Stihl HS 45 Instruction Manual

STIHL HS 45

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.

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 3 Using the Unit 12 Fuel 13 Fueling 15 Starting / Stopping the Engine 16 Operating Instructions 18

Original Instruction ManualPrinted on chlorine-free paper

Cleaning the Air Filter 18 Engine Management 19 Adjusting the Carburetor 19 Spark Plug 20 Engine Running Behavior 22 Lubricating the Gearbox 22 Storing the Machine 23 Sharpening Instructions 23 Inspections and Maintenance by

Dealer 23 Maintenance and Care 24 Main Parts 26 Specifications 27 Maintenance and Repairs 28

Printing inks contain vegetable oils, paper can be recycled.

Disposal 28 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 trimmer.

To receive maximum performance and satisfaction from your STIHL hedge trimmer, 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 trimmer. 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 trimmer is a highspeed 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.

0458-253-8621-B. VA8.L21.

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HS 45

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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

Starting lock

Rotating rear handle

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 Remove the screw (1) N Pull the spark arresting screen (2)

upwards out of the muffler

In addition to the operating instructions, this manual may contain paragraphs that require your special attention. Such paragraphs are indicated 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.

described in this manual, please contact your STIHL dealer or the STIHL distributor for your area for assistance.

Symbols in Text

Many operating and safety instructions are supported by illustrations.

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

N A bullet indicates a step or

procedure.

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

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Safety Precautions and Working Techniques

Because a hedge trim mer is a high-speed, fastcutting power tool with sharp cutting blades, special safety precau tions must be observed to reduce the risk of per sonal 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.

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

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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.

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 protec tive glasses with adequate top and side protection complying with ANSI Z87 "+" (or your applicable national stand ard.) 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.

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

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

WARNING

Never modify this power tool in any way. Only attachments supplied by STIHL or expressly approved by STIHL for use

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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.

It may be carried only in the horizontal position. Grip the front handle and keep the hot muffler away from your body and the cutter blades behind you.

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.

WARNING

Gasoline is an extremely flammable fuel. If spilled and ignited by a spark or other ignition source, it can cause fire and seri ous 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 combus tible fuel vapor may escape from the fuel system.

Fueling Instructions

WARNING

To reduce the risk of fire and serious personal injury, always place the power tool on the ground before attempting to fuel the machine.

WARNING

HS 45

Fuel Your STIHL power tool uses an oil-

gasoline mixture for fuel (see the "Fuel" chapter in this instruction manual).

Pick a Safe Location To reduce the risk of fire and explosion,

fuel your power tool in a well-ventillated area, outdoors away from flames, pilot lights, heaters, electric motors, and other sources of ignition. Vapors can be ignited by a spark or flame many feet away. Select bare ground for fueling and

English

move at least 10 feet (3 m) from the fueling spot before starting the engine. Wipe off any spilled fuel before starting your power tool. Take care not to get fuel on your clothing. If this happens, change your clothing immediately.

Allow the Power Tool to Cool Before Removing the Fuel Cap

WARNING

Gasoline vapor pressure may build up inside the fuel tank. The amount of pressure depends on a number of factors such as the fuel used, altitude and temperature. To reduce the risk of burns and other personal injury from escaping gas, vapor and fumes, always shut off the engine and allow it to cool before removing the fuel cap.

The engine is air cooled. When it is shut off, cooling air is no longer drawn across the cylinder and engine temperatures will rise for several minutes before starting to cool. In hot environments, cooling will take longer. To reduce the risk of burns and other personal injury from escaping gas, vapor and fumes, allow the power tool to cool. If you need to refuel before completing a job, turn off the machine and allow the engine to cool before opening the fuel tank.

Fuel Spraying or “Geysering”

WARNING

Removing the cap on a pressurized fuel tank can result in gasoline, vapors and fumes being forcefully sprayed out from the fuel tank in all directions. The escaping gasoline, vapors or fumes can cause serious personal injury, including fire and burn injury, or property damage.

