Stihl MS 660 Instruction Manual [en, fr]

STIHL MS 660

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Instruction Manual Notice d’emploi

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Contents

English

Guide to Using this Manual 2 Safety Precautions 3 Reactive Forces 8 Working Techniques 9 Cutting Attachment 18 Mounting the Bar and Chain 19 Tensioning the Chain 20 Checking Chain Tension 20

Original Instruction ManualPrinted on chlorine-free paper

Fuel 20 Fueling 21 Chain Lubricant 22 Filling Chain Oil Tank 22 Checking Chain Lubrication 23 Chain Brake 23 Winter Operation 24 Electric Handle Heating 25 Starting / Stopping the Engine 25 Operating Instructions 29 Oil Quantity Control 30 Taking Care of the Guide Bar 30 Air Filter System 31 Remove air filter 32

Printing inks contain vegetable oils, paper can be recycled.

Cleaning the Air Filter 32 Engine Management 32 Adjusting the Carburetor 33 Spark Arresting Screen in Muffler 34 Spark Plug 35 Rewind Starter 36 Storing the Machine 36 Checking and Replacing the Chain

Sprocket 36

Maintaining and Sharpening the Saw Chain 37

Maintenance and Care 41 Main Parts 43 Specifications 45 Special Accessories 46 Ordering Spare Parts 46 Maintenance and Repairs 46 Disposal 47 Important Safety Instructions 47 Key to Symbols 49 CEPA guarantee 50 CSA Standard 52

Dear Customer, Thank you for choosing a quality

engineered STIHL product. It has been built using modern

production techniques and comprehensive quality assurance. Every effort has been made to ensure your satisfaction and troublefree use of the product.

Please contact your dealer or our sales company if you have any queries concerning this product.

Your

Dr. Nikolas Stihl

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0458-178-8221-B. VA8.M13.

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MS 660

English

Guide to Using this Manual

This Instruction Manual refers to a STIHL chain saw, also called a machine in this Instruction Manual.

Pictograms

Pictograms that appear on the machine are explained in this Instruction Manual.

Depending on the machine and equipment version, the following pictograms may appear on the machine.

Fuel tank; fuel mixture of gasoline and engine oil

Tank for chain oil; chain oil

Engage and release chain brake

Coasting brake

Intake air baffle: winter operation

Intake air baffle: summer operation

Handle heating

Actuate decompression valve

Actuate manual fuel pump

Symbols in text

WARNING

Warning where there is a risk of an accident or personal injury or serious damage to property.

Engineering improvements

STIHL's philosophy is to continually improve all of its products. For this reason we may modify the design, engineering and appearance of our products periodically.

Therefore, some changes, modifications and improvements may not be covered in this manual.

Direction of chain travel

Ematic; chain oil flow adjustment

Tension saw chain

NOTICE

Caution where there is a risk of damaging the machine or its individual components.

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Safety Precautions

Special safety precau tions must be observed when using a chain saw because the chain runs at very high speeds and the cutters are extremely sharp.

It is important you read and understand the Instruction Manual before first use and keep the manual in a safe place for future reference. Nonobservance of the Instruction Manual may result in serious or even fatal injury.

General compliance

Comply with national safety regulations issued, e. g. by employers' liability insurance associations, social security institutions, occupational safety and health authorities or other organisations.

The use of noise emitting machines may be restricted to certain times by national or local regulations.

If you have not used this machine before: Have your dealer or other experienced user show you how to operate your machine – or attend a special course in its operation.

Minors should never be allowed to use the machine – except for young trainees over the age of 16 when working under supervision.

Children, animals and bystanders must remain at a distance.

The user is responsible for avoiding injury to third parties or damage to their property.

Only lend or rent your machine to other persons with the Instruction Manual and only to people who are fully familiar with its use.

The machine may only be operated by people who are rested, in good physical condition and mental health. If you have any condition that might be aggravated by strenuous work, check with your doctor before operating a chain saw.

Anyone who has consumed alcohol, medicines affecting their ability to react or drugs must not operate the machine.

Postpone the work if the weather is bad (rain, snow, ice, wind) - higher risk of accidents!

If you have a pacemaker: The ignition system of this machine produces an electromagnetic field of very low intensity. An effect on individual pacemaker types cannot be excluded entirely. STIHL recommends that you consult your doctor and the manufacturer of your pacemaker in order to avoid health hazards.

Intended use

The machine may only be used to saw wood and wooden objects.

Do not the machine for any other purpose – risk of accidents!

Do not modify the machine in any way – this may increase the risk of personal injury. STIHL excludes all liability for personal injury and damage to property caused while using unauthorised attachments.

Clothing and equipment

Wear proper protective clothing and equipment.

Clothing must be sturdy and snug-fitting, but allow complete freedom of movement. Wear snug fitting clothing with cutretardant pads – no loose-fitting jacket.

Avoid clothing that could get caught on branches, brush or moving parts of the machine. Do not wear a scarf, necktie or jewellery. Tie up and confine long hair (headscarf, cap, hard hat, etc.).

Wear suitable safety shoes – with cut-retard ant material, non-slip soles and steel toe caps.

Wear a hard hat – if objects could fall on you. Wear safety glasses or a face shield and "per sonal" hearing protection – e. g., ear defenders.

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001BA115 KN

Wear sturdy protective gloves made of a resist

ant material (e.g. leather).

STIHL can supply a comprehensive range of personal protective clothing and equipment.

Transport

Before any transport – even over short distances – switch off the machine, engage the chain brake and attach the chain scabbard. This avoids the risk of the saw chain starting unintentionally.

Always carry the chain saw by the handle – with the hot muffler away from your body, the guide bar must point to the rear. Avoid touching hot parts of the machine, especially the surface of the muffler – risk of burns!

