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Technical Information · issue 21 of 1996

New versions; shroud; prefilter (only 034 and 036

Model 034, 036 Chainsaws - Series 1125

IssueTI 21/1996
Engine family 1125
From serial 33 781 153

Part changes (2)

WasBecomesWhat the bulletin says
1121 442 1600 1125 442 1600 The original contact spring 1121 442 1600 will be replaced by the version 1125 442 1600 to coincide with the introduction of the new carburetor heating system.
1125 120 1500 1125 120 1501 Prefilter 1125 120 1500 will be replaced by prefilter 1125 120 1501 in all 034 saws from machine number X 33 781 153=~nd in 036 saws without compensator.

Full text

Page 1 of 5

TI 21/1996 page 1
Technical Information

                                                                                  21.96

Model 034, 036 Chainsaws  -  Series 1125

&RQWHQWV

1. New version

   (electric carburetor heating)
2. Shroud
3. Prefilter (only 034 and 036 without compensator)

4. Nameplate

1.=New version

One additional version of model 036 will be
available in the future (machines with a carburetor
heating system).

1.1=Electric carburetor heating =VH

1.1.1=Carburetor

On machines with a “VH” carburetor the thermo-

static switch (2) is secured to the end cover (1)
with clip (3).                                             1



                                                                                            138TI009 KN

1.1.2=Heating element, heating plate

Heating element (4) and heating plate (5) are

installed between the carburetor and air filter.
                                                                       4
Thermostatic switch                                                                     5
cut-out temperature:                 +7 ... +13°C
                                     (45 ... 55°F)
                                                                                     5
                                                                                  112
Resistance at a                                                            TO
temperature of
                                                                                            138TI010 KN

+25°C (77°F):                        8Ω
)Technical Information 21.96  -  Page 2

1.1.3=Contact spring

The original contact spring 1121 442 1600 will be
replaced by the version 1125 442 1600 to coincide
with the introduction of the new carburetor heating
system. The flag connector of the new thermostatic
switch is fitted on the connector tag of this contact
spring (see arrow).

                                                                           133TI013 KN
Parts availability
Contact spring 1125 442 1600 will be supplied
as a universal replacement part for all versions of
models 034 and 036.

1.1.4=Wiring harness, grommet

The wiring harness 1125 440 3000 comprises the

ground wire, short circuit wire and the connecting
wire to the generator. Grommet 1125 123 7500 is
fitted at the entry point in to the carburetor box.

                                                                                             138TI011 KN

1.2=Installing wiring

1.2.1=... in area of ignition module

The wire of the standard generator on machines
with carburetor heating is 102 mm (4”) long and
equipped with a connector pin. It is connected to
the terminal socket of the connecting wire in the

wiring harness behind the ignition module.

In the case of a repair, shorten the wire of the
replacement generator 1118 400 4000 to this
length, attach a terminal pin to it and install as
follows:

• Push wire into slot (1) and the rib (2) in the

    crankcase.
    Important:=qhe wire must be positioned in the
    crankcase so that it is well clear of the flywheel.
•   Move the plug and socket connection (3) to the
    position shown in the illustration.
    Important:=qhe tube must completely cover
    the connectors.
•   Install the ignition module.                                     1 2                 3
                                                                                             138TI012 KN
)Technical Information 21.96  -  Page 3

1.2.2=======.... in the carburetor box

• Make sure that grommet for the wiring harness
      is properly positioned in the tank housing.
      All three wires of the wiring harness must pass
      through the grommet.

Connect the wires as shown in the illustrations:
                                                                    1            2
• Push terminal pin of wire (1) from heating
      element (blue) into connector sleeve.
      Important: qhe tube (2) must completely

      cover the connectors.
•     Push connector sleeve (3) of short circuit wire
      into switch shaft seat.
•                                                                                4

                                                                                       138TI016 ST
      Push connector sleeve of yellow-green ground                  3
      wire (4) into loop of contact spring.