Sometimes also referred to as "fuel geysering," fuel spraying is an expulsion of fuel, vapors and fumes which can occur in hot conditions, or when the engine is hot, and the tank is opened without allowing the power tool to cool adequately. It is more likely to occur when the fuel tank is half full or more.

Pressure is caused by fuel and heat and can occur even if the engine has not been running. When gasoline in the fuel tank is heated (by ambient temperatures, heat from the engine, or other sources), vapor pressure will increase inside the fuel tank.

Some blends of gasoline, particularly those designed for use in winter, are more volatile and may cause tanks to pressurize more quickly or create greater pressure. At higher altitudes, fuel tank pressurization is more likely.

How to Avoid Fuel Spraying Removing the fuel cap on a pressurized

tank can result in gasoline, vapors and fumes being forcefully sprayed out from the fuel tank in all directions. To reduce the risk of burns, serious injuries or property damage from fuel spraying:

– Follow the fueling instructions in this

chapter.

– Always assume your fuel tank is

pressurized.

– Allow the power tool to cool before

removing the fuel cap.

– In hot environments, cooling will

take longer.

– The engine is air cooled. When it is

shut off, cooling air is no longer drawn across the cylinder and the engine temperature will rise for several minutes before starting to cool.

After the power tool has cooled appropriately, follow the safety instructions in this chapter for removing the cap.

Never remove the fuel filler cap by turning it directly to the open position. First check for residual pressure in the tank by slowly turning the cap approximately 1/2 turn counterclockwise. The cap should be held in place by the threads while allowing residual vapor/pressure to be relieved. Once the fumes or vapor have been relieved, turn the cap further until it can be removed from the tank opening.

Use only good quality fuel that is appropriate for the season (summer v. winter blends). Some blends of gasoline, particularly winter blends, are more volatile and can contribute to fuel spraying.

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Removing the Threaded Fuel Filler Cap

WARNING

After allowing the power tool to cool, remove the fuel filler cap slowly and carefully to allow any remaining pressure build-up in the tank to release:

– While maintaining steady,

downward pressure, slowly turn the cap approximately 1/2 turn counterclockwise.

– If any significant venting occurs,

immediately re-seal the tank by turning the cap clockwise to the closed position. Allow the power tool to cool further before attempting to open the tank.

– Turn the cap to the open position

only after the contents of the tank are no longer under pressure.

– Never remove the cap by turning it

directly to the open position. First allow the power tool to cool adequately and then release any residual pressure by slowly turning it approximately 1/2 turn counterclockwise.

– Never attempt to remove the cap

while the engine is still hot or running.

Installing the Threaded Fuel Filler Cap

WARNING

Unit vibrations can cause an improperly tightened fuel filler cap to loosen or come off and spill quanti ties of fuel. To reduce the risk of fuel spillage and fire, tighten the fuel filler cap by hand with as

much force as possible. Damaged or Broken Cap If your fuel cap does not tighten properly,

it may be damaged or broken. Stop using the power tool and take it to your authorized STIHL dealer for repair.

Vapor Lock

WARNING

Vapor lock occurs when fuel in the fuel line or carburetor vaporizes, causing bubbles to block the free flow of liquid fuel into the carburetor. Vapor lock cannot be relieved or affected by opening the fuel tank. Removing the fuel filler cap without first allowing the power tool to cool adequately can result in fuel spraying. Always follow the instructions in this section when removing the fuel cap.

To relieve vapor lock: – Press the manual fuel pump bulb at

least 20 to 30 times – even if the bulb is already filled with fuel – to clear the vapor and send liquid fuel into the carburetor. Then start the

power tool. For specific starting instructions, see the appropriate section of your instruction manual.

– If the manual fuel pump bulb will not

be filled, place the Choke Lever to the cold start position l and pull the starter cord until the engine runs or fires.