In vehicles: Properly secure the machine to prevent tipping, damage and chain oil or fuel spillage.

Cleaning

Clean plastic parts with a cloth. Harsh detergents can damage the plastic.

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

Clean the ventilation slots if necessary. Do not use a high-pressure cleaner to

clean the machine. The hard jet of water can damage parts of the machine.

Accessories

Only use those tools, guide bars, chains, chain sprockets, accessories or technically equivalent components that have been approved by STIHL for this machine. If you have any questions in this respect, consult a servicing dealer. Use only high quality tools and accessories. Otherwise, there may be a risk of accidents and damage to the machine.

STIHL recommends the use of genuine STIHL tools, guide bars, chains, chain sprockets and accessories. They are specifically designed to match your model and meet your performance requirements.

Refuelling

Petrol is an extremely flammable fuel – keep clear of naked flames and fire – do not spill any fuel

– no smoking. Switch off the engine before refuelling. Never refuel the machine while the

engine is still hot – the fuel may spill over – risk of fire!

Open the fuel filler cap carefully so that any excess pressure is relieved gradually and fuel does not splash out.

The machine may only be refuelled in a well ventilated place. Clean the machine immediately if fuel is spilled. Do not spill fuel over your clothing – contaminated clothing must be changed immediately.

The machines can be equipped with the following filler caps as standard:

Cliplock filler cap (bayonet-type)

Place the cliplock filler cap (bayonet-type) in position, turn as far as stop and fold the cliplock down.

This helps reduce the risk of unit vibrations causing an incorrectly tightened filler cap to loosen or come off and spill quantities of fuel.

Look out for leaks! Never start the engine if fuel has been spilled or is leaking – Fatal burns may result!

Before Starting Work

Check that your saw is properly assembled and in good condition – refer to appropriate chapters in the instruction manual.

– Check the fuel system for leaks,

paying special attention to visible parts such as the tank cap, hose connections and the manual fuel pump (on machines so equipped). If

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001BA087 LÄ

there are any leaks or damage, do not start the engine – risk of fire. Have your saw repaired by a servicing dealer before using it again.

– Check operation of chain brake,

front hand guard

– Correctly mounted guide bar – Correctly tensioned chain – The trigger and trigger lockout must

move freely and spring back to the idle position when they are released.

– Master Control lever must move

easily to STOP, 0 or †

– Check that the spark plug boot is

secure – a loose boot may cause arcing that could ignite combustible fumes and cause a fire.

– Never attempt to modify the controls

or safety devices in any way.

– Keep the handles dry and clean –

free from oil and dirt – for safe control of the saw.

– Make sure there is sufficient fuel

and chain oil in the tanks.

To reduce the risk of personal injury, do not operate your saw if it is damaged or not properly assembled.

Starting the chain saw

Always work on a level surface. Ensure a firm and secure footing. Hold the machine securely – the chain must not touch any objects or the floor – danger of injury due to the rotating saw chain.

Your chain saw is a one-person saw. Do not allow other persons to be in the working area – not even while starting.

Do not start the chain saw if the chain is in a cut.

Move at least 3 meters away from the place where the machine was refuelled and never start the motor in enclosed spaces.

Lock the chain with the chain brake before starting – risk of injury due to rotating chain!

Do not drop-start the engine – start as described in the Instruction Manual.

During operation

Ensure you always have a firm and safe footing. Take special care when the bark is wet – danger of slipping!

Always hold the chain saw firmly with both hands: Right hand on the rear handle – even if you are left-handed. To ensure reliable control, wrap your thumbs tightly around the handlebar and handle.

In the event of impending danger or in an emergency, switch off the engine immediately by moving the Master Control lever / stop switch to STOP, 0 or †.

Never let the machine run unattended. Exercise caution with slippery surfaces,

water, snow, ice, steep slopes, uneven ground or green wood that has just been stripped of its bark – danger of slipping!

Use caution with tree stumps, roots, ditches – danger of stumbling!

Do not work alone – keep within calling distance of others who are trained in emergency procedures and can provide help in an emergency. Helpers at the cutting site must also wear protective clothing (helmet!) and stand well clear of the branches being cut.

More care and attention than usual are required when wearing ear protection, as warning sounds (shouts, beeps, etc.) cannot be heard properly.

Take a break in good time to avoid tiredness or exhaustion – risk of accidents!

Dust (e. g., sawdust), fumes and smoke produced while using the machine may be hazardous to health. If dust is generated, wear a dust mask.

When the engine is running: Note that the saw chain continues to rotate for a short period after you let go of the throttle trigger – coasting effect.

No smoking when working with or near the chain saw - risk of fire! Combustible fuel vapour may escape from the fuel system.

MS 660

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Examine the saw chain periodically at short intervals and as soon as you note any tangible changes:

– Switch off the engine; wait until the

saw chain is stationary

– Check condition and secure fitting – Check sharpness

Never touch the saw chain when the engine is running. If the saw chain becomes jammed by an object, switch off the engine immediately before attempting to remove the object – risk of injury!

Always turn off the engine before leaving the machine unattended.

To change the saw chain, switch off the engine. Risk of injury from the motor starting unintentionally!

Keep easily combustible materials (e. g., wood chips, bark, dry grass, fuel) away from hot exhaust gases and hot mufflers – risk of fire! Mufflers with catalytic converters can become especially hot.

Never work without chain lubrication – monitor the oil level in the oil tank. Stop work immediately if the oil level in the oil tank is too low and top up with chain oil – see also "Topping up with chain oil" and "Check chain lubrication".

If the machine 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 – see also "Before starting work".

Check the fuel system for leaks and make sure the safety devices are working properly. Never continue using

a machine that is not in perfect working order. In case of doubt, have the unit checked by your servicing dealer.

