Stihl 024 User manual

STIHL 024
Instruction Manual
0 Flees Manual
Assembling
Safety Precautions
Operating Instructions
Maintenance
Warning! To reduce risk of kickback injury use STIHL reduced kickback bar
Read and follow all safety precautions and STIHL PM 1 (3/s" Picco) orTM 1 (0.325") chain depending on
in Owner's Manual improper use sprocket pitch or otheravailable low kickback components.
can cause serious or fatal injury. @ Andreas Stihl 1985.
STIHL
STIH

Important Safety Precautions
for Chain Saw Users
A. Kickback Safety Precautions
Warning!
Kickbackmay occurwhen the nose ortip ofthe guide
bar touches an object, orwhen thewood closes in and
pinches the saw chain in the cut. Tip contact in some
cases may cause a lightning fast reverse reaction,
kicking the guide bar up and back towards the
operator. Pinching the saw chain along the top of the
guide bar may push the guide bar rapidly back to-
wards the operator. Either of these reactions may
cause you to lose control of the saw which could re-
sult in serious personal injury.
Section 4.12 of ANSI B 175.1-1985 sets certain perfor-
mance and design criteria related to chain saw kick-
back. STIHL has developed a color code system using
green and yellow to help you select a powerhead, bar
and chain combination thatcomplies with the kickback
requirements ofthe ANSI Standard. See the sections
entitled "Safety Precautions" and "Specifications" of
this Manual.
Do not rely exclusively upon the safety devices built
into your saw. As a chain saw user, you should take
several steps to keep your cutting jobs free from acci-
dentor injury.
1. With a basic understanding of kickback, you can
reduce or eliminate the element of surprise. Sud-
den surprise contributes to accidents.
Keep a good firm grip on the saw with both hands,
the right hand on the rear handle, and the left hand
on the front handle, when the engine is running.
Use a firm grip with thumbs and fingers encircling
the chain saw handles. A firm grip will help you re-
duce kickback and maintain control of the saw.
Don't let go.
Make sure that area in which you are cutting is free
from obstructions. Do not let the nose of the guide
bar contact a log, branch, or any other obstruction
which could be hit while you are operating the saw.
Cut at high engine speeds.
Do not overreach or cut above shoulder height.
Follow manufacturer's sharpening and mainten-
ance instructions for the saw chain.
Only use replacement bars and chains specified
by the manufacturer or the equivalent.
B. Other Safety Precautions
Do not operate a chain saw when you are fatigued.
Use safety footwear; snug-fitting clothing; protec-
tive gloves; and eye, hearing, and head protection
devices.
Use caution when handling fuel. Move the chain
saw at least 10 feet (3 m) from the fueling point
before starting the engine.
continued on the back inside cover

This Manual contains operating and safety instructions for
all STIHL 024 series power saws.
Pay special attention to thesafety precautions outlined on
the inside cover and on pages 4 to 23. Allow only persons
who understand this Manual to operateyour chain saw.
To receive maximum performance and satisfaction from
your STIHL chain saw, it is important that you read and
understand the maintenance and safety precautions be-
fore using your saw. Contact your STIHL dealer or the
STIHL distributor for your area if you do not understand
any of the instructions in this Manual.
Because a chain saw is a high-speed wood-cutting tool,
some special safety precautions must be observed as wi-
thany other power saw to reduce the risk of personal inju-
ries. Careless or improper use may cause serious or even
fatal injury.
STIHI2s philosophy is to continually improve all of its pro-
ducts. As a result, engineering changes and improve-
ments are made from time-to-time. If the operating cha-
racteristics or the appearance of your saw differs from
those described in this Manual, please contact your STIHL
dealerfor information and assistance.
STIHL 024 AV Super electronic Quickstop,
024 WB electronic Quickstop
Andreas Stihl
D-7050 Waiblingen
Operating Instructions
Sharpening and Maintenance ofSaw Chains
Contents
Parts of the Chain Saw 2
Safety Precautions 4
The Operator 4
The Saw 6
The Use of the Saw 6
Maintaining and Storing the Saw 23
Fuel 24
Chain Oil 25
Mounting the Bar and Chain 26
Chain Brake 29
General Notes on Operation 30
Master Control 31
Starting 32
Electrically Heated Handles 35
Winter Operation 36
Guide Bar, Chain and Sprocket 38
Replacing the Chain Sprocket 40
Air Filter 41
Carburetor 42
Rewind Starter 44
Maintenance Chart 46
Specifications 47
Sharpening and Maintenance of Saw Chain 49
Ordering Spare Parts 55
0458 127 3021. Mb. F1. T. Printed in Germany X c 1991 Andreas Stihi,Waiblingen
STIHL®

