HT 105, HT 134, HT 135
English
12
recommends having your muffler 
serviced and repaired by a STIHL 
servicing dealer.
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 (e.g. the trunk of a felled 
tree) 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.
Reactive Forces
WARNING
Reactive forces may occur any time the 
chain is rotating. The force used to cut 
wood can be reversed and work against 
the operator. If the rotating chain is 
suddenly stopped by contact with any 
solid object such as a branch or is 
pinched, the reactive forces may occur 
instantly. These reactive forces may 
result in loss of control, which, in turn, 
may cause personal injury. An 
understanding of the causes of these 
reactive forces may help you avoid the 
element of surprise and loss of control.
Because of the design of the pole 
pruner, the reactive forces experienced 
when working with it are generally not as 
severe as those encountered with a 
chainsaw. Nevertheless, you should 
always maintain a proper grip and good 
footing to control the power tool when 
you experience such forces.
The most common reactive forces are:
– kickback,
– pushback,
– pull-in.
Kickback
Kickback may occur when the moving 
saw chain near the upper quadrant of 
the bar nose contacts a solid object or is 
pinched.
The reaction of the cutting force of the 
chain causes a rotational force on the 
pole pruner in the direction opposite to 
the chain movement. This may cause 
the bar to move upward.
To Avoid Kickback
The best protection from kickback is to 
avoid kickback situations:
1. Be aware of the location of the guide 
bar nose at all times.
2. Never let the nose of the guide bar 
contact any object. Do not cut limbs 
with the nose of the guide bar. Be 
especially careful near wire fences 
and when cutting small, tough 
limbs, which may easily catch the 
chain.
3. Cut only one limb at a time.
A = Pull-in