FS 40, FS 40 C, FS 50, FS 50 C
English
37
FS 40, FS 40 C
FS 50, FS 50 C
Ignition System
Electronic magneto ignition
Fuel System
All position diaphragm carburetor with 
integral fuel pump
Weight
Dry, without cutting attachment and 
deflector
Overall length
without cutting attachment
Users of this unit should carry out only 
the maintenance operations described 
in this manual. STIHL recommends that 
other repair work be performed only by 
authorized STIHL servicing dealers.
Warranty claims following repairs can be 
accepted only if the repair has been 
performed by an authorized STIHL 
servicing dealer using genuine STIHL 
replacement parts.
Genuine STIHL parts can be identified 
by the STIHL part number, the 
{ logo and, in some cases, by 
the STIHL parts symbol K. The 
symbol may appear alone on small 
parts.
Displacement: 1.66 cu. in 
(27.2 cc)
Bore: 1.34 in (34 mm)
Stroke: 1.18 in (30 mm)
Engine power to 
ISO 8893:
0.9 HP (0.7 kW) 
at 8,500 rpm
Idle speed: 2,800 rpm
Cut-off speed (rated): 10,000 rpm
Max. output shaft 
speed (cutting 
attachment): 10,600 rpm
Displacement: 1.66 cu. in 
(27.2 cc)
Bore: 1.34 in (34 mm)
Stroke: 1.18 in (30 mm)
Engine power to 
ISO 8893
1.1 HP (0.8 kW) 
at 8,500 rpm
Idle speed: 2,800 rpm
Cut-off speed (rated): 10,000 rpm
Max. output shaft 
speed (cutting 
attachment): 10,600 rpm
Spark plug (resistor 
type): NGK CMR 6 H
Electrode gap: 0.02 in (0.5 mm)
Fuel tank capacity: 11.5 fl.oz (0.34 l)
Standard version
FS 40: 9.7 lbs 
(4.4 kg)
FS 50: 9.7 lbs 
(4.4 kg)
FS 50: with long 
shaft
9.9 lbs 
(4.5 kg)
Versions with Easy2Start
FS 40 C: 9.9 lbs 
(4.5 kg)
FS 50 C: 9.9 lbs 
(4.5 kg)
FS 50 C: with long 
shaft
10.1 lbs 
(4.6 kg)
FS 40, 
FS 40 C: 57 in (1450 mm)
FS 50, 
FS 50 C: 57 in (1450 mm)
FS 50, 
FS 50 C:
with long 
shaft 65 in (1650 mm)
Maintenance and Repairs