2
Parts of the Chain'Saw
7 Front handle
8 Shroud fastener
9 Spark plug terminal
10 Handle heating switch
11 Rear handle
12 Rear hand guard /
20 Chain guard
21 Muffler
22 Starter grip
23 Oil filler cap
24 Fuel fillercap
Front hand guard 6
Chain brake 5
Bumper spike 4
Guide bar
nose 3
Guide bar 2
Oilomatic saw chain 1
Chain sprocket 13
Chain catcher 14
Chain sprocket cover 15
Twist lock 16
Throttle trigger interlock 17
Throttle trigger 18
Master Control lever 19

Definitions 14. Chain Catcher. Helps to reduce the risk of operator
contact by a chain when it brakes or comes offthe bar.
Oilomatic Saw Chain. A loop consisting of cutters,
tie straps and drive links.
Guide Bar. Supports and guides the saw chain.
Guide Bar Nose. The exposed end of the guide bar.
Bumper Spike. Toothed stop for holding saw steady
against wood.
Chain Brake.A device to stop the rotation of the chain
if activated in a kickback situation by the operator's
hand or by inertia.
Front Hand Guard. Provides protection against pro-
jecting branches and helps prevent the left hand from
touching the chain if it slips off the handle bar.
Front Handle. Handle bar for the left hand at front of
saw.
Shroud Fastener. For fastening the shroud.
Spark Plug Terminal. Connects the spark plug with
the ignition wire.
Handle Heating Switch. For switching the electric
handle heating on and off.
Rear Handle. The support handle for the right hand,
located at or toward the rear of the saw.
Rear Hand Guard. Gives added protection to
operator's right hand.
Chain Sprocket. The toothed wheel that drives the
saw chain.
Chain Sprocket Cover. Covers the clutch and the
sprocket.
Twist Lock. Lock for carburetor box cover.
Throttle Trigger Interlock. Must be depressed be-
fore the throttle trigger can be activated.
Throttle Trigger. Controls the speed of the engine.
Master Control Lever. Lever for choke control,
starting throttle, run and stop switch, position.
Chain Guard (Scabbard). Covers the bar and the
chain when the saw is not in use.
Muffler. Reduces engine exhaust noise and directs
the exhaust gases.
Starter Grip. The grip of the starter, for starting the
engine.
Oil Filler Cap. For closing the oil tank.
Fuel Filler Cap. For closing the fuel tank.
Clutch. Couples engine to chain sprocket when
engine is accelerated beyond idle speed.
(Not illustrated.)
Anti-Vibration System. The anti-vibration system in-
cludes a number of buffers designed to reduce the
transmission of vibrations created by the engine and
cutting attachment to the operator's hands.
(not illustrated). 3

Safety Precautions
The use ofany chain sawmay be hazardous.The saw chain
has many sharp cutters. If the cutters contact your flesh,
they will cut you, even if the chain is not moving. At full
throttle, the chain speed can reach 45 mph (20 m/s). It is
important that you read, fully understand and observe the
following safety precautions and warnings. Read the
owner's manual and the safety instructions periodically.
Pay special attention to the section on reactive forces,
pages 10 to 16.
Warning!
Reactive forces, including kickback, can be dangerous.
Careless or improper use of any chain saw may cause
serious or fatal injury.
All safety precautions that are generally observed when
working with an axe or a hand saw also apply to the opera-
tion of chain saws. However, because a chain saw is a
highspeed, fast-cutting power tool, special safety pre-
cautions must be observed to reduce the risk of personal
injury.
Have your STIHL dealer show you how to operate your
chain saw. Observe all applicable local safety regulations,
standards and ordinances.
Warning!
Minors should never be allowed to use a chain saw.
Bystanders, especially children and animals should not be
allowed in the area where a chain saw is in use (ill. 1).
Never let the saw run unattended. Store it in a locked place
away from children and empty the fuel tank before storing
for longer than a few days.
Do not lend or rent your chain saw without the Owner's
Manual. Be sure that anyone using your saw reads and
4 understands the information contained in this Manual.
These safety precautions and warningsapply to the use of
all STIHL chain saws. Different models may have different
parts and controls. See the appropriate section of your
Owner's Manual for a description of the controls and
function of the parts of your model saw.
Safe use of a chain saw involves
the operator
the saw
the use of the saw.
THE OPERATOR
Physical Condition
You must be in good physical condition and mental health
and not under the influence of any substance (drugs,
alcohol) which might impair vision, dexterity or judgment.
Do not operate a chain saw when you are fatigued (ill. 2).
Be alert If you get tired while operating your chain saw,
take a break. Tiredness may result in loss ofcontrol. Work-
ing with any chain saw can be strenuous. If you have any

