← Service bulletins

Technical Information · issue 37 of 2003

Technical description; Specifications; Noise and vibration data; Cutting tools; Deflector; Special accessories for the user; Service accessories; Spare parts; Repairs

IssueTI 37/2003

Full text

Page 1 of 5

TI 37/2003 page 1
STIH)

Technical Information

                                                                  37.2003

  New STIHL FS 38 brushcutter – Series 4140

  Contents
  1.
  2.
       Technical description
       Specifications
  3.   Noise and vibration data
  4.   Cutting tools
  5.   Deflector

  6.   Special accessories for the user
  7.   Service accessories
  8.   Spare parts
  9.   Repairs

  The new lightweight brushcutter STIHL FS 38
  rounds off the bottom end of the range of
  brushcutters and clearing saws.

  The engine is enclosed in a compact housing
  which also incorporates the multi-function handle.

  The ergonomically designed controls and
  advantageous power-to-weight ratio ensure
  easy handling and operation without tiring.

  The FS 38 has a curved shaft.
  The applications and possible uses are the same
  as for the STIHL FS 45.

  TI_37_2003_01_01_02.fm                                               englisch / english
)m~ge 2                                                                        Technical Information 37.2003

1.     Technical description                               2.    Specifications
The new brushcutter is driven by the "basic
                                                           2.1   Power unit
engine 4140" which has already proved its value in
many STIHL power tools (such as FS 45, FS 55,              Displacement:             27.2 cm3
FC 55, HS 45, HL 45, BG 45, BG 55, SH 55, SH 85).          Cylinder bore:            34 mm
Cylinder                                                   Piston stroke:            30 mm
                                                           Power output to           0.65 kW (0.9 HP)
.    Four-port system (better mixture preparation,
                                                           ISO 8893:                 at 7000 rpm
     optimum combustion and lower exhaust
     emissions)                                            Rewind starter:           Single pawl system
                                                           Starter rope:             3 mm dia.,
.    Large cooling-air area

                                                                                     1060 mm long

Crankshaft                                                 Clutch engages at:        3800 rpm
.    Made up of five parts which are pressed               Max. speed of
     together to prevent torsion                           cutting tool:             9500 rpm

.    Both ends mounted in bearings
Carburetor

                                                           2.2   Ignition system
.    With three adjusting screws (H, L, LA), H screw
                                                           Ignition module:         With integrated
     with cap to limit the adjusting range
                                                                                    electronic speed
.    With manually actuated fuel pump (purger)
                                                                  fo                governor
Air filter                                                 Spark plug (interference NGK BPMR 7 A
                                                           suppressed):             Bosch WSR 6 F
.    Felt filter with high separation efficiency and
     long filter life                                      Electrode gap:           0.5 mm

Exhaust muffler
.    Two-chamber muffler, with spark arresting             2.3   Fuel system
     screen in some countries

                                                           The engine must be operated with a mixture of
Clutch                                                     petrol and engine oil.

.    With two unlined clutch shoes                         Fuel mix:
                                                           Branded regular grade petrol with a minimum octane
                                                           rating of 90 RON and high-quality two-stroke engine

                                                           oil for air-cooled high-performance two-stroke
                                                           engines.

                                                           Mixing ratio:
                                                           With STIHL 1 : 50 two-stroke engine oil:
                                                           1 : 50 = 1 part oil + 50 parts petrol

                                                           With any other branded two-stroke engine oil:
                                                           1 : 25 = 1 part oil + 25 parts petrol

                                                                                         TI_37_2003_01_01_02.fm

Page 2 of 5

TI 37/2003 page 2
Technical Information 37.2003                                                                           Page 3

Carburetor:                                        4.   Cutting tools
All-position diaphragm carburetor with integral
fuel pump
Low speed screw L            open 1 turn

                                                                                       2
                                                                                           /L       r
                                                                                                  nu
                                                                                                ch
High speed screw H           open max. 3/4 turn
(standard setting with caps) (as far as stop)           1

                                                                     ch
                                                                       nu
                                                                        /L
Cut-off speed without tool

                                                                                 1
(electronic speed
governor):                   9,500 +/- 800 rpm
Fuel tank capacity:          0.33 l (330 cm3)

2.4   Weight
                                                        2
Without cutting tool         4.1 kg

                                                                                                            234TI001 KN
3.    Noise and vibration data
Sound pressure level
Lpeq to EN ISO 7917 1)       91 dB(A)
                                                   The following cutting tools are approved:
Sound power level                                  STIHL Autocut C 5-2
Lweq to EN ISO 10884 1)      103 dB(A)
                                                   mowing head                       4006 710 2105
1) Values include idling and top speed with the    STIHL Polycut 6-3

same duration of exposure                          mowing head                       4006 710 2110

Vibration acceleration

to EN ISO 11680-1                                  5.   Deflector

Idling
Left-hand handle           6.3 m/s2
Right-hand handle          3.5 m/s2

Top speed
Left-hand handle           5.6 m/s2
                           10.3 m/s2

Right-handle

                                                                                                            234TI002 KN

                                                   The new deflector 4809 710 8101 is used on the
                                                   model FS 38. The cutting circle diameter equals
                                                   350 mm when using nylon line.

