Stihl MS 250 Instruction Manual [en, fr]

STIHL MS 250

Instruction Manual Notice d’emploi

G Instruction Manual

1 - 56

F Notice d’emploi

57 - 118

Contents

English

Guide to Using this Manual 2 Safety Precautions 3 Reactive Forces 8 Working Techniques 9 Cutting Attachment 16 Mounting the Bar and Chain (side

chain tensioner) 17 Mounting the Bar and Chain (quick

chain tensioner) 18

Original Instruction ManualPrinted on chlorine-free paper

Tensioning the Saw Chain (side chain tensioner) 20

Tensioning the Saw Chain (quick chain tensioner) 20

Checking Chain Tension 20 Fuel 21 Fueling 22 Chain Lubricant 23 Filling Chain Oil Tank 24 Checking Chain Lubrication 24 Chain Brake 25 Winter Operation 26 Starting / Stopping the Engine 26

Printing inks contain vegetable oils, paper can be recycled.

Operating Instructions 31 Taking Care of the Guide Bar 32 Air Filter System 32 Cleaning the Air Filter 32 Engine Management 33 Adjusting the Carburetor 33 Spark Plug 34 Engine Running Behavior 36 Replacing the Starter Rope and

Rewind Spring 36

Storing the Machine 40 Checking and Replacing the Chain

Sprocket 40 Maintaining and Sharpening the

Saw Chain 41 Maintenance and Care 45 Main Parts 47 Specifications 49 Ordering Spare Parts 50 Maintenance and Repairs 50 Disposal 50 Important Safety Instructions 51 Key to Symbols 52 STIHL Limited Emission Control

Warranty Statement 53 CSA Standard 55

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 trouble-free use of the product.

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

Your

Dr. Nikolas Stihl

0458-208-8221-D. VA2.E22.

0000001540_020_GB

MS 250

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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 precautions must be observed to reduce the risk of personal injury when working with a chain saw because of the very high chain speed and very sharp cutters.

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

General

Observe all applicable local safety regulations, standards and ordinances.

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

If you have not used this model 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 a chain saw.

Keep bystanders, especially children, and animals away from the work area.

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

Do not lend or rent your chain saw without the instruction manual. Be sure that anyone using it understands the information contained in this manual.

To operate a chain saw you must be 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.

Do not operate the chain saw if you are under the influence of any substance (drugs, alcohol) which might impair vision, dexterity or judgment.

To reduce the risk of accidents or injury, put off the work in poor weather conditions (rain, snow, ice, wind).

Persons with pacemakers only: The ignition system of your chain saw produces an electromagnetic field of a very low intensity. This field may interfere with some pacemakers. To reduce health risks, STIHL recommends that persons with pacemakers consult their physician and the pacemaker manufacturer before operating this power tool.

Intended use

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

Do not use 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-retardant material, non-slip soles and steel toe caps.

WARNING

To reduce the risk of eye injuries, wear tight-fitting safety goggles conforming to standard EN 166 or a face shield. Make sure that the safety goggles and the face shield fit correctly.

Wear "personal" hearing protection – for example, ear defenders.

Wear a hard hat wherever there is any risk of falling objects.

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Wear sturdy protective gloves made of a resistant material (e.g. leather).

STIHL can supply a comprehensive range of personal protective equipment.

Transporting

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. To avoid serious burn injuries, avoid touching hot parts of the machine, especially the surface of the muffler.

In vehicles: Properly secure your saw to prevent turnover, fuel spillage and damage.

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

Gasoline 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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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.

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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, 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.

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001BA037 KN

Reactive Forces

The most common reactive forces that occur during cutting are: kickback, pushback and pull-in.

Dangers of kickback

Kickback can result in serious or fatal injury.

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

Kickback occurs if, e. g.,

– when the upper quadrant of the bar

nose unintentionally contacts wood or another solid object, e.g. when another limb is touched accidentally during limbing.

– when the chain at the nose of the

guide bar is pinched in the cut.