condition that might be aggravated by strenuous work,
check with your doctor before operating a chain saw.
Warning!
Prolonged useof chain saws (or othermachines) exposing
the operator to vibrations may produce whitefinger dis-
ease (Raynaud's phenomenon). This phenomenon re-
duces the hand's ability to feel and regulate temperature,
produces numbness and burning sensations and may
cause nerve and circulation damage and tissue necrosis.
Many STIHL models are available with an anti-vibration
(AV) system designed to reduce engine vibration. An anti-
vibration system is recommended for those using chain
saws on a regular or sustained basis.
Heated handles help to reduce the risk of whitefinger
diseaseand are recommended for cold weather use. Most
STIHL powerheads are available with heated handles.
Anti-vibration systems and heated handles do not gua-
rantee that you will not sustain whitefinger disease. There-
fore, continual and regular users should monitor closely
the condition of their hands and fingers. If any of the above
symptoms appear, seek medical advice immediately.
Proper Clothing
Clothing must be sturdy and snug-fitting, but allow com-
plete freedom of movement. Avoid loose-fitting jackets,
scarfs, neckties, jewelry, flared or cuffed pants, or anything
that could become entangled with the saw or brush. Wear
overallsor jeans with a reinforced cut resistant insert (ill. 3).
Protect your hands with gloves when handling saw and
saw chain. Heavy-duty, nonslip gloves improve your grip
and protect your hands. 5
2

Good footing is most important in chain saw work . Wear
sturdy boots with nonslip soles. Steel-toed safety boots
are recommended.
Proper eye protection is a must. Non-fogging, vonted
goggles or a face screen is recommended. Their use re-
duces the risk of eye injury.
Wear an approved safety hard hat to protect your head.
Chain saw noise may damage your hearing. Always wear
sound barriers (ear plugs or ear mufflers) to protect your
hearing. Continual and regular users should have their
hearing checked regularly.
THE SAW
Parts of the chain saw; for illustrations and definitions of
the parts see pages 2 and 3!
Warning!
Never modify a chain saw in any way. Only attachments
and parts supplied by STIHL or expressly approved by
STIHL for use with the specific STIHL saw models are
authorized. Although certain unauthorized attachments
are useable with the STIHL powerhead, their use may, in
fact, be extremely dangerous.
THE USE OF THE SAW
Transporting thechain saw Preparation forthe use of the saw
Warning!
Always stop the engine before putting a chain saw down
or carrying it. Carrying a chain saw with the engine running
is extremely dangerous. Accidental acceleration of the
6 engine can cause the chain to rotate. During operation,
4
j_19)?r,
the powerhead muffler and the material around it reach
extremely high temperatures. Avoid touching the hot muf-
fler, you could receive serious burns.
By hand: When carrying your saw by hand, the engine
must be stopped and the saw must be in the proper posi-
tion. Grip the front handle and place the muffler away from
the body (ill. 4).
The chain guard (scabbard) should be over the chain and
the guide bar, which should point backwards. When carry-
ing your saw, the bar should be behind you (ill. 4).
By vehicle: When transporting in a vehicle, keep chain
and bar covered with the chain guard. Properly secure
your saw to prevent turnover, fuel spillage and damage to
the saw.
Take off the chain guard and inspect for safety in opera-
tion. For assembly, follow the procedure described in the
chapter "Mounting the Bar and Chain" of your owner's
manual.

