MS 231 Petrol Chainsaw

Product Information

The MS 231 and MS 251 are high-performance chainsaws manufactured by STIHL. They are equipped with a two-stroke engine and are designed for cutting wood and other materials. These chainsaws have a fuel tank for gasoline and engine oil mixture, a chain oil tank, and a chain brake for safety. They are available with either a side
chain tensioner or a quick chain tensioner.

Product Usage Instructions

Before using the chainsaw, it is important to read the instruction manual carefully and observe all safety precautions. Here are the basic steps for using the MS 231 and MS 251 chainsaws:

1. Check the fuel and chain oil levels and fill if necessary.
2. Put on protective gear including eye and ear protection, gloves, and boots.
3. Start the chainsaw according to the instructions in the manual.
4. Hold the chainsaw firmly with both hands and position the chain near the material to be cut.
5. Engage the chain brake and release it just before starting the cut.
6. Make the cut by slowly lowering the chainsaw onto the material, following the marked line of the cut.
7. Continue cutting until the material is completely severed.
8. Release the throttle trigger to stop the chainsaw once the cut is complete.
9. Engage the chain brake after use to prevent accidental start-up.
10. Clean and maintain the chainsaw according to the instructions in the manual.

It is important to follow these instructions carefully to ensure safe and efficient use of the MS 231 and MS 251 chainsaws. If you have any questions or concerns, contact your dealer or STIHL sales company for assistance.

Instruction Manual

Original Instruction Manual 0000006607_013_GB

Printed on chlorine-free paper Printing inks contain vegetable oils, paper can be recycled.

Dear Customer,
Thank you for choosing a quality engineered STIHL product.
It has been built using modern production techni- ques and comprehensive quality assurance. Every effort has been made to ensure your satis- faction 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
1 Guide to Using this Manual
This Instruction Manual refers to a STIHL chain saw, also called a machine in this Instruction Manual.
1.1 Pictograms
Pictograms that appear on the machine are explained in this Instruction Manual. Depending on the machine and equipment ver- sion, 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
Direction of chain travel
Ematic; chain oil flow adjustment
Tension saw chain
Intake air baffle: winter operation
Intake air baffle: summer operation
Handle heating
Actuate decompression valve
Actuate manual fuel pump

© ANDREAS STIHL AG & Co. KG 2022 0458-737-0121-C. VA0.L21.

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0458-737-0121-C

Safety Precautions

1.2 Symbols in text
WARNING
Warning where there is a risk of an accident or personal injury or serious damage to property.
NOTICE
Caution where there is a risk of damaging the machine or its individual components.
1.3 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 man- ual.
2 Safety Precautions
Special safety precautions must be observed to reduce the risk of per- sonal 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. Non- observance of the instruction manual may result in seri- ous or even fatal injury.
2.1 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 ani- mals 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

English
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 sys- tem of your chain saw produces an electromag- netic 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.
2.2 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 dam- age to property caused while using unauthorised attachments.
2.3 Clothing and Equipment
Wear proper protective clothing and equipment. Clothing must be sturdy and snug-fit- ting, but allow complete freedom of movement. Wear snug fitting clothing with cut-retardant pads ­ no loose-fit- ting 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 cutretardant material, non-slip soles and steel toe caps.

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3

English
WARNING To reduce the risk of eye injuries, wear tight-fitting safety goggles con- forming to standard EN 166 or a face shield. Make sure that the safety gog- gles and the face shield fit correctly.
Wear “personal” hearing protection ­ for exam- ple, ear defenders. Wear a hard hat wherever there is any risk of falling objects.
Wear sturdy protective gloves made of a resistant material (e.g. leather).
STIHL can supply a comprehensive range of per- sonal protective equipment.
2.4 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.
2.5 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.
4

001BA115 KN

2 Safety Precautions
2.6 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.
2.7 Refuelling
Gasoline is an extremely flammable fuel ­ keep clear of naked flames and fire ­ do not spill any fuel ­ no smok- ing.
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 ven- tilated place. Clean the machine immediately if fuel is spilled. Do not spill fuel over your clothing ­ contaminated clothing must be changed imme- diately.
The machines can be equipped with the follow- ing filler caps as standard:
Cliplock filler cap (bayonet-type) Place the cliplock filler cap (bayonettype) in position, turn as far as stop and fold the cliplock down.
This helps reduce the risk of unit vibrations caus- ing 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!
2.8 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 spe-
cial attention to visible parts such as the tank
0458-737-0121-C

2 Safety Precautions
cap, hose connections and the manual fuel pump (on machines so equipped). If there are any leaks or damage, do not start the engine ­ risk of fire. Have your saw repaired by a serv- icing 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.
2.9 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 start- ing ­ risk of injury due to rotating chain!
Do not drop-start the engine ­ start as described in the Instruction Manual.
2.10 During operation
Ensure you always have a firm and safe footing. Take special care when the bark is wet ­ danger of slipping!

