Technical Information · issue 12 of 1995
Uprated engine
IssueTI 12/1995
Full text
Page 1 of 3
Technical Information
12.95
STIHL FS 72 Trimmer - Series 4133
Power increase
The trimmer FS 72 will be available in the near
future with a more powerful engine unit.
The engine power has been increased by approx.
15% to 0.8 kW (1.1 bhp).
This increase has been achieved by:
changing the port timing
increasing the compression
enlarging the cross-section of the intake port
changing the shape of the transfer ports
changing the shape of the gasket and
spacer flange
The new cylinder, gasket and spacer flange
versions are generally used as replacement parts.
&\OLQGHU
The new cylinder differs from the original version
in that the cylinder base flange is approx. 3 mm
thicker and the intake cross-section is larger.
The original cylinder version was secured with
spline screws of size M5 x 16 while the new
version is secured with spline screws of size
10,5
M5 x 20.
9
10
15 19
356TI001
Original New
version version
)Technical Information 12.95 - Page 2
*DVNHW
The window for the gas mixture is 19 mm wide in
the new gasket, as compared with only 16 mm in
the original version.
The new gasket can be installed in machines of
the old version.
356TI002
Original gasket New gasket
Spacer flange
The opening of the new spacer flange is
19 mm wide on the side facing the cylinder. The
service notes must be observed when installing
the new spacer flange in machines of the old
version.
Service notes
Only replacement parts of the QHZ type may
be=used=when=rep~iring=machines of the new
YHUVLRQ, otherwise a deterioration in power output
and malfunctions must be expected.
qhe=power=output=of machines of the original
YHUVLRQ can only be increased to approx. 0.8 kW
(1.1 bhp) if all new parts=~re installed.
The new cylinder must be mounted with the
M5 x 20 screws in all cases; tightening torque 3
4
10 Nm.
1
The screw connection filter base / carburetor /
2
flange / cylinder=must be checked when installing
the new spacer flange in machines of the original
version:
356TI003
Size M 5 x 56 (1) screws and plugs 4133 122 6900
(2) must be used in conjunction with the new
spacer flange. The spacer flange must be secured
to the cylinder with size M 5 x 25 screws (3) and A
5.3 washers (4).
)Technical Information 12.95 - Page 3
1RWH
When retrofitting from Non-"Plus Series" for
change to "Plus Series" Versions make sure
all new "Plus Series" Components are used.
6XPPDU\
Part name Original New Key Rem. MOQ
version version H
Cylinder 4133 022 0500 4133 022 0501 1 1) 1
Spline screw
IS-M 5 x 16 (2x) 9022 341 0980 --- 2)
Spline screw
IS-M 5 x 20 (2x) --- 9022 371 1020 2 10
Other parts as before
Gasket 4133 129 0900 4133 129 0902 3) 1
Spacer flange assy.; 4133 120 2202 --- 3)
including items 3 to 6:
Spacer flange
Spline screw
-*- fo4133 121 1602 3 4) 1
IS-M 5 x 56 (2x) 9007 319 1121 9007 319 1121 4
Hexagon nut M 5 (2x) 9210 261 0700 9210 261 0700 5
Plug (2x) 4133 122 6900 4133 122 6900 6
Modification to be introduced: in progress
5HPDUNV
1) Original version of part is no longer available from factory
2) Original version of part remains available
3) Original version of part will be supplied from factory only as long as existing stocks lasts
4) Original version of part is not available as seperate item
Last Technical Information on models FS 72: 01.94
Waiblingen, January 17, 1995 Andreas Stihl - D1/MTK-na
1995 Andreas Stihl Technical Documentation Page 2 of 3
Page 3 of 3
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.