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Technical Information · issue 31 of 2009

Modified carburetor; Summary

IssueTI 31/2009

Part changes (1)

WasBecomesWhat the bulletin says
4128 121 0800 1130 121 0801 3 Improved ethanol compatibility To reduce friction on the throttle trigger, the previous end cover 4128 121 0800 is being replaced by the Due to the use of ethanol resistant materials, the new end cover 1130 121 0801 without a cast arm at MS 170, 180 chain saws can be used with fuels with the idle

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TI 31/2009 page 1
STIH)

Technical Information                                                                          31.2009

  Chain saws STIHL MS 170, 180

  Contents
  1. Modified carburetor
  2. Summary

  1.       Modified carburetor                                        1.2    Idle speed screw

  To further improve function, the C1Q-S57A                           The previous brass anti-twist device is now made of
  carburetors of the MS 170, 180 series are being                     plastic. Because of this, the previous idle speed
  modified.                                                           screw 1130 122 6300 has been by the new idle
                                                                      speed screw 1130 122 6301.
  1.1      End cover
                                                                      1.3    Improved ethanol compatibility
  To reduce friction on the throttle trigger, the previous
  end cover 4128 121 0800 is being replaced by the                    Due to the use of ethanol resistant materials, the
  new end cover 1130 121 0801 without a cast arm at                   MS 170, 180 chain saws can be used with fuels with
  the idle speed screw.                                               up to 10 % ethanol content (E10) without affecting
                                                                      the functioning of the new carburetor.
                                                                      With increasing concentrations of ethanol in fuel
                                                                      (over 10 %), one must reckon with worsening start
                                                                      and running behavior, deterioration in performance
                                                                      and possible engine damage.
                                                                      The MS 170, 180 chain saws are not suitable for
                                                                      operation with fuels containing more than 10 %
                                                                      ethanol (E10).
                                                        207TI028 KN

  Left:    previous carburetor with cast arm (arrow)
  Right:   new carburetor without cast arm

  TI_31_2009_30_01_01.fm                                                                               englisch / English
)m~ge 2                                                                               Technical Information 31.2009

1.4      Identification                                         1.5         Carburetor adjustment
                                                                No changes have been made to the values for the
                                                                basic setting of the carburetor in the service shop.

                                                                1.6         Spare parts
                                                                The modified carburetors can also be used in older
                                                                chain saws.

                                                  207TI029 KN
The modified carburetors will be assigned a new
index in the designation on the carburetor.

Carburetor part     previous       new
numbers             designation    designation
1130 120 0603       C1Q-S57A       C1Q-S57B

2.       Summary
Item     Part Name                                                    Previous            New             Rem.
 1       Carburetor C1Q-S57A;                                         1130 120 0603       ---             1)
         including Items 3 and 4
 2       Carburetor C1Q-S57B;                                         ---                 1130 120 0603   3)
         including Items 3 and 4
 3       End cover                                                    4128 121 0800       1130 121 0801   3) 4)
 4       Idle speed screw                                             1130 122 6300       1130 122 6301   2)

Modification to be introduced continuously
Remarks
1) Previous version of part no longer available from factory
2) Previous version of part remains available for older models
3) New version of part can also be used for older machines
4) Previous version of part remains available for other models

© ANDREAS STIHL AG & Co. KG, 2010                               Technical Documentation
                                                                D1/MTK-ro

                                                                                                 TI_31_2009_30_01_01.fm

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TI 31/2009 page 2

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