English
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 emer- gency, switch off the engine immediately by mov- ing 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 proce- dures and can provide help in an emergency. Helpers at the cutting site must also wear protec- tive 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 pro- duced while using the machine may be hazard- ous 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.

001BA087 LÄ

0458-737-0121-C

5

English
Examine the saw chain periodically at short inter- vals 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 unintention- ally!
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 colour- less and odourless 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 cata- lytic converter.

2 Safety Precautions
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 prob- lems (e. g., your field of vision gets smaller), hearing problems, dizziness or inability to con- centrate, stop work immediately. Such symptoms may be caused by an excessively high concen- tration of exhaust emissions ­ risk of accident!
2.11 After finishing work
Switch off the motor, engage the chain brake and attach the chain scabbard.
2.12 Storage
When the machine is not in use, it should be stored in such a way that no-one is endangered. Secure the machine against unauthorised use.
Store the machine in a safe, dry room.
2.13 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 cir-
culation (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.
2.14 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 inad- vertently!
Exception: adjustment of carburettor and idle speed.

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0458-737-0121-C

Reactive Forces

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 acci- dents!
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 “Speci- fications”.
Check ignition lead (insulation in good condition, secure connection).
Check that the muffler is in perfect working con- dition.
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 influ- ences 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 lubrica- ted.

English 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! Con- sult a servicing dealer ­ do not use the machine until the malfunction has been remedied, see “Chain brake”.
3 Reactive Forces
The most common reactive forces that occur dur- ing cutting are: kickback, pushback and pull-in.
3.1 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.
3.2 Kickback occurs if, e. g.,
­ when the upper quadrant of the bar nose unin- tentionally contacts wood or another solid

001BA036 KN

001BA257 KN

0458-737-0121-C

7

English
object, e.g. when another limb is touched acci- dentally during limbing. ­ when the chain at the nose of the guide bar is pinched in the cut.
3.3 Quickstop chain brake:
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.
3.4 To reduce the risk of kickback
­ Work cautiously and avoid situations which could cause kickback.
­ Hold the saw firmly with both hands and main- tain a secure grip.
­ always cut at full throttle. ­ Be aware of the location of the guide bar nose
at all times. ­ 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 previ-
ous 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, prop- erly tensioned chain ­ the depth gauge setting must not be too large. ­ Use a low kickback chain and a narrow radius guide bar.
3.5 Pull-in (A)
A
Pull-in occurs when the chain on the bottom of the bar is suddenly pinched, caught or encoun- ters a foreign object in the wood. The reaction of
8

001BA037 KN

Working Techniques

the chain pulls the saw forward ­ to reduce this risk, always engage the spiked bumper securely in the tree or limb.
3.6 Pushback (B)
B
Pushback occurs when the chain on the top of the bar is suddenly pinched, caught or encoun- ters 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
3.7 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) repre- sents 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 nec- essary, inform the police, utility company or rail- way authority.
4 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!
0458-737-0121-C

001BA038 KN

4 Working Techniques
Country-specific legislation on felling technique must be complied with during felling work.
4.1 Sawing
Do not operate your saw with the starting throttle lock engaged. Engine speed cannot be control- led 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 cut- ting 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.
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
0458-737-0121-C

001BA082 KN 001BA033 KN

English
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 possi-
ble. ­ 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)), oth-
9

English erwise the cutting attachment may stick in the cut or kick back ­ risk of injury!
1

4 Working Techniques
4.2 Preparing for felling
Check that there are no other persons in the fell- ing area ­ other than helpers.
Make sure no-one is endangered by the falling tree ­ the noise of your engine may drown any warning calls.

2

001BA151 KN

001BA088 LÄ

1

1/2

1

2

21/2

1
Make relieving cut at the compression side (1) 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 touch- ing the ground because the saw chain will other- wise be damaged. Ripping:

001BA152 KN

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 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)

001BA189 KN 001BA040 KN

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!
10

B

B

A Direction of fall B Escape path (escape routes)

­ Establish escape paths for each worker ­ approx. 45° diagonally opposite to the direc- tion of fall
0458-737-0121-C

4 Working Techniques ­ Clear escape paths, eliminate obstacles ­ Put down tools and equipment at a safe dis-
tance ­ but not on the escape paths ­ When felling, stand only to the side of the fall-
ing trunk and only move back laterally onto the escape path ­ 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
4.3 Felling notch
Preparing the felling notch

001BA146 KN

English
Determine direction of fall with gunning sight on cover and fan housing
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 direc- tion of fall. 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 techni- que. Make a bottom (horizontal) cut Make the top (angled) cut approx. 45° 60° to
the bottom cut Checking the direction of fall

001BA153 KN

001BA153 KN

C C
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
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001BA271 KN

Insert the chainsaw with guide bar in the bot- tom 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.
11

English
4.4 Sapwood cuts

4 Working Techniques
­ With rotten trunks, leave a wider strip
Plunge cutting ­ For relieving cuts during shortening ­ For wood carving

001BA150 KN

001BA269 KN

Sapwood cuts in long-fibered softwood help pre- vent sapwood splintering when the tree falls. Make cuts at both sides of the trunk at same height as bottom of 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.
4.5 Basic information on felling cut
Basic dimensions

3. 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 push- back!
   3. Make the plunge cut very carefully. Risk of pushback.