Check for correct idling, so that the saw chain stops moving when the throttle trigger is released. Check the idle setting regularly and correct when possible. Have the machine repaired by a STIHL servicing dealer if the saw chain still continues to move during idling.

The chain saw produces

poisonous exhaust gases

as soon as the engine

starts. These gases may

be colourless and odour

less and may contain

unburnt hydrocarbons

and benzene. Never work

with the machine indoors

or in poorly ventilated

areas, even if your

machine is equipped with

a catalytic converter. Ensure proper ventilation when working

in trenches, hollows or other confined locations – risk of fatal injury from breathing toxic fumes!

If you feel sick, have a headache, vision problems (e. g., your field of vision gets smaller), hearing problems, dizziness or inability to concentrate, stop work immediately. Such symptoms may be caused by an excessively high concentration of exhaust emissions – risk of accident!

After finishing work

Switch off the motor, engage the chain brake and attach the chain scabbard.

Storage

When the machine is not in use, it should be stored in such a way that noone is endangered. Secure the machine against unauthorised use.

Store the machine in a safe, dry room.

Vibrations

Prolonged use of the power tool may result in vibration-induced circulation problems in the hands (whitefinger disease).

No general recommendation can be given for the length of usage because it depends on several factors.

The period of usage is prolonged by: – Hand protection (wearing warm

gloves) – Work breaks The period of usage is shortened by: – Any personal tendency to suffer

from poor circulation (symptoms:

frequently cold fingers, tingling

sensations).

– Low outside temperatures. – The force with which the handles

are held (a tight grip restricts

circulation). Continual and regular users should

monitor closely the condition of their hands and fingers. If any of the above symptoms appear (e.g. tingling sensation in fingers), seek medical advice.

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Maintenance and repairs

Always switch off the engine before any repair, cleaning or maintenance work and any work on the chain. Risk of injury if the engine starts inadvertently!

Exception: adjustment of carburettor and idle speed.

The machine must be serviced regularly. Do not attempt any maintenance or repair work not described in the Instruction Manual. All other work should be carried out by a servicing dealer.

STIHL recommends that maintenance and repair work be carried out only by authorised STIHL dealers. STIHL dealers receive regular training and are supplied with technical information.

Use only high-quality spare parts. Otherwise, there may be a risk of accidents and damage to the machine. If you have any questions in this respect, consult a servicing dealer.

Do not modify the machine in any way – this may increase the risk of personal injury –risk of accidents!

To reduce the risk of fire due to ignition outside the cylinder, move the master control level to STOP, 0 or † before turning the engine over on the starter when the spark plug boot is removed or the spark plug is unscrewed!

Do not service or store the machine near a naked flame – risk of fire due to the fuel.

Check fuel cap regularly for tightness. Use only spark plugs that are in perfect

condition and have been approved by STIHL – see "Specifications".

Check ignition lead (insulation in good condition, secure connection).

Check that the muffler is in perfect working condition.

Do not use the machine if the muffler is damaged or missing – risk of fire, damage to hearing!

Never touch a hot muffler – risk of burns! The condition of the anti-vibration

elements influences vibration behaviour – inspect anti-vibration elements periodically.

Inspect chain catcher – replace if damaged.

Switch off the engine

– To check the chain tension – To retension the chain – To replace the chain – For remedying malfunctions

Observe sharpening instructions – for safe and proper handling, always keep the chain and guide bar in flawless condition. Keep the chain properly sharpened, tensioned and well lubricated.

Change chain, guide bar and chain sprocket in due time.

Regularly check that the clutch drum is in perfect working condition.

Always store fuel and chain lubricant only in the specified type of containers and ensure they are correctly labelled. Store in a dry, cool and secure place protected against light and sunlight.

In the event of a chain brake malfunction, switch off the machine immediately – risk of injury! Consult a

servicing dealer – do not use the machine until the malfunction has been remedied, see "Chain brake".

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.

For any maintenance please refer to the maintenance chart and to the warranty statement near the end of the instruction manual.

MS 660

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001BA036 KN

001BA257 KN

001BA037 KN

Reactive Forces

The most common reactive forces are: kickback, pushback and pull-in.

Dangers of kickback

Kickback can result in fatal cuts.

Kickback occurs if, for example,

– The saw chain in the area of the

upper quarter of the guide bar nose unintentionally comes into contact with wood or a solid object – e. g., unintentionally touches another limb during limbing

– The saw chain at the nose of the

guide bar is briefly pinched in the cut

QuickStop chain brake:

This device reduces the risk of injury in certain situations – it cannot prevent kickback. If activated, the brake stops the saw chain within a fraction of a second – refer to chapter "Chain brake" in this Instruction Manual.

– Be especially careful with small,

tough limbs, undergrowth and

offshoots – the saw chain may

become caught in them

– Never cut several limbs at once – Do not lean too far forward – Do not cut above shoulder height – Use extreme caution when re-

entering a previous cut – Do not attempt plunge cuts if you

are not experienced in this cutting

technique – Be alert for shifting of the log or

other forces that may cause the cut

to close and pinch the chain – Always cut with a correctly

sharpened, properly tensioned saw

chain – the depth gauge setting

must not be too large – Use low-kickback saw chains as

well as narrow-radius guide bars

Pull-in (A)

Kickback occurs when the saw is suddenly thrown up and back in an uncontrolled arc towards the operator.

Reducing the risk of kickback

– Work cautiously and methodically – Hold the chain saw firmly with both

hands and maintain a secure grip

– Always cut at full throttle – Be awar e of the loc ation of the guide

bar nose

– Do not cut with the guide bar nose

When the chain on the bottom of the bar – overbucking – is suddenly pinched, caught or encounters a foreign object in the wood, the chain saw may suddenly

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001BA038 KN

be drawn forward toward the log – to avoid this, engage the bumper spike firmly in the wood.

