000 930 2267            ---                     2)
            Starter rope, dia. 4.5 mm / set of 28     ---                      0000 930 2268

            Other parts as before
Modification to be introduced from serial No. X 38 430 817 onwards
Remarks
1) Original version of part is no longer available from factory
2) Original version of part remains available for older machines and other series

4. Tank housing

The replacement tank housing 4223 350 0800 is available with additional equipment from now onwards.
Impulse hose, fuel pick-up body with hose, tank vent and filler cap are now fully fitted and included in the

scope of supply for the tank housing.

This simplifies replacement of the tank housing.

Summary

Item        Part name                                 Original                  New                    Remarks
                                                      version                   version

            Tank housing, complete;                   4223 350 0800            4223 350 0800           1)
            including Items 1 to 5:
  1         Impulse hose                              ---                      4223 141 8600

  2         Pick-up body                              ---                      0000 350 3500
  3         Hose                                      ---                      1127 358 7705
  4         Tank vent, complete;                      ---                      4223 350 5800

  5         Filler cap, complete                      ---                      4223 350 0500

            Other parts as before
Modification to be introduced continuously
Remarks
1) Only modified version of part is now available from factory

Last Technical Information on series TS 400: 45.96

 1998 Andreas Stihl                                        Andreas Stihl - D1/MTK-sc
                                                            Technical Documentation                            6225

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