001BA259 KN

C

E

C

1/10 Ø

G

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 diam-
eter ­ 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) sup- ports 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
12

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 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
0458-737-0121-C

001BA270 KN

4 Working Techniques
damage the saw chain and cause dangerous kickback.
Select suitable felling wedges dependent on the trunk diameter and the width of the kerf (ana- logue to felling cut (E)).
Contact the STIHL dealer for the selection of the felling wedge (suitable length, width and height).
4.6 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 var- iants:

English
Shout a warning before starting the felling cut. Plunge cut the felling cut (E) ­ plunge the
guide bar fully in Engage the spiked bumper behind the hinge
and use this as the rotation point ­ reposition the chainsaw as little as possible Make the felling cut up to the hinge (1) ­ Do not cut into the hinge Make the felling cut up to the stabilizing strap (2) ­ Do not cut into the stabilizing strap
3.

001BA273 KN

left: right:

Normal tree ­ vertically upright tree with uniform crown Leaner tree – crown pointing in direc- tion of fall

4.7 Felling cut with stabilizing strap (normal tree)

A) Thin trunks
Implement this felling cut when the trunk diame- ter is smaller than the cutting length of the chain- saw.

1. 2.

001BA261 KN

001BA260 KN

Set the felling wedge (3)
Shout a second warning immediately before the tree falls. Cut through the stabilizing strap, horizontal
level with the felling cut, with arms fully exten- ded
B) Thick trunks
Implement this felling cut when the trunk diame- ter is greater than the cutting length of the machine.

Shout a warning before starting the felling cut. 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 Tip of the guide bar must penetrate the wood before the hinge (1) ­ guide the chainsaw absolutely horizontally and swivel as widely as possible Make the felling cut up to the hinge (2) ­ Do not cut into the hinge

0458-737-0121-C

13

001BA263 KN

English
Make the felling cut up to the stabilizing strap (3) ­ Do not cut into the stabilizing strap
The felling cut must be continued on the oppo- site side of the trunk.
Ensure that the second cut is at the same level as the first cut. Plunge cut the felling cut Make the felling cut up to the hinge (4)
­ Do not cut into the hinge Make the felling cut up to the stabilizing
strap (5) ­ Do not cut into the stabilizing strap
6.

4 Working Techniques Make the felling cut towards the holding strap
(2) ­ Cut horizontally ­ Do not cut into the holding strap.
Shout a second warning immediately before the tree falls. With outstretched arms, cut through the hold-
ing strap at a downward angle from outside. B) Thick trunks

001BA266 KN

001BA274 KN

001BA267 KN

Set the felling wedge (6)
Shout a second warning immediately before the tree falls. Cut through the stabilizing strap, horizontal
level with the felling cut, with arms fully exten- ded

4.8 Felling Cut with Holding Strap (Leaner)

A) Thin trunks
Implement this felling cut when the trunk diame- ter is smaller than the cutting length of the chain- saw.

Plunge cut the guide bar into the trunk until it exits on the other side
Make the felling cut (E) towards the hinge (1) ­ Cut horizontally ­ Do not cut into the hinge

001BA265 KN

Perform this felling cut when the tree diameter is greater than the cutting length of the chainsaw. Engage the spiked bumper behind the holding
strap and use it as a pivot ­ avoid reposition- ing the chainsaw more than necessary. The guide bar nose enters the wood (1) before it reaches the hinge ­ hold the chainsaw hori- zontally and swing it as far as possible. ­ Do not cut into the holding strap or hinge. Make the felling cut up to the hinge (2) ­ Do not cut into the hinge 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 oppo- site side of the trunk.
Ensure that the second cut is at the same level as the first cut. Engage the spiked bumper behind the hinge
and use this as the rotation point ­ reposition the chainsaw as little as possible

14

0458-737-0121-C

001BA244 KN

5 Cutting Attachment

Tip of the guide bar must penetrate the wood

5.1

before the holding strap (4) ­ guide the chain-

saw absolutely horizontally and swivel as

widely as possible

Make the felling cut up to the hinge (5)

­ Do not cut into the hinge

Make the felling cut up to the holding strap (6)

­ Do not cut into the holding strap.

Chain Scabbard

English

Shout a second warning immediately before the tree falls. With outstretched arms, cut through the hold-
ing strap at a downward angle from outside.
5 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.
1 2

001BA268 KN

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 cor- rect length which covers the complete guide bar.
The length of the matching guide bars is marked on the side of the chain scabbard.
6 Mounting the Bar and Chain (side chain ten- sioner)
6.1 Removing the chain sprocket cover

001BA248 KN

a

3

­ The pitch (t) of the saw chain (1), chain sprocket and the nose sprocket of the Rollo- matic 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 cut- ting attachment may be damaged beyond repair after a short period of operation.

