Stihl MS 661 C-M Instruction Manual

0458-759-8221-C
2
English 1 Introduction
Thank you for your purchase. The information contained in
this manual will help you receive maximum performance and
satisfaction from your STIHL chain saw and, if followed,
reduce the risk of injury from its use.
SAVE THIS MANUAL!
Have your authorized STIHL servicing dealer show you how
to operate your chain saw. All safety precautions that are
generally observed when working with an axe or a hand saw
also apply to the operation of chain saws. Observe all
applicable federal, state and local safety regulations,
standards and ordinances.
Do not lend or rent your chain saw without this instruction
manual. Allow only persons who have the proper training
and fully understand the information in this manual to
operate the chain saw.
For further information, or if you do not understand any of
the instructions in this manual, please go to www.stihl.ca or
contact your authorized STIHL servicing dealer.
2.1 Signal Words
This manual contains safety information that requires your
special attention. Such information is introduced with the
following symbols and signal words:
20 Storing
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
20.1 Storing the Chain Saw
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
21 Cleaning
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
21.1 Cleaning the Chain Saw
. . . . . . . . . . . . . . . . . . . . . . . . . . . 50
21.2 Cleaning the Guide Bar and Saw Chain
. . . . . . . . . . . . 50
21.3 Cleaning the Air Filter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
21.4 Cleaning the Spark Plug
. . . . . . . . . . . . . . . . . . . . . . . . . . . 52
22 Inspection and Maintenance
. . . . . . . . . . . . . . . . . . . . . . . . 53
22.1 Inspection and Maintenance Chart
. . . . . . . . . . . . . . . . . 53
22.2 Inspecting and Maintaining the Chain Saw
. . . . . . . . . 54
22.3 Inspecting and Maintaining the Chain Sprocket
. . . . . 54
22.4 Inspecting and Maintaining the Guide Bar
. . . . . . . . . . 54
22.5 Inspecting, Maintaining and Sharpening the Saw
Chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
23 Troubleshooting Guide
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
23.1 Chain saw
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
23.2 Clearing the Combustion Chamber
. . . . . . . . . . . . . . . . . 60
24 Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
24.1 CEPA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
24.2 STIHL MS 661 C-M
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
24.3 Chain Sprockets
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
24.4 Minimum Groove Depth of Guide Bars
. . . . . . . . . . . . . 61
24.5 Depth Gauge Setting
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
24.6 Symbols on the Chain Saw
. . . . . . . . . . . . . . . . . . . . . . . . . 61
24.7 Engineering Improvements
. . . . . . . . . . . . . . . . . . . . . . . . . 62
25 CSA Standard
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
25.1 Chain Saw Class
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
25.2 Definition of the Chain Saw Classes according to
CSA Z62.1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
26 Combinations of Guide Bars and Saw Chains
. . . . . . 63
26.1 STIHL MS 661 C-M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
27 Replacement Parts and Equipment
. . . . . . . . . . . . . . . . . 65
27.1 Genuine STIHL Replacement Parts
. . . . . . . . . . . . . . . . 65
28 Disposal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
28.1 Disposal of the Power Tool
. . . . . . . . . . . . . . . . . . . . . . . . . 65
29 Emission Control Warranty
. . . . . . . . . . . . . . . . . . . . . . . . . 65
29.1 STIHL Limited Federal Emission Control
Warranty Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
1 Introduction
Because a chain saw is a high-speed wood-
cutting tool, special safety precautions must be
observed to reduce the risk of personal injury.
Read this instruction manual thoroughly before
use and periodically thereafter. Follow all safety
precautions. Careless or improper use of the
chain saw can cause serious or fatal injury.
2 Guide to Using this Manual

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