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Technical Information · issue 27 of 2001

Carburetor with LD Screw (Flange and End Cover Mou

Model HL 45 Hedge Trimmer – Series 4232

IssueTI 27/2001

Part changes (3)

WasBecomesWhat the bulletin says
4140 120 0610 4140 120 0603 1 Carburetor with 3 Adjusting Screws The carburetor 4140 120 0610 discussed in chapter 1 (BIS* carburetor with LD screw) will be replaced by the new version 4140 120 0603 (with H, L and LA screws).
4140 121 1600 4140 121 1605 The previous spacer flange 4140 121 1600 will be replaced by the new version 4140 121 1605 when the new carburetor is introduced (chapter 2.
4140 160 2000 4140 160 2001 To achieve a further improvement in operation, the 1 previous clutch 4140 160 2000 has been replaced by the new version 4140 160 2001 (1) on which a cup spring (2) is bonded to the inboard side of the carrier.

Full text

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TI 27/2001 page 1
Technical Information

                                                                                                      27.2001
Model HL 45 Hedge Trimmer                                       – Series 4232
Model FC 55 Power Edger                                         – Series 4140
Model FS 55 Trimmer                                             – Series 4140
Model FS 45 Trimmer                                             – Series 4140

Contents

1. Carburetor with LD Screw
   (Flange and End Cover Mounting, Fixed Jet)

2. Model Update
   2.1 Carburetor with 3 Adjusting Screws
   2.2 Spacer Flange

   2.3 Tensioner, Throttle Cable
   2.4 Filter Housing (Choke Shutter), Filter Cover
   2.5 Ignition Module, Crankshaft
   2.6 Fuel Tank, Hose, Retainer
   2.7 Clutch (Cup Spring), Washer
   2.8 Rewind Starter
   2.9 Summary

1.       Carburetor with LD Screw
         (Flange and End Cover Mounting, Fixed Jet)
                                                                The previous C1Q-S44 carburetor was initially

                                             1                  replaced by the C1Q-S53 and then by the C1Q-S58
                         1

                                                                (with a modified fixed jet). The end cover and flange
                                                                on the C1Q-S53 and C1Q-S58 carburetors are now
                         2                   2                  mounted with 4 screws of the same length instead
                                                                of separately with two short screws and two long

                                                                screws. The individual parts of the previous C1Q-
                                                                S44 and C1Q-S53 carburetors remain available as
     3                   3

                                                                spares (see Illustrated Parts List).
                         4                   5
                                                                Parts availability
                         6                   6                  The new versions of the end cover and flange may

                                                                only be used together. For this reason, flange kit
                         7                   7                  4140 120 2250 has been put together for the

                                                                C1Q-S44 carburetor. This flange kit comes
                                                                complete with gasket, metering diaphragm, end
                                                                cover, 4 new mounting screws and illustrated
                                                  253TI001 KN

                                                                instructions.
                                                                The new flange and end cover are also available as
Left: Carburetor 4140 120 0600 (C1Q-S44)                        separate items for repairs to the new version of the
Right: Carburetor 4140 120 0601 (C1Q-S53)                       carburetor.
       or 4140 120 0610 (C1Q-S58)

TI_27_2001_02_01_01.fm                                                                             englisch / english
)m~ge 2                                                                         Technical Information 27.2001

Summary

Item     Part Name                                  Previous                New                      Remarks
         Carburetor C1Q-S44;                        4140 120 0600           4140 120 0610            1)
         Carburetor C1Q-S53;                        4140 120 0601           4140 120 0610            1)
         Carburetor C1Q-S58;                        ---                     4140 120 0610
         including items 1, 2, 5 to 7:
 1       Screw                                      4226 122 7100           4226 122 7100            2)
 2       End cover                                  4226 121 0800           4140 121 0800            1), 4)
 3       Screw (2x)                                 1128 122 7100           ---                      3)
 4       Flange                                     4226 120 2200           ---                      1), 4)

 5       Flange                                     ---                     4140 120 2200
 6       Metering diaphragm                         4129 121 4700           4129 121 4700
 7       Gasket                                     4129 129 0902           4129 129 0902

 8       Flange kit;                                ---                     4140 120 2250            4)
         including items 1, 2, 5 to 7
Modification to be introduced: in progress

Remarks
1) Previous version of part no longer available from factory
2) Quantity changed from 2 to 4
3) Previous version of part remains available for other models
4) Use 4140 120 2250 flange kit as replacement part for carburetor 4140 120 0600 (C1Q-S44)

2.     Model Update
Apart from further optimizing and improving functionality and reliability, the aim of the model update is to

comply with the new emission regulations. The modifications to the parts and assemblies affected are
described below.

