Stihl MS 661 C-M Instruction Manual

0458-759-8221-C
52
English 21 Cleaning
21.4 Cleaning the Spark Plug
WARNING
To reduce the risk of fire and burn injury, use only spark
plugs authorized by STIHL. Always press the spark plug
boot snugly onto the spark plug terminal.
WARNING
Do not use a spark plug with a detachable SAE adapter
terminal (1). Arcing may occur that could ignite combustible
fumes and cause a fire. This can result in serious injuries or
damage to property. Only use resistor type spark plugs with
solid, non-threaded terminals (2).
Using the wrong fuel mix (too much engine oil in the
gasoline), a dirty air filter, and unfavorable running
conditions (running for extended periods at partial throttle)
can affect the condition of the spark plug and cause deposits
to form on the insulator nose, degrading performance.
To clean the spark plug:
► Shut off the engine, @ 15.1.
► Engage the chain brake, @ 12.1.
► Allow the chain saw to cool down.
► Remove the filter cover (1).
► Remove the spark plug boot (2) by pulling the tab.
► Clean the area around the spark plug with a damp cloth or
soft brush.
► Unscrew the spark plug.
► Clean the spark plug with a damp cloth.
► If the spark plug is corroded, install a new spark plug.
► If damp, dry the spark plug thoroughly before re-inserting
it.
► Insert the spark plug and tighten it down firmly.
► Connect the spark plug boot (2) and press it down firmly.
► Mount the filter cover (1).
0000-GXX-1662-A0
1
2
2
1
0000-GXX-A379-A0
2
0000-GXX-A380-A0

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