Pushback (B)

When the chain on the top of the bar – underbucking – is suddenly pinched, caught or encounters a foreign object in the wood, the chain saw may suddenly be driven straight back toward the operator – to avoid this:

– Do not allow the top of the guide bar

to become jammed

– Do not twist the guide bar in the cut

Be very careful

– With freely hanging limbs – With trunks that are under tension

between other trees because they

fell unfavourably – When working in windbreaks In these cases, do not use a chain saw –

use a hoist, winch or dragline instead. Pull out trunks that are lying about and

have been cut free. Whenever possible, deal with them in open areas.

Dead wood (brittle, rotten or dead wood) poses a significant, highly unpredictable hazard. It is extremely difficult or even practically impossible to recognise the danger. Use aids such as winches or draglines.

When felling close to roads, rail lines, power lines, etc., work with particular care. If necessary, notify police, power companies or railway authorities.

Working Techniques

Sawing and felling work, including all related work (plunge cutting, limbing, etc.) may only be carried out by persons who have been specially trained and instructed. Persons who are not experienced chain saw users should not carry out any such work – increased risk of accidents!

Country-specific legislation on felling technique must be complied with during felling work.

Cutting

Do not operate your saw with the starting throttle lock engaged. Engine speed cannot be controlled with the throttle trigger in this position.

Work calmly and carefully – in daylight conditions and only when visibility is good. Ensure you do not endanger others – stay alert at all times.

First-time users are advised to practice cutting logs on a sawhorse – see "When cutting small logs".

Use the shortest possible guide bar: The chain, guide bar and chain sprocket must match each other and your saw.

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001BA082 KN

001BA033 KN

Position the saw so that your body is clear of the cutting attachment.

Always pull the saw out of the cut with the chain running.

Use your chain saw for cutting only. It is not designed for prying or shoveling away limbs, roots or other objects.

Do not underbuck freely hanging limbs. Take care when cutting scrub and young

trees. The saw chain may catch and throw thin shoots in your direction.

To reduce the risk of injury, take special care when cutting shattered wood because of the risk of injury from slivers being caught and thrown in your direction.

Make sure your saw does not touch any foreign materials: Stones, nails, etc. may be flung off and damage the saw chain. The saw may kick back unexpectedly – risk of accidents.

If the rotating chain makes contact with a rock or other solid object there is a risk of sparking which may cause easily combustible material to catch fire under certain circumstances. Dry plants and scrub are also easily combustible, especially in hot and dry weather conditions. If there is a risk of fire, do not use your chainsaw near combustible

materials, dry plants or scrub. Always contact your local forest authority for information on a possible fire risk.

If on a slope, stand on the uphill side of the log. Watch out for rolling logs.

When working at heights:

– Always use a lift bucket – Never work on a ladder or in a tree – Never work on an insecure support – Do not work above shoulder height – Never operate your power tool with

one hand

Begin cutting with the saw at full throttle and engage the spiked bumper firmly in the wood, and then continue cutting.

Never work without the spiked bumper because the saw may pull you forwards and off balance. Always engage the spiked bumper securely in the tree or limb.

Note when reaching the end of a cut that the saw is no longer supported in the kerf. You have to take the full weight of the machine since it might otherwise go out of control.

When cutting small logs: – Use a sturdy and stable support –

sawhorse.

– Never hold the log with your leg or

foot.

– Never allow another person to hold

the log or help in any other way.

Limbing:

– Use a low kickback chain. – Work with the saw supported

wherever possible.

– Do not stand on the log while

limbing it.

– Do not cut with the bar nose. – Watch for limbs which are under

tension. – Never cut several limbs at once. Lying or standing logs under tension: Always make cuts in the correct

sequence (first at the compression side (1), then at the tension side (2), the saw may otherwise pinch or kick back – risk of injury.

MS 660

N Make relieving cut at the

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1 1

compression side (1)

N Make bucking cut at the tension

side (2)

Be wary of pushback when making bucking cut from the bottom upwards (underbuck).

NOTICE

Do not cut a lying log at a point where it is touching the ground because the saw chain will otherwise be damaged.

Ripping cut:

Cutting technique in which the spiked bumper is not used – risk of pull-in – start the cut with the guide bar at the shallowest possible angle – take extra care since there is an increased danger of kickback.

Preparations for Felling

Check that there are no other persons in the felling area – other than helpers.

Make sure no-one is endangered by the falling tree – the noise of your engine may drown any warning calls.

English

Maintain a distance of at least 2 1/2 tree lengths from the next felling site.

Determine direction of fall and escape path.

Select gap in stand into which you want the tree to fall.

Pay special attention to the following points:

– The natural lean of the tree – Any unusually heavy limb structure,

damage – The wind direction and speed – do

not fell in high winds

– Sloping ground – Neighboring trees – Snow load – Soundness of tree – take special

care if trunk is damaged or in case

of deadwood (dry, decayed or rotted

wood)

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001BA040 KN

45°

001BA146 KN

001BA271 KN

A Direction of fall B Escape path (or retreat path)

– Establish paths of escape for

everyone concerned – opposite to direction of fall at about 45°.

– Remove all obstacles from escape

paths.

– Place all tools and equipment a safe

distance away from the tree, but not on the escape paths.

– Always keep to the side of the falling

tree and only walk away along the preplanned escape path.

– On steep slopes, plan escape

routes parallel to the slope.

– When walking away along the

escape path, watch out for falling limbs and watch the top of the tree.

Preparing work area at base of tree – First clear the tree base and work

area from interfering limbs and brush to provide a secure footing.

– Clean lower portion of tree base

(e.g. with an axe) – sand, stones and other foreign objects will dull the saw chain.