STIHL Oilomatic chain, guide bar and sprocket must
match each other in gauge and pitch.
Before replacing any bar and chain, see the sections on
"Specifications", kickback and the ANSI B 175.1-1985
chain saw kickback standard in this manual.
Warning!
Proper tension of the chain is extremely important. In or-
der to avoid improper setting, the tensioning procedure
must be followed as described in your manual. Always
make sure the hexagonal nut(s) for the sprocket cover is
(are) tightened securely after tensioning the chain. Never
start the saw with the sprocket cover loose. Check chain
tension once more after having tightened the nut(s) and
thereafter at regular intervals (whenever the saw is shut
off). If the chain becomes loose while cutting, shut off the
engine and then tighten. Never try to tighten the chain
while the engine is running!
Fueling
Your STIHL chain saw uses an oil-gasoline mixture forfuel
(see chapter "Fuel" of your owner's manual).
Warning!
Gasoline is an extremely flammable fuel. Use extreme
caution when handling gasoline or fuel mix. Do not smoke
or bring any fire or flame near the fuel (ill. 5).
Fueling Instructions
Fuel your chain saw in well-ventilated areas, outdoors
only.
Always shut off the engine and allow it to cool before
refueling. Gasoline vapor pressure may build up inside the
gas tank of a two cycle engine depending on the fuel
used, the weather condition, and the venting system ofthe
tank. In order to reduce the risk of burns or other personal
injury from escaping gas vaporand fumes, remove the gas
cap on the STIHL product carefully so as to allow any
pressure build-up in the tank to release slowly. Never re-
move fuel filler cap while engine is running.
Select bare ground for fueling and move at least 10 feet
(3 m) from fueling spot before starting the engine. Wipe off
any spilled fuel before starting your saw, and check for
leakage.
Check for fuel leakage while refueling and during opera-
tion. If fuel or oil leakage is found, do not start or run the
engine until leak is fixed and spilled fuel has been wiped
away. Tighten the fuel cap after filling to avoid spillage and
risk of fire.
Starting
Warning!
Your chain saw is a one-person saw. Do not allow other
persons to be near the running chain saw. Start and oper-
ate your saw without assistance. For specific starting in-
structions, see the appropriate section of the owner's
manual. Proper starting methods reducethe risk of injury. 7
5

Do not drop start. This method is very dangerous because
you may lose control ofthe saw (ill 6).
There are two recommended methods for starting your
chain saw. With the first method, the chain saw is started
on the ground. Engage the chain brake (see "Chain Brake"
chapter in your owner's manual) and place the chain saw
on firm ground or other solid surface in an open area.
Maintain good balance and secure footing. Grip the front
handlebar of the saw firmly with your left hand and press
down. For saws with a rear handle level with the ground,
put the toe of your rightfoot into the rear handle and press
down. With your right hand pull out the starter grip slowly
until you feel a definite resistance and then give it a brisk,
strong pull.
The second recommended method for starting your
chain saw allows you to start the saw without placing it on
the ground. Engage the chain brake, grip the front handle
of the chain saw firmly with your left hand. Keep the arm
on the front handle in a locked (straight) position. Hold the
rear handle of the sawtightly between your legs just above
the knees. Maintain good balance and secure footing. Pull
the starting grip slowly with your right hand until you feel a
8 definite resistance and then give it a brisk, strong pull.
Warning!
Be sure that the guide bar and chain are clear of you and
all other obstructions and objects, including the ground.
When the engine is started, the engine speed with the
starting throttle lock engaged will be fast enough for the
clutch to engage the sprocket and turn the chain. If the up-
per quadrant of the tip of the bar touches any object, it
may cause kickback to occur (see section on reactive for-
ces on pp. 10-16). To reduce this risk, always engage the
chain brake before starting. Never attempt to start the
chain saw when the guide bar is in a cut or kerf.
When you pull the starter grip, do not wrap the starting
rope around your hands. Do not allow the grip to snap
back, but guide the starter rope slowly back to permit the
rope to rewind properly. Failure to follow this procedure
may result in injury to hand or fingers and maydamagethe
starter mechanism.
Important adjustments
Warning!
At correct idle speed, the chain should not rotate. For di-
rections to adjust idle speed, see the appropriate section
of your owner's manual.
Do not use a saw with incorrect idle speed adjustment.
If you cannot set the correct idle speed, have your STIHL
dealer check your saw and make proper adjustments or
repairs.
After adjusting a chain, start the saw, let the engine run for
a while, then switch engine off and recheck chain tension.
Proper chain tension is very important at all times.
6