2.1    Carburetor with 3 Adjusting Screws
The carburetor 4140 120 0610 discussed in chapter

1 (BIS* carburetor with LD screw) will be replaced
by the new version 4140 120 0603 (with H, L and LA

screws).
*BIS = Balanced Idle System
The new carburetor’s high speed screw is equipped

with a cap to limit its range of adjustment. The low
speed screw and idle speed screw are also
                                                                                                               392TI033 KN

equipped with funnel-shaped caps to ease insertion

of the carburetor screwdriver.
                                                            Left: Carburetor with LD screw
                                                            Right: Carburetor with H, L and LA screws

                                                                                           TI_27_2001_02_01_01.fm

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Technical Information 27.2001                                                                                          Page 3

2.1.1 Construction                                                     2.1.3 Repairs / Servicing

     4                                         1
                                               2
                                                    3

                                                                                                                               392TI036 KN
                                                         392TI034 KN

.   Low speed mixture screw (1)                                        The limiter cap has to be removed from the high
                                                                       speed screw to replace a damaged high speed

.   High speed mixture screw (2)
                                                                       screw or clean the carburetor.
.   Limiter cap (3) for high speed screw
                                                                       .   Use suitable pliers to pull off the cap.

.   Stop pin (4)
                                                                       Do not re-use caps because they are damaged
                                                                       during removal.
                                                                       2.1.4 Adjustment after Repairs / Servicing
                                                                       .   Check the air filter and clean or replace as
                                                                           necessary.
                                                                       .   Check spark arresting screen and clean or

                                                                           replace as necessary.
                                                                       .   Check fuel filter and clean or replace as
                                                                           necessary.
                                 295TI012 KN

                                                                       2.1.5 Standard Setting of H Screw

                                                                             (without cap)

The cap is pushed over the knurled head of the

H adjusting screw. The stop pin (see arrow) in the
carburetor body serves to limit adjustment.
                                                                                       H

2.1.2 Function

                                                                                                       392TI037 KN

                         270°
                                                                       .   Starting with the screw lightly against its seat:
                                                                           Open high speed screw (H) 11/2 turns.
                                392TI035 KN

The pin limits rotation of the cap and thus the
range of adjustment of the high speed screw to 3/4
turn (270 degrees).

TI_27_2001_02_01_01.fm
)m~ge 4                                                                         Technical Information 27.2001

2.1.6 Installing the Cap                                    2.1.9 Setting Instructions for Users
                                                            The user may adjust the carburetor’s high speed
                                                            screw within a range of 270 degrees.
                                                            This enables the user to make the mixture leaner if
                                                            necessary, e.g. for operation at high altitude.
                       H                                    In most cases the H screw should remain at the
                                                            "rich" stop setting.
                                                            The procedure for setting the new carburetor is as
                                                            described in the owner’s manual (see chapter
                                                            "Adjusting the Carburetor").
                                392TI038 KN

                                                            2.2   Spacer Flange
Caps that have been removed once must not be
re-used because they are damaged during

removal.
.   Position new cap for high speed screw (H) so

    that it is in line with “rich” stop (arrow).
.   Push cap home as far as stop against
    carburetor body.                                                fo
2.1.7 Adjusting Idle Speed

                                                                                                              232TI005 KN

                                                            Left: Previous spacer flange 4140 121 1600
                        L                                   Right: New spacer flange 4140 121 1605

                                                            The previous spacer flange 4140 121 1600 will be
                                                            replaced by the new version 4140 121 1605 when

                                                            the new carburetor is introduced (chapter 2.1). The
                                                            inner surface of the new spacer flange is structured
                                 392TI039 KN

          LA                                                (arrow) for optimized gas flow.

                                                            2.3   Tensioner, Throttle Cable
Starting with the screws lightly against their seats:

.   Open low speed screw (L) one full turn
    counterclockwise.

.   Use idle speed screw (LA) to set engine speed
    to 2,800 RPM.
This adjustment must be checked with a

tachometer.

