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Technical Information · issue 14 of 1995

New version with decompression valve

IssueTI 14/1995

Full text

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TI 14/1995 page 1
Technical Information

                                                                                            14.95

Cutquik STIHL TS 460 - type 4221

New version with decompression valve

The STIHL TS 460 Cutquik will be available with a   This reduces the physical effort required to start
decompression valveK================================the machine and improves the operating con-
                                                    venience. The valve is opened manually and
This valve reduces the pressure in the combustion   closes automatically as soon as combustion of the
chamber when starting the machine so that less      fuel-air mixture starts.
force is required to pull the starter rope.
)Technical Information 14.95 - Page 2

Mechanical design and function

The housing (1) and valve (2) are the most
important elements of the decompression valve.
The piston can move axially in the housing.
A cone is fitted at the bottom end.
Three spring-loaded balls offset at angles of
120 degrees hold the piston in its upper and lower
limit position. The complete decompression valve
is screwed into the cylinder.
                                                                     3
                                                           1


                                                                         337TI002
Before starting, the valve (2) is forced into the lower
limit position and the cone lifts off the housing (1).
The decompression valve is now open.

Some of the pressure in the cylinder can now
escape through the hole (see arrow) in the valve.
The remaining mixture in the cylinder is compressed,
but the resultant pressure remains below the

closing pressure of the decompression valve.
                                                                     3

The pressure in the cylinder cannot rise above the         1
closing pressure of the decompression valve until the
fuel-air mixture ignites. The valve (2) is then forced
upwards and the hole is sealed by the cone.
                                                                     2

                                                                         337TI003

Service notes

The decompression valve can be installed and

removed with a commercially available, deep well
socket wrench, size 13 Tightening torque 14 Nm.
It is advisable temporarily to remove the
decompression valve and seal the threaded bore
with a plug, No. 1122 025 2200, in order to test the
power unit for leaks.
)Technical Information 14.95 - Page 3

New replacement parts

Designation                                    Part Number        Item              Comments     MAM
                                                                                      H
Cylinder with piston                          4221 020 1201                                           1
Decompression valve                           4221 020 9400                                           1
Shroud;                                       4221 080 1602           1                               1
includes Items 2, 3 and 4:
Grommet                                       4221 084 7400           2                               10
Rating plate                                  4221 967 1501           3                               10
Instruction plate                             0000 967 3673           4                                5

Plug                                          1122 025 2200                          1)

&RPPHQWV

1) Special accessory for service shops

Last technical information on the STIHL TS 460 Cutquiks: 02.94

Waiblingen, February 8, 1995                                              Andreas Stihl - D1/MTK-sc
 1995 Andreas Stihl                                                      Technical Documentation

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TI 14/1995 page 2

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