Technical Information · issue 43 of 1995
New cut-off saw
IssueTI 43/1995
Full text
Page 1 of 12
Technical Information
43.95
New STIHL TS 460 cut-off saw, type 4221
1. General description
The new STIHL TS 460 adds a handy, powerful, With regard to the advanced technical design, the
allpurpose machine to the range of cut-off saws from TS 460 is characterized by complex function
STIHL. With an engine power of 3.5 kW (4.75 HP) groups containing fewer components and the ease
and a maximum torque of 4.6 Nm (0.46 kpm), this with which it can be repaired (short repair times).
new machine meets the high demands imposed,
for instance, in harsh continuous duty on the STIHL Other innovative features include the top handle
cart for cut-off saws, its low weight of only 11.3 kg designed in line with ergonomic requirements and
(24.9 lb) also making it eminently suitable for freehand the semi-automatic V-belt tensioner and the
cutting. decompression valve.
The machine can be used by construction com- The effective anti-vibration system with five rubber
panies, municipal authorities, highway departments, buffers considerably reduces the stress due to
water works and public utilities, companies trading vibrations.
in building materials and steel, garden and
landscape architects, fire services and emergency The slide control with function symbols on the
rescue services, as well as others. handle ensures convenient operation of the various
functions with just one hand.
Above all, it can be used for a variety of profes-
sional purposes in the construction of roads and
buildings, civil engineering and canal construction. Page 2 of 12
Technical Information 43.95 - Page 2
2. Technical description
2.1 Engine unit
The newly developed engine comprises a cylinder
(1) and two-part crankcase (2). The crankcase is
sealed off by two rotary shaft seals with additional
dust lip.
1
The cylinder is made from a special aluminium
alloy and the bore galvanically lined with an
extremely wear-resistant special alloy.
The piston is also made from a special aluminium
alloy and has two piston rings (1.5 mm/0.06 in thick).
The piston pin is secured by two hookless snap rings.
The crankshaft is made up of two drop-forgings 2
which are compressed onto the crankpin so that
they cannot twist before being finished. The conrod
and big-end bearing consequently cannot be re-
placed.
The crankcase is split into two halves and made
from diecast magnesium.
The engine housing is made of heavy-duty diecast
magnesium and extremely resistant to torsion. In
addition to the power unit, it also accommodates
other components and the function groups, such
as the ignition module, AV handle system and the
complete cast arm (with cutting wheel drive), as
well as the fuel tank with compensator reservoir.
The thermally insulated, dust-proof diaphragm
carburetor is installed in the engine housing and
fitted with a compensator.
The purpose of the compensator is to ensure a
constant proportion of fuel in the mixture, regard-
less of the degree of soiling of the air filter. The
distinct decline in performance as the air filter
becomes more and more soiled does not become
apparent until very much later in machines with
compensator, thus considerably extending the
intervals between cleaning and the service life of
the air filter system. The optimum performance is
restored as soon as the prefilter has been cleaned
or the main filter cartridge replaced. In this way,
the compensator helps to cut costs and permits
even more effective use of the machine. Page 3 of 12
Technical Information 43.95 - Page 3
,
Mechanical design of the compensator: The metering 3 2 1
chamber end cover of the carburetor includes a con-
nector which is linked with the intake manifold by a
hose. This ensures that the pressure is the same Pa
on the clean-air side of the air filter and at the
Pi
control diaphragm.
Function: The air flow is reduced by a soiled air
filter, thus causing the pressure to drop not only in
the venturi valve of the carburetor, but also on the Pr Pa
outside of the control diaphragm. The control
diaphragm moves outwards and the needle valve 11 == Luftfilter
Air filter 4
closes partly so that the supply of fuel is reduced. 22 == Vergaser
Carburetor
This prevents the fuel mixture from becoming too 33 == Zylinder
Cylinder
rich and eliminates the need for further adjustment 44 == Kraftstofftank
Fuel tank
of the high-speed adjusting screw as the air filter PiPi == Innendruck
Internal pressure
becomes increasingly soiled. Pa
Pa== Außendruck
External pressure
Pr == Druck
Pressure in the metering chamber
im Regelraum
The combustion air is taken in between the carbu-
retor box cover and shroud: the dust load is lower
here than anywhere else in the machine. The air
filter system is made up of a prefilter, main filter and
auxiliary filter. The filters have been specially
developed for use in the TS 460 and therefore meet
special standards with regard to their mechanical
design, materials and manufacturing quality:
• strength
Extremely uniform pore size, pleat position and
of the filter paper
• accuracy of the filterstrength 1 2 3
High compressive and dimensional
cartridges
1 = Prefilter
All three of the air filter components featured in this
2 = Main flilter
machine have been carefully matched as regards
3 = Auxiliary filter
the filter efficiency and air permeability.