TI_37_2003_01_01_02.fm
)m~ge 4                                                                           Technical Information 37.2003

6.    Special accessories for the user

6.1   General
Part name                  Part No.                     Use
Harness                    4130 710 9000
Starter rope               0000 195 8200                Rewind starter, also for ElastoStart
ElastoStart                0000 190 3400                Rewind starter (grip with rope)
STIHL gear lubricant                                    Drive shaft in tube
- 80 g tube                0781 120 1109
- 225 g tube               0781 120 1110

STIHL special oil                                       Rewind spring in rewind starter,

- 100 ml bottle            0781 417 1315                bearing bore in rope rotor

6.2   Mowing heads: nylon line and blades

Part name                  Part No.                     Use

Nylon line, 2 mm, green    0000 930 2217                Autocut C 5-2
Blades (set of 12)         4111 007 1001                Polycut 6-3
7.    Service accessories

7.1   Special tools

The special tools are listed in the repair manual for
the FS 45 or basic engine 4140.

7.2   Service aids

Part name                  Part No.                     Use
Carburetor parts kit       4140 007 1060                Zama C1Q-S71 carburetor

Set of gaskets             4140 007 1050                Engine
Standard commercial,       ---                          Cleaning the crankshaft stub

solvent-based
degreasant without
chlorinated or

halogenated
hydrocarbons

8.    Spare parts
The spare parts list for the model FS 38 brushcutter
is integrated into the spare parts list for the model
FS 45 and will be available when the model is
launched on the market.

                                                                                               TI_37_2003_01_01_02.fm

Page 3 of 5

TI 37/2003 page 3
Technical Information 37.2003                                                                                  Page 5

9.      Repairs
If the machine is started up in the course
of repairs, it is essential to observe all                               Repair procedure                    FS 38
country-specific safety regulations and the
safety precautions outlined in the user's                            1   Remove and refit engine               10
manual.                                                              2   Crankcase, pressure test*             55
                                                                     3   Crankshaft, bearings,                 55
9.1     Service note                                                     pressure test*
For servicing and repair procedures on the power                     4   Sealing rings, pressure test*         55
tool, refer to the repair manuals for the STIHL                      5   Crankcase leakage test, test run      55
basic engine 4140 and STIHL FS 45; see also

                                                                     6   Cylinder, piston, pressure test*      55
STIHL Service Training System "Diagnosis".

                                                                     7   Ignition system, contact*             10
                                                                     8   Fuel supply, tank vent, test run      10
9.2     Tightening torques
                                                                     9   Manifold or flange, pressure test      -

The tightening torques for the engine and for the
shaft and gearbox are listed in the respective                      10   Carburetor, check*                    25
repair manuals.                                                     11   Handle and throttle control           10

                                                                    12   Rewind starter, test run              15
9.3     Mounting and dismounting the deflector                      13   Clutch, test run                      20
                                                                    14   Muffler                               10
                     2
                                                                    15   Air filter                             5
                                                                    16   Stop switch, test run                 20
                                                                    17   Clutch housing                         -
                                                                    18   Drive tube                            15

                                             1                      19   Replace gear head or bearing
                                                                         housing                                5
                                                                    20   Limit stop or deflector                5

                                                                    21   Drive shaft                           10
                                                      234TI003 KN

                                                                    22   Fuel tank                             10

                                                                    23   Check compression pressure             -
.     Slide deflector onto the holder as far as possible            24   Adjust valve clearance                 -
.                                                                   25   Replace crankcase, bottom half         -

      Insert nut (1) in the hexagon socket on the
      deflector – holes must line up                                26   Replace crankshaft                     -
                                                                    27   Replace cylinder, piston               -

.     Insert bolt (2) and screw in tightly
                                                                    28   Oil supply                             -
9.4     Repair times                                                29   Oil pump, test run                     -

The specified repair times assume that the work
is performed by trained personnel in a properly
equipped service workshop.

The repair times are stated in minutes.                             * Test run under load
The following table can be added to the STIHL table
of repair times.

© ANDREAS STIHL AG & Co. KG, 2003                                   Technical Documentation
                                                                    D1/MTK-ja                                       7939

TI_37_2003_01_01_02.fm

Page 4 of 5

TI 37/2003 page 4

Page 5 of 5

TI 37/2003 page 5

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 →