Unscrew the nut and remove the chain sprocket cover.
1
2

533BA001 KN

001BA185 KN

0458-737-0121-C

15

English

7 Mounting the Bar and Chain (quick chain tensioner)

Turn the screw (1) counterclockwise until the tensioner slide (2) butts against the left end of the housing slot.
6.2 Disengage the chain brake.

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.
Refit the sprocket cover and screw on the nut only fingertight.
Go to chapter on “Tensioning the Saw Chain”

7 Mounting the Bar and Chain (quick chain ten- sioner)

7.1 Removing the chain sprocket cover

001BA186 KN

Pull the hand guard towards the front handle until there is an audible click ­ the chain brake is disengaged.
6.3 Fitting the chain

1

3

2

WARNING
Wear work gloves to protect your hands from the sharp cutters. Fit the chain ­ start at the bar nose.

143BA003 KN

Swing grip (1) into position (until it engages) Turn the wing nut (2) to the left until it hangs
loosely in the chain sprocket cover (3) Remove chain sprocket cover (3)
7.2 Mounting the tensioning gear
1

2310BA013 KN

2310BA014 KN

3

11

24

Fit the guide bar over the studs (1) ­ the cut- ting edges on the top of the bar must point to the right.
Engage the peg of the tensioner slide in the locating hole (2) ­- place the chain over the sprocket (3) at the same time.
16

001BA187 KN

Remove and reverse tensioning gear (1)
2
0458-737-0121-C

2310BA015 KN

181BA012 KN

7 Mounting the Bar and Chain (quick chain tensioner)

Remove screw (2)

7.4

1

Fitting the saw chain

English

3

2310BA016 KN

Position tensioning gear (1) and guide bar (3) relative to one another

2 1

2310BA017 KN

Insert and tighten screw (2)
7.3 Releasing the chain brake

WARNING
Put on protective gloves ­ risk of injury by the sharp cutters.
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
Turn tensioning gear (1) to the right as far as possible
Turn the guide bar so that the tensioning gear faces the user

001BA186 KN

Pull hand guard towards the front handle until it engages audibly ­ chain brake is released

3

2

181BA013 KN

0458-737-0121-C

Place the saw chain on the chain sprocket (2) Slide the guide bar over the collar screw (3);
the head of the rear collar screw must pro- trude into the oblong hole
17

English

8 Tensioning the Saw Chain (side chain tensioner)
8 Tensioning the Saw Chain (side chain tensioner)

142BA063 KN

1

Guide the drive link into the bar groove (see arrow) and turn the tensioning gear to the left as far as possible
Fit chain sprocket cover, sliding the guide lugs into the engine housing openings
4 5

135BA011 KN

Retensioning during cutting work: Switch off the engine. Loosen the nut. Hold the bar nose up. Use a screwdriver to turn the tensioning
screw (1) clockwise until the chain fits snugly against the underside of the bar. While still holding the bar nose up, tighten down the nut firmly. Go to “Checking Chain Tension”.
A new chain has to be retensioned more often than one that has been in use for some time. Check chain tension frequently ­ see chapter
on “Operating Instructions”.
9 Tensioning the Saw Chain (quick chain tensioner)
1

2310BA018 KN

When fitting the chain sprocket cover, the teeth of the adjusting wheel and the tensioning gear must mesh; if necessary, turn the adjusting wheel (4) a little until the
chain sprocket cover can be slid completely against the engine housing Swing grip (5) into position (until it engages) Fit wing nut and tighten lightly Next step: see “Tensioning the Saw Chain”
18

2
Retensioning during cutting work: Shut off the engine. Pull out the hinged clip and loosen the wing-
nut. Turn the adjusting wheel (1) clockwise as far
as stop. Tighten down the wingnut (2) firmly by hand. Fold down the hinged clip. Go to “Checking Chain Tension” A new chain has to be retensioned more often than one that has been in use for some time.
0458-737-0121-C

001BA112 KN

10 Checking Chain Tension Check chain tension frequently ­ see chapter
on “Operating Instructions”.
10 Checking Chain Tension
Shut off the engine. Wear work gloves to protect your hands. The chain must fit snugly against the under-
side of the bar and it must still be possible to pull the chain along the bar by hand when the chain brake is released. If necessary, retension the chain. A new chain has to be retensioned more often than one that has been in use for some time. Check chain tension frequently ­ see chapter on “Operating Instructions”.
11 Fuel
The engine requires a mixture of gasoline and engine oil.
WARNING Avoid direct skin contact with fuel and breathing in of gasoline fumes.
11.1 STIHL MotoMix
STIHL recommends using STIHL MotoMix. This pre-blended fuel is free of benzene and lead, is distinguished by a high octane rating, and always provides the proper mixing ratio. STIHL MotoMix uses STIHL HP Ultra two-stroke engine oil for optimum engine life. MotoMix is not available in all markets.