In combination with the prescribed servicing and
maintenance work, they optimally protect the
engine unit against entrained dirt particles.
The filter cover is secured by means of a central
locking nut and can be removed quickly and easily
in order to clean the filter system.
As in all STIHL power tools, the ignition system is
based on the principle of magnetic induction and is
electronically controlled (breakerless).
An electronic speed limiter ensures that the maxi-
mum permissible speed is not exceeded. The con-
trol electronics is integrated into the ignition module
together with the ignition coil. The ignition module is
located on the outside of the flywheel, thus ensu-
ring easy access. It is not necessary to remove the
flywheel in order to dismantle the ignition module. Page 4 of 12
Technical Information 43.95 - Page 4
The starter is designed as a single-pawl system in
which the starting torque is positively transmitted
to the starter wheel via a plastic pawl inserted in
the rope rotor. The plastic pawl is the only wear
part here and can be replaced without difficulty.
The decompression valve reduces the compres-
sion force in the combustion chamber when star-
ting the cut-off saw, thus reducing the force requi-
red to pull the starter rope. This in turn reduces the
physical effort needed to start the machine and en-
hances its ease of operation. The valve is opened
manually and closes automatically as soon as
combustion of the fuel-air mixture starts.
Mechanical design and function
The housing (1) and piston (2) are the main ele-
ments of the decompression valve. The piston can
move in axial direction in the housing. A cone is
moulded onto the bottom end of the piston. Three
spring-loaded balls (3) at angles of 120° to one
another engage the piston in its upper and lower
holding positions. The complete decompression
valve is screwed into the cylinder.
3
337TI002
Before starting, the piston (2) is forced into the lower
holding position, the cone lifts off the housing (1)
and the decompression valve is open.
The crank is moved via the starter. The resultant
compression in the cylinder allows some of the
gas in the cylinder to escape through the opening
(see arrow).
The gas remaining in the cylinder is compressed,
3
the resultant pressure remaining below the closing 1
pressure of the decompression valve.
The pressure in the cylinder does not rise above
2
the closing pressure of the decompression valve
until a mixture capable of sustained combustion is
ignited. The piston (2) is then pressed upwards
and the opening is sealed by the cone.
337TI003 Page 5 of 12
Technical Information 43.95 - Page 5
The cutting wheel drive with V-belt pulley, V-belt
and V-belt tensioner is integrated into the cast arm
and thus protected against dust.
The V-belt tensioner is a new feature and consi-
derably enhances the convenience of operation.
The belt is tensioned simply by turning the tensioning
nut to the tensioning position. The V-belt is then
automatically tensioned correctly by the force of
a spring. Retensioning is even easier and quicker:
only three hexagon bolts on the V-belt guard need
be released and retightened. The tensioning nut
need not be adjusted.
The fuel tank has a capacity of 0.96 litres/2.02 pt
(960 ccm). The large filler opening is located on
top of the housing and fuel can easily be filled
without spilling (e.g. using the STIHL filling system) V-belt tensioner:
while the machine remains in its normal working setting the nut to the tensioning position
position.
The tank is vented via a compensator reservoir
which is installed in the engine housing together
with the fuel tank and thus well protected against
damage. If excess pressure builds up in the fuel
tank, fuel flows via a connecting hose into the com-
pensator reservoir, from where it is returned to the
tank by a negative pressure. This ensures that
neither fuel nor fuel vapours can escape into the
air.
The AV system comprises five rubber buffers
mounted on the engine housing, thus separating
the handle system from the engine unit and all
other assemblies mounted on the engine housing.
This considerably reduces the vibration loads on
the handle system.
The exhaust muffler is generously dimensioned
and ensures that the noise is reduced effectively.
The exhaust gases are emitted to the front.
2.2 Cutting wheel mount and wheel guard
The new cut-off saws are supplied for use with
cutting wheels measuring either 300 mm (12 in) or
350 mm (14 in) in diameter. The relevant attach-
ments ("Bearing with guard" dia. 300 mm and dia.
