Important Safety Precautions for Chain Saw Users
A. Kickback Safety Precautions
!Warning!
Kickback may occur when the nose or tip of the guide bar touches an object, or when the wood 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 towards the operator. Either of these reactions may cause you to lose control of the saw which could result in serious personal injury.
Section 5.12 of ANSI B 175.1-1991 sets certain performance and design criteria related to chainsaw kickback. STIHL has developed a color code system using green and yellow to help you select a powerhead, bar and chain combination that complies with the kickback requirements of the 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 chainsaw user, you should
take several steps to keep your cutting jobs free from accident or injury.
1. With a basic understanding of kickback, you can reduce or eliminate the element of surprise. Sudden surprise contributes to accidents.
2. 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 chainsaw handles. A firm grip will help you reduce kickback and maintain control of the saw. Don’t let go.
3. Make sure the 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 while you are operating the saw.
4. Cut at high engine speeds.
5. Do not overreach or cut above shoulder height.
6. Follow manufacturer’s sharpening and maintenance instructions for the saw chain.
7. Only use replacement bars and chains specified by the manufacturer or the equivalent.
8. Reduced kickback bars and low kickback chains are designed to reduce the risk of kickback injury. Ask your STIHL dealer about these devices.
B. Other Safety Precautions
1. Do not operate a chainsaw with one hand! Serious injury to the operator, helpers, bystanders, or any combination of these persons may result from onehanded operation. A chainsaw is intended to be used with two hands.
2. Do not operate a chainsaw when you are fatigued.
3. Use safety footwear; snug-fitting clothing; protective gloves; and eye, hearing, and head protection devices.
continued on the back inside cover
Contents
Main Parts of the Saw 2 Definitions 3 Safety Precautions 4
- The Operator 4
- The Saw 6
- The Use of the Saw 6
- Maintaining and Storing the Saw 23 Mounting the Bar and Chain 25 Tensioning the Saw Chain 26 Checking Chain Tension 26 Fuel 26 Fueling 27 Chain Lubricant 28 Filling Chain Oil Tank 28 Checking Chain Lubrication 28 Chain Brake 29 Information Before You Start 30 Starting 30 Oil Quantity Control 33 Taking Care of Guide Bar 34 During Break- in Period 34 During Operation 35
Printed on chlorine-free paper
Printing inks contain vegetable oils, paper is recyclable
After Finishing Work 35 Storing the Machine 35 Air Filter System 36 HD Filter* 37 Winter Operation 38 Electrically Handle Heating* 38 Adjusting Carburetor 39 Motor Management 39 Spark Arresting Screen in Muffler 40 Checking Spark Plug 40 Replacing Starter Rope and Rewind Spring 39 Checking and Replacing Chain Sprocket 42 Ordering Spare Parts 43 Maintaining and Sharpening Saw Chain 44 Maintenance Chart 47 Specifications 48 STIHL Incorporated Federal Emission Control Warranty Statement 49
This Manual contains operating and safety instructions for all STIHL 044 series power saws. Pay special attention to the safety precautions outlined on the inside cover and on pages 4 to 24. Allow only persons who understand this Manual to operate your chainsaw. To receive maximum performance and satisfaction from your STIHL chainsaw, it is important that you read and understand the maintenance and safety precautions before 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.
!
Warning!
Because a chainsaw is a high-speed wood-cutting tool, some special safety precautions must be observed as with any other power saw 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 improvements are made from time-to-time. If the operating characteristics or the appearance of your saw differs from those described in this Manual, please contact your STIHL dealer for informations and assistance.
2000 Andreas Stihl AG & Co., Waiblingen
0458 132 3021. M10. F0. Fi. Printed in Germany
044 1
* Special equipment
Main Parts of the Saw
1
1 = Twist lock 2 = Spark plug boot 3 = Chain sprocket cover 4 = Chain sprocket 5 = Chain brake 6 = Chain catcher
2
7 = Chain tensioner 8 = Bumper spike 9 = Guide bar 10 = Oilomatic saw chain
13
12
11
3
14
15
5
4
7
8
9
10
6
TR
139BA012
11 = Oil filler cap 12 = Muffler 13 = Front hand guard 14 = Front handle (handlebar) 15 = Starter grip 16 = Master Control lever 17 = Fuel filler cap 18 = Throttle trigger 19 = Throttle trigger interlock 20 = Rear handle 21 = Rear hand guard
19
16
18
17
20
21
143BA033
2 044
Definitions
1. Carburetor Box Cover Twist Lock
Lock for carburetor box cover.