Quickstop chain brake:

001BA036 KN

This device reduces the risk of injury in certain situations – it cannot prevent kickback. When activated, the chain brake stops the saw chain within a fraction of a second – see the section "Saw chain" in this Instruction Manual.

– do not cut with the bar nose. – Take special care with small, tough

limbs, they may catch the chain.

– never cut several limbs at once. – do not overreach. – never cut above shoulder height. – Use extreme caution when re-

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

are not experience 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

chain – the depth gauge setting

must not be too large. – Use a low kickback chain and a

narrow radius guide bar.

Pull-in (A)

To reduce the risk of kickback

– Work cautiously and avoid

situations which could cause kickback.

– Hold the 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 at all times.

Pull-in occurs when the chain on the bottom of the bar is suddenly pinched, caught or encounters a foreign object in the wood. The reaction of the chain pulls the saw forward – to reduce this risk, always engage the spiked bumper securely in the tree or limb.

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Pushback (B)

Pushback occurs when the chain on the top of the bar is suddenly pinched, caught or encounters a foreign object in the wood. The reaction of the chain drives the saw straight back toward the operator – to avoid this risk:

– Be alert to situations that may cause

the top of the guide bar to be pinched

– Do not twist the guide bar in the cut

Exercise extreme caution

– with leaners – with trees that have fallen

unfavorably between other trees

and are under strain – when working in blowdown areas. In these cases, do not use a chain saw –

use a hoist, winch or drag line instead. Pull out exposed and cleared logs.

Select clear area for cutting. Deadwood (dry, decayed or rotted

wood) represents a considerable risk that is difficult to assess. Identifying the extent of the dangers is complicated, if not impossible. Use aids such as a cable winch or tractor in such cases.

When felling in the vicinity of roads, railways, power lines, etc., take extra precautions. If necessary, inform the police, utility company or railway authority.

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.

Sawing

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.

It is advisable for first-time users to practice cutting logs on a sawbuck – see "Sawing thin wood".

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

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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. Be careful when cutting scrub and young

trees. Thin shoots can be scooped up by the chain saw and hurled towards the user.

Be careful when cutting splintered wood – Risk of injury from ejected pieces of wood!

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

If a rotating saw chain hits a stone or another hard object, sparks may be generated which may ignite easily flammable materials under certain conditions. Also dried-out plants and brushwood are combustible, above all in hot and dry weather. If there is a risk of fire, do not use the chain saw in the vicinity of easily combustible materials,

dry plants or scrub. It is mandatory that you ask the responsible forestry office about the current fire hazard.

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 use the machine while

standing on a ladder or in a tree

– Never work on an insecure support – Never work above shoulder height – Never use the machine with just 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 hold the spiked bumper securely against the tree or limb.

At the end of the cut, the chain saw is no longer supported by the cutting attachment in the cut. The chain saw's weight must be borne by the user – risk of loss of control!

Sawing thin wood: – 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 the cuts in the correct

order (first compression side (1), then tension side (2)), otherwise the cutting attachment may stick in the cut or kick back – risk of injury!

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1 1

N Make relieving cut at the

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:

Sawing technique without use of the spiked bumper – risk of pull-in – position the guide bar at as shallow an angle as possible – be especially careful – increased risk of kickback!

Preparing 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.

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

Determining 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 inclination of the tree – Unusually heavy limb structure,

asymmetrical growth, damage to

tree – The wind direction and speed – do

001BA189 KN

not fell in high winds

– Direction of slope – Neighboring trees – Snow load – Take the general condition of the

tree into account – be especially

careful with trunk damage or

deadwood (brittle, rotten or dead

wood)

A Direction of fall B Escape path (escape routes)

– Establish escape paths for each

worker – approx. 45° diagonally

opposite to the direction of fall – Clear escape paths, eliminate

obstacles – Put down tools and equipment at a

safe distance – but not on the

escape paths – When felling, stand only to the side

of the falling trunk and only move

back laterally onto the escape path

001BA040 KN

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– Plan escape paths on slopes

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. – Carefully clear the base of the trunk

(e.g., with an axe) – sand, stones

and other foreign objects will blunt

the saw chain

– Remove largest buttresses: first the

largest buttress – saw first vertically,

then horizontally – only if the tree is

in sound condition

Felling notch

Preparing the felling notch

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

Important: – Make a felling notch at right angle to

direction of fall

– Saw as close to the ground as

possible

– Cut to a depth of approx. 1/5 to 1/3

of the diameter of the trunk

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

During the procedure, various sequences are permitted for making a felling notch with a bottom (horizontal) cut and top (angled) cut – comply with national legislation regarding felling technique.

