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Technical Information · issue 36 of 2004

Carburetor; Decompression valve; Oil pump (MS 290); Cylinder (MS 290)

IssueTI 36/2004
Engine family 1127

Part changes (1)

WasBecomesWhat the bulletin says
1127 121 3300 1133 121 3301 Carburetor (throttle shutter) To improve operation, the throttle shutter 1127 121 3300 is generally (on HD -18 and HD -21) replaced by the version 1133 121 3301.

Full text

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TI 36/2004 page 1
STIH)

Technical Information                                     36.2004

  Chain saws STIHL MS 290, MS 310, MS 390 – Series 1127

  Contents
  1.   Decompression valve (MS 390)
  2.   Oil pump (MS 290)
  3.   Carburetor (throttle shutter)
  4.   Cylinder / muffler (MS 290)

  1.      Decompression valve (MS 390)

  All versions of chain saw model MS 390 will be built
  with decompression valve from serial number
  2 63 855 676 onwards.
  It is located in a specially shaped grommet (arrow)
  matching the design of the handle housing.
  Supply of spare parts and service notes
  The previous version of the cylinder with piston and
  handle housing remain available for machines
  without decompression valve.
  The decompression valve must be screwed in with
  a torque wrench (required tightening torque:
  10 ft. lbs. or 14 Nm).

  TI_36_2004_30_01_01.fm                                   englisch / English USA
)m~ge 2                                                                       Technical Information 36.2004

When fitting the grommet in the hole of the handle
housing, the contours of the two parts must be lined
up exactly to prevent any loss of cooling air.
Summary
Item     Part name                                 Previous                New                  Remarks
 1       Handle housing; including Item 2:         1127 790 1002           1127 790 1008        1)
 2       Grommet                                   ---                     1127 084 7400
 3       Cylinder with piston dia.                 1127 020 1213           1127 020 1216        1)
         1.93 in (49 mm)
 4       Decompression valve                       ---                     1127 020 9400
Modification to be introduced: as from serial No. 2 63 855 676
Remarks
1) Previous version of part remains available for older models

2.       Oil pump (MS 290)
To continue the standardization of parts, the oil
pump 1127 640 3201 (with 0.88 stroke) previously
only installed in the MS 310 and MS 390 will also be
fitted in the MS 290. The previous oil pump
1127 640 3200 (with 0.75 stroke) is no longer
required.
Summary

Item     Part name                                 Previous                New                  Remarks
 1       Oil pump (0.75); including Item 2:        1127 640 3200           ---                  1)
 2       Pump piston                               1127 647 0600           ---                  1)
 3       Oil pump (0.88); including Item 4:        ---                     1127 640 3201        2)
 4       Pump piston                               ---                     1127 647 0601        2)
         Other parts remain unchanged
Modification to be introduced continuously
Remarks
1) Previous version of part is no longer available after inventories are depleted
2) Part was already a spare part for MS 310 and MS 390

                                                                                       TI_36_2004_30_01_01.fm

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TI 36/2004 page 2
Technical Information 36.2004                                                                 Page 3

3.     Carburetor (throttle shutter)
To improve operation, the throttle shutter
1127 121 3300 is generally (on HD -18 and HD -21)
replaced by the version 1133 121 3301. The
carburetor type designation consequently changes
from HD-18B to HD-19C and from HD-21 B to
HD-21C.
Summary

Item     Part name                                   Previous            New             Remarks
 1       Carburetor HD-18B/C;                        1127 120 0604       1127 120 0604   1)
 2       Carburetor HD-21B/C;                        1127 120 0605       1127 120 0605
         each including:
 3       Throttle shutter                            1127 121 3300       1133 121 3301   2)
         Other parts remain unchanged
Modification to be introduced continuously
Remarks
1) Only modified version of part is available from factory
2) Previous version of part is no longer available from factory

4.     Cylinder / muffler (MS 290)
A new cylinder with optimized transfer ducts and a
new muffler will be installed in the chain saws of
series MS 290.

Summary

Item     Part name                                   Previous            New             Remarks
 1       Cylinder with piston dia.                   1127 020 1210       1127 020 1217   1)
         1.81 in (46 mm)
 2       Muffler;                                    1127 140 0606       1127 140 0607   2)
         Other parts remain unchanged
Modification to be introduced continuously
Remarks
1) Previous version of part is no longer available from factory
2) Previous version of part remains available for MS 310 and MS 390

Last Technical Information on the STIHL MS 290, MS 310, MS 390: 35.2002

© ANDREAS STIHL AG & Co. KG, 2004                          Technical Documentation
                                                           D1/MTK-sc

TI_36_2004_30_01_01.fm

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TI 36/2004 page 3

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