2. Spark Plug Boot
Connects the spark plug with the ignition wire.
3. Chain Sprocket Cover
Covers the clutch and the sprocket.
4. Chain Sprocket
The toothed wheel that drives the saw chain.
5. 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.
6. Chain Catcher
Helps to reduce the risk of operator contact by a chain when it breaks or comes off the bar.
7. Chain Tensioner
Permits precise adjustment of chain tension.
8. Bumper Spike
Toothed stop for holding saw steady against wood.
9. Guide Bar
Supports and guides the saw chain.
10. Oilomatic Saw Chain
A loop consisting of cutters, tie straps and drive links.
11. Oil Filler cap
For closing the oil tank.
12. Muffler
Reduces engine exhaust noise and directs the exhaust gases.
13. Front Hand Guard
Provides protection against projecting branches and helps prevent left hand from touching the chain if it slips off the handle bar. It also serves as the lever for chain brake activation.
14. Front Handle
Handle bar for the left hand at front of saw.
15. Starter Grip
The grip of the starter, for starting the engine.
16. Master Control Lever
Lever for choke control, starting throttle, run and stop switch position.
17. Fuel Filler Cap
For closing the fuel tank.
18. Throttle Trigge.
Controls the speed of the engine.
19. Throttle Trigger Interlock
Must be depressed before the throttle trigger can be activate.
20. Rear Handle
The support handle for the right hand, located at or toward the rear of the saw.
21. Rear Hand Guard
Gives added protection to operator’s right hand.
Guide Bar Nose
The exposed end of the guide bar. (not illustrated, see chapter “Tensioning the Saw Chain”).
Clutch
Couples engine to chain sprocket when engine is accelerated beyond idle speed. (not illustrated).
Anti-Vibration System
The anti-vibration system includes 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).
044 3
Safety Precautions
The use of any chainsaw may 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.
!
Warning!
Reactive forces, including kickback, can be dangerous. Careless or improper use of any chainsaw may cause serious or fatal injury.
All safety precautions that are generally observed when working with an ax or a hand saw also apply to the operation of chainsaws. However, because a chainsaw is a high-speed, fast-cutting power tool, special safety precautions must be observed to reduce the risk of personal injury.
Have your STIHL dealer show you how to operate your chainsaw. Observe all applicable local safety regulations, standards and ordinances.
!
Warning!
Minors should never be allowed to use a chainsaw. Bystanders, especially children, and animals should not be allowed in the area where a chainsaw is in use. 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 chainsaw without the Owner‘s Manual. Be sure that anyone using your
saw reads and understands the information contained in this manual.
These safety precautions and warnings apply to the use of all STIHL chainsaws. 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 chainsaw involves
1. the operator
2. the saw
3. 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 chainsaw when you are fatigued. Be alert – If you get tired while operating your chainsaw, take a break. Tiredness may result in loss of control. Working with any chainsaw can be strenuous. If you have any condition that might be aggravated by strenuous work, check with your doctor before operating a chainsaw.
!
Warning!
Prolonged use of chainsaws (or other machines) exposing the operator to vibrations may produce whitefinger disease (Raynaud’s phenomenon) or carpal tunnel syndrome. These conditions
4
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 whitefinger 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:
– Many STIHL models are available
with an anti-vibration (“AV”) system designed to reduce the transmission of vibrations created by the engine and cutting attachment to the operator’s hands. An AV system is recommended for those persons using chainsaws on a regular or sustained basis.
– Wear gloves and keep your hands
warm. Heated handles, which are available on most STIHL powerheads, are recommended for cold weather use.
– Keep the saw chain sharp and the
saw, including the AV system, well maintained. A dull chain will increase cutting time, and pressing a dull chain through wood will increase the vibrations transmitted to your hands. A saw with loose components or with damaged or worn AV buffers will also tend to have higher vibration levels.
– Maintain a firm grip at all times, but
do not squeeze the handles with constant, excessive pressures. 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 monitor closely the condition of their hands and fingers. If any of the above symptoms appear, seek medical advice immediately.
Proper Clothing
!Warning!
To reduce the risk of injury, the operator should wear proper protective apparel.