– Make the vertical cut first, then the

horizontal – but only if the wood is sound

Felling Notch

Preparing felling notch

The felling notch (C) determines the direction of fall.

Important: – Make felling notch at a right angle to

the planned direction of fall.

– Cut close to the ground. – Cut to a depth of about 1/5 to 1/3 of

the trunk diameter.

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001BA150 KN

001BA259 KN

1/10

Determine direction of fall with gunning sight on shroud and fan housing

Your chainsaw has a gunning sight on the shroud and fan housing. Use this gunning sight.

Making Felling Notch Position the saw so that the felling notch

is at a right angle to the direction you want the tree to fall.

The sequence in which the felling notch is made with a horizontal cut (bottom) and angled cut (top) is defined in country-specific regulations.

N Make horizontal cut (bottom) N Make the angled cut (top) at about

45°- 60° to the horizontal cut.

Check direction of fall

N Position the saw in the horizontal

cut. The gunning sight must point in the planned direction of fall – if necessary, correct direction of fall by re-cutting the felling notch.

Sapwood cuts

felling notch to a depth of about 1/10 of trunk diameter. On large diameter trees, cut to no more than width of guide bar.

Do not make sapwood cuts if wood is diseased.

Basic Information on Felling Cut

Stump dimensions

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The felling notch (C) determines the direction of fall.

The hinge (D) helps control the falling tree.

– Width of hinge: about 1/10 of tree

Sapwood cuts in long-fibered softwood help prevent sapwood splintering when the tree falls. Make cuts at both sides of the trunk at same height as bottom of

diameter. – To reduce the risk of accidents, do

not cut through the hinge – you

could lose control of the direction of

fall. – Leave a broader hinge on rotten

trees.

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001BA269 KN

001BA270 KN

001BA260 KN

The tree is felled with the felling cut (E).

– Cut horizontally. – 1/10 (at least 3 cm) of width of

hinge (D) higher than bottom of felling notch (C).

The holding strap (F) or stabilizing strap (G) supports the tree and helps prevent it from falling prematurely.

– Width of strap: about 1/10 to 1/5 of

tree diameter.

– Do not cut into the strap while

making the felling cut.

– Leave a broader strap on rotten

trees.

Plunge cutting

– For relieving cuts during bucking – For wood carving

N Use a low kickback chain and

exercise particular caution

1. Begin cut by applying the lower portion of the guide bar nose – do not use upper portion because of – risk of kickback. Start cutting at full throttle until depth of kerf is twice the width of the guide bar.

2. Swing saw slowly into plungecutting position – take care because of the risk of kickback or pushback.

3. Make the plunge cut very carefully. Danger of pushback.

Use the plunge-cutting sight if possible. The plunge-cutting sight and the top and bottom of the guide bar are parallel.

When making the plunge cut, the sight helps keep the hinge horizontal, i.e. the same thickness all round. To do this, hold the plunge-cutting sight parallel to the chord of the felling notch.

Felling wedges Make use of wedges as soon as

possible, i.e. providing they do not interfere with cutting. Drive wedge into felling cut with a suitable tool.

Use only aluminum or plastic wedges – never steel. Steel wedges can seriously damage the saw chain and cause dangerous kickback.

Select felling wedges that suit the diameter of the tree and width of the kerf (felling cut (E)).

Contact your STIHL dealer for advice on selecting the right felling wedge (length, width and height).

Choosing Right Felling Cut

The criteria for choosing the right felling cut are the same as those for determining the direction of fall and the escape path.

There are many different variations of these characteristics. Only the two most common characteristics are described in this manual:

Left: Normal tree – vertical trunk

with uniform tree crown.

Right: Leaner – tree crown leans in

direction of fall.

Felling Cut with Stabilizing Strap (Normal Tree)

A) Small diameter trees Perform this felling cut when the tree

diameter is smaller than the length of the guide bar.

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001BA261 KN

001BA273 KN

001BA263 KN

Shout a warning before starting the felling cut.

N Start felling cut (E) using plunge-cut

method – insert full length of guide bar in the trunk.

N Engage the spiked bumper behind

the hinge and use it as a pivot – avoid repositioning the saw more than necessary.

N Enlarge felling cut as far as

hinge (1).

– Do not cut into the hinge. N Enlarge felling cut as far as

– Do not cut into the stabilizing strap.

stabilizing strap (2).

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N Insert a felling wedge (3). Shout a second warning immediately

before the tree falls. N Holding the saw with outstretched

arms, cut through the stabilizing strap horizontally at the same level as the felling cut.

B) Large diameter trees Perform this felling cut when the tree

diameter is greater than the length of the guide bar.

Shout a warning before starting the felling cut.

N Engage the spiked bumper at the

required height of the felling cut and use it as a pivot – avoid repositioning the saw more than necessary.

N The guide bar nose enters the

wood (1) before it reaches the hinge – hold the saw horizontally and swing it as far as possible.

N Enlarge felling cut as far as

hinge (2).

– Do not cut into the hinge. N Enlarge felling cut as far as

stabilizing strap (3). – Do not cut into the stabilizing strap. Continue the felling cut on the other side

of the trunk. Make sure the second cut is at the same

height as the first cut.

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001BA274 KN

001BA265 KN

001BA266 KN

N Start felling cut using plunge-cut

method.

N Enlarge felling cut as far as

hinge (4).

– Do not cut into the hinge. N Enlarge felling cut as far as

stabilizing strap (5).

– Do not cut into the stabilizing strap.

N Insert a felling wedge (6). Shout a second warning immediately

before the tree falls. N Holding the saw with outstretched

arms, cut through the stabilizing strap horizontally at the same level as the felling cut.

Felling Cut with Holding Strap (Leaner)

A) Small diameter trees Perform this felling cut when the tree

diameter is smaller than the length of the guide bar.