2.1.8 Checking Running Behavior
                                                                                                               232TI006 KN

.   Open the throttle several times to check that
    engine accelerates smoothly.
Engine must run smoothly at idle speed.                     Left: Previous tensioner 4140 182 7600
                                                            Right: Tensioner 4140 182 7602
                                                                   (interim version)

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Technical Information 27.2001                                                                                      Page 5

The tensioner 4140 182 7600 was initially replaced                  applied to the new filter cover. Furthermore, a
by the version 4140 182 7602. This tensioner is                     modified choke shutter is installed.
supported in the spacer flange on an integrally
                                                                    Parts availability
molded pivot pin. Therefore, the bearing pin
4137 123 8900 and the push nut 9417 003 7512 are                    Filter cover 4140 141 0500 remains available as a
no longer required and have been deleted.                           spare for carburetors 4140 120 0600 / 0601 / 0610
                                                                    (BIS carburetors with LD screw).
                                                                    The new filter housing 4140 140 2850 must be
                                                                    used as a replacement for a damaged filter
                                                                    housing – irrespective of the carburetor version.
                                                                    The replacement part includes the new replacement

                                                                    filter cover 4140 141 0502. As there are no setting

                                                                    symbols on this filter cover, it can be used as a
                                                                    universal replacement.
                                                                    The modified choke shutter is made from orange-

                                                      232TI007 KN   colored plastic so that it can be easily distinguished
                                                                    from the previous choke shutter (black).

Throttle cable on the tensioner                                     2.5   Ignition Module, Crankshaft
Left: Tensioner 4140 182 7602
Right: Tensioner 4140 182 7601
Throttle cable 4140 180 1105 (on all machines with
a loop handle) and tensioner 4140 182 7601 will be
installed in a further line modification from serial
number 2 51 188 982. The sheath of the new

throttle cable has been lengthened so that it extends
over the whole tensioner and is held in position by it.

2.4   Filter Housing (Choke Shutter), Filter

                                                                                                                         253TI004 KN

      Cover

Modified versions of the filter housing, choke shutter
and the filter cover will be installed at the same time             Position of keyway slot for flywheel
as the new carburetor described in chapter 2.1.                     Left: Previous crankshaft 4140 030 0400
                                                                    Right: New crankshaft 4140 030 0401

                                                                    Ignition timing and governor cut-off speed range

                                                                    have been optimized. For this reason the ignition
                                    H    L                          module 4140 400 1300 will be replaced by ignition
                                   3/4   1
                                                                    module 4140 400 1303 together with a new
                                                                    crankshaft. Compared with the previous version, the

                 LD
                                                                    position of the keyway slot for the flywheel (see
                                                                    arrows) has been changed on the new crankshaft
                                                                    4140 030 0401.

                                                                    Service note
                                                      253TI003 KN

                                                                    In case of a repair, only the new versions of the parts
                                                                    may be used for machines with carburetor
The position of the hinge on the filter housing and                 4140 120 0603.
filter cover has been moved further outboard (see
arrows) to allow good access to the adjusting
screws of the new carburetor.

Setting symbols for the new carburetor have been

TI_27_2001_02_01_01.fm
)m~ge 6                                                                       Technical Information 27.2001

2.6   Fuel Tank, Hose, Retainer
Modified fuel tanks will be installed to coincide with
the introduction of the new carburetor (see 2.1).
The change in the shape of the tanks has improved
access to the carburetor adjusting screws.
Furthermore, the capacity of the tanks has been
increased from 10 oz. (0.3 liter) to 11 oz. (0.33 liter).
The new tank shape makes the use of a new,
approx. 3/8“ (10 mm) longer retainer necessary. The
retainer is mounted to the tank with an IS P5x20
spline screw. The fuel hose has also been modified

and standardized for all machines.

Parts availability / Service note

Fuel tank 4232 350 0401 will be supplied as a
replacement for all machines. This tank comes
complete with the new hose 4140 358 7702 (with

pickup body 0000 350 3506) and the modified
retainer 4140 353 2402 with mounting screw.
The previous fuel tanks 4140 350 0400 (for FS
45/FS 55, FC 55) and 4232 350 0400 (for HL 45)
have been deleted. The previous retainer
4140 353 2400 and its IS D5x24 mounting screw
remain available for repairs to older machines.

                                                                                                           232TI008 KN

                                                            Top:    Component parts of previous version
                                                            Bottom: Component parts of new version

2.7   Clutch (Cup Spring), Washer

To achieve a further improvement in operation, the                                           1
previous clutch 4140 160 2000 has been replaced
by the new version 4140 160 2001 (1) on which a

cup spring (2) is bonded to the inboard side of the
carrier. The previous washer 4130 162 8900
(1.5 mm thick) between the clutch and flywheel has
been replaced by a 1.2 mm thick washer                               3
4140 162 8900 (3). New replacement clutches are                              2
supplied with the thinner washer and are therefore
                                                                                                           232TI009 KN

fully interchangeable.