Working Conditions
Operate your chain saw only outdoors in a ventilated area.
Operate the saw under good visibility and daylight condi-
tions only.
Don't work alone. Keep within calling distance of others in
case help is needed.
Your chain saw is equipped with a chain catcher. It is de-
signed to reduce the risk of personal injury in the event of
a thrown or broken chain. From time to time the catcher
may be damaged or removed. To reduce the risk of perso-
nal injury, do not operate a chain saw with a damaged or
missing catcher.
Inspect buffers periodically. Replace damaged, broken or
excessively worn buffers immediately, since they may re-
sult in loss of control of the saw. A "sponginess" in the feel
of the saw, increased vibration or increased "bottoming"
during normal operation may indicate damage, breakage
or excessive wear. Buffers should always be replaced in
sets. If you have any questions as to whether the buffers
should be replaced, consult your STIHL servicing dealer.
Warning!
Take extreme care in wet and freezing weather (rain, snow,
ice). Put off the work when the weather is windy, stormy or
rainfall is heavy. Clear the area where you are working.
fling!
Avoid stumbling on obstacles such as stumps, roots or
rocks and watch out for holes or ditches. Be extremely
cautious when working on slopes or uneven ground. There
is increased danger of slipping on freshly debarked logs.
Cutting Instructions
Grip: Always hold the saw firmly with both hands when the
engine is running. Place your left hand on front handle bar
and your right hand on rear handle and throttle trigger.
Left-handers should follow these instructions too.
Wrap your fingers tightly around the handles, keeping the
handles cradled between your thump and forefinger (ill. 7).
With your hands in this position, your can best oppose and
absorb the push, pull and kickback forces of your saw
without losing control (see section on reactive forces).
Make sure your chain saw handles and grip are in good
condition and free of moisture, pitch, oil or grease.
To reduce the risk of serious or fatal injury to the operator
or bystanders, never use the saw with one hand. You can-
not control reactive forces (see pages 10 to 16), and you
may lose control of the saw, which can result in the skating
or bouncing of the bar and chain along the limb or log.
Even for those compact saws designed for use in confined
spaces, one-handed operation is dangerous because the
operator may lose control.
Do not operate your chain saw with the starting throttle
lock engaged. Cutting with the starting throttle lock enga-
ged does not permit the operator proper control of the
saw or chain speed. 9
7

Warning!
Never touch a chain with your hand or any part of your
body when the engine is running, even when the chain is
not rotating. The chain continues to rotate for a short pe-
riod after the throttle trigger is released.
Warning!
Do not cut any material other than wood or wooden ob-
jects.
Use your chain saw for cutting only. It is not designed for
10 prying or shoveling away limbs, roots or other objects.
When sawing, make sure that the saw chain does not
touch any foreign materials such as rocks, fences, nails
and the like (i11.8). Such objects may be flung off, damage
thesaw chain or cause the saw to kick back.
In order to keep control of yoursaw, always maintain a firm
foothold, Never work on a ladder, in a tree or on any other
insecure support. Never use the saw above shoulder
height (ill. 9).
Position the chain saw in such a way that your body is
clearof the cutting attachment wheneverthe engine is run-
ning. Stand to the left of cut while bucking (see ill. 10).
Don't put pressure on the saw when reaching the end of a
cut. The pressure may cause the bar and rotating chain to
pop out of the cut or kerf, go out of control and strike the
operator or some other object. If the rotating chain strikes
some other object, a reactive force (see pages 10 to 16)
may cause the moving chain to strikethe operator.
Reactive forces including kickback
,ng!
Reactive forces may occur any time the chain is rotating.

Reactives forces can be dangerous! In any chain saw, the
powerful 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 like a log or branch or is pinched, the reac-
tive forces may occur instantly. These reactive forces may
result in loss of control which may, in turn, cause serious
or fatal injury. An understanding of the causes of these re-
active forces may help you avoid loss of control.
The most common reactive forces are
kickback,
pushback,
pull-in.
Kickback:
Kickback occurs when the upper quadrant of the bar nose
contacts a solid object or is pinched (ill. 11). The reaction
of the cutting force of the chain causes a rotational force
on the chain saw in the direction opposite to the chain mo-
vement. This may fling the bar up and back in an uncon-
trolled arc mainly in the plane of the bar. Under some cut-
ting circumstances the bar moves towards the operator,
who may suffer servereor fatal injury. Kickback may occur
when the nose of the guide bar is pinched unexpectedly,
unintentionally contacts solid material in the wood, (ill. 12)
or is incorrectly used to begin a plunge or boring cut. It
may also occur during limbing.
The greater the force of the kickback reaction, the more
difficult it becomes for the operator to control the saw. ANSI B 175.1-1985 chain saw kickback standard
Many factors influence the occurrence and force of the
kickback reaction. These include chain speed, the speed
at which the bar and chain contact the object, the angle of
contact, the condition of the chain and other factors.
The type of bar and saw chain you use is an important fac-
tor in the occurrence and force of the kickback reaction.
Some STIHL bar and chain types are designed to reduce
kickback forces. STIHL recommends the use of reduced
kickback bars and low kickback chains.
Section 4.12 of ANSI standard B 175.1-1985, sets certain
performance and design criteria related to chain saw kick-
back. 11