– If your power tool will not restart, or

if vapor lock occurs again, the power tool is being used in conditions too extreme for the fuel being used. Discontinue use and let the engine cool completely before attempting to start the power tool.

Before Operation Take off the blade scabbard and inspect

the power tool for proper condition and operation. (See the maintenance chart near the end of the instruction manual.)

WARNING

Always check your power tool for proper condition and operation before starting, particularly the throttle trigger, throttle trigger lockout, 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.

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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 power tool repaired by a STIHL servicing dealer before using it.

WARNING

Never operate your power tool if it is damaged, improperly adjusted or maintained, or not completely and 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, fuel mix, 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.

For specific starting instructions, see the appropriate section of your instruction manual.

Starting 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.

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, 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.

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

hands on the handles while you are working. Wrap your fingers and thumbs around the handles.

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Right-hand Use

Put your right hand on the rear handle, left hand on the front handle.

Operate the machine so that the cutting blades are always away from your body.

Left-hand Use

Put your left hand on the rear handle, right hand on the front handle.

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 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 gen erates toxic exhaust fumes containing chemi cals, such as unburned hydrocarbons (including benzene) and carbon monoxide, that are known to cause respira tory problems, cancer, birth defects, or other reproductive harm. Some of the gases (e.g. carbon monoxide) may be color less and odorless. To reduce the risk of serious or fatal injury / illness from inhaling toxic fumes, never run the machine indoors or in poorly venti lated 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

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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, as you do not have control of the engine speed.

In the event of an emergency, switch off the engine immediately – move the slide control / stop switch to 0 or STOP.

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

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.

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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.

WARNING

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 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 cata

lytic converter, which is

designed to reduce the

exhaust emissions of the

engine by a chemical pro

cess in the muffler. Due

to this process, the muf

fler does not cool down

as rapidly as conven

tional mufflers when the

engine returns to idle or

is shut off. To reduce the

risk of fire and burn inju

ries 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 com

bustible 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, 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

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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 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 power tool during other people's normal rest periods.

Cutting Sequence

Use lopping shears or a chain saw to cut out thick branches first.

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

Disposal

Do not throw cuttings in the garbage can – they can be composted!

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Working Technique

Vertical Cut

Swing the cutting blade from the bottom upwards in an arc – lower the nose of the blade, move along the hedge and then swing the blade up again in an arc.

Any working position above head height is tiring. To minimize the risk of accidents, work in such positions for short periods only.

Horizontal Cut

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

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

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.

HS 45

English

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 NMMA 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.

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 by hand to ensure proper mix of oil and gasoline.

WARNING

Shaking fuel can cause pressure to build in the fuel container. To reduce the risk of fire and severe personal injury or property damage from fuel spraying, allow the fuel container to sit for several minutes before opening. Open the container slowly to release any residual pressures. Never open the fuel container in the vicinity of any ignition source. Read and follow all warnings and instructions that accompany your fuel container.

Gaso line

US gal. US fl.oz.

12.6 2 1/2 6.4 5 12.8

Dispose of empty mixing-oil containers only at authorized disposal locations.

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

HS 45

English

253BA001 KN

002BA447 KN

Fueling

WARNING

Removing the cap on a pressurized fuel tank can result in gasoline, vapors and fumes being forcefully sprayed out from the tank in all directions. The escaping gasoline, vapors or fumes, sometimes referred to as fuel spraying or "geysering," can cause serious personal injury, including fire and burn injury, or property damage.

Fuel spraying can occur when the engine is hot and the tank is opened while under pressure. It can occur in hot environments even if the engine has not been running. Spraying is more likely to occur when the fuel tank is half full or more.

Avoid Injuries from Fuel Spraying. Always follow the fueling instructions in

this manual: – Treat every fuel tank as if it is

pressurized, particularly if it is half full or more.

– Always allow the power tool to cool

adequately before attempting to open the fuel tank or refueling; this will take longer in hot conditions.

