← Service bulletins

Technical Information · issue 4 of 2003

Technical description; Specifications; Versions wi

IssueTI 4/2003

Full text

Page 1 of 4

TI 4/2003 page 1
Technical Information

                                                                                     04.2003

  Trimmers STIHL FS 45 C, FS 46 C, FS 55 C – Series 4140

  CombiEngine STIHL KM 55 C – Series 4140

  Contents
  1.   Technical description
  2.   Specifications
  3.   Versions with Easy2Start
  4.   Service notes

  5.   Summary
                                                           1.    Technical description
  Additional new versions of the models FS 45 C,
                                                           1.1   Function of the starter system with

  FS 46 C, FS 55 C and KM 55 C are now available
  with Easy2Start for distinctly more convenient                 Easy2Start

  starting. A helical spring stores the energy
  produced as the starter rope is pulled and transfers                  F1
  this energy to the engine via drive lugs.

  This yields the following advantages for the user:
                                                                                                     F2
  .    Significantly less effort is needed to start the

                                                                                            4
       engine.
                                                                                                           5
  .    Individual peak forces due to the compression
       process are no longer felt on the starter handle.                 1

                                                                               2
                                                                                                               233TI026 KN

  .    The speed required to pull the starter handle is
                                                                                     3
       reduced considerably.

                                                           A spring housing (1) with spring (2) and two drive
                                                           lugs (3, 4) are installed between the rope rotor and
                                                           the crankshaft. Force F1 when pulling on the starter
                                                           rope tensions the spring (2) against the opposing
                                                           force F2 generated by the piston (5) during
                                                           compression.
                                                           When the torque of the prestressed spring (2)
                                                           exceeds the resultant torque of force F2, the
                                                           crankshaft turns and the engine starts.

  TI_04_2003_02_01_01.fm                                                                     englisch / english
)m~ge 2                                                                              Technical Information 04.2003

1.2   Starting effort
                                                              (N)
The effort required to start the engine is reduced
significantly.
Individual peak forces due to the compression                              a
process are not transmitted to the starter handle.                         b
This is perceived by the user as smoother starting.
a = FS 55 Standard model
b = FS 55 C with Easy2Start

                                                                                                                        233TI028 KN
Vertical axis: Starting effort
                                                                  0
Horizontal axis: Turns of the crankshaft                              0        1           2            3           4

1.3   Mechanical design of the starter system

      with Easy2Start



           4
                                                         8                11
                                                             10

                                                                                   12
                             1         5
                                               6     7
                                                         9                                14


                                                                                     13                        17
                                                                                                                        233TI027 KN


1 = Starter mechanism 1)                                     10 = Washer 1)
2 = Handle 2)                                                11 = Spring housing with spring 1)
3 = Starter rope 1)                                          12 = Drive lug 1)
4 = Model plate 1)                                           13 = Washer 1)
5 = Rewind spring 2)                                         14 = Screw IS-M5x10-10.9 1)
6 = Rope rotor 1)                                            15 = Pawl 1)
7 = Pawl 2)                                                  16 = Leg spring 1)
8 = Washer 2)                                                17 = Drive lug 1)
9 = Spring 2)

                                                             1) New part for Easy2Start versions
                                                             2) Same part as previously in Standard version

                                                                                                    TI_04_2003_02_01_01.fm

Page 2 of 4

TI 4/2003 page 2
Technical Information 04.2003                                                                      Page 3

2.    Specifications                                  2.3   Dimensions

The specifications for all versions remain
unchanged except for the weight, dimensions of the
starter rope and overall length of the power tool.

2.1   Weight
                                                                                                25 mm
Versions with Easy2Start are approx. 8 ounces
heavier than the standard versions.
FS 45 C with Easy2Start

                                                                                                           233TI029 KN
FS 45 C                  9.5 lbs. (4,3 kg)

FS 46 C with Easy2Start                               The overall length of all versions with Easy2Start
                                                      increases by 25 mm (approx. 1 in.).