N Make a bottom (horizontal) cut N Make the top (angled) cut

approx. 45°- 60° to the bottom cut

Checking the direction of fall

001BA271 KN

N Insert the chainsaw with guide bar in

the bottom of the felling notch. 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

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

Making the felling notch When making a felling notch, align the

chainsaw so that the notch lies at a right angle to the direction of fall.

001BA150 KN

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

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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

Basic dimensions

1/10

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

The hinge (D) functions like a real hinge to guide the tree to the ground.

– Width of hinge: approx. 1/10 of the

trunk diameter – Never saw through the hinge while

felling – otherwise the tree will fall in

a direction other than the one

planned – risk of accident! – With rotten trunks, leave a wider

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

– Cut horizontally – 1/10 (at least 3 cm) of tree diameter

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 strip: approx. 1/10 to 1/5 of

the trunk diameter

– Do not cut into the strip during the

felling cut

– With rotten trunks, leave a wider

strip

Plunge cutting

– For relieving cuts during shortening – For wood carving

001BA259 KN

N Use a low kickback saw chain and

proceed with special care

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

2. Swing the machine slowly into the plunge cutting position – risk of kickback and pushback!

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

Where possible, use a plunge blade. The plunge blade and the upper/lower side of the guide bar are parallel.

During plunge cutting, the plunge bar helps to keep the hinge parallel in form, i.e. the same thickness at all points. To do this, guide the plunge bar parallel to the sink chord.

Felling wedges Insert the felling wedge as soon as

possible, i.e. as soon as no obstruction of saw control is to be expected. Position

001BA269 KN

the felling wedge in the felling cut and drive in with suitable tools.

Only use aluminum or plastic wedges – do not use steel wedges. Steel wedges can seriously damage the saw chain and cause dangerous kickback.

Select suitable felling wedges dependent on the trunk diameter and the width of the kerf (analogue to felling cut (E)).

Contact the STIHL dealer for the selection of the felling wedge (suitable length, width and height).

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Selecting the appropriate felling cut

The selection of the appropriate felling cut is dependent on the same tree characteristics that must be noted when determining the direction of fall and the escape paths.

There are various different features of these characteristics. This User Manual will only describe the two most commonly occurring variants:

left: Normal tree – vertically

upright tree with uniform crown

right: Leaner tree - crown pointing in

direction of fall

Felling cut with stabilizing strap (normal tree)

A) Thin trunks Implement this felling cut when the trunk

diameter is smaller than the cutting length of the chainsaw.

Shout a warning before starting the felling cut.

N Plunge cut the felling cut (E) –

plunge the guide bar fully in

N Engage the spiked bumper behind

the hinge and use this as the rotation point – reposition the chainsaw as little as possible

N Make the felling cut up to the

hinge (1)

– Do not cut into the hinge N Make the felling cut up to the

stabilizing strap (2)

– Do not cut into the stabilizing strap

N Set the felling wedge (3) Shout a second warning immediately

before the tree falls. N Cut through the stabilizing strap,

horizontal level with the felling cut, with arms fully extended

B) Thick trunks Implement this felling cut when the trunk

diameter is greater than the cutting length of the machine.

001BA261 KN

Shout a warning before starting the felling cut.