To comply with section 4.12 ofANSI B 175.1-1985:
a) saws with a displacement of less than 3.8 cubic inches
must, in their original condition, meet a 45° computer
derived kickback angle when equipped with certain
cutting attachments described on page 12,
and must be equipped with at least two devices to re-
duce the risk of kickback injury, such as a chain brake,
low kickback chain, reduced kickback bar, etc.
b) saws with a displacement of 3.8 cubic inches and
above
must be equipped with at least one device designed
to reduce the risk of kickback injury such as a chain
brake, low kickback chain, reduced kickback bar, etc.
These kickback requirements do not apply to chain saws
fitted with bow guides. Bow-equipped saws are only for
use by thoroughly instructed and experienced operators.
Use of bow guides may result in serious or fatal injury. See
section entitled "Bow Guides" of this Manual.
The computer derived angles for saws below 3.8 cubic
inch displacement are measured by applying a computer
program to test results from a kickback test machine.
Warning!
The computer derived angles of § 4.12 of ANSI B 175.1
1985 may bear no relationship to actual kickback bar rota-
tion angles that may occur in real life cutting situations.
Compliance with § 4.12 of ANSI B 175.1-1985 does not au-
tomatically mean that in a real life kickback the bar and
chain will rotate at most 45°.
Warning
In order for powerheads below 3.8 cubic inch displace-
ment to comply with the computed kickback angle re-
quirements of § 4.12 of ANSI B 175.1-1985 use only the
12 following cutting attachments:
bar and chain combinations listed as complying in the
"Specifications" section of the Owner's Manual or
other replacement bar and chain combinations marked
in accordance with the standard for use on the power-
head or
replacement chain designated "low kickback saw
chain".
Warning! There are potential powerhead and bar combi-
nations with which low kickback saw chains can be used
which have not been specifically certified to comply with
the 45° computer derived kickback angle of § 4.12 ofANSI
B 175.1-1985. Some low kickback chains have not been
tested with all powerhead and barcombinations.
STIHL offers a variety of bars and chains. STIHL reduced
kickback bars and low kickback chains are designed to re-
ducethe risk of kickback injury. Other chains are designed
to obtain higher cutting efficiency or sharpening ease but
may result in higher kickback tendency.
STIHL has developed a color code system to help you
identify the STIHL reduced kickback bars and low kick-
back chains. Cutting attachments with green warning de-
cals or green labels on the packaging are designed to re-
duce the risk of kickback injury. The matching of green de-
caled powerheads under 3.8 cubic inch displacement with
green labeled bars and green labeled chains gives com-
pliance with the computed kickback angle requirements of
ANSI B 175.1-1985 when the products are in their original
condition. Products with yellow decals or labels are for
users with extraordinary cutting needs and experience
1) "Low kickback saw chain" is a chain which has met the
kickback performance requirements of § 4.12.2.4 of ANSI
B 175.1-1985 (Safety Requirements for Gasoline-Powered
Chain Saws) when tested on a selected representative
sample of chain saws below 3.8 cubic inch displacement
specified in ANSI B 175.1-1985.

ror
©
and specialized training for dealing with kickback.
STIHL recommends the use of its green labeled redu-
ced kickback bars, green labeled low kickback chains
and a STIHL Quickstop chain brake for both experien-
ced and inexperienced chain saw users.
Please ask your STIHL dealer to properly match your po-
werhead with the appropriate bar/chain combinations to
reduce the risk of kickback injury. Green labeled bars and
chains are recommended for all powerheads. See your
"STIHL Barand Chain Information" leaflet for details.
Warning! Use of other, non-listed bar/chain combinations
may increase kickback forces and increase the risk of kick-
back injury.
New bar/chain combinations may be developed after pu-
blication of this literature, which will, in combination with
certain powerheads, comply with § 4.12 of ANSI B 175.1
1985. Check with your STIHL dealer for such combina-
tions.
Bow Guides
Warning! Any chain saw equipped with a bow guide is po-
tentially very dangerous. Improper use can result in kick-
back, pushback or pull-in, and very serious injury or death.
Only thoroughly instructed and experienced operators
should use a chain saw equipped with a bow guide.
A bow guide (or bow bar) is a specially designed substitu-
tion for a regular guide bar. Like a regular guide bar, it
supports and guides the saw chain. Unlike a regular guide
bar, it consists of a narrow rail structure with a large open
space in the middle.
Warning! The risk of kickback is increased with a bow
guide because of the increased kickback contact area.
STIHL recommends the use of the STIHL Quickstop chain
brake. Low kickback chain will not significantly reduce
the risk of kickback injury when used on a bow guide.
13
Guard
Only STIHL bow guides are approved for use with STIHL
powerheads. The use of other bow guides with a STIHL
powerhead can be hazardous to the operator due to the
absence of safety guards and spurs and necessary un-
authorized modifications needed to mount the bow guide
to the STIHL powerhead.
Do not use a STIHL bow guide on any powerhead except
a STIHL powerhead. Unauthorized combinations are dan-
gerous.
Never attempt to operate a chain saw equipped with a
bow guide unless the spurs and both guards are in place
(ill. 13). Under no circumstances should any of the spurs or
guards be removed. Keep the nuts which hold these items
in place tightened at all times.
The guards at the top and bottom of the bow guide are re-
quired to reduce the possibility of injury caused by contact
with the chain. These guards are slotted to allow position-
ing as close to the powerhead as possible. After the bow
guide is mounted on the chain saw, slide the guards as
close to the powerhead as possible. 13