– Never remove the cap by turning it

directly to the open position. Turn it first approximately 1/2 of a turn counter-clockwise to relieve any residual pressure.

– Never open the fuel tank while the

engine is still hot or running.

– Never open the fuel tank or re-fuel

the power tool near any sparks, flames or other ignition sources.

– Pick the right fuel: use only good

quality (89 octane or higher), fresh fuel blended for the season.

– Vapor lock: do not remove the fuel

cap in an effort to relieve vapor lock. Removing the cap has no effect on vapor lock.

– Be aware that fuel spraying is more

likely at higher altitudes.

Preparations

N Before fueling, clean the filler cap

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

N Position the machine so that the

filler cap is facing up.

WARNING

In order to reduce the risk of fire and other personal injury from escaping gas vapor and fumes, remove the fuel filler cap slowly and carefully so as to allow any pressure build-up in the tank to release slowly.

Opening

WARNING

After allowing the power tool to cool, remove the fuel filler cap slowly and carefully to allow any remaining pressure build-up in the tank to release:

N While maintaining steady,

downward pressure, slowly turn the cap approximately a 1/2 turn counter-clockwise.

N If any significant venting occurs,

immediately re-seal the tank by turning the cap clockwise to the closed position. Allow the power tool to cool further before attempting to open the tank.

N Turn the cap to the open position

only after the contents of the tank are no longer under pressure.

N Remove the fuel filler cap.

HS 45

English

002BA448 KN

253BA020 KN

253BA021 KN

WARNING

Never remove the cap by turning it directly to the open position. First allow the power tool to cool adequately and then release any residual pressure by slowly turning the cap approximately 1/2 turn counter-clockwise. Never attempt to remove the cap while the engine is still hot or running.

Refueling

Take care not to spill fuel while fueling and do not overfill the tank – leave approximately 1/2" (13 mm) air space.

Closing

N If your fuel cap still does not tighten

properly, it may be damaged or broken. Stop using the power tool and take it to your authorized STIHL dealer for repair or replacement.

Starting / Stopping the Engine

N Observe safety precautions – see

chapter on "Safety Precautions and Working Techniques".

N Move the stop switch (1) to I. N Press down the throttle trigger

lockout (2) and squeeze the throttle trigger (3) – hold both levers in that position.

N Press in the starting throttle lock (4). N Let go of the throttle trigger lockout,

throttle trigger and starting throttle lock. This is the starting throttle position.

WARNING

An improperly tightened fuel filler cap can loosen or come off and spill quantities of fuel. To reduce the risk of fuel spillage and fire from an improperly installed fuel cap, tighten the fuel filler cap by hand with as much force as possible:

N Set the choke lever (5) to

l if the engine is cold j for warm start – also use this posi

tion if the engine has been running but is still cold.

HS 45

English

253BA022 KN

N Press the manual fuel pump

bulb (6) at least five times – even if the bulb is filled with fuel.

Cranking

N Place the unit on the ground. N Remove the blade scabbard. Check

that the cutting blades are not touching the ground or any other obstacles.

N Make sure you have a safe and

secure footing.

N Hold the unit firmly with your left

hand on the front handle and press down.

N Pull the starter grip slowly with your

right hand 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.

If the engine is cold (choke lever set to l)

N Pull the starter rope five times. N Set choke lever to j and N continue cranking until the engine

runs.

If conditions are unfavorable and the engine does not start after 10 pulls with the choke lever set to j :

N Set choke lever to l and pull

starter rope five times. Set choke lever to j and continue cranking.

If the engine is warm (choke lever set to j)

N Continue cranking until the engine

runs.

As Soon as Engine Runs

N Blip the throttle trigger – the engine

settles down to idle speed.

If the engine stops during warm-up or acceleration

N Repeat the starting procedure as

described under "If the engine is cold".

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 Move the stop switch to O.

Other Hints on Starting

If the engine does not start N Make sure all settings are correct

(choke lever, throttle trigger in starting throttle position, stop switch to I).

