Stihl MS 661 C-M Installation, Operation & Maintenance Manual

MS 661 C-M
English
53
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
Ignition system
Electronic magneto ignition
Fuel system
All position diaphragm carburettor with
integral fuel pump
Chain lubrication
Fully automatic, speed-controlled oil
pump with reciprocating piston-
additional manual oil flow control
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.
Rollomatic ES guide bars
Actual cutting length will be less than
listed bar length.
Specifications
A = 300 hours
B = 125 hours
C = 50 hours
Displacement: 5.56 cu. in.
(91.1 cm
3
)
Cylinder bore: 2.20 in. (56 mm)
Piston stroke: 1.46 in. (37 mm)
Engine power
according to
ISO 7293:
7.2 bhp (5.4 kW)
at 9,500 rpm
Idle speed: 2,800 rpm
Maximum speed
with bar and chain: 13,500 rpm
Spark plug
(suppressed):
Bosch WSR 6 F,
NGK BPMR 7 A
Electrode gap: 0.02 in. (0.5 mm)
Fuel tank capacity: 28.7 oz (0.85 l)
Oil tank capacity: 13.5 oz (0.325 l)
Dry, without cutting attachment
MS 661 C-M: 16.5 lbs. (7.5 kg)
MS 661 C-M with loop
handle 16.8 lbs. (7.6 kg)
Reduced kickback STIHL guide bars
(with green label)
Bar lengths: 40, 45, 50, 63 cm (16,
18, 20, 25 in.)
Pitch: 3/8" (9.32 mm)
Groove width: 1.3 mm (0.050 in) or
1.6 mm (0.063 in.)
Sprocket nose: 10
-
tooth for cutting
lengths 40, 45, 50 cm
(16, 18, 20 in.), 11
-
tooth
for cutting lengths 40,
45, 50, 63 cm (16, 18,
20, 25 in.)
Reduced kickback STIHL guide bars
(with green label)
Bar lengths: 40, 45, 50, 63, 71 cm
(16, 18, 20, 25, 28 in.)
Pitch: 3/8" (9.32 mm)
Groove width: 1.3 mm (0.050 in) or
1.6 mm (0.063 in.)
Sprocket nose: 10
-
tooth for cutting
length 63 cm (25 in.),
11
-
tooth for cutting
lengths 40, 45, 50, 63,
71 cm (16, 18, 20, 25,
28 in.)

Stihl MS 661 C-M Specifications

General

Idle speed	- RPM
Motor type	2-stroke motor
Chain pitch	3/8 \
Blade length	800 mm
Product color	Black, Grey, Orange
Automatic oiling	Yes
Engine displacement	91.1 cm³
Power source	Gasoline
Sound power level	118 dB
Vibration emission	6.9 m/s²
Sound pressure level	105 dB

Weight and Dimensions

Weight	7400 g