350 mm) are the same as in the present range of
cut-off saws. Page 6 of 12
Technical Information 43.95 - Page 6
3. Cutting wheels
All cutting wheels approved for use with the
TS 350, TS 360, TS 400, TS 510 and TS 760 can
also be used with the TS 460. STIHL cutting wheels
can be used to cut the following materials:
Composite wheels Diamond wheels
Asphalt Asphalt1)
Concrete Concrete2)
Stone Stone (hard rock)3)
Ductile cast pipes
Railway tracks
Steel
Abrasive concrete
Green concrete
Clay bricks and pipes
1)
All types and blends of asphalt commonly used for civil engineering,
building construction and road construction, including the respective
aggregates, as well as green concrete and screed topping
2)
Cast stones of all types commonly used for civil engineering and
building construction, including light reinforced concrete
3)
Natural stones of every hardness, including granite stones of the
hardest wear class, cast stones and concrete
4. Special accessories
All the special accessories already available can also be used with the TS 460, such as the cart for
cut-off saws with dirt guard and the "cutting depth limiter", "wet cutting", "water tank" and "pressurized
water tank" attachment kits.
The new attachment kit 4221 007 1000 must be ordered separately in order to secure the TS 460 on
the cart. All the requisite fastening elements are included with the attachment kit.
Cart for cut-off saw 4201 710 1403
Cart attachment kit - TS 460 4221 007 1000
Cutting depth limiter 4201 007 1026
Wet cutting attachment kit 4201 007 1038
Water tank attachment kit 4201 007 1048
Pressurized water tank attachment kit 4201 007 1037 Page 7 of 12
Technical Information 43.95 - Page 7
5. Technical data
5.1 Engine
STIHL single-cylinder two-stroke engine with specially impregnated cylinder bore
Displacement: 72.4 cm3 (4.42 cu. in)
Cylinder bore: 48 mm (1.89 in)
Piston stroke: 40 mm (1.57 in)
Output to DIN 70020: 3.5 kW (4.75 HP)
Max. torque: 4.6 Nm (0.46 kpm)
at n = 5500 rpm
Maximum spindle speed: 4900 rpm
Max. permissible speed: 9600 rpm (electronic speed limiter)
Maximum working speed: 9100 rpm
Average idling speed: 2500 rpm
Crankshaft: Three-part, drop-forged
Bearing: Crankshaft supported in heavy-duty deep groove ball bearings,
needle cages on small and big ends
Conrod length: 70 mm (2.75 in)
Starter system: Single-pawl system
with automatic rewinding of the starter rope
Starter rope: Dia. 4.5 mm, 1000 mm (3/16" x 3 5/16") long
Clutch: Centrifugal clutch without linings, dia. 80 mm (3.15 in)
Clutch engages at:
Crankcase leakage test
approx. 3200 rpm fo
at gauge pressure: pe = 0.5 bar
under vacuum: pn = 0.5 bar
5.2 Fuel system
Carburetor: All-position diaphragm carburetor with
integral fuel pump
Adjustment
High speed adjusting screw H: Back off approx. 1 turn
Low speed adjusting screw L: Back off approx. 1 turn
(starting with the screws tight against their seats)
Carburator leakage test
at gauge pressure: pe = 0.8 bar
Fuel tank capacity: 0.96 l/2.02 pt (960 ccm)
Fuel mixture: Brandname regular gasoline and brandname two-stroke engine oil
Mix ratio: 1:50 when using STIHL two-stroke engine oil 1:50
1:25 when using any other brandname two-stroke engine oil
Air filter: Prefilter (felt filter), main filter (paper filter cartridge),
auxiliary filter (flock-coated plastic material)
5.3 Ignition system
Principle: Transistorized (breakerless) magneto ignition
with integrated control and electronic speed limiter
Air gap: 0.2 - 0.5 mm (0.008 - 0.02 in)
Ignition timing: 2.8 - 3.2 mm (0.11 - 0.02 in) before UDC at n = 8000 rpm
Spark plug
(interference suppressed): Bosch WSR 6 F or
NGK BPMR 7 A
Electrode gap: 0.5 mm (0.02 in)
Spark plug thread: M 14 x 1.25
Thread length: 9.5 mm (0.37 in)
Heat range: 200
Lenght of ignition lead: 360 mm (14 3/16") Page 8 of 12
Technical Information 43.95 - Page 8
5.4 Weight
Machine without fuel,
complete with attachment
for cutting wheel, dia. 300 mm (12")
(without cutting wheel): 11.3 kg (24.9 lb)
5.5 Dimensions
Length with cutting wheel
(dia. 300 mm/12"): 750 mm (29.5 in)
Width with handle: 300 mm (12")
Height to handle: 370 mm (14.5 in)
5.6 Accessories
Combination wrench
Locking pin
Screwdriver
6. Special servicing tools fo
6.1 New special servicing tools for STIHL TS 460
Part name Item Part No. Application
Locking strip 1 4221 893 5900 Blocking the crankshaft
Size 21 insert, long 2 5910 893 5616 Releasing/tightening the clutch
1 2
Important note: Only the new locking strip
(Item 1) may be used to block the crankshaft of the
TS 460. The piston will be damaged if one of the
former locking strips in the range of STIHL special
servicing tools is used. The new locking strip can
be used for all STIHL engines with central, vertical
spark plug seat. Page 9 of 12
Technical Information 43.95 - Page 9
6.2 Existing special servicing tools
Part name Part No. Application Rem.
Press sleeve 1127 893 2400 Pressing in the rotary shaft seal
Assembly sleeve 1122 893 4600 Protecting the rotary shaft seal
on the clutch side
Puller 0000 890 4400 Removing rotary shaft seals
- Jaws (No. 3.1 + 4) 0000 893 3706
- Jaws (No. 6) 0000 893 3711
Puller 1116 893 0800 Removing the flywheel
Crimping tool 5910 890 8210 Attaching connectors to electrical
wiring
Assembly pin 1108 893 4700 Fitting the piston pin
Strap retainer 0000 893 2600 Tensioning the piston rings
Wooden assembly block 1108 893 4800 Positioning the piston
Carburetor and
crankcase tester 1106 850 2905 Testing for leaks (crankcase
and carburetor)
- Connector 0000 855 9200
- Fuel line 1110 141 8600
Vacuum pump 0000 850 3501 Testing for leaks (crankcase)
Sealing plate 0000 855 8106 fo
Sealing the exhaust port when testing
for leaks
Test flange 1119 850 4200 Testing for leaks
- Bushings 0000 963 1008
- Screws 9043 319 8100
Setting gauge 1111 890 6400 Setting the air gap between ignition
module and flywheel
Size 13 insert 5910 893 5608 Nut for flywheel
Size 17 insert 5910 893 5610 Nut for starter wheel
Torque wrench 5910 890 0301/02 Screw connections (0.5 to 18 Nm) 1)2)
Torque wrench 5910 890 0311/12 Screw connections (6 to 80 Nm) 1)2)
Insert 1-5x 120 x 6.3 0812 542 2104 Tightening the socket-head screws
with internal star
Assembly hook 5910 893 8800 Removing the pick-up bodies
Assembly tool 12 5910 890 2212 Inserting the snap rings in
the piston eye
Assembly hook 5910 890 2800 Detaching the clutch spring
(clutch)
Assembly tool 0000 890 2201 Flaring the rope guide bush
Screwdriver with
T-handle Q1-5 x 150 5910 890 2400 For all hexagon socket-head screws
Pliers A10 0811 611 8200 Outer circlip on the
thrust washer
Pliers C19 0811 641 8380 Inner circlip on the spindle bearing
and crankshaft
Press arbor 1119 893 7200 Inserting and removing the needle sleeve
in the V-belt pulley
Press arbor 4119 893 7200 Pressing out the deep groove ball bearings
in the spindle bearing
Remarks
1) A torque wrench must be used to tighten DG screws
2) Versions 5910 890 0302 and 5910 890 0312 are fitted with an
optical/acoustic warning device Page 10 of 12
Technical Information 43.95 - Page 10
7. Repairs
No. Repair procedure TS 460
The national safety regulations and the safety in- 4221
structions in the Owner’s Manual must be observed
if the cut-off saw has to be started up during repairs
or maintenance work. 1 Installing and removing engine 5
The decompression valve can be removed and
installed with the aid of a standard long socket 2 Guard 5
wrench insert, width across flats 13 mm (to
ISO 2725 or DIN 3124). Tightening torque 14 Nm. 3 Motor arm 25
In order to check the engine for leaks, it is advisable 4 V-belt pulley on the
to remove the decompression valve temporarily and cutting wheel 10
to seal the threaded bore with plug 4221 025 2200.
5 Shaft 15
7.1 Repair times 6 Deep groove ball bearing
(on the cutting wheel) 15
The repair times specified are based on the times 7 V-belt pulley
required by duly trained professionals with a (on clutch side) –
perfectly equipped service shop.
8 Pin –
The repair times are specified in minutes.
9 Deep groove ball bearing
Note: The table of repair times for cut-off saws of
series TS 460 can be transferred to the STIHL table
(on clutch side) –
10 Cast arm 15
of repair times (page 9) (either cut along the dotted
line and paste into the table or transfer the values 11 Pressure-testing the crankcase* 140
by hand).
12 Pressure-testing the
crankshaft, bearing* 140
13 Pressure-testing the sealing rings* 65
14 Testing the crankcase for
leaks, trial run 30
15 Pressure-testing the cylinder,
pistons* 60
16 Ignition system, contact* 20
17 Fuel supply, venting the tank,
tank, trial run 20
18 Pressure-testing the
manifold or flange 20
19 Carburetor, testing* 35
20 Starter with trial run 15
21 Clutch, trial run 20
22 Handle frame, handle, handle
housing, shroud, with trial run
in each case 25
23 Muffler 10
24 Air filter 5
25 Stop switch with trial run 10
* Trial run under load ✂ Page 11 of 12
Technical Information 43.95 - Page 11
5.4 Tightening torques
DG screws are screwed into the plastic parts of the TS 460. These screws are self-tapping when screwed
into a material for the first time. The material undergoes permanent deformation. The screws can be remo-
ved and retightened as often as desired. The strength of the screw connection is not impaired as long as the
specified tightening torque is maintained. This consequently makes it imperative to use a torque wrench.
Fastener Thread For Tightening Rem.
size component torque
Nm
Socket-head screw IS-M5x58x22 Cylinder/crankcase 10.0
Socket-head screw IS-M5x35x22 Crankcase/engine housing 10.0
Socket-head screw IS-M5x20 Spacer flange 10.0
Clutch 40.0
Socket-head screw IS-M5x20 Cast arm/engine housing 10.0
Hexagon nut M10x1 Starter wheel 40.0
Collar nut M8x1 Flywheel 25.0
Socket-head screw IS-M5x14 Filter base/engine housing 6.0
Socket-head screw IS-M5x58x35 Connector/carburetor/flange 5.0
Socket-head screw IS-M5x14 Housing cover/engine housing 6.0 1)
Socket-head screw IS-M5x20 Ignition module 8.0 1)
Socket-head screw
Socket-head screw
IS-M5x20
IS-M5x14
Fan cover
Muffler/cylinder
6.0
10.0
Socket-head screw IS-M5x35 Muffler/engine housing 10.0 2)3)
Socket-head screw IS-M4x6 Deflector/muffler 2.5
Socket-head screw IS-M5x14 Tensioner 4.0
Socket-head screw IS-M4x6 Short circuit wire/ground 2.5
Socket-head screw IS-DG5x24 Handle molding/handle 3.0
Socket-head screw IS-M5x14 Rubber buffer/engine housing 8.0
Socket-head screw IS-DG5x24 AV molding/handle 3.0
Socket-head screw IS-M5x14 Rubber buffer/handle bracket 8.0
Socket-head screw IS-M5x14 Support/handle bracket 8.0
Socket-head screw IS-M5x14 Handle/handle bracket 8.0
Socket-head screw IS-DG5x24 Handle/handle 8.0
Socket-head screw IS-M5x20 Shroud/engine housing 6.0
Socket-head screw IS-M5x20 Carburetor box cover 6.0
Socket-head screw IS-M5x20 Starter cover 6.0
M14x1,25 Spark plug 27.5
Decompression valve 14.0
When screwing the DG screws into a precut thread:
• slightly
Insert the screw in the hole and turn anticlockwise until it drops
into the hole in axial direction.
• Turn the screw clockwise and tighten with the specified torque.
This procedure ensures that the screw engages in the existing thread and does not cut a new thread,
for this would weaken the screw connection.
Remarks
1) Ensure that a washer is used
2) Screw must be secured with adhesive 0786 111 1101 (Loctite 243)
3) Unsure that tensioning washer 9331 630 0120 is used
Note: Screws which have been secured with adhesive can be released more easily if the connection is gent-
ly heated with a blow-drier. Great care must be taken when heating plastic components! Page 12 of 12
Technical Information 43.95 - Page 12
8. Servicing aids
Part name Part No. Application
Lubricating grease 0781 120 1111 Rotary shaft seals, needle sleeve in the
Threadlocking adhesive, V-belt pulley
solid (Loctite 270) 0786 111 1109 Fastening screw for throttle shutter, sealing
Threadlocking adhesive plug in carburetor
(Loctite 243) 0786 111 1101 Screw connection, muffler/engine
housing
Dirko sealing compound, 100 g 0783 830 2120 Sealing faces on crankcase, exterior of
rotary shaft seals
STIHL multi-purpose grease 0781 120 1109 High-voltage connection on ignition module
HTR ignition lead, 10 m (33’) 0000 930 2251
Gasket Chart 0457 281 6202
Waiblingen, September 6,1995 Andreas Stihl - D1/MTK-sc
1995 Andreas Stihl Technical Documentation 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.