Stihl MS 661 C-M

16 MS 661, MS 661 C-M
Condition Cause Remedy
Engine running extremely rich, has
no power and a very low maximum
speed
Choke shutter does not open fully Check carburetor and choke shaft,
service or replace if necessary
Models with M-Tronic, carburetor
setting too rich
Check M-Tronic with STIHL MDG 1
and troubleshooting chart, b 8.7,
adjust or calibrate control unit,
b 8.1