The spurs should always be placed firmly against the
wood before starting a cut (ill. 14) and should be kept
against the wood until the cut is completed. Failure to
keep the spurs firmly against the wood during the entire
cut could cause the saw to react violently and could result
in serious injury or death to the operator.
Warning!
Be sure to keep the chain properly tensioned. A chain
which "sags" or is too loose could jump off the bow and
result in serious injury to the operator. Felling with a bow
bar is dangerous, because it is more difficult to follow safe
felling techniques.
Cut only one log at a time.
A chain catcher which has been removed to allow mount-
ing of a bow guide must be reattached when remounting
the regularguide bar.
Devicesfor reducing the risk of kickback injury
STIHL recommends the use of the STIHL Quickstop chain
brake on your powerhead with green labeled reduced
14 kickback bars and low kickback chains.
Quickstop chain brake
STIHL has developed a chain stopping system designed
to reduce the risk of injury in certain kickback situations. It
is called a Quickstop chain brake. The Quickstop is availa-
ble as standard equipment on your STIHL chain saw and
is available for installation on most older STIHL saws. Ask
your dealer to retrofit your older model saw with a chain
brake.
When a kickback occurs,the guide bar may rotate around
the front handle. If the cutting position is such that the
operator's left hand is gripping thefront handle behind the
hand guard, and it the left hand rotates around the front
handle and contacts the front hand guard, which is the
Quickstop activating lever, this contact will activate the
Quickstop (see ill. 15). The chain brake on mostnew model
STIHL chain saws can also be activated by inertia. See the
chapter entitled "Chain Brake" of your Owner's Manual.
Warning!
Never operate your chain saw without a front hand guard.
In a kickback situation this guard helps protect your left
hand or other parts of your body. In addition, removal of
the hand guard on a saw equipped with a chain brake will
deactivate the chain brake.

Warning!
No Quickstop or other chain brake device prevents kick-
back. These devices are designed to reduce the risk of
kickback injury, if activated, in certain kickback situations.
In order for the Quickstep to reducethe risk of kickback in-
jury, it must be properly maintained and in good working
order. See the chapter entitled "Chain Brake" and "Mainte-
nance, Repair and Storing" of your Owner's Manual. In ad-
dition, there must be enough distance between the bar
and the operator to ensure that the Quickstep has suffi-
cient time to activate and stop the chain before potential
contact with the operator.
Warning!
An improperly maintained chain brake may increase the
time needed to stop the chain after activation, or may not
activate at all.
Reduced kickback bar
STIHL green labeled reduced kickback bars are designed
to reduce the risk of kickback injury when used with STIHL
green labeled low kickback chains.
Warning!
When used with other, more aggressive chains, these bars
may be less effective in reducing kickback, and may result
in higher kickback forces.
Low kickback chain
Some types of saw chain have specially designed compo-
nents to reduce theforce of nose contact kickback. STIHL
has developed low kickback chain for your powerhead.
Warning!
A dull or improperly sharpened chain may reduce or ne-
gate the effects of the design features intended to reduce
kickback energy. Improper lowering or sharpening of the
depth gauges or shaping of the cutters may increase the
chance and the potential energy of a kickback. Always cut
with a properly sharpened chain.
Warning!
Reduced kickback bars and low kickback chains do not
prevent kickback, but they are designed to reducethe risk
of kickback injury. They are available from your STIHL dea-
ler.
Warning!
Even if your saw is equipped with a Quickstep, a reduced
kickback bar and/or low kickback chain, this does not eli-
minate the risk of injury by kickback. Therefore always ob-
serve all safety precautions to avoid kickback situations.
To avoid kickback
The best protection from personal injury that may result
from kickback is to avoid kickback situations:
Hold the chain saw firmly with both hands and main-
tain a secure grip.
Be aware of the location of the guide bar nose at all
times.
Never let the nose of the guide bar contact anyobject.
Do not cut limbs with the nose of the guide bar. Be
especially careful when cutting small, tough limbs,
small size brush and saplings which may easily catch
the chain.
Don't overreach.
Don't cut above shoulder height.
Begin cutting and continue at full throttle.
Cut only one log at a time.
Use extreme caution when re-entering a previous cut.
Do not attempt to plunge cut (see page 20) if you are
not experienced with these cutting techniques.
Be alert for shifting of the log or other forces that may
cause the cut to close and pinch the chain.
Maintain saw chain properly. Cut with a correctly shar-
pened, properly tensioned chain at all times.
Stand to the side of the cutting path of the chain saw. 15