Shout a second warning immediately before the tree falls.

N Cut through the holding strap at a

downward angle from outside with

outstretched arms.

N Plunge the guide bar into the trunk

until it emerges at the other side.

N Enlarge the felling cut (E) in

direction of hinge (1).

– Cut horizontally. – Do not cut into the hinge.

N Enlarge the felling cut in direction of

holding strap (2).

– Cut horizontally. – Do not cut into the holding strap.

MS 660

English

001BA267 KN

001BA268 KN

B) Large diameter trees

Perform this felling cut when the tree diameter is greater than the length of the guide bar.

N Engage the spiked bumper behind

the holding strap and use it as a pivot – avoid repositioning the saw more than necessary.

N The guide bar nose enters the

wood (1) before it reaches the hinge – hold the saw horizontally and swing it as far as possible.

– Do not cut into the holding strap or

hinge.

N Enlarge felling cut as far as

hinge (2).

– Do not cut into the hinge. N Enlarge felling cut as far as holding

strap (3).

– Do not cut into the holding strap.

MS 660

Continue the felling cut on the other side of the trunk.

Make sure the second cut is at the same height as the first cut.

N Engage the spiked bumper behind

the hinge and use it as a pivot – avoid repositioning the saw more than necessary.

N The guide bar nose enters the

wood (4) before it reaches the holding strap – hold the saw horizontally and swing it as far as possible.

N Enlarge felling cut as far as

hinge (5).

– Do not cut into the hinge. N Enlarge felling cut as far as holding

strap (6).

– Do not cut into the holding strap.

Shout a second warning immediately before the tree falls.

N Cut through the holding strap at a

downward angle from outside with

outstretched arms.

English

001BA248 KN

001BA244 KN

001BA245 KN

Cutting Attachment

A cutting attachment consists of the saw chain, guide bar and chain sprocket.

The cutting attachment that comes standard is designed to exactly match the chain saw.

– The pitch (t) of the saw chain (1),

chain sprocket and the nose sprocket of the Rollomatic guide bar must match.

– The drive link gauge (2) of the saw

chain (1) must match the groove width of the guide bar (3).

If non-matching components are used, the cutting attachment may be damaged beyond repair after a short period of operation.

Chain Scabbard

Your saw comes standard with a chain scabbard that matches the cutting attachment.

If guide bars of different lengths are mounted to the saw, always use a chain scabbard of the correct length which covers the complete guide bar.

The length of the matching guide bars is marked on the side of the chain scabbard.

Guide bars longer than 90 cm require one scabbard extension. Guide bars longer than 120 cm require two scabbard extensions.

Depending on the model, the scabbard extension either comes standard with the saw or is available as a special accessory.

Fitting Chain Scabbard Extension

N Push the scabbard extension and

chain scabbard together – the

lugs (1) must engage in the chain

scabbard.

MS 660

English

143BA034 KN

001BA185 KN

001BA186 KN

143BA003 KN

001BA187 KN

Mounting the Bar and Chain

Removing the chain sprocket cover

N Unscrew the nuts and take off the

chain sprocket cover.

N Turn the screw (1)

counterclockwise until the tensioner slide (2) butts against the left end of the housing slot.

Disengaging the chain brake.

N Pull the hand guarad towards the

front handle until there is an audible click – the chain brake is disengaged.

Fitting the chain

WARNING

Wear work gloves to protect your hands from the sharp cutters.

N Fit the chain – start at the bar nose.

N Fit the guide bar over the studs (1) –

the cutting edges on the top of the

bar must point to the right. N Engage the peg of the tensioner

slide in the locating hole (2) –- place

the chain over sprocket (3) at the

same time. N Turn the tensioning

screw (4)clockwise until there is

very little chain sag on the

underside of the bar – and the drive

link tangs are engaged in the bar

groove. N Refit the sprocket cover and screw

on the nuts only fingertight. N Go to chapter on "Tensioning the

Saw Chain"

MS 660

English

133BA024 KN

143BA007 KN

Tensioning the Chain

Retensioning during cutting work:

N Shut off the engine. N Loosen the nuts. N Hold the bar nose up. N Use a screwdriver to turn the

tensioning screw (1) clockwise until the chain fits snugly against the underside of the bar.

N While still holding the bar nose up,

tighten down the nuts firmly.

N Go to "Checking Chain Tension". A new chain has to be retensioned more

often than one that has been in use for some time.

N Check chain tension frequently –

see chapter on "Operating Instructions".

Checking Chain Tension

N Shut off the engine. N Wear work gloves to protect your

hands.

N The chain must fit snugly against

the underside of the bar and it must still be possible to pull the chain along the bar by hand.

N If necessary, retension the chain. A new chain has to be retensioned more

often than one that has been in use for some time.

N Check chain tension frequently –

see chapter on "Operating Instructions".

Fuel

This engine is certified to operate on unleaded gasoline and with the mix ratio 50:1.

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

Use premium branded unleaded gasoline with a minimum octane rating of 89 (R+M)/2.

Note: Models equipped with a catalytic converter require unleaded gasoline. A few tankfuls of leaded gasoline can reduce the efficiency of the catalytic converter by more than 50%.

Fuel with a lower octane rating may result in preignition (causing "pinging") which is accompanied by an increase in engine temperature. This, in turn, increases the risk of the 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 as well. This could cause running problems or even damage the engine. For this reason it is essential that you use only high-quality fuels!

Fuels with different percentages of ethanol are being offered. Ethanol can affect the running behaviour of the engine and increase the risk of lean seizure.

MS 660

English

143BA000 KN

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

Engines equipped with M-Tronic can be run on gasoline with an ethanol content of up to 25% (E25).

Use only STIHL two-stroke engine oil or equivalent high-quality two-stroke aircooled engine oils for mixing.

