Technical Information · issue 1 of 2002
New Brushcutters FS 100, 110
IssueTI 1/2002
Full text
Page 1 of 14
Technical Information
01.2002
New STIHL FS 110 Brushcutters – Series 4180
Contents
1. Technical description
2. Specifications
3. Cutting tools
4. Accessories
5. Service accessories
6. Service notes
7. Spare parts
FS 110 R FS 110 RT FS 110
The new STIHL FS 110 brushcutter with The powerhead features a displacement of
4-MIX engine is the latest model in the professional 1.92 cu.in (31.4 cm³) and a power output of
and semi-professional line of trimmers. 1.34 HP (1 kW).
The new 4-MIX engine operates with the patented Typical applications are the same as those for the
STIHL lubrication system. The engine operates model FS 85.
according to the four-stroke cycle principal but uses
the same fuel-oil mix as STIHL two-stroke engines.
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)m~ge 2 Technical Information 01.2002
1. Technical description 1.1.2 Engine control
1.1 STIHL 4-MIX engine
The 4-MIX engine works with mixed lubrication. 7
Unlike a conventional four-stroke cycle engine,
the 4-MIX engine does not have any supply of oil in
the crankcase. The engine is lubricated entirely with
a mixture of gasoline and two-cycle engine oil. 1 2
This design yields the following advantages: 6
. Same fuel as other STIHL equipment 5
. Lower fuel consumption
. Can be operated in all positions 4
. Fewer emissions
. Good acceleration
. Compact size – attractive design 3
254TI011 KN
. Advantageous power-to-weight ratio
. Easy maintenance – easy to service
. Lower noise level
. fo
Overhead valves (OHV), one inlet valve (1) and
one exhaust valve (2)
. Lower vibrations . Valve actuation via crankshaft gear (3), cam
. Easy starting gear (4), valve lifter (5), pushrod (6) and
rocker arm (7)
1.1.1 Engine design
Single-cylinder engine with overhead valves.
Cylinder head, cylinder and upper half of crankcase
have been combined into a single unit.
The crankcase is horizontally split along the
crankshaft.
254BA016 KN
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Technical Information 01.2002 Page 3
1.1.3 Engine lubrication
The engine is lubricated in two phases during each
revolution of the crankshaft.
Phase 1 Phase 2
The piston travels to top dead center. The piston descends to bottom dead center.
5 fo
254TI019 KN
254TI017 KN
The increase in volume in the crankcase produces Excess pressure builds up in the crankcase due to
a vacuum. The mixture of air, fuel and oil is drawn the decrease in volume.
from the intake duct (1) via the lubrication port (2), The mixture of air, fuel and oil in the crankcase is
valve train (3) and cam gear (4) into the crankcase
returned to the intake duct via the cam gear, valve
(5). The oil contained in this mixture lubricates the
train and lubrication port, re-oiling each lubricating
crankshaft, cam gear, valve train and cylinder wall.
point in the process.
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1.2 Fuel filler cap
The new fuel filler cap with hinged grip permits quick
and easy handling.
1.2.1 Opening the cap: 1.2.2 Closing the cap
254TI020 KN
254TI022 KN
. Raise the grip until it is upright . Fit the cap - grip upright -marks
must line up
.
Turn the cap clockwise as far as
stop (approx. a quarter turn)
254TI021 KN
. Turn the cap counterclockwise 254TI023 KN
(approx. a quarter turn)
. Remove the filler cap
. Fold the grip flush with the top of the
cap
If the grip does not lie completely flush with the cap
and the detent on the grip does not engage the
recess in the filler neck, the cap is not properly
seated and tightened and you must repeat theabove
steps.
