Instruction Manual

MS 271, MS 271 C, MS 291, MS 291 C
English
54
EPA / CEPA
The Emission Compliance Period
referred to on the Emissions
Compliance Label indicates the number
of operating hours for which the engine
has been shown to meet Federal
emission requirements.
Category
Engine
STIHL single cylinder two-stroke engine
MS 271, MS 271 C
MS 291, MS 291 C
Ignition system
Electronic magneto ignition
Fuel system
All position diaphragm carburetor with
integral fuel pump
Chain lubrication
Fully automatic, speed-controlled oil
pump with rotary piston
Weight
Cutting Attachments
Recommended cutting attachments
conforming with the 45 degree
computed kickback angle requirement
of Section 5.11 of
ANSI/OPEI B175.1-2012 when used on
this model chain saw (see the chapter
on "Safety Precautions and Working
Techniques"):
Rollomatic E guide bars
Actual cutting length will be less than
listed bar length.
Saw chain .325"
Chain sprocket
Specifications
A = 300 hours
B = 125 hours
C = 50 hours
Displacement: 3.06 cu. in.
(50.2 cm
3
)
Cylinder bore: 1.76 in.
(44.7 mm)
Piston stroke: 1.26 in. (32 mm)
Engine power accord-
ing to ISO 7293:
3.5 hp (2.6 kW)
at 9,500 rpm
Idling speed: 2,800 rpm
Maximum permissible
speed with cutting
attachment: 13,000 rpm
Displacement: 3.39 cu. in.
(55.5 cm
3
)
Cylinder bore: 1.85 in.
(47.0 mm)
Piston stroke: 1.26 in. (32 mm)
Engine power accord-
ing to ISO 7293:
3.8 hp (2.8 kW)
at 9,500 rpm
Idling speed: 2,800 rpm
Maximum permissible
speed with cutting
attachment: 13,000 rpm
Spark plug
(suppressed):
Bosch WSR 6 F,
NGK BPMR 7 A
Electrode gap: 0.02 in. (0.5 mm)
Fuel tank capacity: 16.9 fl.oz (0.50 l)
Oil tank capacity: 8.1 fl.oz (0.24 l)
Dry, without cutting attachment
MS 271: 12.3 lbs.
(5.6 kg)
MS 291: 12.3 lbs.
(5.6 kg)
Reduced kickback STIHL guide bars
(with green label)
Bar lengths: 40, 45, 50 cm (16, 18,
20 in.)
Pitch: .325" (8.25 mm)
Groove width: 1.6 mm (0.063 in.)
Sprocket nose: 11-tooth
Low kickback STIHL saw chain (with
green label)
Rapid Micro 3 (26 RM3) Type 3634
Pitch: .325" (8.25 mm)
Drive link gauge: 1.6 mm (0.063 in)
7-tooth for .325" (spur sprocket)