N Repeat the starting procedure. If the engine still does not start N Remove the spark plug – see

"Spark Plug".

N Dry the spark plug. N Open the throttle wide. N Crank the engine several times with

the starter to clear the combustion chamber.

N Install the spark plug – see "Spark

Plug".

N Move the stop switch to I. N Set choke lever to j – even if the

engine is cold.

N Now start the engine.

HS 45

English

253BA023 KN

253BA008 KN

If fuel tank has been run completely dry and then refueled

N Press the manual fuel pump

bulb (6) at least five times – even if the bulb is filled with fuel.

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

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".

If there is a noticeable loss of engine power

N Move the choke lever to l. N Press in the tab (1) and swing the

filter cover (2) down.

N Clean away loose dirt from around

the filter.

HS 45

253BA024 KN

Engine Management Adjusting the Carburetor

253BA018 KN

English

N Remove the foam element (3) and

felt element (4).

N Wash the foam element in a clean,

non-flammable solution (e.g. soapy water) and then dry.

N Fit a new felt element. As a

temporary measure you can knock it out on the palm of your hand or blow it out with compressed air. Do not wash.

N Replace any damaged parts. N Fit the foam element (3) in the filter

cover (2) and the felt element (4) in the filter housing (5).

N Close the filter cover so that it snaps

into position.

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

General Information

The carburetor comes from the factory with a standard setting.

This setting provides an optimum fuel-air mixture under most operating conditions.

Preparations

N Shut off the engine. N Check the air filter and clean or

replace if necessary.

N Inspect cutting blades and clean if

necessary (clean, move freely, not warped).

Standard Setting

HS 45

N Turn high speed screw (H)

counterclockwise as far as stop (no more than 3/4 turn).

N Turn the low speed screw (L)

clockwise as far as stop, then turn it back 3/4 turn.

English

253BA016 KN

Adjusting Idle Speed

N Carry out the standard setting. N Start and warm up the engine.

N Adjust idle speed with the idle speed

screw (LA) so that the cutting blades do not run.

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

slowly clockwise until the engine runs smoothly – the cutting blades must not run.

Cutting blades run when engine is idling N Turn the idle speed screw (LA)

counterclockwise until the cutting blades stop moving – then turn it another 1/2 to 1 turn in the same direction.

N Turn the low speed screw (L) slowly

counterclockwise until the engine runs and accelerates smoothly.

It is usually necessary to change the setting of the idle speed screw (LA) after every correction to the low speed screw (L).

Fine Tuning for Operation at High Altitude

A slight correction of the setting may be necessary if engine does not run satisfactorily:

N Carry out the standard setting. N Warm up the engine. N Turn high speed screw (H) slightly

clockwise (leaner) – no further than stop.

NOTICE

After returning from high altitude, reset the carburetor to the standard setting.

If the setting is too lean there is a risk of engine damage due to insufficient lubrication and overheating.

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 approximately 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 Move the stop switch to O.

253BA030 ST

WARNING

If the cutting blades continue moving when the engine is idling, have your power tool checked and repaired by your servicing dealer.

Erratic idling behavior, poor acceleration (despite correction to setting of LA screw).

Idle setting is too lean

N Pull off the spark plug boot. N Unscrew the spark plug.

HS 45

English

000BA039 KN

0000-GXX-1830-A0

Checking the spark plug

N Clean the spark plug if it is dirty N Check the electrode gap (A) and

readjust if necessary – see "Specifications"

N Use only resistor type spark plugs of

the approved range. See the chapter "Specifications" in this instruction manual

Correct the problems that have caused fouling of the spark plug:

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

operating at part throttle.

Installing the spark plug

N Fit the spark plug by hand and

screw it in

N Tighten spark plug with combination

wrench

N Press the spark plug boot firmly

onto the spark plug

WARNING

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

HS 45

+ 53 hidden pages

Stihl HS 45 Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual