Stihl HL 91 K User Manual

STIHL HL 91 K

WARNING

Read Instruction Manual thoroughly before use and follow all safety precautions – improper use can cause serious or fatal injury.

ADVERTENCIA

Antes de usar la máquina lea y siga todas las precauciones de seguridad dadas en el manual de instrucciones – el uso incorrecto puede causar lesiones graves o mortales.

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Instruction Manual Manual de instrucciones

Instruction Manual 1 - 34

Manual de instrucciones 35 - 73

Contents

English

Guide to Using this Manual 2 Safety Precautions and Working

Techniques 2 Using the Unit 11 Approved Power Tool Attachments 12 Assembling the Unit 13 Fuel 14 Fueling 15

Original Instruction ManualPrinted on chlorine-free paper

Starting / Stopping the Engine 16 Operating Instructions 18 Cleaning the Air Filter 18 Engine Management 19 Adjusting the Carburetor 19 Spark Plug 20 Lubricating the Gearbox 21 Sharpening Instructions 21 Storing the Machine 22 Inspection and Maintenance by

User 22 Inspections and Maintenance by

Dealer 23 Maintenance and Care 24

Printing inks contain vegetable oils, paper can be recycled.

Main Parts 26 Specifications 28 Maintenance and Repairs 28 Disposal 29 Limited Warranty 29 STIHL Incorporated Federal

Emission Control Warranty Statement 29

STIHL Incorporated California Exhaust and Evaporative Emissions Control Warranty Statement 31

Trademarks 33

Allow only persons who fully 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, understand and follow the safety precautions and the operating and maintenance instructions in chapter "Safety Precautions and Working Techniques" before using your hedge cutter. For further information you can go to www.stihlusa.com.

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.

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HL 91 K

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Guide to Using this Manual

Pictograms

The meanings of the pictograms attached to or embossed on the machine are explained in this manual.

Depending on the model concerned, the following pictograms may be on your machine.

Fuel tank for gasoline and engine oil mixture

Press to operate manual fuel pump

Filler hole for gear lubricant

Symbols in Text

Many operating and safety instructions are supported by illustrations.

The individual steps or procedures described in the manual may be marked in different ways:

N A bullet marks a step or procedure. A description of a step or procedure that

refers directly to an illustration may contain item numbers that appear in the illustration. For example:

N Loosen the screw (1). N 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 and signal words described below:

DANGER

Indicates a hazardous situation that, if not avoided, will result in death or serious injury.

WARNING

Indicates a hazardous situation that, if not avoided, could result in death or serious injury.

NOTICE

Indicates a risk of property damage, including damage to the machine or its individual components.

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. Therefore, some changes, modifications and improvements may not be covered in this manual. If the operating characteristics or the appearance of your machine differs from those described in this manual, please contact your STIHL dealer or the STIHL distributor for your area for assistance.

Safety Precautions and Working Techniques

Because a hedge trimmer is a high-speed, fastcutting 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.

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WARNING

Do not use it for other purposes, since misuse may result in personal injury or property damage, including 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.

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 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:

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 elements 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.

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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 Z87 "+" (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.

Wear an approved safety hard hat to reduce the risk of injury to your head when there is a danger of head injuries.

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.

Always wear heavy duty work gloves (e.g. made of leather or other wear resistant material) when handling the machine and the cutting tool. Heavy-duty, nonslip gloves improve your grip and help to protect your hands.

Clothing must be sturdy and snug-fitting, but allow complete freedom of movement. Wear long pants made of heavy material to help protect your legs. Do not wear shorts, sandals or go barefoot.

Avoid loose-fitting jackets, scarfs, neckties, jewelry, flared or cuffed pants, unconfined long hair or anything that could become caught on branches, brush or the moving parts of the unit. Secure hair so it is above shoulder level.

Good footing is very important. Wear sturdy boots with nonslip soles. Steel-toed safety boots are recommended.

THE POWER TOOL

WARNING

Never modify this power tool in any way. Only attachments supplied by STIHL or expressly approved by STIHL for use with the specific STIHL model are authorized. Although certain unauthorized attachments are useable with STIHL power tools, their use may, in fact, be extremely dangerous.

If this tool is subjected to unusually high loads for which it was not designed (e.g. heavy impact or a fall), always check that it is in good condition before continuing work. Check in particular that the fuel system is tight (no leaks) and that the controls and safety devices are working properly. Do not continue operating this machine if it is damaged. In case of doubt, have it checked by your STIHL servicing dealer.