Clothing must be sturdy and snug-fitting, but allow complete freedom of movement. Avoid loose-
fitting jackets, scarfs, neckties, jewelry, flared or cuffed pants, unconfined long hair or anything that could become entangled with the saw or brush. Wear overalls or jeans with a reinforced cut retardant insert or cut retardant chaps.
Protect your hands with
gloves when handling
saw and saw chain.
Heavyduty, nonslip
gloves improve your grip
and protect your hands.
Good footing is most
important in chainsaw
work. Wear sturdy boots
with nonslip soles.
Steel-toed safety boots
are recommended.
To reduce the risk of injury to your eyes never operate a chainsaw unless wearing goggles or properly fitted safety glasses with adequate top and side protection complying with your national standard.
5
Wear an approved safety hard hat to protect your head. Chainsaw 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 USE OF THE SAW
Transporting the chainsaw
!
Warning!
Always stop the engine before putting a chainsaw down or carrying it. Carrying a chainsaw with the engine running is extremely dangerous.
THE SAW
Parts of the chainsaw; for illustrations and definitions of the parts see the chapter on “Main Parts of Saw”.
!
Warning!
Never modify a chainsaw 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.
Accidental acceleration of the engine can cause the chain to rotate. During operation, the powerhead muffler and the material around it reach extremely high temperatures. Avoid touching the hot muffler, 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 position.
Grip the front handle and place the muffler away from the body.
001BA027 LÄ
The chain guard (scabbard) should be over the chain and the guide bar, which should point backwards. When carrying your saw, the bar should be behind you.
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.
6
Preparation for the use of the saw
Take off the chain guard and inspect for safety in operation. 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 175.1-1991 chainsaw kickback standard" in this manual.
!
Warning!
Proper tension of the chain is extremely important. In order 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 chainsaw uses an oil-gasoline mixture for fuel (see chapter “Fuel” of your Owner’s Manual).
!
Warning!
Gasoline is an extremely flammable fuel. If spilled or ignited by a spark or other ignition source, it can cause fire and serious burn injury or property damage. Use extreme caution when handling gasoline or fuel mix.
Do not smoke or bring any fire or flame near the fuel or the chainsaw. Note that combustible fuel vapors may be vented from the fuel system.
Fueling Instructions
!Warning!
Fuel your chainsaw 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 conditions, and the venting system of the tank. In order to reduce the risk of burns or other personal injury from escaping gas vapor and fumes, remove the fuel filler cap on the STIHL product carefully so as to allow any pressure build-up in the tank to release slowly. Never remove 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.
!Warning!
Check for fuel leakage while refueling and during operation. 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. Take care not to get fuel on your clothing. If this happens, change your clothing immediately.
7
!
Warning!
Unit vibrations can cause an improperly tightened fuel filler cap to loosen or come off and spill quantities of fuel. In order to reduce the risk of fuel spillage and fire, tighten fuel filler cap by hand with as much force as possible.
The screwdriver end of the STIHL combination wrench or other similar tool can be used as an aid in tightening slotted fuel filler caps.
Starting
The chain brake must be engaged when starting the saw.
Ä
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143BA019 KN
!
Warning!
Your chainsaw is a one-person saw. Do not allow other persons to be near the running chainsaw. Start and operate your saw without assistance. For specific starting instructions, see the appropriate section of the Owner’s Manual. Proper starting methods reduce the risk of injury. Do not drop start. This method is very dangerous because you may lose control of the saw.
There are two recommended methods for starting your chainsaw.
8
With the first method, the chainsaw is started on the ground. Make sure the chain brake is engaged (see “Chain Brake” chapter in your Owner’s Manual) and place the chainsaw 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 right foot 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 chainsaw allows you to start the saw without placing it on the ground. Make sure the chain brake is engaged, grip the front handle of the chainsaw firmly with your left hand. Keep your arm on the front handle in a locked (straight) position. Hold the rear handle of the saw tightly 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 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, if the chainbrake is not activated, turn the chain. If the upper quadrant of the tip of the bar touches any object, it may cause kickback to occur (see section on reactive forces). To reduce this risk, always engage the chain brake before starting. Never attempt to start the chainsaw when the guide bar is in a cut or kerf.
!
Warning!
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 may damage the starter mechanism.
Important adjustments
!
Warning!
To reduce the risk of personal injury from loss of control or contact with the running chain, do not use a saw with incorrect idle adjustment. At correct idle speed, the chain should not rotate. For directions to adjust idle speed, see the appropriate section of your Owner’s Manual. 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.
