4
English / USA
FS 90, FS 90 R
!Warning!
To reduce the risk of injury to bystanders 
and damage to property, never let your 
power tool run unattended. When it is 
not in use (e.g. during a work break), 
shut it off and make sure that 
unauthorized persons do not use it.
Most of these safety precautions and 
warnings apply to the use of all STIHL 
trimmer/brushcutters. Different models 
may have different parts and controls. 
See the appropriate section of your 
instruction manual for a description of 
the controls and the function of the parts 
of your model.
Safe use of a trimmer/brushcutter 
involves
1. the operator
2. the power tool
3. the use of the power tool.
THE OPERATOR
Physical Condition
You must be in good physical condition 
and mental health and not under the 
influence of any substance (drugs, 
alcohol, etc.) which might impair vision, 
dexterity or judgment. Do not operate 
this machine when you are fatigued.
!Warning!
Be alert – if you get tired, take a break. 
Tiredness may result in loss of control. 
Working with any power tool can be 
strenuous. If you have any condition that 
might be aggravated by strenuous work, 
check with your doctor before operating 
this machine.
!Warning!
Prolonged use of a power tool (or other 
machines) exposing the operator to 
vibrations may produce whitefinger 
disease (Raynaud's phenomenon) or 
carpal tunnel syndrome. 
These conditions reduce the hand's 
ability to feel and regulate temperature, 
produce numbness and burning 
sensations and may cause nerve and 
circulation damage and tissue necrosis.
All factors which contribute to white-
finger disease are not known, but cold 
weather, smoking and diseases or 
physical conditions that affect blood 
vessels and blood transport, as well as 
high vibration levels and long periods of 
exposure to vibration are mentioned as 
factors in the development of whitefinger 
disease. In order to reduce the risk of 
whitefinger disease and carpal tunnel 
syndrome, please note the following:
Most STIHL power tools are available 
with an anti-vibration (“AV”) system 
designed to reduce the transmission of 
vibrations created by the machine to the 
operator's hands. An AV system is 
recommended for those persons using 
power tools on a regular or sustained 
basis.