THE USE OF THE POWER TOOL

Transporting the Power Tool

WARNING

To reduce the risk of injury from blade contact, never carry or transport your power tool with the cutter blades moving.

For illustrations and definitions of the power tool parts see the chapter on "Main Parts and Controls".

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002BA247 KN

It may be carried only in a horizontal position. Grip the shaft in a manner that the machine is balanced horizontally. Keep the hot muffler away from your body and the cutting attachment behind you.

WARNING

To reduce the risk of burn injury, do not touch hot parts of the machine and the gear housing when they are hot.

WARNING

Always switch off the engine and fit the scabbard over the cutter blades before transporting the power tool over long distances. When transporting it in a vehicle, properly secure it to prevent turnover, fuel spillage and damage to the unit.

On machines with an adjustable cutter bar: Make sure the cutter bar is secured in position. See chapter in instruction manual entitled "Adjusting Cutter Bar Angle." On machines with a transport position: Move cutter bar to transport position and secure.

Fuel Your STIHL power tool uses an oil-

gasoline mixture for fuel (see the chapter on "Fuel" of your instruction manual).

WARNING

Gasoline is an extremely flammable fuel. If spilled and 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 power tool. Note that combustible fuel vapor may escape from the fuel system.

Fueling Instructions

WARNING

To reduce the risk of serious injury from burns, never attempt to refuel the unit until it has been completely removed from the operator.

WARNING

Fuel your power tool in well-ventilated areas, outdoors. Always shut off the engine and allow it to cool before refueling. Gasoline vapor pressure may build up inside the fuel tank depending on the fuel used, the weather conditions and the tank venting system.

In order to reduce the risk of burns and other personal injury from escaping gas vapor and fumes, remove the fuel filler cap on your power tool carefully so as to allow any pressure build-up in the tank to release slowly. Never remove the fuel filler cap while the engine is running.

Select bare ground for fueling and move at least 10 feet (3 m) from the fueling spot before starting the engine. Wipe off any spilled fuel before starting your machine.

WARNING

Check for fuel leakage while refueling and during operation. If fuel leakage is found, do not start or run the engine until the leak is fixed and any spilled fuel has been wiped away. Take care not to get fuel on your clothing. If this happens, change your clothing immediately.

WARNING

In order to reduce the risk of fuel spillage and fire from an improperly tightened fuel cap, correctly position and tighten the fuel cap in the fuel tank opening.

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002BA245 KN

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 the fuel filler cap by hand as securely as possible.

See also the "Fueling" chapter in your Instruction Manual for additional information.

Before Starting

WARNING

Always check your power tool for proper condition and operation before starting, particularly the throttle trigger, throttle trigger lockout, throttle set wheel, stop switch and cutting tool. The throttle trigger must move freely and always spring back to the idle position. Never attempt to modify the controls or safety devices.

WARNING

Check fuel system for leaks, especially the visible parts, e.g., filler cap, hose connections, manual fuel pump (only for power tools equipped with a manual fuel pump). Do not start the engine if there are leaks or damage – risk of fire! Have the machine repaired by a servicing dealer before using it.

WARNING

Never operate your power tool if it is damaged, improperly adjusted or maintained, or not completely or securely assembled.

WARNING

Check that the spark plug boot is securely mounted on the spark plug – a loose boot may cause arcing that could ignite combustible fumes and cause a fire.

Keep the handles clean and dry at all times; it is particularly important to keep them free of moisture, pitch, oil, grease or resin in order for you to maintain a firm grip and properly control your power tool.

WARNING

The cutting tool must be properly tightened and in safe operating condition. Inspect for loose parts (nuts, screws, etc.) and for cracked, bent, warped or damaged blades. Regularly check the condition and tightness of the cutter blades – with the engine stopped! Replace damaged cutter blades before using the power tool. Always keep blades sharp.

STIHL recommends that you always spray the cutter blades with STIHL resin solvent before starting work – with the engine stopped! You can obtain this protective spray from your dealer. Apply generously.

Starting On machines with an adjustable cutter

bar: Secure the cutter bar in the starting position as described in the chapter "Starting/Stopping the Engine." If this starting position is not the desired cutting position, you will then need to carefully adjust the machine to the desired position once the engine has returned to idle and the blades are no longer moving.

On machines with a defined transport position (cutter bar folded against the drive tube): Never start the machine in the transport position, since the blades are not engaged in that position and you therefore cannot visually check to see that they will be stopped at idle when you start to adjust the cutter bar to the desired cutting position (where the blades are engaged).

Start the engine at least 10 feet (3 m) from the fueling spot, outdoors only.