142BA064 KN

11.2 Mixing fuel

English

NOTICE

Unsuitable fuels or a mixing ratio that deviates from the specification can lead to severe engine damage. The engine, seals, fuel lines and fuel tank may be damaged if low-quality gasoline or engine oil is used.

11.2.1 Gasoline

Use only high-quality gasoline with an octane rat- ing of at least 90 ROC ­ leaded or unleaded.

Gasoline with an alcohol component exceeding 10% can cause impaired engine performance in engines with manually adjustable carburetors and thus should not be used in these engines.

Engines with M-Tronic deliver full engine per- formance using gasoline with an alcohol compo- nent of up to 27% (E27).

11.2.2 Engine oil

If you mix the fuel yourself, use only STIHL twostroke engine oil or another high-performance engine oil classified as JASO FB, JASO FC, JASO FD, ISO-L-EGB, ISO-L-EGC or ISO-LEGD.

STIHL specifies STIHL HP Ultra two-stroke engine oil or an equivalent high- performance engine oil in order to maintain emission limits over the machine’s service life.

11.2.3 Mixing ratio

with STIHL two-stroke engine oil 1:50; 1:50 = 1 part oil + 50 parts gasoline

11.2.4 Examples

Quantity of gaso- STIHL two-stroke

line

engine oil 1:50

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)

Pour oil into an approved safety fuel canister first, then add gasoline and mix thoroughly

11.3 Storing fuel mixture

Store in approved safety fuel canisters only in a dry, cool and secure place protected against light and sunlight.

0458-737-0121-C

19

001BA236 KN

English
Fuel mixture deteriorates with age ­ mix only as much as needed for a few weeks. Do not store fuel mixture for longer than 30 days. The fuel mixture can become unusable more quickly if exposed to light, sunlight or low or high tempera- tures. STIHL MotoMix however can be stored for up to 5 years without any problems. Shake the canister containing the fuel mixture
thoroughly before refueling
WARNING
Pressure may have built up in the canister ­ open it carefully. The fuel tank and the canister in which fuel
mixture is stored should be cleaned thoroughly from time to time Residual fuel and the liquid used for cleaning must be disposed of in accordance with regula- tions and without harming the environment!
12 Fueling
12.1 Preparing the machine

12.2 Opening

12 Fueling

Raise grip to vertical position.

Turn the cap counterclockwise (about a quar- ter turn).

001BA232 KN

001BA234 KN

001BA229 KN

001BA237 KN

Before fueling, clean the cap and the area around it to ensure that no dirt falls into the fuel tank
Always position the machine so that the cap is facing upwards

Marks on tank cap and fuel tank must line up.

Remove the tank cap.

20

0458-737-0121-C

12 Fueling
12.3 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 noz- zle for fuel (special accessory). Fill the fuel tank.
12.4 Closing
Fold the grip down.

English

001BA235 KN

001BA234 KN

001BA241 KN

001BA238 KN

Grip must be vertical: Fit the cap ­ marks on tank cap and fuel tank
must line up. Press the cap down as far as stop.

Tank cap is locked.
12.5 If the tank cap cannot be locked in the fuel tank opening
Bottom of cap is twisted in relation to top. Remove the cap from the fuel tank and check
it from above.

001BA233 KN

While holding the cap depressed, turn it clock-

wise until it engages in position.

1

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

001BA231 KN

Bottom of cap is twisted ­ inner mark (1) in line with outer mark. Bottom of cap in correct position ­ inner mark is under the grip. It is not in line with the outer mark.

0458-737-0121-C

21

English

13 Chain Lubricant

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

001BA239 KN 001BA158 KN

Place the cap on the opening and rotate it counterclockwise until it engages the filler neck.
Continue rotating the cap counterclockwise (about a quarter turn) ­ this causes the bottom of the cap to be turned to the correct position.
Turn the cap clockwise and lock it in position ­ see section on “Closing”.
13 Chain Lubricant
For automatic and reliable lubrication of the chain and guide bar ­ use only an environmen- tally compatible quality chain and bar lubricant. Rapidly biodegradable STIHL BioPlus is recom- mended.
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 formu- lated chain lubricant.

NOTICE Waste oil does not have the necessary lubricat- ing properties and is unsuitable for chain lubrica- tion.
14 Filling Chain Oil Tank
14.1 Preparations
Thoroughly clean the oil filler cap and the area around it to ensure that no dirt falls into the tank.
Position the machine so that the filler cap is facing up.
Open the filler cap.
14.2 Fill up with chain oil.
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 noz- zle for chain oil (special accessory). 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, con- tact your dealer for assistance if necessary STIHL recommends that you have servicing and repair work carried out exclusively by an author- ized STIHL servicing dealer.

22

0458-737-0121-C

15 Checking Chain Lubrication
15 Checking Chain Lubrica- tion

English
due to kickback: Saw chain is blocked – and stops running.
16.2 Disengage the chain brake.

