Instruction Manual

Original Instruction ManualPrinted on chlorine-free paper
Printing inks contain vegetable oils, paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2020 0458-737-0121-B. VB0.J20. 0000006607_011_GB
MS 231, MS 231 C, MS 251, MS 251 C
English
1
This instruction manual is protected by copyright. All rights reserved, especially the rights to reproduce, translate and process
with electronic systems.
Contents
Dear Customer,
Thank you for choosing a quality
engineered STIHL product.
It has been built using modern
production techniques and
comprehensive quality assurance.
Every effort has been made to ensure
your satisfaction and trouble-free use of
the product.
Please contact your dealer or our sales
company if you have any queries
concerning this product.
Your
Dr. Nikolas Stihl
Guide to Using this Manual 2
Safety Precautions 3
Reactive Forces 8
Working Techniques 9
Cutting Attachment 18
Mounting the Bar and Chain (side
chain tensioner) 18
Mounting the Bar and Chain (quick
chain tensioner) 19
Tensioning the Saw Chain (side
chain tensioner) 21
Tensioning the Saw Chain (quick
chain tensioner) 22
Checking Chain Tension 22
Fuel 22
Fueling 23
Chain Lubricant 25
Filling Chain Oil Tank 25
Checking Chain Lubrication 26
Chain Brake 26
Winter Operation 27
Starting / Stopping the Engine 28
Operating Instructions 32
Taking Care of the Guide Bar 33
Shroud 34
Air Filter System 34
Cleaning the Air Filter 35
Adjusting the Carburetor 36
Spark Plug 37
Storing the Machine 38
Checking and Replacing the Chain
Sprocket 38
Maintaining and Sharpening the
Saw Chain 39
Maintenance and Care 43
Minimize Wear and Avoid Damage 45
Main Parts 46
Specifications 47
Ordering Spare Parts 48
Maintenance and Repairs 49
Disposal 49
EC Declaration of Conformity 49