\\e
Pushback:
Pushback occurs when the chain on the top of the bar is
suddenly stopped when it is pinched, caught or encoun-
ters a foreign object in the wood. The reaction of the chain
drives the saw straight back toward the operator and may
cause loss of saw control. Pushback frequently occurs
when the top of the bar is used for cutting (see ill. 16).
To avoid pushback
Be alert to forces or situations that may cause material
to pinch the top of the chain.
Do not cut more than one log at a time.
Do not twist the saw when withdrawing the bar from a
plunge cut or underbuck cut (figures 26 to 30 and 34,
16 pages 19, 20 and 22), because the chain can pinch.
Pull-in:
Pull-in occurs when the chain on the bottom of the bar is
suddenly stopped. The chain on the bottom of the bar
stops when it is pinched, caught or encounters a foreign
object in the wood (see ill. 17). The reaction of the chain
pulls the saw forward and may cause the operator to lose
control.
Pull-in frequently occurs when the bumper spike of the
saw is not held securely against the tree or limb and when
the chain is not rotating at full speed before it contacts the
wood.
Warning!
Use extreme caution when cutting small size brush and
saplings which may easily catch the chain and pull you off
balance.
To avoid pull-in
Always start a cut with the chain rotating at full speed
and the bumper spike in contact with the wood.
Pull-in may also be prevented by using wedges to open
the kerf or cut.

(A\
Cutting Techniques
Felling
Felling is cutting down a tree.
Before felling a tree, consider carefully all conditions which
may affect the direction of fall, including:
The intended direction of the fall.
The natural lean of the tree.
Any unusually heavy limb structure.
Surrounding trees and obstracles.
The wind direction and speed.
Warning!
Always observe the general conditions of the tree. Look for
decay and rot in the trunk. If it is rotted inside, it could
snap and fall toward the operator while being cut.
Also lookfor broken or dead branches which could vibrate
loose and fall on the operator. When felling on a slope, the
operator should stand on the uphill side if possible.
When felling in the vicinity of roads, railways and power li-
nes, etc., take extra precautions. Inform the police, utility
company or railway authority before beginning to cut.
When felling, maintain a distance of at least 21/2 tree
lengths from the nearestperson (see ill. 18).
Note:
The noise of your engine may drown any warning call.
19
r711 -Escape path
Direction
of fall
Felling Instructions:
First clear the tree base and work area from interfering
limbs and brush and clean its lower portion with an axe.
Then, establish a path of escape and remove all obstacles.
This path should be generally opposite to the planned di-
rection of the fall of the tree and about at a 45° angle (ill.
19). An alternate path must also be selected. Place all
tools and equipment a safe distance away from the tree,
but not on the escape path. 17

20
-
21
If the tree has large buttress roots, cut into the largest but-
tress vertically first (horizontally next) and remove the re-
sulting piece (ill. 20).
Two felling techniques are recommended, the conventio-
nal cut and the open-face cut. With either technique the
first step is to determine the placement of thefelling notch
on the side of the tree in the planned direction of the fall
(ill. 21). When properly placed the felling notch determines
the direction in which the treewill fall. It is made perpendi-
18 cular to the line of fall and should be close to the ground.
Hinge
Felling notch
22
Felling cut
With the conventional cut begin with the top cut of the
felling notch, and cut down at approximately a 45-degree
angle to a depth of about 1/5 to 1/4 of the trunk diameter.
Make the second or lower cut horizontal until it meets the
first cut. Remove the resulting 45-degree piece (ill. 22).
With the open-face technique, the object is to make a
90-degree notch in thetree trunk to a depth of approxima-
tely 1/5 to 1/4 of the tree's diameter. Beginning with the top
cut of the notch, cut down at approximately a 50-degree
angle to a depth of approximately 1/5 to 1/4 of the dia-
meter of the tree. Make a second cut from below also at
approximately a 40-degree angle. Remove the resulting
90-degree open-face piece (ill. 23).
With both techniques, the felling notch should be made
very carefully. When making the second cuts, lookthrough
the previously made kerf to insure that to two cuts meet
properly.
Once the felling notch has been completed, you are ready
to begin the felling cut on the opposite side of the tree.
With the conventional and open face notch, begin the