We recommend STIHL 50:1 two-stroke engine oil since it is specially formulated for use in STIHL engines.

Do not use BIA or TCW (two-stroke water cooled) mix oils!

Use only STIHL 50:1 heavy-duty engine oil or an equivalent quality two-stroke engine oil for the fuel mix in models equipped with a catalytic converter.

Take care when handling gasoline. Avoid direct contact with the skin and avoid inhaling fuel vapour.

The canister should be kept tightly closed in order to avoid any moisture getting into the mixture.

The fuel tank and the canister in which fuel mix is stored should be cleaned from time to time.

Fuel mix ratio

Only mix sufficient fuel for a few days work, not to exceed 30 days of storage. Store in approved safety fuel-canisters only. When mixing, pour oil into the canister first, and then add gasoline.

Examples Gasoline Oil (STIHL 50:1 or equiva

lent high-quality oils)

liters liters (ml)

10.02(20) 5 0.10 (100) 10 0.20 (200) 15 0.30 (300) 20 0.40 (400) 25 0.50 (500)

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

Fueling

Preparing the machine

N Before fueling, clean the filler cap

and the area around it so that dirt

cannot fall into the tank. N Always position the machine so that

the filler cap is facing upwards N Open the filler cap

Refueling

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

STIHL recommends use of the STIHL filling system for fuel (special accessory).

WARNING

After fueling, tighten down the filler cap by hand as securely as possible.

Use a suitable tool (e. g., screwdriver of the combination wrench) for slotted filler caps.

MS 660

English

143BA009 KN

001BA158 KN

Fuel pick-up body replacement

Change the fuel pick-up body every year; to do this:

N Drain the fuel tank N Pull the fuel pick-up body out of the

tank with a hook and disconnect it from the hose

N Connect a new fuel pick-up body to

the hose

N Return the fuel pick-up body to the

tank

Chain Lubricant Filling Chain Oil Tank

For automatic and reliable lubrication of the chain and guide bar – use only an environmentally compatible quality chain and bar lubricant. Rapidly biodegradable STIHL BioPlus is recommended.

NOTICE

Biological chain oil must be resistant to aging (e.g. STIHL BioPlus), since it will otherwise quickly turn to resin. This results in hard deposits that are difficult to remove, especially in the area of the chain drive and chain. It may even cause the oil pump to seize.

The service life of the chain and guide bar depends on the quality of the lubricant. It is therefore essential to use only a specially formulated chain lubricant.

WARNING

Do not use waste oil. Renewed contact with waste oil can cause skin cancer. Moreover, waste oil is environmentally harmful.

NOTICE

Waste oil does not have the necessary lubricating properties and is unsuitable for chain lubrication.

Preparing the machine

N Thoroughly clean the oil filler cap

and the area around it to ensure that

no dirt falls into the oil tank. N Always position the machine so that

the filler cap is facing upwards. N Open the filler cap.

Filling the chain oil tank

Standard oil pump N Fill the chain oil tank each time the

fuel tank has been filled

Oil pump with increased delivery rate (available option)

It is necessary to check and refill the oil tank frequently – see "Adjusting the oil quantity".

N Refill the oil tank when the fuel tank

is approximately half empty

MS 660

English

143BA024 KN

143BA011 KN

All versions Take care not to spill chain oil while

refilling and do not overfill the tank. STIHL recommends use of the STIHL

filling system for chain oil (available option).

N Close the filler cap There must still be a small amount of oil

in the oil tank when the fuel tank is empty.

If the oil tank is still partly full, the reason may be a problem in the oil supply system: Check chain lubrication, clean the oil passages, contact a servicing dealer if necessary. STIHL recommends that maintenance and repair work be carried out only by authorized STIHL dealers.

Checking Chain Lubrication

The saw chain must always throw off a small amount of oil.

NOTICE

Never operate your saw without chain lubrication. If the chain runs dry, the whole cutting attachment will be irretrievably damaged within a very short time. Always check chain lubrication and the oil level in the tank before starting work.

Every new chain has to be broken in for about 2 to 3 minutes.

After breaking in the chain, check chain tension and adjust if necessary – see "Checking Chain Tension".

Chain Brake

Locking the chain

– in an emergency – when starting – at idling speed

The chain brake is activated by pushing the hand guard toward the bar nose with your left hand – or by inertia in certain kickback situations: The chain is stopped and locked.

MS 660

English

143BA012 KN

137BA014 KN

Releasing the chain brake

N Pull the hand guard back toward the

front handle,

NOTICE

Always disengage chain brake before accelerating the engine (except when checking its operation) and before starting cutting work.

High revs with the chain brake engaged (chain locked) will quickly damage the powerhead and chain drive (clutch, chain brake).

The chain brake is also activated by the inertia of the front hand guard if the kickback force of the saw is high enough: The hand guard is accelerated toward the bar nose – even if your left hand is not behind the hand guard, e.g. during felling cut.

The chain brake will operate only if the hand guard has not been modified in any way.

Check operation of the chain brake

Before starting work: Run engine at idle speed, engage the chain brake (push hand guard toward bar nose) and open the throttle wide for no more than 3 seconds – the chain must not rotate. The hand guard must be free from dirt and move freely.

Chain brake maintenance

The chain brake is subject to normal wear. It is necessary to have it serviced and maintained regularly by trained personnel. STIHL recommends that you have servicing and repair work carried out exclusively by an authorized STIHL servicing dealer. Maintain the following servicing intervals:

Full-time usage: every 3

months

Part-time usage: every 6

months

Occasional usage: every 12

months

Winter Operation

At temperatures below +10 °C

N Remove the carburetor box cover

N in the carburetor box cover, move

the slide (1) from summer position

to winter position (2) Heated air is now drawn in from around

the cylinder and mixed with cold air – this helps prevent carburetor icing.

