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Technical Information · issue 4 of 1997

HS 72 ... 85: Gearbox; Cutting blade assemblies; F

Model HS 72, 74, 76, 75, 80, 85 Hedge Trimmers==============- Series 4226

IssueTI 4/1997
From serial 32 106 939, 34 573 587

Part changes (4)

WasBecomesWhat the bulletin says
4221 353 9201 0000 989 0516 The grommet 4221 353 9201 included in the fuel tank 4226 350 0405 and fuel hose kit 4226 007 1001 will be replaced by grommet 0000 989 0516.
4226 141 0300 4226 141 0301 4226 141 0300 will be replaced by debris filter 4226 141 0301 from machine number X 34 573 587.
4226 129 0901 4226 129 0902 The gasket 4226 129 0901 between the cylinder and spacer flange will be replaced by gasket 4226 129 0902.
4226 350 3500 0000 350 3503 366TI017 KN Pick-up body 4226 350 3500 will be replaced by the optimized version 0000 350 3503.

Full text

Page 1 of 7

TI 4/1997 page 1
Technical Information

                                                                                              04.97

Model HS 72, 74, 76, 75, 80, 85 Hedge Trimmers==============- Series 4226

&RQWHQWV

1.   Gearbox (gear ratio)

2.   Cutting blade assemblies (modified blades)
3.   Fuel tank/grommet
4.   Prefilter (standardization)

5.   Fuel filler cap assy. (filter, gasket, pick-up body)
6.   Carburetor WT 412 (control valve)

1.=Gearbox

The blade speed will be increased to further
improve cutting quality.
From machine number X 36 360 021 the gear ratio
will be changed from 7.1 to 5.6.                             1
The parts affected by this change are listed on the
summary. The main differences are shown in the

following illustrations.

Service notes
Original and new versions of the parts cannot be

used together in any combination.

                                                             2
Original and new versions of gearbox housing
covers will come with the correct gasket for

                                                                                                      366TI005 KN
easy replacement.

                                                            Gearbox housing
                                                            1 = Old version
                                                            2 = New version

                                                                 1                    2
                                                                                                              366TI008 KN

                                                            1 = Old version (bushing)
                                                            2 = New version (needle sleeve)
)Technical Information 04.97  -  Page 2

   1                                                          1

   2                                                          2

                                                                                              366TI007 KN
                                          366TI006 KN

Gearbox housing cover                                   Gasket

          Z = 57                Z = 56
                                                                   Z=8                Z =10

                                                                                              366TI009 KN
                                          366TI010 KN

   1                      2                                   1                   2

Spur gear (Z = teeth)                                   Clutch drum (Z = teeth)

                                                          1
   1

                                                          2
                                                                                              366TI012 KN

                                                        Thrust plate
   2
                                          366TI011 KN

Connecting rod                                          All illustrations:
                                                        1 = Old version
                                                        2 = New version
)Technical Information 04.97  -  Page 3

6XPPDU\

Item     Part Name                                 Original                  New                   Rem.
                                                   version                   version

 1       Gearbox housing;                          4226 640 0500            4226 640 0501          1)
         including items 2 to 6:
 2       Ball bearing                              9503 003 5290            9503 003 5382          1)
 3       bushing                                   4226 642 9700            ---                    1)
 4       Circlip                                   9456 621 3600            9456 621 3860          1)
 5       Needle sleeve                             ---                      9513 003 0912
 6       Roll pin 6 x 12                           ---                      9381 003 2070

 7       Clutch drum                               4226 160 2900            4226 160 2901          1)

 8       Spur gear                                 4226 640 7500            4226 640 7504          1)
 9       Connecting rod (2x)                       4206 642 6500            4226 642 6501          1)
10       Thrust plate (2x)                         4211 642 4800            4230 642 4800          2)

11       Circlip                                   9455 621 1380            9455 621 1670          1)

12       Gearbox housing cover;                    4226 640 5800            4226 640 5850          1)

         including items 13 to 15:
13       Screw plug                                4117 713 6501            4226 641 6500          2)
14       Bushing                                   4226 642 9700            ---                    1)
15       Needle sleeve                             ---     fo               9513 003 0912

16       Gasket                                    4226 649 0300            4226 649 0302          3)

Modification to be introduced from machine number X 36 360 021
5HPDUNV
1) Original version of part remains available as spare for older models

2) Original version of part will be supplied from factory only as long as existing stocks last
3) Original and new versions of part included in scope of supply of respective gearbox housing cover in future
)Technical Information 04.97  -  Page 4

2.=Cutting blade assemblies

The original cutting blade assemblies have been
replaced by new versions (for part numbers see
Summary) in connection with the modifications
described in chapter 1. The new versions of the                 1
blades have longer slots.
                                                                        28 mm
Service notes
These cutting blade assemblies should also be                          (1.10 in)
used for older machines.

Before installing individual blades, check the

length of the first slot (see illustration).