N Engage the spiked bumper at the

height of the felling cut and use this as the rotation point – reposition the chainsaw as little as possible

N Tip of the guide bar must penetrate

the wood before the hinge (1) – guide the chainsaw absolutely horizontally and swivel as widely as possible

N Make the felling cut up to the

hinge (2)

– Do not cut into the hinge N Make the felling cut up to the

stabilizing strap (3)

– Do not cut into the stabilizing strap

001BA273 KN

The felling cut must be continued on the opposite side of the trunk.

Ensure that the second cut is at the same level as the first cut.

N Plunge cut the felling cut N Make the felling cut up to the

hinge (4)

– Do not cut into the hinge

001BA263 KN

MS 250

English

001BA266 KN

001BA267 KN

N Make the felling cut up to the

stabilizing strap (5)

– Do not cut into the stabilizing strap

N Set the felling wedge (6) Shout a second warning immediately

before the tree falls. N Cut through the stabilizing strap,

horizontal level with the felling cut, with arms fully extended

Felling Cut with Holding Strap (Leaner)

A) Thin trunks Implement this felling cut when the trunk

diameter is smaller than the cutting length of the chainsaw.

N Plunge cut the guide bar into the

trunk until it exits on the other side

N Make the felling cut (E) towards the

hinge (1)

– Cut horizontally – Do not cut into the hinge

N Make the felling cut towards the

holding strap (2)

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

001BA274 KN

Shout a second warning immediately before the tree falls.

N With outstretched arms, cut through

the holding strap at a downward angle from outside.

B) Thick trunks

Perform this felling cut when the tree diameter is greater than the cutting length of the chainsaw.

001BA265 KN

N Engage the spiked bumper behind

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

N The guide bar nose enters the

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

– Do not cut into the holding strap or

hinge.

N Make the felling cut up to the

hinge (2)

– Do not cut into the hinge N Make the felling cut up to the

holding strap (3) – Do not cut into the holding strap. The felling cut must be continued on the

opposite side of the trunk. Ensure that the second cut is at the

same level as the first cut. N Engage the spiked bumper behind

the hinge and use this as the

rotation point – reposition the

chainsaw as little as possible N Tip of the guide bar must penetrate

the wood before the holding strap

(4) – guide the chainsaw absolutely

horizontally and swivel as widely as

possible N Make the felling cut up to the

hinge (5) – Do not cut into the hinge N Make the felling cut up to the

holding strap (6) – Do not cut into the holding strap.

MS 250

English

001BA248 KN

001BA244 KN

Shout a second warning immediately before the tree falls.

N With outstretched arms, cut through

the holding strap at a downward angle from outside.

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

001BA268 KN

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.

MS 250

English

143BA034 KN

001BA185 KN

001BA186 KN

143BA003 KN

001BA187 KN

Mounting the Bar and Chain (side chain tensioner)

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 250

English

2310BA013 KN

2310BA014 KN

2310BA015 KN

2310BA016 KN

2310BA017 KN

001BA186 KN

181BA012 KN

Mounting the Bar and Chain (quick chain tensioner)

Removing the chain sprocket cover

N Swing grip (1) into position (until it

engages)

N Turn the wing nut (2) to the left until

it hangs loosely in the chain sprocket cover (3)

N Remove chain sprocket cover (3)

Mounting the tensioning gear

Releasing the chain brake

N Remove screw (2)

N Pull hand guard towards the front

handle until it engages audibly –

chain brake is released

Fitting the saw chain

N Position tensioning gear (1) and

guide bar (3) relative to one another

N Remove and reverse tensioning

gear (1)

N Insert and tighten screw (2)

WARNING

Put on protective gloves – risk of injury by the sharp cutters.