Working Conditions
Operate the chainsaw under good visibility and daylight conditions only.
!
Warning!
Your chainsaw produces poisonous exhaust fumes as soon as the combustible engine is running.
These gases (e.g. carbon monoxide) may be colorless and odorless.
To reduce the risk of serious or fatal injury from breathing toxic fumes, never run the chainsaw indoors or in poorly ventilated locations. Ensure proper ventilation when working in trenches or other confined areas.
!W
Warning!
Use of this product (including sharpening the saw chain) can generate dust, mists and fumes containing chemicals known to cause respiratory disease, cancer, birth defects, or other reproductive harm. If you are unfamiliar with the risks associated with the particular dust, mist or fume at issue, consult your employer, governmental agencies such as OSHA and NIOSH and other sources on hazardous materials. California and some other authorities, for instance, have published lists of substances known to cause cancer, reproductive toxicity, etc.
Control dust (such as sawdust), mists (such as oli mist from chain lubrication) and fumes at the source where possible. In this regard use good work practices and follow the recommendations of OSHA / NIOSH and occupational and trade associations. When the inhalation of toxic dust, mists and fumes cannot be
9
eliminated, the operator and any bystanders should always wear a respirator approved by NIOSH / MSHA for the type substance at issue.
!
Warning!
Breathing asbestos dust is dangerous and can cause severe or fatal injury, respiratory illness or cancer. The use and disposal of asbestos containing products have been strictly regulated by OSHA and the Environmental Protection Agency. Do not cut or disturb asbestos, asbestos containing products (e.g. asbestos containing drywall or other construction products), or products such as pipes which are wrapped or covered with asbestos insulation. If you have any reason to believe that you might be cutting asbestos, immediately contact your employer or a local OSHA representative.
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. Don’t work alone. Keep within calling distance of others in case help is needed.
Your chainsaw is equipped with a chain catcher. It is designed 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 personal injury, do not operate a chainsaw with a damaged or missing catcher.
Inspect buffers periodically. Replace damaged, broken or excessively worn buffers immediately, since they may result 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.
!
Warning!
Avoid stumbling on obstacles such as stumps, roots or rocks and watch out for holes or ditches. Clear the area where you are working. Be extremely cautious when working on slopes or uneven ground. There is increased danger of slipping on freshly debarked logs.
!
Warning!
To reduce the risk of serious or fatal injury to the operator or bystanders, never use the saw
with one hand. You cannot control reactive forces 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.
10
Ä
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 thumb and forefinger. With your hands in this position, you 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 chainsaw handles and grip are in good condition and free of moisture, pitch, oil or grease.
!
Warning!
Do not operate your chainsaw with the starting throttle lock engaged. Cutting with the starting throttle lock engaged does not permit the operator proper control of the saw or chain speed.
001BA087 L
!
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 period after the throttle trigger is released.
!
Warning!
Do not cut any material other than wood or wooden objects. Use your chainsaw for cutting only. It is not designed for 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.
Such objects may be flung off, damage the saw chain or cause the saw to kickback.
!
Warning!
In order to keep control of your saw, always maintain a firm foothold.
001BA018 LA
Never work on a ladder, or on any other insecure support. Never use the saw above shoulder height.
!
Warning!
Never work in a tree unless you have received specific, professional training for such work, are properly secured (such as tackle and harness system or a lift bucket), have both hands free for operating the chainsaw in a cramped environment and have taken proper precautions to avoid injury from falling limbs or branches.
Ä
001BA031 L
11
Ä
Position the chainsaw in such a way that your body is clear of the cutting attachment whenever the engine is running. Stand to the left of cut while bucking.
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 may cause the moving chain to strike the operator.
Reactive forces including kickback
!
Warning!
Reactives forces may occur any time the chain is rotating. Reactives forces can be dangerous! In any chainsaw, the
001BA082 KN
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 reactive 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 reactive forces may helpyou avoid loss of control.
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.
001BA093 L
Ä
001BA035 L
The reaction of the cutting force of the chain causes a rotational force on the chainsaw in the direction opposite to the chain movement. This may fling the bar up and back in an uncontrolled arc mainly in the plane of the bar. Under some cutting circ*mstances the bar moves towards the operator, who may suffer severe or fatal injury.
