Stihl MS 661 C-M Instruction Manual

0458-759-8221-C
19
English 6 Kickback and Other Reactive Forces
result of the heat from the muffler and need no service or
maintenance. To reduce the risk of fire from the emission
of hot particles:
– Never operate your chain saw with a missing or
damaged spark arresting screen.
– If you experience loss of performance and suspect a
clogged screen, have your muffler serviced. Some
state or federal laws or regulations may require a
properly maintained spark arrester for certain uses.
￭ In California, it is a violation of § 4442 or § 4443 of the
Public Resources Code to use or operate gasoline-
powered tools on forest-covered, brush-covered or grass-
covered land unless the engine's exhaust system is
equipped with a complying spark arrester that is
maintained in effective working order. The owner/operator
of this product is responsible for properly maintaining the
spark arrester. Other states or governmental
entities/agencies, such as the Canadian Forest Service,
may have similar requirements.
– Do not use your chain saw around flammable
materials or around vegetation or brush when there
is a risk of fire or wildfire.
– Contact your local fire authorities or the Canadian
Forest Service if you have any question about laws
or regulations relating to fire protection
requirements.
DANGER
￭ To reduce the risk of electrocution:
6.1 Reactive Forces
WARNING
￭ Reactive forces may occur any time the chain is rotating.
Reactive forces can cause serious or fatal personal injury.
￭ The powerful forces used to cut wood can be reversed and
work against the operator. If the rotating saw chain is
suddenly and significantly slowed or stopped by contact
with any solid object such as a log or branch, or is
pinched, the reactive forces may occur instantly.
￭ These reactive forces may result in loss of control, which,
in turn, may cause serious or fatal injury.
– An understanding of the causes of these reactive
forces may help you avoid the element of surprise
and loss of control. Surprise contributes to
accidents.
The most common reactive forces are:
– Kickback
– Pull-in
– Pushback
– Never operate this chain saw in the
vicinity of any wires or cables that may
be carrying electric current.
– Never cut near power lines.
– Do not rely on the chain saw's insulation
against electric shock.
6 Kickback and Other Reactive Forces

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