Stihl MS 661 C-M User Manual

8 MS 661, MS 661 C-M
3. Troubleshooting
3.1 Clutch
Condition Cause Remedy
Saw chain stops under full load Clutch shoes badly worn Install new clutch
Clutch drum badly worn Install new clutch drum
Saw chain runs while engine is
idling
Engine idle speed too high Depending on model: Readjust idle
speed screw LA or check M-Tronic
Clutch springs stretched Replace the clutch springs or install
new clutch
Clutch springs broken Replace the clutch springs
Loud noises Clutch springs stretched Replace all clutch springs
Needle cage damaged Fit new needle cage
Clutch shoe retainer broken Install new retainer or clutch
Clutch shoes and carrier worn Install new clutch

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