For specific starting instructions, see the appropriate section of your manual. Place the power tool on firm ground or other solid surface in an open area. Maintain good balance and secure footing.

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002BA246 KN

WARNING

To reduce the risk of injury from blade contact, be absolutely sure that the cutting tool is clear of you and all other obstructions and objects, including the ground, because when the engine starts at starting-throttle or with the choke knob engaged, engine speed will be fast enough for the clutch to engage and move the blades on the cutting tool.

Once the engine has started, immediately blip the throttle trigger, which should release the starting throttle and allow the engine to slow down to idle.

WARNING

Your power tool is a one-person machine. Do not allow other persons in the general work area, even when starting.

WARNING

To reduce the risk of injury from loss of control, do not attempt to "drop start" your power tool.

WARNING

When you pull the starter grip, do not wrap the starter rope around your hand. Do not let the grip snap back, but guide the starter rope to rewind it properly. Failure to follow this procedure may result in injury to your 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 cutting tool, do not use your unit with incorrect idle adjustment. At correct idle speed, the cutting tool should not move. For directions on how to adjust idle speed, see the appropriate section of your instruction manual.

If you cannot set the correct idle speed, have your STIHL dealer check your power tool and make proper adjustments and repairs.

WARNING

This unit is equipped with an ignition system that is normally in operational readiness. After the stop switch is used to stop the engine, it automatically springs back to the "on" position. If the engine is warm, it may be possible to start it by simply pulling the starter rope, with no further adjustments. To reduce the risk of injury, be particularly alert to keep children away from the unit.

During Operation

Holding and Controlling the Power Tool Always hold the unit firmly with both

hands on the handles while you are working.

Models with loop handle

Place your left hand on hose grip of shaft and your right hand on rear grip and throttle trigger. Wrap your fingers and thumbs around the handles. This also applies to left-handers.

WARNING

Never attempt to operate your power tool with one hand. Loss of control of the power tool resulting in serious or fatal injury may result. To reduce the risk of cut injuries, keep hands and feet away from the cutting tool. Never touch a moving cutting tool with your hand or any other part of your body.

WARNING

Do not overreach. Keep proper footing and balance at all times. Special care must be taken in slippery conditions (wet ground, snow) and in difficult, overgrown terrain. Watch for hidden obstacles such as tree stumps, roots and ditches to avoid stumbling. For better footing, clear

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5m (17ft)

away fallen branches, scrub and cuttings. Be extremely cautious when working on slopes or uneven ground.

WARNING

To reduce the risk of injury from loss of control, never work on a ladder, in a tree or any other insecure support. Never hold the machine above shoulder height.

Working Conditions Operate and start your power tool only

outdoors in a well ventilated area. Operate it under good visibility and daylight conditions only. Work carefully.

WARNING

As soon as the engine is running, this product generates toxic exhaust fumes containing chemicals, such as unburned hydrocarbons (including benzene) and carbon monoxide, that are known to cause respiratory problems, cancer, birth defects, or other reproductive harm. Some of the gases (e.g. carbon monoxide) may be colorless and odorless. To reduce the risk of serious or fatal injury/illness from inhaling toxic fumes, never run the machine indoors or in poorly ventilated locations.

WARNING

If the vegetation being cut or the surrounding ground is coated with a chemical substance (such as an active pesticide or herbicide), read and follow the instructions and warnings that accompanied the substance at issue.

WARNING

Inhalation of certain dusts, especially organic dusts such as mold or pollen, can cause susceptible persons to have an allergic or asthmatic reaction. Substantial or repeated inhalation of dust and other airborne contaminants, in particular those with a smaller particle size, may cause respiratory or other illnesses. Control dust at the source where possible. Use good work practices, such as operating the unit so that the wind or operating process directs any dust raised by the power tool away from the operator. Follow the recommendations of EPA/OSHA/NIOSH and occupational and trade associations with respect to dust ("particulate matter"). When the inhalation of dust cannot be substantially controlled, i.e., kept at or near the ambient (background) level, the operator and any bystanders should wear a respirator approved by NIOSH/MSHA for the type of dust encountered.

Operating Instructions

WARNING

Do not operate your power tool using the starting throttle lock or with the choke knob engaged, as you do not have control of the engine speed.

In the event of an emergency, switch off the engine immediately by pressing the stop switch.

WARNING

The cutter blades continue to move for a short period after the throttle trigger is released (flywheel effect).

Accelerating the engine while the blades are blocked increases the load and will cause the clutch to slip continuously. This may result in overheating and damage to important components (e.g. clutch, polymer housing components) – which can then increase the risk of injury from the blades moving while the engine is idling.