1.3=====Connecting carburetor

• First push the carburetor into position so
      that it is just flush with the collar screws (see
      illustration).
      Make sure the wires are not pinched in the pro-
                                                               2

      cess.                                                         TOP
                                                                          1125

      Important:=mush Master Control lever all the
      way down - to “cold start” position.
•     Push thermostatic switch’s flag connector (1)            1

      onto contact spring’s connector tag.
•

                                                                                      138TI014 KN
      Slip the heating element (2) over the collar

                                                                                 3
      screws and onto the carburetor.
•     Fit the heating plate (3) so that the designation
      ³TOP 1125´ is in the position shown.

• Carefully push carburetor over collar screws
      and up to stop against manifold flange.
      Check that wires are properly positioned

      (see illustration).
•     Tighten down M5 hexagon nuts.

                                                                                     138TI015 KN
)Technical Information 21.96  -  Page 4

1.4=New parts

Item      Part Name                                          Part No.
 1        Carburetor (VH);                                   1125 120 0609
          including items 2 to 6:
 2        Thermostatic switch                                1125 430 0500
 3        Clip                                               1128 122 9301
 4        Round head screw                                   1125 122 7403
 5        Washer                                             1128 122 1502
 6        Washer                                             1128 122 1501

 7        Heating element                                    1128 434 5101

 8        Heating plate                                      1125 121 9900
 9        Wiring harness                                     1125 440 3000
10        Grommet                                            1125 123 7500

          All other parts as on
          standard carburetor

Modification to be introduced: in progress
2.===Shroud

The rotary shutter, B 4.8x13 self-tapping screw and O-ring will no longer be installed on the production line in
models 034 and 036. However, shrouds with rotary shutter, self-tapping screw and O-ring will be available as
replacements in future (except 036 QS).

6XPPDU\

Item      Part Name                               Original               New                    Rem.
                                                  version                version

          Shroud 034;                             1125 080 1603          1125 080 1603          1)
          Shroud 036;                             1125 080 1614          1125 080 1614          1)

          each of above includes
          items 1 to 3:
1         Rotary shutter;                         1125 080 8000          1125 080 8000          2)

          including items 2 and 3:
2         Self-tapping screw B 4.8x13             9099 021 3760          9099 021 3760          2)
3         O-ring 8.0x2.0                          9646 945 0590          9646 945 0590          2)

          All other parts as before

Modification to be introduced: in progress
5HPDUNV

1) Only modified version of part is available from factory
2) Part is QRW included in original version of shrouds
)Technical Information 21.96  -  Page 5

3.===Prefilter =only 034 and 036 without 
     FRPSHQVDWRU

Prefilter 1125 120 1500 will be replaced by prefilter
1125 120 1501 in all 034 saws from machine
number X 33 781 153=~nd in 036 saws without
compensator.

4.===Nameplate

The original riveted aluminium nameplates will be
replaced in the near future by clip-in plastic name-

plates. The new plastic nameplate is pushed into

the shroud and held in position by two retaining
lugs. The two holes in the shroud are countersunk
for this purpose.

Service note
Plastic nameplates cannot be fitted in the original

version of the shroud because it does not have
countersunk mounting holes. For this reason the
aluminium nameplates and round head rivets
remain available as replacements.                             fo
6XPPDU\

Item      Part Name                               Original               New             Rem.
                                                  version                version

1         Nameplate 034;                           1125 967 1506         1125 967 1507   1)
2         Nameplate 036;                           1125 967 1505         1125 967 1508   1)

          each of above includes:
3         Round head rivet 3x6 (2x)                0000 974 1000         ---             1)

Modification to be introduced: in progress
5HPDUNV

1) Original version of part remains available for older machines

Last Technical Information on models 034, 036: 30.95

                                                             Andreas Stihl - D1/MTK-al
 1996 Andreas Stihl                                         Technical Documentation            5809

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