MS 250

English

181BA013 KN

135BA011 KN

2310BA018 KN

N Fit the saw chain – starting at the

nose of the guide bar – pay attention to the position of the tensioning gear and the cutting edges

N Turn tensioning gear (1) to the right

as far as possible

N Turn the guide bar so that the

tensioning gear faces the user

N Place the saw chain on the chain

sprocket (2)

N Slide the guide bar over the collar

screw (3); the head of the rear collar screw must protrude into the oblong hole

N turn the adjusting wheel (4) a little

until the chain sprocket cover can

be slid completely against the

engine housing N Swing grip (5) into position (until it

engages)

N Fit wing nut and tighten lightly N Next step: see "Tensioning the Saw

Chain"

N Guide the drive link into the bar

groove (see arrow) and turn the tensioning gear to the left as far as possible

N Fit chain sprocket cover, sliding the

guide lugs into the engine housing openings

MS 250

When fitting the chain sprocket cover, the teeth of the adjusting wheel and the tensioning gear must mesh; if necessary,

English

133BA024 KN

001BA112 KN

143BA007 KN

Tensioning the Saw Chain (side chain tensioner)

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".

Tensioning the Saw Chain (quick chain tensioner)

Retensioning during cutting work:

N Shut off the engine. N Pull out the hinged clip and loosen

the wingnut.

N Turn the adjusting wheel (1)

clockwise as far as stop.

N Tighten down the wingnut (2) firmly

by hand.

N Fold down the hinged clip. 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".

MS 250

English

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.

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.

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.

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) 1 0.02 (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.

MS 250

English

001BA229 KN

001BA236 KN

001BA232 KN

001BA234 KN

001BA237 KN

001BA234 KN

001BA233 KN

001BA231 KN

Fueling

Preparing the machine

N Before fueling, clean the cap and

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

N Always position the machine so that

the cap is facing upwards

Opening

Closing

N Turn the cap counterclockwise

(about a quarter turn).

Grip must be vertical: N Fit the cap – marks on tank cap and

fuel tank must line up.

N Press the cap down as far as stop.

Marks on tank cap and fuel tank must line up.

N While holding the cap depressed,

turn it clockwise until it engages in position.

N Raise grip to vertical position.

N Remove the tank cap.

Filling Up with Fuel

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

STIHL recommends you use the STIHL filler nozzle for fuel (special accessory).

N Fill the fuel tank.

The marks on the tank cap and fuel tank are then in alignment.

MS 250

N Fold the grip down.

001BA235 KN

001BA241 KN

001BA238 KN

001BA239 KN

Tank cap is locked.

If the tank cap cannot be locked in the fuel tank opening

Left: Bottom of cap is twisted –

inner mark (1) in line with outer mark.

Right: Bottom of cap in correct posi-

tion – inner mark is under the grip. It is not in line with the outer mark.

English

Chain Lubricant

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.

Bottom of cap is twisted in relation to top.

N Remove the cap from the fuel tank

and check it from above.

MS 250

N Place the cap on the opening and

rotate it counterclockwise until it engages the filler neck.

N Continue rotating the cap

counterclockwise (about a quarter turn) – this causes the bottom of the cap to be turned to the correct position.

N Turn the cap clockwise and lock it in

position – see section on "Closing".

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.

English

001BA158 KN

Filling Chain Oil Tank

Preparations

N Thoroughly clean the oil 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.

N Open the filler cap.

Fill up with chain oil.

N Refill the chain oil tank every time

you refuel.

Take care not to spill chain oil while refilling and do not overfill the tank.

STIHL recommends you use the STIHL filler nozzle for chain oil (special accessory).

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 level in the tank does not go down, the reason may be a fault in the oil supply system: Check chain lubrication, clean the oilways, contact your dealer for assistance if necessary STIHL recommends that you have servicing and repair work carried out exclusively by an authorized STIHL servicing dealer.

Checking Chain Lubrication

143BA024 KN

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

NOTICE

Never operate your machine without chain lubrication. If the saw chain runs dry, the cutting attachment may very quickly be damaged beyond repair. Before starting work, always check the chain lubrication and oil level in the tank.

Every new saw chain needs a run-in time of 2 to 3 minutes.

After the saw chain has run in, check the tension of the chain and correct if necessary – see "Checking the chain tension".

MS 250

English

143BA011 KN

Chain Brake

Saw chain, lock

– in an emergency – when starting – when idling

Press the hand guard towards the nose of the guide bar with the left hand - or automatically due to kickback: Saw chain is blocked - and stops running.

Disengage the chain brake.