Original-type blades must not be used with the==================O
new version of the gearbox =see chapter 1.=.
                                                                        31 mm

                                                                                                        366TI014 KN
                                                                       (1.22 in)

                                                            1 = Old version
                                                            2 = New version

6XPPDU\                                                             fo
Item      Part Name                                  Original                      New           Rem.
                                                     version                       version

  1       Cutting blade assy. 420 DS; (16")          4226 710 5930              4226 710 5931    1)2)
          including item 2:
  2       Blade, 420 DS (16")                        4226 710 6006              4226 710 6026    1)2)

  3       Cutting blade assy. 550 DS; (21")          4226 710 5900              4226 710 5901    1)2)
          including item 4:

  4       Blade, 550 DS                              4226 710 6000              4226 710 6020    1)2)
  5       Cutting blade assy. 700 DS; (27")          4226 710 5940              4226 710 5941    1)2)
          including item 6:
  6       Blade, 700 DS (27")                        4226 710 6003              4226 710 6023    1)2)

  7       Cutting blade assy. 550 ES; (21")          4226 710 5910              4226 710 5911    1)2)
          including items 8 and 9:

 8        Blade, top, 550 ES (21")                   4226 710 6001              4226 710 6021    1)2)
 9        Blade, bottom, 550 ES (21")                4226 710 6002              4226 710 6022    1)2)
10        Cutting blade assy. 700 ES; (27")          4226 710 5920              4226 710 5921    1)2)
          including items 11 and 12:

11        Blade, top, 700 ES (27")                   4226 710 6004              4226 710 6024    1)2)
12        Blade, bottom, 700 ES (27")                4226 710 6005              4226 710 6025    1)2)
13        Cutting blade assy. 1000 ES; (39")         4226 710 5950              4226 710 5951    1)2)

          including items 14 and 15:
14        Blade, top, 1000 ES (39")                  4226 710 6007              4226 710 6027    1)2)
15        Blade, bottom, 1000 ES (39")               4226 710 6008              4226 710 6028    1)2)
          All other parts as before

Modification to be introduced for item 10: from machine number X 36 209 590
5HPDUNV
1) Original version of part will be supplied from factory only as long as existing stocks last
2) New version of part can also be used for older machines
)Technical Information 04.97  -  Page 5

3.=Fuel tank/grommet

The grommet 4221 353 9201 included in the
fuel tank 4226 350 0405 and fuel hose kit
4226 007 1001 will be replaced by grommet
0000 989 0516.

6XPPDU\

Item      Part Name                                     Original          New             Rem.
                                                        version           version

  1       Fuel tank;                                    4226 350 0405     4226 350 0405   1)

  2       Fuel hose kit;                                4226 007 1001     4226 007 1001   1)
          each of above includes:
  3       Grommet                                       4221 353 9201     0000 989 0516   2)

Modification to be introduced: in progress

5HPDUNV
1) Only modified version of part is available from factory
2) Original version of part remains available as spare for other models
4.=Prefilter

To further standardize inventories, the debris filter

4226 141 0300 will be replaced by debris filter
4226 141 0301 from machine number
X 34 573 587.

                                                                                                 366TI016 KN

6XPPDU\

Item      Part Name                                     Original          New             Rem.
                                                        version           version

  1       Debris filter                                 4226 141 0300     4226 141 0301   1)

Modification to be introduced from machine number X 34 573 587

5HPDUNV
1) Original version of part no longer available from factory
)Technical Information 04.97  -  Page 6

5.=Fuel filler cap assembly 

Filter 0000 358 1810 will be included with fuel
filler cap 4226 350 0501 from machine number
X 32 106 939=to further improve its function.

The gasket 4226 129 0901 between the cylinder
and spacer flange will be replaced by gasket
4226 129 0902.

                                                                                                        366TI017 KN
Pick-up body 4226 350 3500 will be replaced by
the optimized version 0000 350 3503.

                                                                  1                        2

                                                                                                        366TI015 KN
                                                            1 = Old version
                                                            2 = New version

6XPPDU\

Item      Part Name                                  Original                   New              Rem.

                                                     version                    version

  1       Fuel filler cap assembly;                  4226 007 1002              4226 007 1002    1)
          including items 2 and 3:

  2       Pick-up body                               4226 350 3500              0000 350 3503    2)
  3       Gasket                                     4226 129 0901              4226 129 0902    3)

  4       Fuel filler cap;                           4226 350 0501              4226 350 0501    1)
          including:
  5       Filter                                     ---                        0000 358 1810

Modification to be introduced: in progress, for item 5 from machine number X 32 106 939
for item 2 from machine number X 36 287 313

5HPDUNV
1) Only modified version of part is available from factory
2) Original version of part will be supplied from factory only as long as existing stocks last
3) Original version of part no longer available from factory
)Technical Information 04.97  -  Page 7

6.=Carburetor WT 412
                                                                    WT         6         WT     6
Control valve 4226 120 8701 will be installed in
the WT 412 carburetor 4226 120 0603 in place of                     412       20        412A   49
control valve 4133 120 8701 in order to ensure
maximum engine power and reliability when using
cutting blade assemblies of different lengths.
The type designation of the carburetor with this
control valve changes from WT 412=to WT 412 A.

                                                                                                     366TI013 KN
                                                           Left:     Old version

                                                           Right:    New version

6XPPDU\

Item     Part Name                                  Original                  New               Rem.

                                                    version                   version

 1       Carburetor WT 412                          4226 120 0603             4226 120 0603     1)

 2
         including:
         Control valve
                                                    4133 120 8701             4226 120 8701     2)
Modification to be introduced: in progress
5HPDUNV

1) Unmodified version of part will be supplied until existing factory stocks are exhausted
2) Original version of part remains available for other models

Last Technical Information on models

HS 72, 74, 76: 02.95
HS 75, 80, 85: 17.96

 1997 Andreas Stihl                   Andreas Stihl - D1/MTK-al
                                       Technical Documentation                                       5919

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