WARNING

On units with an adjustable cutter bar: To reduce the risk of injury, never touch the blades while making adjustments.

The power tool has a large range. In order to reduce the risk of personal or even

fatal injury to bystanders from falling objects or inadvertent contact with the moving cutter blades of your power tool always keep bystanders at least 17 feet (5 m) away when the power tool is running.

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Stop the engine and cutting tool immediately if you are approached.

WARNING

Before you start work, examine the hedge area for stones, fence wire, metal or other solid objects which could damage the cutter blades.

Take particular care when cutting hedges next to or against wire fences. Do not touch the wire with the cutting blades. When working close to the ground, make sure that no sand, grit or stones get between the cutter blades.

Striking solid foreign objects such as stones, fence wire or metal could damage the cutting attachment and may cause blades to crack, chip or break. STIHL does not recommend the use of your power tool when cutting in areas where the blades could contact such objects.

WARNING

Observe the cutting blades at all times – do not cut any areas of the hedge that you cannot see. When cutting the top of a taller hedge, check the other side of the hedge frequently for bystanders, animals and obstructions.

DANGER

Your power tool is not insulated against electric shock. To reduce the risk of electrocution, never operate this power tool in the vicinity of any wires or cables (power, etc.) which may be carrying electric current.

WARNING

If the cutting tool becomes clogged or stuck, always turn off the engine and make sure the cutting tool has stopped before cleaning. Grass, weeds, etc. should be cleaned off the cutting tool at regular intervals.

Check the cutting blades at regular short intervals during operation, or immediately if there is a noticeable change in cutting behavior:

– Shut off the engine. – Wait until the cutting blades have

come to a complete standstill.

– Check condition and tightness, look

for cracks.

– Check sharpness. – Replace damaged or dull cutting

tools immediately, even if they have only superficial cracks.

WARNING

The gearbox becomes hot during operation. To reduce the risk of burn injury, do not touch the gear housing when it is hot.

WARNING

Never modify your muffler. Any modification could cause an increase in heat radiation, sparks or sound level, thereby increasing the risk of fire, burn injury or hearing loss. You may also permanently damage the engine. Have your muffler serviced and repaired by your STIHL servicing dealer only.

WARNING

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. Keep the area around the muffler clean. Remove excess lubricant and all debris such as pine needles, branches or leaves. Let the engine cool down sitting on concrete, metal, bare ground or solid wood (e.g. the trunk of a felled tree) away from any combustible substances.

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An improperly mounted or damaged cylinder housing or a damaged/deformed muffler shell may interfere with the cooling process of the muffler. To reduce the risk of fire or burn

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injury, do not continue work with a damaged or improperly mounted cylinder housing or a damaged/deformed muffler shell.

Your muffler is furnished with a spark arresting screen designed to reduce the risk of fire from the emission of hot particles. Never operate your unit with a missing or damaged spark arresting screen. If your gas/oil mix ratio is correct (i.e., not too rich), this screen will normally stay clean as a result of the heat from the muffler and need no service or maintenance. If you experience loss of performance and you suspect a clogged screen, have your muffler maintained by a STIHL servicing dealer. Some state or federal laws or regulations may require a properly maintained spark arrestor for certain uses. See the "Maintenance, Repair and Storing" section of these Safety Precautions. Remember that the risk of a brush or forest fire is greater in hot or dry conditions.

WARNING

Some STIHL power tools are equipped with a catalytic converter, which is designed to reduce the exhaust emissions of the engine by a chemical process in the muffler. Due to this process, the muffler does not cool down as rapidly as conventional mufflers when the engine returns to idle or is shut off. To reduce the risk of fire and burn injuries when using a catalytic converter, always set your power tool down in the upright position and never locate it where the muffler is near dry brush, grass, wood chips or other combustible materials while it is still hot.

After Finishing Work

Always clean dust and dirt off the machine – do not use any grease solvents for this purpose.

Spray the blades with STIHL resin solvent. Start and run the engine briefly so that the solvent is evenly distributed.

MAINTENANCE, REPAIR AND STORING

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 or if nonapproved replacement parts were used, STIHL may deny coverage.

WARNING

Use only identical STIHL replacement parts for maintenance and repair. Use of non-STIHL parts may cause serious or fatal injury.

Strictly follow the maintenance and repair instructions in the appropriate section of your instruction manual. Please also refer to the maintenance chart in this manual.

WARNING

Always stop the engine and make sure that the cutting blades are stopped before doing any maintenance or repair work or cleaning the power tool. Do not attempt any maintenance or repair work not described in your instruction manual. Have such work performed by your STIHL servicing dealer only.

Wear gloves when handling or performing maintenance on blades.

WARNING

Use the specified spark plug and make sure it and the ignition lead are always clean and in good condition. Always press spark plug boot snugly onto spark plug terminal of the proper size. (Note: If terminal has detachable SAE adapter nut, it must be securely attached.) A loose connection between spark plug terminal and the ignition wire connector

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in the boot may create arcing that could ignite combustible fumes and cause a fire.

WARNING

Never test the ignition system with the ignition wire boot removed from the spark plug or with a removed spark plug, since uncontained sparking may cause a fire.

WARNING

Do not operate your power tool if the muffler is damaged, missing or modified. An improperly maintained muffler will increase the risk of fire and hearing loss. Your muffler is equipped with a sparkarresting screen to reduce the risk of fire; never operate your power tool if the screen is missing, damaged or clogged. Remember that the risk of a brush or forest fire is greater in hot or dry weather.

In California, it is a violation of § 4442 or

§ 4443 of the Public Resources Code to use or operate gasoline-powered tools on forest-covered, brush-covered or grass-covered land unless the engine’s exhaust system is equipped with a complying spark arrester that is maintained in effective working order. The owner/operator of this product is responsible for properly maintaining the spark arrester. Other states or governmental entities/agencies, such as the U.S. Forest Service, may have similar requirements. Contact your local fire agency or forest service for the laws or regulations relating to fire protection requirements.

WARNING

Never repair damaged cutting attachments by welding, straightening or modifying the shape. This may cause parts of the cutting blades to come off and result in serious or fatal injuries.

Keep the cutting blades sharp. Tighten all nuts, bolts and screws, except the carburetor adjustment screws, after each use.

Do not clean your machine with a pressure washer. The solid jet of water may damage parts of the machine.

Store the power tool in a dry and high or locked location out of reach of children.

Before storing for longer than a few days, always empty the fuel tank. See chapter "Storing the machine" in this manual.

Using the Unit

Cutting Season

Observe country-specific or municipal rules and regulations for cutting hedges.

Do not use your hedge trimmer during rest periods customary in the neighborhood.

Cutting Sequence

If a radical cut is necessary, cut a little at a time in several stages.

Use lopping shears to cut out thick branches first.

Cut the sides of the hedge first, then the top.

Disposal

Do not throw cuttings into the garbage can – they can be composted.

Preparations

N Model with adjustable cutter bar:

Set the cutter bar to the straight (0°) position.

N Remove the blade scabbard. N Start the engine

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445BA001 KN

445BA007 KN

445BA002 KN

Working Techniques

Vertical Cut

Extra long reach without the need for other aids.

Swing the cutter bar up and down in an arc as you move along the hedge – use both sides of the cutting blades.

Horizontal Cut

Hold the cutter bar at an angle of 0° to 10° as you swing the hedge trimmer horizontally.

Approved Power Tool Attachments

The following STIHL attachments may be used with the basic power tool:

Interchangeable Attachment Application

HL 0°, 500 mm, with cutter guard

HL 0°, 600 mm, with cutter guard

Long reach hedge trimmer

Swing the cutter bar in an arc towards the outside of the hedge so that the cuttings are swept to the ground.

Recommendation: Only cut hedges that are no more than chest high.

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0000-GXX-1855-A0

Assembling the Unit

Mounting the Hand Guard

If a cap is fitted on the end of the drive tube:

N Pull the protective cap off the end of

the drive tube and keep it in a safe place.

N Push the hand guard (1) over the

drive tube (2) as far as stop with its convex side facing the control handle (3).

N Fit washer (4) on the screw (5). N Insert the screw (5) with washer (4)

and tighten it down firmly.

Mounting the Gearbox

N Loosen the clamp screws (10). N Push the gearbox (11) onto the

drive tube (5), turn the gearbox (11) back and forth as necessary.

0000-GXX-5443-A0

0000-GXX-1856-A0

Once the end of the drive tube is inserted beyond the slot in the clamp (12):

N Push the gearbox (11) fully home as

far as stop.

N Tighten down the clamp screws

moderately.

N Line up the gearbox (11) with the

powerhead.

N Tighten down the clamp screws

firmly.

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Fuel

This engine is certified to operate on unleaded gasoline and the STIHL twostroke engine oil at a mix ratio of 50:1.

Your engine requires a mixture of highquality gasoline and two-stroke air cooled engine oil.

Use mid-grade unleaded gasoline with a minimum octane rating of 89 ((R+M)/2) and no more than 10% ethanol content.

NOTICE

Fuel with an octane rating below 89 may increase engine temperatures. This, in turn, increases the risk of piston seizure and damage to the engine.

The chemical composition of the fuel is also important. Some fuel additives not only detrimentally affect elastomers (carburetor diaphragms, oil seals, fuel lines, etc.), but magnesium castings and catalytic converters as well. This could cause running problems or damage the engine. For this reason STIHL recommends that you use only quality unleaded gasoline!

NOTICE

Gasoline with an ethanol content of more than 10% can cause running problems and major damage in engines and should not be used.

For further details, see www.STIHLusa.com/ethanol

The ethanol content in gasoline affects engine speed – it may be necessary to readjust the carburetor if you use fuels with various ethanol contents.

WARNING

To reduce the risk of personal injury from loss of control and/or contact with the running cutting tool, do not use your unit with an incorrect idle adjustment. At correct idle speed, the cutting tool should not move.

If your machine’s idle speed is incorrectly adjusted, have your authorized STIHL servicing dealer check your machine and make the proper adjustments and repairs.

The idle speed and maximum speed of the engine change if you switch from a fuel with a certain ethanol content to a fuel with a much higher or lower ethanol content.

This problem can be avoided by always using fuel with the same ethanol content.

To ensure the maximum performance of your STIHL engine, use a high quality 2cycle engine oil. To help your engine run cleaner and reduce harmful carbon deposits, STIHL recommends using STIHL HP Ultra 2-cycle engine oil or ask your dealer for an equivalent fully synthetic 2-cycle engine oil.

To meet the requirements of EPA and CARB we recommend to use STIHL HP Ultra oil.

STIHL MotoMix

STIHL recommends the use of STIHL MotoMix. STIHL MotoMix has a high octane rating and ensures that you always use the right gasoline/oil mix ratio.

STIHL MotoMix uses STIHL HP Ultra two-stroke engine oil suited for high performance engines.

For further details, see www.STIHLusa.com/ethanol

If not using MotoMix, use only STIHL two-stroke engine oil or equivalent highquality two-stroke engine oils that are designed for use in air cooled two-cycle engines.

The use of non-seasonal gasoline blends may increase the potential for pressure to build in the fuel tank during operation. For example, using a winter blend during the summer will increase pressure in the fuel tank. Always use gasoline blends appropriate to the season, altitude and other environmental factors.

Do not use BIA or TCW rated (twostroke water cooled) mix oils or other mix oils that state they are for use in both water cooled and air cooled engines (e.g., outboard motors, snowmobiles, chain saws, mopeds, etc.).

WARNING

Take care when handling gasoline. Avoid direct contact with the skin and avoid inhaling fuel vapor. When filling at the pump, first remove the container from your vehicle and place the container on the ground before filling. To reduce the risk of sparks from static discharge and resulting fire and/or explosion, do not fill fuel containers that are sitting in or on a vehicle or trailer.

The container should be kept tightly closed in order to limit the amount of moisture that gets into the mixture.

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The machine‘s fuel tank should be cleaned as necessary.

Fuel mix ages

If not using MotoMix, only mix sufficient fuel for a few days of work, not to exceed 30 days of storage. Store in approved fuel-containers only. When mixing, pour oil into the container first, and then add gasoline. Close the container and shake it vigorously by hand to ensure proper mix of oil and gasoline.

Gasoline

Oil (STIHL 50:1 or equivalent high-quality oils)

US gal. US fl.oz.

12.6 2 1/2 6.4

512.8 Dispose of empty mixing-oil containers

only at authorized disposal locations.

Fueling

Preparations

WARNING

When fueling on a slope, always position the machine so that the filler cap is facing uphill.

N On level ground, position the

machine so that the filler cap is facing up.

N Before fueling, clean the filler cap

and the area around it to ensure that no dirt falls into the tank.

Always thoroughly shake the mixture in the canister before fueling your machine.

escape slowly. Use the proper seasonal gasoline blend, i.e., winter blend in winter, summer blend in summer.

Opening the screw cap

N Turn the cap counterclockwise until

it can be removed from the tank opening.

N Remove the filler cap.

Refueling

Take care not to spill fuel while fueling and do not overfill the tank.

Closing the screw cap

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WARNING

To reduce the risk of fire and personal injuries due to escaping fuel and vapor, remove the fuel filler cap carefully so that any excess pressure in the tank can

N Position cap. N Turn the cap clockwise as far as it

will go and tighten it as securely as possible by hand.

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Starting / Stopping the Engine

Controls

1 Throttle trigger lockout 2 Throttle trigger 3 Stop switch with Run and Stop

positions. Depress the stop switch (…) to switch off the ignition – see "Function of stop switch and ignition system".

4 Throttle set wheel – limits travel of

throttle trigger – see "Function of throttle set wheel".

Function of stop switch and ignition system

The ignition is switched off and the engine stopped when the stop switch is pressed. The stop switch returns automatically to the Run position when it

is released: The ignition is switched on again after the engine stops – the engine is then ready to start.

Function of throttle set wheel

The throttle set wheel (4) enables the travel of the throttle trigger to be preset anywhere between idle and full throttle.

– Turn throttle set wheel (4) in

direction of – to reduce throttle trigger travel and maximum engine speed.

– Turn throttle set wheel (4) in

direction of + to increase throttle trigger travel and maximum engine speed.

– It is possible to override the preset

stop and open the throttle wide by pulling the throttle trigger firmly – the preset stop remains unaffected. The original setting is restored when the throttle trigger is released.

Starting the Engine

N Press the manual fuel pump

bulb (5) at least five times – even if the bulb is already filled with fuel.

Cold engine (cold start)

N Turn choke knob (6) and then push

it in at g

Also use this setting if the engine has been running but is still cold.

– Turn throttle set wheel in direction of

+ as far as stop.

Hot engine (hot start) N Choke knob (6) remains in F

position.

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Cranking

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N Place the unit on the ground: It must

rest securely on the engine support and the gearbox housing.

N On units with an adjustable cutter

bar and defined transport position: Set the cutter bar to the straight (0°) position.

N If fitted: Remove blade scabbard

from the cutting blades.

To reduce the risk of accidents, check that the cutting blades are not touching the ground of any other obstacles.

N Make sure you have a firm footing,

either standing, stooping or kneeling.

N Hold the unit firmly on the ground

with your left hand and press down – do not touch the throttle trigger, lockout lever or stop switch.

NOTICE

Do not stand or kneel on the drive tube.

N Hold the starter grip with your right

hand.

N Pull the starter grip slowly until you

feel it engage and then give it a brisk strong pull.

NOTICE

Do not pull out the starter rope all the way – it might otherwise break.

N Do not let the starter grip snap back.

Guide it slowly back into the housing so that the starter rope can rewind properly.

N Continue cranking until the engine

runs.

As soon as the engine runs At temperatures below +10 °C (+50 °F) Warm up the engine for at least

10 seconds in position g. At temperatures above +10 °C (+50°F) Warm up the engine for at least

5 seconds in position g.

N Depress throttle trigger lockout and

pull the throttle trigger – the choke knob moves to the Run F position.

Warm up a cold engineat varying speeds.

WARNING

Make sure the carburetor is correctly adjusted. The cutting blades must not move when the engine is idling.

Your machine is now ready for operation.

Stopping the Engine

N Depress the momentary contact

stop switch – the engine stops – release the stop switch – it springs back to the run position.

Other Hints on Starting

Engine stalls in cold start position g. N Depress throttle trigger lockout and

pull the throttle trigger – the choke knob moves to the Run F position.

N Continue cranking in position F until

the engine runs.

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Running engine stalls in cold start position g or under acceleration.

N Continue cranking in position F until

the engine runs.

If the engine does not start

N Check that all settings are correct. N Check that there is fuel in the tank

and refuel if necessary.

N Check that the spark plug boot is

properly connected.

N Repeat the starting procedure. Engine is flooded N Move the choke knob to F and

continue cranking until the engine runs.

Fuel tank run until completely dry N After refueling, press the manual

fuel pump bulb at least five times – even if the bulb is already filled with fuel.

N Set the choke knob according to

engine temperature.

N Now start the engine.

Operating Instructions Cleaning the Air Filter

During break-in period

A factory-new machine should not be run at high revs (full throttle off load) for the first three tank fillings. This avoids unnecessary high loads during the break-in period. As all moving parts have to bed in during the break-in period, the frictional resistances in the engine are greater during this period. The engine develops its maximum power after about 5 to 15 tank fillings.

During Operation

After a long period of full throttle operation, allow the engine to run for a short while at idle speed so that engine heat can be dissipated by the flow of cooling air. This protects enginemounted components (ignition, carburetor) from thermal overload.