NOTICE

Above +20 °C: Always return the shutter to the position for "summer operation" again! Risk of engine malfunction – overheating!

N Replace the carburetor box cover

and tighten the knob

Air filter system

N Retrofit new air filter if necessary –

see "Air filter system"

MS 660

English

137BA015 KN

137BA016 KN

STOP

001BA140 KN

At temperatures below -10 °C

Under extreme winter conditions (temperatures below -10 °C, powdered or drifting snow), it is recommended to mount the cover plate (special accessory) on the fan housing.

The partial covering of the slits in the fan housing keeps out powdered or drifting snow.

When the cover plate is mounted, the slide must be in winter position in the carburetor box cover.

N if the chain saw is extremely cold

(frost formation) – after starting, bring the engine up to operating temperature at increased idle speed (disengage chain brake!)

N If engine trouble occurs, first check

whether use of the cover plate is necessary

Electric Handle Heating

Switching on the handle heating system (depending on equipment version)

N To switch on, set switch to F and to

switch off, return switch to the 0 position

Overheating during continuous use is impossible. The heating system is maintenance-free.

Starting / Stopping the Engine

Positions of Master Control Lever

Stop 0 – engine off – the ignition is switched off

Normal run position (F) – engine runs or can fire.

Starting throttle (n) – this position is used to start a warm engine. The Master Control lever moves to the normal run position as soon as the throttle trigger is squeezed.

Choke shutter closed (l) – this position is used to start a cold engine.

MS 660

English

143BA018 KN

143BA019 KN

Setting the Master Control Lever

To move the Master Control lever from the normal run position (F) to choke closed (l), press down the throttle trigger lockout and squeeze the throttle trigger at the same time and hold them in that position – now set the Master Control lever.

To select the starting throttle position (n), move the Master Control lever to choke closed (l) first, then push it into the starting throttle position (n).

The Master Control lever must be in the choke closed position (l) for the changeover to the starting throttle position (n).

The Master Control lever moves from the starting throttle position (n) to the run position (F) when you press down the throttle trigger lockout and blip the throttle trigger at the same time.

To switch off the engine, move the Master Control lever to Stop (0).

Choke shutter closed (l)

– if the engine is cold – if the engine stalls when you open

the throttle after starting.

– if the fuel tank was run until empty

(engine stopped).

Starting throttle position (n) – if the engine is warm, i.e. if it has

been running for about one minute.

– after engine begins to fire, – after clearing a flooded combustion

chamber.

Holding the Saw

There are two ways of holding the saw when starting.

On the ground

N Place your saw on the ground.

Make sure you have a firm footing – check that the chain is not touching any object or the ground.

N Hold the saw firmly on the ground

with your left hand on the front handle – your thumb should be under the handle.

N Put your right foot into the rear

handle and press down.

Between knees or thighs

N Hold the rear handle tightly between

your legs, just above the knees. N Hold the front handle firmly with

your left hand – your thumb should

be under the handle.

MS 660

English

143BA020 KN

133BA001 K

STOP

178BA007 KN

Cranking

N Pull the starter grip slowly with your

right hand until you feel it engage – and then give it a brisk strong pull and push down the front handle at the same time. Do not pull out the starter rope to full length – it might otherwise break. Do not let the starter grip snap back. Guide it slowly back into the housing so that the starter rope can rewind properly.

Machines without additional manual fuel pump: If the engine is new or after a long out-of-service period, it may be necessary to pull the starter rope several times to prime the fuel system.

Starting the Saw

WARNING

Bystanders must be well clear of the general work area of the saw.

N Press in the button to open the

decompression valve.

The decompression valve closes as soon as the engine fires. For this reason you must press in the button before each starting attempt.

N Push the hand guard (1) forward –

the chain is locked. N Press down the trigger lockout (2)

and pull the throttle trigger (3) at the

same time. Set Master Control

lever (4) to: Choke shutter closed (l) – if the engine is cold (also use this

position if the engine stopped when

you opened the throttle after

starting) Starting throttle position (n) – if the engine is warm, i.e. if it has

been running for about one minute. N Hold and start your saw as

described.

MS 660

English

178BA008 KN

STOP

178BA009 KN

STOP

001BA186 KN

When engine begins to fire

N Set the Master Control lever (1) to

the starting throttle position (n).

N Press the button to open the

decompression valve.

N Hold and start your saw as

described.

As soon as the engine runs

N Pull the hand guard back toward the

front handle.

The chain brake is now disengaged – your saw is ready for operation.

NOTICE

Always disengage chain brake before accelerating the engine. High revs with the chain brake engaged (chain locked) will quickly damage the clutch and chain brake.

At very low outside temperatures

N Allow engine to warm up at part

throttle.

N Change over to winter operation if

necessary – see “Winter Operation”.

position (n) quickly enough after the engine began to fire, the combustion chamber may be flooded.

N Move the Master Control lever to the

stop position (0). N Remove the spark plug – see

"Spark Plug".

N Dry the spark plug. N Crank the engine several times with

the starter to clear the combustion

chamber. N Refit the spark plug – see "Spark

Plug". N Set Master Control lever to the

starting throttle position (n) – even

if the engine is cold. N Press the button to open the

decompression valve.

N Now start the engine.

N Press down trigger lockout and the

blip the throttle trigger (2) – the Master Control lever (1) moves to the run position (F) and the engine settles down to idling speed.

Stopping the engine

N Move the Master Control lever to the

stop position (0).

If engine does not start

If you did not move the Master Control lever from the choke closed position (l) to the starting throttle

MS 660

+ 86 hidden pages

Stihl MS 660 Instruction Manual [en, fr]

Specifications and Main Features

Frequently Asked Questions

User Manual