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Technical Information 01.2002 Page 5
2. Specifications 2.2 Fuel system
Carburetor: All-position diaphragm carburetor with
2.1 Powerhead integral fuel pump
Single-cylinder four-stroke engine with mixed
lubrication
Displacement: 1.92 cu. in (31.4 cm3) Idle speed screw L
(standard setting): max. 3/4 turn
Bore: 1.57 in (40 mm)
(up to the stop)
Stroke: .98 in (25 mm)
High speed adjusting
Engine power to 1.34 HP (1 kW)
screw H (standard setting): max. 3/4 turn
ISO 8893 at 7,000 rpm
(up to the stop)
Idle speed: 2,800 rpm Cutoff speed range without
Rewind starter: Single pawl system cutting tool
Starter rope: Diameter .120 in, (electronic speed
33.46 in long governor): 10,500 +/- 500 rpm
(dia. 3.0 mm, Fuel tank capacity: 18.0 fl.oz (.53 l)
850 mm long)
Clutch:
Engages at: 3,700 rpm Fuel mix:
Valve clearance, Mid-grade gasoline (89 octane) and STIHL
Inlet valve:
Exhaust valve:
.004 in (.10 mm)
.004 in (.10 mm)
“Low-Smoke“ 2-cycle engine oil or equivalent
engine oil for 2-cycle air-cooled engines with
classification ISO-L-EGD
Mix ratio:
50:1 for STIHL “Low-Smoke“ 2-cycle engine oil and
equivalent brandname ISO-L-EGD oils
2.3 Ignition system
Ignition module: Electronic with integral
speed governor
Spark plug NGK CMR 6 H
(suppressed): (note: 10 mm thread dia.)
Electrode gap: .028 in (.7 mm)
2.4 Gearbox
Gear ratio: 1:1.4
2.5 Weight
Without cutting tool and
deflector
FS 110: 12.1 lb (5.5 kg)
FS 110 R: 11.7 lb (5.3 kg)
FS 110 RT 12.5 lb (5.7 kg)
FS 110 RX: 11.2 lb (5.1 kg)
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3. Cutting tools
The following cutting tools are approved
1 STIHL-SuperCut 20-2 4002 710 2184 1 2
2 STIHL-AutoCut 25-2 4002 710 2191
3 STIHL-AutoCut 30-2 4002 710 2187
4 STIHL-TrimCut 30-2 4002 710 2193
5 STIHL-PolyCut 20-3 4002 710 2189
1) 2) 3 4
6 Grass cutting blade 230-4 4001 713 3801
7 Grass cutting blade 230-8 1) 2) 4001 713 3803
Brush knife 250-3 1) 2)
8 4112 713 4100
9 Circular saw blade 200 4112 713 4201
5
(scratcher tooth) 1) 3)
10 Circular saw blade 200 4112 713 4203
(chisel tooth) 1) 3)
6
1) Not approved for FS 110 RX
2) Not approved for FS 110 without barrier bar
3) Not approved for FS 110 with loop handle
7
fo 8
"All of the above cutting attachments must be used
with the appropriate deflector or limit stop.
See Cutting Attachment catologue"
9 10
393TI014 KN
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Technical Information 01.2002 Page 7
4. Accessories
4.1 General
Part name Part No. Application
Transport guard for metal 4116 790 3901 Grass cutting blade 230-2, 230-4, 230-8,
cutting tools brush knife 250-3, circular saw blade 200
4119 790 3906 Grass cutting blade 230-2, 230-4, 230-8,
brush knife 250-3
4119 790 3901 Circular saw blade 200
Starter rope 0000 195 8203 Rewind starter
STIHL gear lubricant for Gearhead
brushcutters
- 80 g tube 0781 120 1117
- 225 g tube 0781 120 1118
4.2 Nylon line for mowing heads
Line diameter / color Use
.095“ / orange SuperCut 20-2, AutoCut 25-2, AutoCut 30-2, TrimCut 30-2, PolyCut 20-3
.105“ / red PolyCut 20-3
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5. Service accessories
5.1 Special servicing tools
To be purchased specially for model FS 110
Part name Part No. Application
Compression tester 5910 850 2000 Test the cylinder compression
Extension piece 4180 893 4400 Force out the clutch drum and AV element in
combination with puller 4112 890 4502
Circlip Mounting tool, dia. 8 5910 890 2206 Fit hookless wire retaining rings (piston boss)
Sleeve 5910 893 1703 Fit hookless wire retaining rings (piston boss) in
combination with old mounting tool 5910 890 2208
Feeler gauge 0.1 mm 4180 893 6400 Check and adjust valve clearance
Piston stop 4180 890 2700 Block crankshaft
The existing special servicing tools are listed in the service manual for STIHL series 4180 powerhead.
5.2 Servicing aids
Part name Part No. Application
Set of parts for adjusting valve 4180 007 1005 Checking, adjusting valve clearance
clearance (consists of feeler gauge and valve cover gaskets)
Set of gaskets 4180 007 1006 Engine
Set of carburetor parts 4180 007 1060 Carburetor
Lubricating grease (225 g tube) 0781 120 1111 Oil seals
Dirko sealant 0783 830 2120 Sealing faces between engine pan /
cylinder and between cylinder / cam gear cover
Standard commercial Cleaning the crankshaft stub
solvent-based degreasant
containing no chlorinated or
hydrogenated hydrocarbons
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Technical Information 01.2002 Page 9
6. Service notes
Specific national safety regulations and the safety
instructions in the Owner’s Manual must be
observed when starting the machine. 6
6.1 Check valve clearance
5
The valve clearance should be checked once after
approx. 135 hours of operation and adjusted if
necessary. The valve clearance may only be 4
254TI002 KN
checked and adjusted when the engine is cold. Kit 4
4180 007 1005 "Parts for adjusting valve clearance"
can be used for this purpose. The kit comprises a
setting gauge, sealing washer and gasket. . Undo screws (4)
. Remove shroud (5)
6.1.1 Preparatory steps
. Unplug spark plug boot (6)
. Clean area around spark plug
3 . Unscrew spark plug
1 1
7
2
8
254TI001 KN
. Move stop switch in direction of c arrow
towards STOP $ 9
. Undo screws (1)
. Remove starter cover (2) from housing
. Undo screw (3)
254TI003 KN
. Clean area around valve cover
. Undo screw (7)
. Remove sealing washer (8), valve cover (9) and
gasket (10)
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6.1.2 Top dead center
Top dead center (TDC) is defined as the point at
which the piston ends its upward stroke and starts
its downward stroke. In a 4-cycle engine, the power
stroke occurs once in every two revolutions of the
crankshaft. The piston consequently passes
through top dead center twice in order to execute
one power stroke. Refer to the STIHL Service
Training System "Carburetor", under the heading
four-stroke principle.
Top dead center, valve overlap Top dead center, ignition
2
2
3 3
1 1
254TI010 KN
254TI009 KN
Cam (1) points upwards. Cam (1) points downwards.
The rocker arms (2) and valve stems (3) move up The rocker arms (2) and valve stems (3) do not
and down (see arrows above) when the crankshaft move up and down when the crankshaft is turned
is turned back and forth a few degrees. back and forth a few degrees.
This represents the change of cycle between the This represents the change of cycle between the
exhaust stroke and intake stroke. compression stroke and power stroke.
The valve clearance must be set at top dead
center for the compression/ignition stroke.
The intake and exhaust valves are fully closed in
this position.
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Technical Information 01.2002 Page 11
6.1.3 Determine top dead center 6.1.4 Check valve clearance
2 2
1
1 3
254TI008 KN
2
. Turn crankshaft until arrow on flywheel (1) is
lined up with the right-hand screw (2) of the
ignition coil
The piston is now at the top dead center, valve
254TI005 KN
1
overlap or ignition.
. foInsert feeler gage (1) between rocker arm (2)
and valve stem (3). The valve clearance is
correct when there is a slight tension on the
feeler gauge.
The valve clearance must be adjusted if it is found
to be too loose or too tight.
6.2 Set valve clearance
n 254TI004 KN
. Turn the crankshaft back and forth a few
degrees – if the rocker arms and valve stems 2
move up and down (see arrows), the piston is in
the top dead center for valve overlap
. Turn the crankshaft once more until the arrow is
again lined up with the right-hand screw of the
254TI006 KN
ignition coil
1
Rocker arms and valve stems do not move and the
piston is now in the top dead center for ignition. . Insert feeler gage (1) between rocker arm and
. Turn the crankshaft back counterclockwise valve stem
approx.1/4 turn and then slowly turn it clockwise Depending on the valve clearance:
again until the arrow is lined up with the right-
hand screw head. . Turn nut (2) clockwise to reduce the valve
clearance or counterclockwise to increase it –
the feeler gage must have a slight tension on it
The crankshaft must be turned backwards in order when it is pulled through
to eliminate the backlash from the timing gear.
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. Turn the crankshaft through two revolutions
until the arrow on the flywheel is once again
lined up with the right-hand screw of the ignition
coil
. Check the valve clearance again and re-adjust if
necessary
6.3 Assembly
Use the new gaskets in kit 4180 007 1005
"Parts for adjusting valve clearance".
254TI007 KN
. Fit gasket (1) in position (arrows)
. Fit valve cover and tighten screw with a torque
of 3.5 Nm
. Screw in spark plug, fit shroud and plug in spark
plug boot
. Fit starter cover and tighten down screws
. Start engine and let it warm up
. Check engine for proper idle, acceleration and
full throttle operation
. Switch off engine
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Technical Information 01.2002 Page 13
6.4 Adjust throttle cable
After fitting the bike handle, the throttle cable must
be set to a defined position on the control handle
with integrated throttle cable adjustment. STO
254TI014 KN
1
. Squeeze both the throttle trigger interlock and
the throttle trigger completely (full throttle) – this
254TI012 KN
ensures that the throttle cable is set correctly –
the detent moves away from the edge of the
groove
. On the control handle, check that the detent
underneath the throttle trigger interlock is at the
bottom (arrow) end of the groove
254TI015 KN
n 254TI013 KN
If the detent is not at the end of the groove:
. Push the detent towards the end of the groove
with a screwdriver
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6.5 Tightening torques
The tightening torques for model FS 110 Code Type of Repair FS 110
are listed in the service manual for the STIHL series FS 110 T
4180 powerhead. FC 110
1 Crankcase, Crankshaft, 1.5
6.6 Service note Crankshaft Bearings
The service manual for the STIHL series 4180 2
powerhead is available for servicing and repair of 3 Crankcase Gasket/Sealing 1.3
the STIHL FS 110. Refer also to the STIHL Service 4 Crankshaft Seals (includes 0.9
Training System "Troubleshooting". pressure & vacuum testing)
5 Cylinder, Piston, Replace Valves 1.8
6.7 Repair times
6 Ignition Module 0.4
The specified repair times assume that the work is
7 Fuel Hose 0.4
performed by trained personnel in a properly
equipped service workshop. 8 Replace Gear Box/Arbor Assy. 0.4
9 Repair/Rebuild Carburetor 0.7
The repair times are given in tenths of an hour
(0.1 = 6 minutes). 10 Replace Carburetor, Carburetor 0.4
Jet (if tried to repair use code 9)
This table for the FS 110 can be added to the STIHL
11 Front Handle, Throttle Control, 0.4
repair times table.
Throttle Cable
7. Spare parts
12
Recoil Starter 0.4
13 Clutch, Clutch Drum, 0.5
Clutch Drum Housing
A separate illustrated parts list is available for the
new machine. 14 Drive Tube, Drive Shaft 0.4
15 Muffler 0.4
16 Air Filter, Filter Cover, Tank Cap, 0.4
Tank Vent, Fuel Filter, Spark
Plug, Cutting Attachment,
Miscellaneous Minor Repairs
17 Stop Switch 0.4
18 Fuel Tank 0.4
19 Repair Gear Box, Gears, 0.8
Arbor Bearings
20 All Other Repairs 0.5
50 No Labor 0.0
✂
© 2002 Andreas Stihl AG & Co. Technical Documentation
Waiblingen D1/MTK-bl 7472
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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.