After Finishing Work

If there is a noticeable loss of engine power

N Set knob for warm start (1) to g N Turn screw (2) in filter cover (3)

counterclockwise until the cover is loose

N Remove filter cover (3) N Clean away loose dirt from around

the filter

Storing for a short period: Wait for the engine to cool down. Empty the fuel tank and keep the machine in a dry place, well away from sources of ignition, until you need it again. For longer out-ofservice periods – see "Storing the Machine".

N Grip into the recess (4) in the filter

housing and remove the felt filter (5)

N Replace felt filter (5) – as a

temporary measure you can knock it out on the palm of you hand or blow it out with compressed air – do not wash

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NOTICE

Replace any damaged parts! N Insert felt filter (5) form-fittingly into

the filter housing

N Set knob for warm start (1) to g N Fit filter cover (3) – make sure not to

tilt the screw (2) – insert screw and tighten

Engine Management Adjusting the Carburetor

Exhaust emissions are controlled by the design of the engine and components (e.g. carburation, ignition, timing and valve or port timing).

The carburetor of the machine has been adjusted at the factory for optimum performance and fuel efficiency in all operating states.

Setting the idle speed

Engine stops when idling N Turn the idle speed screw (LA)

slowly clockwise until the engine runs smoothly.

Cutting blades move when idling N Turn the idle speed adjusting

screw (LA) slowly counterclockwise until the cutting blades stop moving

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WARNING

If the cutting blades continue to move in idle even after adjustment, have the machine repaired by a STIHL servicing dealer.

English

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Spark Plug

If there is a loss of engine power, the machine is difficult to start or runs poorly at idle, first check the spark plug.

Install a new spark plug after approx. 100 operating hours or earlier if the electrodes are eroded/corroded.

The wrong fuel mix (too much engine oil in the gasoline), a dirty air filter and unfavorable running conditions (mostly at part throttle etc.) affect the condition of the spark plug. These factors cause deposits to form on the insulator nose, which may degrade performance.

Removing the spark plug

N Turn screw (1) in cap (2) until cap

can be removed

N Lay down cap

N Unplug spark plug boot (3) N Unscrew spark plug

Checking the Spark Plug

N Clean dirty spark plug. N Check electrode gap (A) and

readjust if necessary – see chapter "Specifications."

N Use only resistor type spark plugs of

the approved range.

Rectify problems which have caused fouling of spark plug:

– too much oil in fuel mix, – dirty air filter, – unfavorable running conditions, e.g.

operating at part load.

WARNING

To reduce the risk of fire and burn injury, use only spark plugs authorized by STIHL. Always press the spark plug boot (1) snugly onto the spark plug terminal (2).

Do not use a spark plug with a detachable SAE adapter terminal (3). Arcing may occur that could ignite combustible fumes and cause a fire. This can result in serious injuries or damage to property.

N Only use resistor type spark plugs

with solid, non-threaded terminals

Installing the Spark Plug

N Fit the spark plug and tighten it

down firmly.

N Press the boot firmly onto the spark

plug.

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N Fit the cap (1), insert the screw (2)

and tighten it down firmly.

Lubricating the Gearbox

Blade Drive Gear

Lubricate the blade drive gear with STIHL gear lubricant for hedge trimmers – see "Special Accessories".

HL 0° version

N Check the lubricant level at regular

intervals of about every 25 hours of operation. Unscrew the filler plug (1) – if no grease can be seen on the inside of the filler plug, screw the tube of grease into the filler hole.

N Squeeze up to 10 g (2/5 oz) grease

into the gearbox.

NOTICE

Do not completely fill the gearbox with grease.

N Unscrew the tube of grease from the

filler hole.

N Refit the filler plug and tighten it

down firmly.

Sharpening Instructions

When cutting performance and behavior begin to deteriorate, i.e. blades frequently snag on branches: Resharpen the cutting blades.

It is best to have the cutting blades resharpened by a dealer on a workshop sharpener. STIHL recommends an authorized STIHL servicing dealer.

It is also possible to use a flat crosscut sharpening file. Hold the sharpening file at the prescribed angle (see "Specifications").

N Only sharpen the cutting edges –

take care not to file the cutter guard (see “Main Parts”).

N Always file towards the cutting

edge.

N The file only sharpens on the

0000-GXX-1776-A0

forward stroke – lift it off the blade on the backstroke.

N Use a whetstone to remove burr

from cutting edge.

N Remove as little material as

possible.

N After sharpening, clean away filing

or grinding dust and then spray the cutting blades with STIHL resin solvent.

NOTICE

Do not operate your machine with dull or damaged cutting blades. This may cause overload and will give unsatisfactory cutting results.

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