143BA024 KN 143BA012 KN

The saw chain must always spin off a small amount of oil.
NOTICE Never operate your machine without chain lubri- cation. 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”.
16 Chain Brake
16.1 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
0458-737-0121-C

143BA011 KN

Pull the hand guard back towards the front handle.

NOTICE

The chain brake must be released before open- ing the throttle (except during functional check- out) and before sawing.
Running the engine at high revs with the chain brake engaged (chain locked) will quickly dam- age 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 acceler- ated 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.

16.3 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.

16.4 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 recom- mends that maintenance and repair work be car- ried out only by authorised STIHL dealers. The following intervals must be complied with:

Full-time use:

quarterly

23

English

Part-time use: occasional use:

every six months annually

Winter Operation

17.1 Pre-heating carburetor
Remove the shroud ­ see “Shroud”
17.1.1 At temperatures below +10 °C

17 Winter Operation
In case of erratic idling behavior or poor acceler- ation Turn the low speed screw (L) 1/4 turn counter-
clockwise
Whenever the low speed screw (L) has been adjusted, it is usually also necessary to adjust the idle speed adjusting screw (LA), see “Setting the carburetor”.
17.3 Air filter system
Retrofit new air filter if necessary ­ see “Air fil- ter system”
18 Starting / Stopping the Engine
18.1 Positions of Master Control Lever

2310BA000 KN

Using a screwdriver, pry the shutter out of the s (summer operation) position

STOP
0

2310BA001 KN

Place the shutter with the opening in the direc- tion of the chain saw in the r position (winter operation) ­ shutter must audibly snap into place
Fit the shroud ­ see “Shroud”
Heated air is now drawn in from around the cylin- der and circulates around the carburetor ­ this helps prevent carburetor icing.
17.1.2 At temperatures above +20 °C Ensure that the shutter is always returned to
position s (summer operation), otherwise the engine may malfunction due to overheating
17.2 At temperatures below -10 °C
if the chain saw is extremely cold (frost forma- tion) ­ after starting, bring the engine up to operating temperature at increased idle speed (disengage chain brake!)

Stop 0 ­ engine off ­ the ignition is switched off
Normal run position F ­ engine runs or can fire.
Starting throttlen ­ 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.

001BA140 KN

24

0458-737-0121-C

2310BA008 KN

18 Starting / Stopping the Engine
18.2 Setting the Master Control Lever
To move the Master Control lever from the nor- mal 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 posi- tion (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 Con- trol lever to Stop (0).
18.2.1 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).
18.2.2 Starting throttle position (n) ­ if the engine is warm, i.e. if it has been running
for about one minute. ­ When the engine begins to fire ­ after clearing a flooded combustion chamber.
18.3 Fuel pump
Press the manual 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).
18.4 Holding the Saw
There are two ways of holding the saw when starting.

18.4.1 On the ground

English

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.
Hold the saw firmly on the ground with your left hand on the front handle ­ your thumb should be under the handle.
Put your right foot into the rear handle and press down.

0458-737-0121-C

25

English 18.4.2 Between knees or thighs
Hold the rear handle tightly between your legs, just above the knees.
Hold the front handle firmly with your left hand ­ your thumb should be under the handle.
18.5 Cranking
18.5.1 Standard versions

2310BA009 KN

18 Starting / Stopping the Engine
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 han- dle 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.
18.5.2 Versions with ErgoStart
WARNING
This machine is extremely simple and easy to start, even for children ­ risk of accidents.
Do not allow children or other unauthorized per- sons to attempt to start or otherwise use the machine: ­ Never leave the machine unattended during
work breaks. ­ After work, store the machine in a safe, secure
location.
The ErgoStart stores the energy required to start the saw. For this reason there may be a delay of a few seconds between cranking the engine and it actually starting.
There are two ways of starting with the Ergo- Start: Hold the starter grip with your right hand and
pull it out slowly and steadily ­ or ­ hold the starter grip with your right hand and give it several short pulls, using only a short length of rope for each pull. Push down the handle while cranking. Do not pull out the rope to its full length ­ it might oth- erwise break. Do not let the starter grip snap back. Guide it slowly back into the housing so that the starter rope can rewind properly.
18.6 Starting the Saw
WARNING
Bystanders must be well clear of the general work area of the saw.
Observe safety precautions.

231BA010 KN

26

0458-737-0121-C

18 Starting / Stopping the Engine 18.6.1 Versions with manual fuel pump

English
18.7 When engine begins to fire

STOP

4

0

2310BA003 KN

2310BA021 KN

2310BA004 KN

Press the manual fuel pump bulb at least five times ­ even if the bulb is already filled with fuel.
18.6.2 All models

Set the Master Control lever (4) to the starting throttle position (n).
Hold and start your saw as described.
18.8 As soon as the engine runs

STOP

4

0

0
3 1

42

Press down trigger lockout and the blip the throttle trigger (3) ­ the Master Control lever (4) moves to the run position (F) and the engine settles down to idling speed.
NOTICE

As the chain brake is still engaged, the engine

3

must be returned to idling speed immediately ­ or the engine housing and chain brake might oth-

erwise be damaged.

