HL 91 K
English
7
After finishing work
Clean the machine to remove dust and 
dirt – do not use degreasing agents.
Spray the blades with STIHL resin 
solvent. Run the engine briefly so that 
the solvent is evenly distributed.
Vibrations
Prolonged use of the power tool may 
result in vibration-induced circulation 
problems in the hands (whitefinger 
disease).
No general recommendation can be 
given for the length of usage because it 
depends on several factors.
The period of usage is prolonged by:
– Hand protection (wearing warm 
gloves)
– Work breaks
The period of usage is shortened by:
– Any personal tendency to suffer 
from poor circulation (symptoms: 
frequently cold fingers, tingling 
sensations).
– Low outside temperatures.
– The force with which the handles 
are held (a tight grip restricts 
circulation).
Continual and regular users should 
monitor closely the condition of their 
hands and fingers. If any of the above 
symptoms appear (e.g. tingling 
sensation in fingers), seek medical 
advice.
Maintenance and Repairs
Service the machine regularly. Do not 
attempt any maintenance or repair work 
not described in the instruction manual. 
Have all other work performed by a 
servicing dealer.
STIHL recommends that you have 
servicing and repair work carried out 
exclusively by an authorized STIHL 
servicing dealer. STIHL dealers are 
regularly given the opportunity to attend 
training courses and are supplied with 
the necessary technical information.
Only use high-quality replacement parts 
in order to avoid the risk of accidents 
and damage to the power tool. If you 
have any questions in this respect, 
consult a servicing dealer.
STIHL recommends the use of original 
STIHL replacement parts. They are 
specifically designed to match your 
model and meet your performance 
requirements.
To reduce the risk of injury, always shut 
off the engine before carrying out any 
maintenance or repairs or cleaning the 
machine. – Exception: Carburetor and 
idle speed adjustments.
Do not turn the engine over on the 
starter with the spark plug boot or spark 
plug removed since there is otherwise a 
risk of fire from uncontained sparking.
To reduce the risk of fire, do not service 
or store your machine near open flames.
Check the fuel filler cap for leaks at 
regular intervals.
Use only a spark plug of the type 
approved by STIHL and make sure it is 
in good condition – see "Specifications".
Inspect the ignition lead (insulation in 
good condition, secure connection).
Check the condition of the muffler.
To reduce the risk of fire and damage to 
hearing, do not operate your machine if 
the muffler is damaged or missing. 
Do not touch a hot muffler since burn 
injury will result.
Vibration behavior is influenced by the 
condition of the AV elements – check the 
AV elements at regular intervals.
Maintenance, replacement, or repair of 
the emission control devices and 
systems may be performed by any 
nonroad engine repair establishment or 
individual. However, if you make a 
warranty claim for a component which 
has not been serviced or maintained 
properly, STIHL may deny coverage.
For any maintenance please refer to the 
maintenance chart and to the warranty 
statement near the end of the instruction 
manual.