Stihl HL 90 User manual

Instruction Manual
Manual de instrucciones
Warning!
Read and follow all safety precautions in
Instruction Manual – improper use can cause
serious or fatal injury.
Advertencia!
Lea y siga todas las precauciones de
seguridad dadas en el manual de
instrucciones – el uso incorrecto puede
causar lesiones graves o mortales.
STIH)
STIHL HL 90
BA_U1_86_02.fm Seite 0 Mittwoch, 18. April 2007 1:20 13

1HL 90 K
English / USA
BA_SE_212_003_01_03.fmPrinted on chlorine-free paper.
Printing inks contain vegetable oils; paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2008 0458 445 8621 A. M1. C8. PM. Printed in USA
STIHl
Contents
Guide to Using this Manual .............. 2
Safety Precautions and
Working Techniques ......................... 3
Using the Hedge Trimmer .............. 13
Mounting the Gearbox .................... 14
Adjusting the Throttle Cable ........... 15
4-MIX Engine .................................. 16
Fuel ................................................ 16
Fueling ............................................ 17
Starting / Stopping
the Engine ...................................... 18
Operating Instructions .................... 21
Cleaning the Air Filter ..................... 21
Motor Management ........................ 21
Adjusting the Carburetor ................ 22
Spark Arresting Screen in Muffler ... 23
Checking the Spark Plug ................ 24
Lubricating the Gearbox ................. 25
Replacing Starter Rope
and Rewind Spring ......................... 26
Storing the Machine ........................ 29
Sharpening Instructions .................. 29
Inspections and Maintenance
by Dealer ........................................ 29
Maintenance Chart ......................... 30
Main Parts and Controls ................. 32
Specifications ................................. 34
Special Accessories ....................... 35
Maintenance and Repairs ............... 35
STIHL Incorporated
Federal Emission Control
Warranty Statement ........................ 36
STIHL Incorporated California
Exhaust and Evaporative Emissions
Control Warranty Statement ........... 38
Trademarks .................................... 40
Allow only persons who understand this
manual to operate your hedge cutter.
To receive maximum performance and
satisfaction from your STIHL hedge
cutter, it is important that you read and
understand the maintenance and safety
precautions, starting on page 3, before
using your hedge cutter.
Contact your STIHL dealer or the STIHL
distributor for your area if you do not
understand any of the instructions in this
manual.
!Warning!
Because a hedge cutter is a high-speed
cutting tool some special safety
precautions must be observed to reduce
the risk of personal injury.
Careless or improper use may cause
serious or even fatal injury.
STIHL's philosophy is to continually
improve all of its products. As a result,
engineering changes and improve-
ments are made from time to time. If the
operating characteristics or the
appearance of your hedge cutter differs
from those described in this manual,
please contact your STIHL dealer for
information and assistance.

2
English / USA
HL 90 K
Pictograms
All the pictograms attached to the
machine are shown and explained in
this manual.
The operating and handling instructions
are supported by illustrations.
Symbols in text
The individual steps or procedures
described in the manual may be marked
in different ways:
:A bullet marks a step or procedure
without direct reference to an
illustration.
A description of a step or procedure that
refers directly to an illustration may
contain item numbers that appear in the
illustration.
Example:
Loosen the screw (1)
Lever (2) ...
In addition to the operating instructions,
this manual may contain paragraphs
that require your special attention. Such
paragraphs are marked with the
symbols described below:
Warning where there is a risk of an
accident or personal injury or
serious damage to property.
Caution where there is a risk of
damaging the machine or its
individual components.
Note or hint which is not essential
for using the machine, but may
improve the operator’s under-
standing of the situation and result
in better use of the machine.
Note or hint on correct procedure in
order to avoid damage to the
environment.
Equipment and features
This instruction manual may refer to
several models with different
features. Components that are not
installed on all models and related
applications are marked with an
asterisk (*). Such components may
be available as special accessories
from your STIHL dealer.
Engineering improvements
STIHL’s philosophy is to continually
improve all of its products. As a result,
engineering changes and improvements
are made from time to time. If the
operating characteristics or the
appearance of your machine differ from
those described in this manual, please
contact your STIHL dealer for
assistance.
Therefore some changes, modifications
and improvements may not be covered
in this manual.
Guide to Using this Manual

3HL 90 K
English / USA
Because a hedge trimmer
is a high-speed, fast-
cutting power tool with
sharp cutting blades,
special safety precautions
must be observed to
reduce the risk of
personal injury.
It is important that you
read, fully understand and
observe the following
safety precautions and
warnings. Read the
instruction manual and
the safety precautions periodically.
Careless or improper use may cause
serious or fatal injury.
Have your STIHL dealer show you how
to operate your power tool. Observe all
applicable local safety regulations,
standards and ordinances.
!Warning!
Do not lend or rent your power tool
without the instruction manual. Be sure
that anyone using it understands the
information contained in this manual.
!Warning!
The use of this machine may be
hazardous. If the cutting tool comes in
contact with your body, it will cut you.
Use your hedge trimmer only for cutting
hedges, shrubs, scrub, bushes and
similar material. It must not be used for
any other purposes, since such misuse
may result in an accident or damage to
the machine.
!Warning!
Minors should never be allowed to use
this power tool. Bystanders, especially
children, and animals should not be
allowed in the area where it is in use.
!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
hedge trimmers. 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 hedge trimmer 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.
Safety Precautions and
Working Techniques

4
English / USA
HL 90 K
!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.
Wear gloves and keep your hands
warm.
Keep the AV system well maintained. A
power tool with loose components or
with damaged or worn AV buffers will
tend to have higher vibration levels.
Maintain a firm grip at all times, but do
not squeeze the handles with constant,
excessive pressure. Take frequent
breaks.
All the above-mentioned precautions do
not guarantee that you will not sustain
whitefinger disease or carpal tunnel
syndrome. Therefore, continual and
regular users should closely monitor the
condition of their hands and fingers. If
any of the above symptoms appear,
seek medical advice immediately.
!Warning!
The ignition system of the STIHL unit
produces an electromagnetic field of a
very low intensity. This field may
interfere with some pacemakers. To
reduce the risk of serious or fatal injury,
persons with a pacemaker should
consult their physician and the
pacemaker manufacturer before
operating this tool.
Proper Clothing
!Warning!
To reduce the risk of injury, the operator
should wear proper protective apparel.
!Warning!
To reduce the risk of injury
to your eyes never
operate your power tool
unless wearing goggles or
properly fitted protective
glasses with adequate top
and side protection complying with ANSI
Z 87.1 (or your applicable national
standard). To reduce the risk of injury to
your face STIHL recommends that you
also wear a face shield or face screen
over your goggles or protective glasses.
!Warning!
Power tool noise may
damage your hearing.
Wear sound barriers (ear
plugs or ear mufflers) to
protect your hearing.
Continual and regular
users should have their hearing checked
regularly.
Be particularly alert and cautious when
wearing hearing protection because
your ability to hear warnings (shouts,
alarms, etc.) is restricted.