                                                                                       TI_27_2001_02_01_01.fm

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Technical Information 27.2001                                                                         Page 7

2.8    Rewind Starter
A modified version of the rewind starter
4140 190 4000 will be installed to coincide with the
introduction of the new carburetor (see 2.1). The
longer starter rope 1120 195 8200 (Ø 3x1060 mm -
41 3/8“) and the new rewind spring 4140 190 0601
will be installed to increase the pull length for
improved starting convenience.
Service note
The new (longer) starter rope may only be installed

                                                                                                          232TI012 KN
together with the new rewind spring. For this reason

the previous starter rope 0000 195 8200 (Ø 3 x
800 mm 31 1/2“) and the previous rewind spring
4140 190 0600 will remain available as                   Replacement rewind spring (with transport keeper)
replacements for repairs on older machines.              Left: Previous version

                                                         Right: New version
The new carburetor (see 2.1) is an easy way of
identifying machines with the new starter rope

and new rewind spring.

2.9    Summary

Item     Part Name                                 Previous             New                    Remarks
 1       Carburetor C1Q-S58                        4140 120 0610        ---                    1)
 2       Carburetor C1Q-S66                        ---                  4140 120 0603          2)

 3       Spacer flange                             4140 121 1600        4140 121 1605          1)

 4       Tensioner                                 4140 182 7602        4140 182 7601          1)
 5       Pin                                       4137 123 8900        ---                    1)
 6       Push nut                                  9417 003 7512        ---                    1)

 7       Throttle cable                            4140 180 1100        4140 180 1105          1)

 8       Filter housing;                           ---                  4140 140 2850          3)
         including items 9 to 14:
 9       Filter housing;                           4140 140 2800        -*-                    4)5)

         including items 10 to 12:
10       Lever                                     4140 141 3700        4140 141 3700
11       Choke shutter                             4140 141 3800        4140 141 3801          1)

12       Push nut                                  9417 003 7512        9417 003 7512
13       Filter                                    4140 124 2800        4140 124 2800
14       Filter cover                              4140 141 0500        4140 141 0502          1)

15       Ignition module                           4140 400 1300        4140 400 1303          1)
16       Crankshaft                                4140 030 0400        4140 030 0401          1)

17       Fuel tank (FS 45/55, FC 55)               4140 350 0400        ---                    6)
18       Fuel tank (HL 45)                         4232 350 0400        ---                    6)

TI_27_2001_02_01_01.fm
)m~ge 8                                                                     Technical Information 27.2001

Item     Part Name                                Previous               New                    Remarks
19       Fuel tank;                               ---                    4232 350 0401
         each of above includes items 20 to 24:
20       Hose                                     4140 358 7700          4140 358 7702          6)
21       Pickup body                              0000 350 3502          0000 350 3506          1)
22       Retainer                                 4140 353 2400          4140 353 2402          1)
23       Spline screw IS D5x24                    9075 478 4159          ---                    1)
24       Spline screw IS P5x20                    ---                    9074 478 4135

25       Clutch; including:                       4140 160 2000          4140 160 2001          6)

26       Cup spring 31.7x20.4x0.4                 ---                    -*-                    5)
27       Washer                                   4130 162 8900          4140 162 8900          1)

28       Rewind starter; including:               4140 190 4000          4140 190 4000          6)
29       Rewind spring                            4140 190 0600          4140 190 0601          1)
30       Starter rope Ø 3x800 mm (31 1/2“)        0000 195 8200          ---                    1)

31       Starter rope Ø 3x1060 mm (41 3/4“)       ---                    1120 195 8200
Modification to be introduced: in progress
Remarks
1) Previous version of part remains available for older machines and/or other models
2) For component parts see illustrated parts list
3) Use as replacement for previous and new versions of the filter housing
4) Previous version of part no longer available from factory (use item 8 as replacement)

5) New version of part is not available as separate item
6) Previous version of part no longer available from factory

Last Technical Information on models HL 45: 55.1999; FC 55: 41.1999;
                                     FS 55: 39.1999; FS 45: 02.1999

© 2001 Andreas Stihl AG & Co.                            Technical Documentation
  Waiblingen                                             D1/MTK-sc                                     7467

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