NOTICE

The chain brake must be released before opening the throttle (except during functional checkout) and before sawing.

Running the engine at high revs with the chain brake engaged (chain locked) will quickly damage the engine 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.

Checking Operation of the Chain Brake

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

Full-time use: quarterly Part-time use: every six

months

occasional use: annually

N Pull the hand guard back towards

the front handle.

MS 250

Chain Brake Maintenance

The chain brake is subject to (normal wear). It is necessary to have it serviced and maintained regularly by trained

143BA012 KN

personnel. STIHL recommends that maintenance and repair work be carried out only by authorised STIHL dealers. The following intervals must be complied with:

English

208BA005 KN

135BA029 LÄ

Winter Operation

At temperatures below +10°C

N Press down the throttle trigger

lockout and move the Master Control lever to choke closed l.

N Turn the knob above the rear handle

90° counterclockwise.

N Lift off the carburetor box cover

vertically.

N Lift out the shutter (in front of spark

plug) vertically.

N Turn the shutter 180°. N Refit the shutter. N Refit the carburetor box cover and

secure it with the knob.

Heated air is now drawn in from around the cylinder to warm the carburetor – this helps prevent carburetor icing.

Starting / Stopping the Engine

Versions with Easy2Start

WARNING

This machine is extremely simple and easy to start, even for children.

To reduce the risk of serious or fatal injury:

– do not allow children or other

unauthorized persons to attempt to start or otherwise use the machine

– never allow children or

unauthorized persons access to the machine

– never leave the machine

unattended while working or during work breaks

– after work, store in a safe, secure

location out of the reach of children and other unauthorized persons

Positions of the Master Control lever

NOTICE

At temperatures above + 20°C, always close the shutter again. This is necessary to avoid engine running problems and overheating.

STOP

001BA140 KN

Stop 0 – engine off – the ignition is switched off

Normal run position F – engine runs or can fire

MS 250

English

143BA018 KN

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

Adjust Master Control lever

To move the Master Control lever from the normal run position (F) to choke closed (l), press down the throttle 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 (n) before it can be moved to the starting throttle position (l).

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

To switch off the engine, set the master control lever to Stop 0.

Position starting acceleration n – if engine is warm (once the engine

has been running for approx. one minute)

– when Engine Begins to Fire – After ventilation of the combustion

chamber, if the engine was flooded

Fuel pump

Press the fuel pump bulb several times – even if the bulb is already filled with fuel:

– When starting for the first time – if the fuel tank was run until empty

(engine stopped)

Holding the Chain Saw

There are two methods of starting the saw.

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 place your right foot through the rear

handle.

Position choke shutter closed l

– if the engine is cold – if the engine stalls during opening of

throttle after starting

– if the fuel tank was run until empty

(engine stopped)

MS 250

English

143BA019 KN

143BA020 KN

Between knees

N clamp the rear handle between the

knees or thighs

N Hold the front handle firmly with

your left hand – your thumb should be under the handle.

Actuating

Standard versions

N Pull the starter grip slowly with your

right hand up to the limit stop – and then give it a quick strong pull and push down on the handlebar 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 cord can rewind properly.

Machines without additional manual fuel pump: If the engine is new or has not been used for a longer period of time, it may be necessary to pull the starter cord several times to prime the fuel system.

Versions with Easy2Start The Easy2Start stores the energy

required to start the chainsaw. For this reason, there may be a delay of a few seconds between cranking the engine and actually starting.

For versions with Easy2Start, there are two ways to start the machine:

N Pull the starter grip slowly and

smoothly with the right hand – or – with the right hand, pull the starter grip in several short pulls of the starter rope, pulling the rope out only a little bit each time

N During starting, press down on the

handlebar – do not pull out the starter rope all the way – risk of breakage!

N Do not let the starter grip snap back.

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

Starting the Chainsaw

WARNING

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

N Observe safety precautions

MS 250

+ 94 hidden pages

Stihl MS 250 Instruction Manual [en, fr]

Specifications and Main Features

Frequently Asked Questions

User Manual