FS 131, FS 131 R
English
11
superficial cracks. Such attachments 
may shatter at high speed and cause 
serious or fatal injury.
WARNING
When using rigid blades, avoid cutting 
close to fences, sides of buildings, tree 
trunks, stones or other such objects that 
could cause the power tool to kick out or 
could cause damage to the blade. 
STIHL recommends use of the nylon line 
heads for such jobs. In addition, be alert 
to an increased possibility of ricochets in 
such situations.
WARNING
If a rotating metal blade strikes a rock or 
other hard object, sparks may be 
created, which can ignite flammable 
materials under certain circumstances. 
Flammable materials can include dry 
vegetation and brush, particularly when 
weather conditions are hot and dry. 
When there is a risk of fire or wildfire, do 
not use metal blades around flammable 
materials or around dry vegetation or 
brush. Contact your local fire authorities 
or the U.S. Forestry Service if you have 
any question about whether vegetation 
and weather conditions are suitable for 
the use of a metal blade.
WARNING
If the head, blade or deflector becomes 
clogged or stuck, always shut off the 
engine and make sure the cutting 
attachment has stopped before 
cleaning. Grass, weeds, etc. should be 
cleaned off the blade or from around the 
head at regular intervals.
WARNING
To reduce the risk of unintentional 
rotation of the cutting attachment and 
injury, always shut off the engine and 
remove the spark plug boot before 
replacing the cutting attachment. To 
reduce the risk of injury, always shut off 
the engine before adjusting the length of 
the nylon line on manually adjustable 
mowing heads.
WARNING
The gearbox becomes hot during 
operation. To reduce the risk of burn 
injury, do not touch the gear housing 
when it is hot.
WARNING
Never modify your muffler. Any 
modification could cause an increase in 
heat radiation, sparks or sound level, 
thereby increasing the risk of fire, burn 
injury or hearing loss. You may also 
permanently damage the engine. Have 
your muffler serviced and repaired by 
your STIHL servicing dealer only.
WARNING
The muffler and other parts of the engine 
(e.g. fins of the cylinder, spark plug) 
become hot during operation and remain 
hot for a while after stopping the engine. 
To reduce risk of burns, do not touch the 
muffler and other parts while they are 
hot. Keep the area around the muffler 
clean. Remove excess lubricant and all 
debris such as pine needles, branches 
or leaves. Let the engine cool down 
sitting on concrete, metal, bare ground 
or solid wood (away from any 
combustible substances.
WARNING
An improperly mounted or damaged 
cylinder housing or a 
damaged/deformed muffler shell may 
interfere with the cooling process of the 
muffler. To reduce the risk of fire or burn 
injury, do not continue work with a 
damaged or improperly mounted 
cylinder housing or a 
damaged/deformed muffler shell.
Your muffler is furnished with a spark 
arresting screen designed to reduce the 
risk of fire from the emission of hot 
particles. Never operate your unit with a 
missing or damaged spark arresting 
screen. If your gas/oil mix ratio is correct 
(i.e., not too rich), this screen will 
normally stay clean as a result of the 
heat from the muffler and need no 
service or maintenance. If you 
experience loss of performance and you 
suspect a clogged screen, have your 
muffler maintained by a STIHL servicing 
dealer. Some state or federal laws or 
regulations may require a properly 
maintained spark arrestor for certain 
uses. See the "Maintenance, Repair and 
Storing" section of these Safety 
Precautions. Remember that the risk of 
a brush or forest fire is greater in hot or 
dry conditions.