2310BA002 KN

Push the hand guard (1) forward ­ the chain is locked.
Press down the trigger lockout (2) and pull the throttle trigger (3) at the same time. Set Mas- ter 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. Hold and start your saw as described.
0458-737-0121-C

Pull the hand guard back towards the front handle.
The chain brake is now disengaged ­ your saw is ready for operation.
27

001BA186 KN

English
NOTICE
Always disengage chain brake before accelerat- ing the engine. High revs with the chain brake engaged (chain locked) will quickly damage the clutch and chain brake.
18.9 At very low outside tempera- tures
Allow engine to warm up at part throttle. Change over to winter operation if necessary ­
see “Winter Operation”.
18.10 Stopping the engine
Move the Master Control lever to the stop position (0).
18.11 If the engine does not start
If you did not move the Master Control lever from the choke closed position (l) to the starting throttle position (n) quickly enough after the engine began to fire, the combustion chamber may be flooded. Move the Master Control lever to the stop
position (0). Remove the spark plug ­ see “Spark Plug”. Dry the spark plug. Crank the engine several times with the starter
to clear the combustion chamber. Refit the spark plug ­ see “Spark Plug”. Set Master Control lever to the starting throttle
position (n) ­ even if the engine is cold. Now start the engine.
19 Operating Instructions
19.1 During the break-in period
A factory new machine should not be run at high revs (full throttle off load) for the first three tank fillings. This avoids unnecessarily high loads dur- ing the break-in period. As all moving parts have to bed in during the break- in period, the frictional resistances in the shortblock are greater during this period. The engine develops its maximum power after about 5 to 15 tank fillings.

19.2

19 Operating Instructions
During work

NOTICE

Do not make the mixture leaner to achieve an apparent increase in power ­ this could damage the engine ­ see “Adjusting the Carburetor”.

NOTICE
Open the throttle only when the chain brake is off. Running the engine at high revs with the chain brake engaged (chain locked) will quickly damage the shortblock and chain drive (clutch, chain brake).
19.2.1 Check chain tension frequently
A new saw chain must be retensioned more fre- quently than one that has been in use already for an extended period.
19.2.2 Chain cold
Tension is correct when the chain fits snugly against the underside of the bar but can still be pulled along the bar by hand. Retension if neces- sary ­ see “Tensioning the Saw Chain”.
19.2.3 Chain at operating temperature
The chain stretches and begins to sag. The drive links must not come out of the bar groove on the underside of the bar ­ the chain may otherwise jump off the bar. Retension the chain ­ see “Ten- sioning the Saw Chain”.
NOTICE
The chain contracts as it cools down. If it is not slackened off, it can damage the crankshaft and bearings.
19.2.4 After a long period of full-throttle oper- ation
After a long period of full-throttle operation, allow engine to run for a while at idle speed so that the heat in the engine can be dissipated by flow of cooling air. This protects engine-mounted com- ponents (ignition, carburetor) from thermal over- load.
19.3 After finishing work
Slacken off the chain if you have retensioned it at operating temperature during work.

28

0458-737-0121-C

2710BA003 KN

20 Taking Care of the Guide Bar
NOTICE
Always slacken off the chain again after finishing work. The chain contracts as it cools down. If it is not slackened off, it can damage the crankshaft and bearings.
19.3.1 Short-term storage Wait for engine to cool down. Keep the machine with a full tank of fuel in a dry place, well away from sources of ignition, until you need it again.
19.3.2 Long-term storage See “Storing the machine”
20 Taking Care of the Guide Bar

2

1

3

Turn the guide bar over ­ every time you sharpen the chain and every time you replace the chain ­ this helps avoid one-sided wear, especially at the nose and underside of the bar.
Regularly clean the oil inlet hole (1), the oil- way (2) and the bar groove (3)
Measure the groove depth ­ with the scale on the filing gauge (special accessory) ­ in the area used most for cutting

Chain type Chain pitch

Picco Rapid Picco Rapid Rapid

1/4″ P 1/4″ 3/8″ P 3/8″; 0.325″ 0.404″

Minimum groove depth 4.0 mm 4.0 mm 5.0 mm 6.0 mm 7.0 mm

If groove depth is less than specified: Replace the guide bar

The drive link tangs will otherwise scrape along the bottom of the groove ­ the cutters and tie straps will not ride on the bar rails.

143BA026 KN

English
21 Shroud
21.1 Remove shroud
Move the Master Control Lever to the stop position 0
Push the front hand guard forwards ­ the saw chain is blocked
1
2 1
1
Loosen screws (1) Remove the shroud (2)
21.2 Refitting the shroud
Refit the shroud and tighten the screws
22 Air Filter System
The air filter system can be adapted to suit differ- ent operating conditions by installing different fil- ters. Changing a filter is accomplished quickly and simply. Different air filters are available for suit different conditions.
22.1 Fleece Filter
­ Fleece filter for normal operating conditions and dry work areas.