FS 46 C                  9.5 lbs. (4,4 kg)
FS 46 C Kat              9.9 lbs. (4,5 kg)
                                                      3.    Versions with Easy2Start

                                                      The following versions with Easy2Start are
FS 55 C with Easy2Start                               available:
FS 55 C1)
FS 55 RC
                         11.5 lbs. (5.2 kg)
                         11.0 lbs. (5.0 kg)
                                                      FS 45 C with Easy2Start
                                                      FS 45 C
FS 55 C Kat1)            11.7 lbs. (5.3 kg)
FS 55 RC Kat             11.2 lbs. (5.1 kg)
1)
  Version with bike handle                            FS 46 C with Easy2Start

R Version with loop handle                            FS 46 C
                                                      FS 46 C Kat
KM 55 C with Easy2Start

KM 55 RC                 9.3 lbs. (4.2 kg)

                                                      FS 55 C with Easy2Start
KM 55 RC Kat             9.5 lbs. (4.3 kg)
                                                      FS 55 C1)
R Version with loop handle                            FS 55 RC

                                                      FS 55 C Kat1)
2.2   Starter rope
                                                      FS 55 RC Kat
Starter rope 4137 195 8200 (2.7 x 910 mm-36 in.) is

                                                      1)Version with bike handle
used in all versions with Easy2Start.
                                                      R Version with loop handle

                                                      KM 55 C with Easy2Start
                                                      KM 55 RC

                                                      KM 55 RC Kat
                                                      R Version with loop handle

TI_04_2003_02_01_01.fm
)m~ge 4                                                                        Technical Information 04.2003

4.     Service notes                                        4.3   Spring

The specific national safety regulations and the            The spring (9) 1118 195 3500 must be lubricated
safety instructions in the Owner's Manual must be           with STIHL gear lubricant 0781 120 1117 or
observed if the machine has to be started.                  0781 120 1118 when necessary.
The item numbers in brackets, such as (10), refer to        Undo screw (14) IS-M5x10-10.9 for this purpose.
the illustration in section 1.3.
                                                            4.4   Screw IS-M5x10-10.9
4.1    Tensioning the rewind spring                         The screw (14) IS-M5x10-10.9 securing the drive
The rewind spring is tensioned as described in the          lug to the spring housing has a microcapsule of
corresponding Repair Manual for series 4140.                adhesive applied to it. Either a new screw must be
                                                            fitted during assembly or the old screw must be

The only difference is that it must be possible to turn     resecured with Loctite 242.

the rope rotor at least two turns before the rewind
spring reaches its maximum travel.                          4.5   Tightening torques
                                                             Screw (14)            5 Nm       Drive lug on

4.2    Spring housing with spring
                                                             IS-M5x10-10.9         44 in. lbs spring housing
The spring housing with spring (10) 4140 190 0710
                                                             Drive lug (17)        17 Nm Drive lug on
must be lubricated with STIHL gear lubricant

                                                                                   12 ft. lbs crankshaft
0781 120 1117 or 0781 120 1118 when necessary.
Screw IS-M5x10-10.9 must be unscrewed and the
drive lug removed for this purpose. The spring must
never be removed from the spring housing: risk of
injury if the pretensioned spring jumps out
uncontrollably.

5.     Summary
Item     Part name                                    Part No.                                    Remarks

 1        Starter mechanism                           4140 190 4010

 2        Rope rotor                                  4140 195 0410
 3        Starter rope dia. 2.7x910 mm (36 in)        4137 195 8200
 5        Spring housing (with spring)                4140 190 0710

 6        Drive lug                                   4140 195 2010
 7        Washer DIN9021-A5,3                         9307 021 0120

 8        Screw IS-M5x10-10.9                         9022 399 0950
 9        Model plate FS 45 C                         4140 967 1515
10        Model plate FS 46 C                         4140 967 1516

11        Model plate FS 55 C                         4140 967 1517
13        Model plate KM 55 RC                        4140 967 1520

14        Drive lug                                   4140 190 2010
15        Leg spring                                  0000 998 0612
16        Pawl                                        4133 195 7201
All other parts as before

Last Technical Information on the STIHL FS 45, FS 55, KM 55: 36.2002
© ANDREAS STIHL AG & Co. KG, 2003                      Technische Dokumentation
                                                       D1/MTK-ja                                          7850

                                                                                         TI_04_2003_02_01_01.fm

Page 3 of 4

TI 4/2003 page 3

Page 4 of 4

TI 4/2003 page 4

Extracted from the manufacturer's 2012 service catalogue. Most of these PDFs embed fonts with a shifted character map, so the text above was recovered rather than copied — read it as a faithful but imperfect transcription, and treat the page image above each block as the authority where the two disagree — the figures exist only there, because they are vector drawings that text extraction cannot keep.

Report a transcription error →