Kickback may occur when the nose of the guide bar is pinched unexpectedly, unintentionally contacts solid material in the wood or is incorrectly used to begin a plunge or boring cut.
12
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. 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 factor 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.
ANSI B 175.1-1991 chainsaw kickback standard
Section 5.12 of ANSI standard B 175.1– 1991, sets certain performance and design criteria related to chainsaw kickback. To comply with section 5.12 of ANSI B
175.1-1991:
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.
– and must be equipped with at least
two devices to reduce 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.
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 § 5.12 of ANSI B 175.1-1991 may bear no relationship to actual kickback bar rotation
angles that may occur in real life cutting situations. Compliance with § 5.12 of ANSI B 175.1-1991 does not automatically 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 displacement to comply with the computed kickback angle requirements of § 5.12 of ANSI B 175.1-1991 use only the 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 powerhead or
– replacement chain designated
“low kickback saw chain’’. See the section on "Low kickback saw chain and reduced kickback bars"
13
Devices for reducing the risk of kickback injury
STIHL recommends the use of the STIHL Quickstop chain brake on your powerhead with green labeled reduced kickback bars and low kickback chains.
!
Warning!
To reduce the risk of injury, stop using the saw immediately if the chain brake does not function properly. Take the saw to your local STIHL Service Centre! Do not use the saw until the problem has been rectified (see the section “Chain Brake”).
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 available as standard equipment on your STIHL chainsaw 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 the front handle behind the hand guard, and if the left hand rotates around the front handle and makes a sufficiently forceful contact with the front hand guard, which is the Quickstop activating lever, this contact will activate the Quickstop. The chain brake on most new model STIHL chainsaws can also be activated by inertia. See the chapter entitled “Chain Brake” of your Owner’s Manual.
!
Warning!
Never operate your chainsaw 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 kickback. These devices are designed to reduce the risk of kickback injury, if activated, in certain kickback situations. In order for the Quickstop to reduce the risk of kickback
001BA036 LA
injury, it must be properly maintained and in good working order. See the chapter entitled “Chain Brake” and “Maintenance, Repair and Storing” of your Owner’s Manual. In addition, there must be enough distance between the bar and the operator to ensure that the Quickstop has sufficient time to activate and stop the chain before potential contact with the operator.
14
!
Warning!
An improperly maintained chain brake may increase the time needed to stop the chain after activation, or may not activate at all.
!
Warning!
Never run the chainsaw above idle speed for more than 3 seconds when the chain brake is engaged or the chain is pinched or otherwise caught in the cut. Clutch slippage can cause excessive heat, leading to severe damage of the motor housing, clutch and oiler component and may interfere with the operation of the chain brake. If clutch slippage in excess of 3 seconds has occured, allow the motor housing to cool before proceeding and check the operation of your chain brake as described in the chapter entitled “Chain Brake”. Also make sure that the chain is not turning at idle speed (see above “Important Adjustments”).
Low kickback saw chain and reduced kickback bars"
STIHL offers a variety of bars and chains. STIHL reduced kickback bars and low kickback chains are designed to
reduce the 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 kickback chains. Cutting attachments with green warning decals or green labels on the packaging are designed to reduce the risk of kickback injury. The matching of green decaled powerheads under 3.8 cubic inch displacement with green labeled bars and green labeled chains gives compliance with the computed kickback angle requirements of ANSI B
175.1-1991 when the products are in their original condition. Products with yellow decals or labels are for users with extraordinary cutting needs and experience and specialized training for dealing with kickback.
STIHL recommends the use of its green labeled reduced kickback bars, green labeled low kickback chains and a STIHL Quickstop chain brake for both experienced and inexperienced chainsaw users.
Please ask your STlHL dealer to properly match your powerhead 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 Bar and Chain Information” leaflet for details.
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Warning!
Use of other, non-listed bar/chain combinations may increase kickback forces and increase the risk of kickback injury. New bar/chain combinations may be developed after publication of this literature, which will, in combination with certain powerheads, comply with § 5.12 of ANSI B 175.1-1991. Check with your STIHL dealer for such combinations.
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Warning!
Reduced kickback bars and low kickback chains do not prevent kickback, but they are designed to reduce the risk of kickback injury. They are available from your STIHL dealer.
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Warning!
Even if your saw is equipped with a Quickstop, a reduced kickback bar and/or low kickback chain, this does not eliminate the risk of injury by kickback. Therefore, always observe all safety precautions to avoid kickback situations.
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