5902BA009 KN

0458-737-0121-C

29

English
22.2 HD2 Filter

23.1.1

23 Cleaning the Air Filter Removing the Air Filter (round filter)

NOTICE

To avoid damaging the filter, do not use tools for removing and installing the air filter.

5902BA008 KN

2710BA000 KN

­ HD2 filter (black filter frame, pleated filter material) for extreme wintry conditions (e.g. powder or drifting snow) or very dusty work areas.
22.3 Synthetic Fiber/Fleece Filter

2. Rotate the air filter a 1/4 turn counterclockwise and lift it away in the direction of the rear han- dle.
   Always replace a damaged filter. 23.1.2 Removing the Air Filter (synthetic fiber
   filter)

208BA028 KK

0000-GXX-0845-A0 KN

­ Fleece filter for normal operating conditions and dry work areas.
­ Synthetic fiber filter for wintry conditions.
23 Cleaning the Air Filter
23.1 If there is a noticeable loss of engine power
Remove the shroud ­ see “Shroud”. Clean away loose dirt from around the filter.
30

1

1

Squeeze both locking tabs (1) and lift filter away.
Always replace a damaged filter.
23.1.3 Cleaning the Air Filter Knock out the filter or blow it clear with com-
pressed air from the inside outwards.
Wash the filter thoroughly if knocking it out or blowing it clear is not sufficient to remove stub- born dirt, or if the filter fabric is sticky.
Washing the filter Wash the filter in STIHL special cleaner (spe-
cial accessory) or a clean, non-flammable sol- ution (e.g. warm soapy water). Rinse the filter from the inside outwards under a jet of water ­ do not use a pressure washer. Dry the filter components ­ do not expose to high temperatures. Do not impregnate the filter with oil.
0458-737-0121-C

24 Adjusting the Carburetor Reinstall the air filter. 23.1.4 Installing the Air Filter (round filter)
2. 1.

English
Turn the low speed adjusting screw (L) clock- wise until it is firmly in its seat ­ then back off 1/4 turn
24.3 Setting the idle speed
Make standard setting Start engine and let it warm up

2710BA001 KN 2310BA028 KN

Place the air filter in position. Push the air filter in the direction of the filter
housing and turn it clockwise at the same time until it engages ­ the “STIHL” name must be horizontal. Install the shroud ­ see “Shroud”. 23.1.5 Installing the Air Filter (synthetic fiber
filter) Place the air filter in position. Push the filter towards the filter housing until
the locking tabs snap into place. Install the shroud ­ see “Shroud”.
24 Adjusting the Carburetor
24.1 Basic information
The carburetor comes from the factory with a standard setting. The carburetor has been adjusted for optimum performance and fuel efficiency in all operating states.
24.2 Standard setting
Switch off the engine Check the air filter ­ clean or replace it if nec-
essary
Turn the high speed adjusting screw (H) coun- terclockwise as far as possible (max. 3/4 turn)

2310BA027 KN

24.3.1 Engine stops when idling Turn the idle speed adjusting screw (LA)
clockwise until the saw chain begins to run ­ then turn it back 2 3/4 turn.
24.3.2 Saw chain rotates at idle speed Turn the idle speed screw (LA) counterclock-
wise until the saw chain stops turning ­ then turn another 2 3/4 turns in the same direction

WARNING

If the saw chain continues to keep rotating in idle even after adjustment, have the chain saw checked by a servicing dealer.

24.3.3

Speed erratic when idling; poor accel- eration (despite standard setting of low speed adjusting screw)

The idle setting is too lean. Carefully turn the low speed adjusting
screw (L) counterclockwise until the engine runs smoothly and accelerates properly.

Whenever the low speed adjusting screw (L) has been adjusted, it is usually also necessary to readjust the idle speed adjusting screw (LA).

24.4 Correcting the carburetor set- ting for use at high altitudes

The setting may have to be marginally corrected if engine performance is unsatisfactory at high altitudes: Make standard setting Let the engine warm up

0458-737-0121-C

31

English
Turn the high speed adjusting screw (H) slightly clockwise (leaner) ­ max. up to the stop
NOTICE
After descending from a high altitude, restore the carburetor setting to the standard setting.
If you make the setting too lean it will increase the risk of engine damage through lack of lubri- cation and overheating.
25 Spark Plug
If the engine is down on power, difficult to start or runs poorly at idle speed, first check the spark plug.
Fit a new spark plug after about 100 operating hours ­ or sooner if the electrodes are badly eroded. Install only suppressed spark plugs of the type approved by STIHL ­ see “Specifica- tions”.
25.1 Removing the spark plug
Remove the shroud ­ see “Shroud”

25 Spark Plug Possible causes are: ­ Too much oil in fuel mix. ­ Dirty air filter. ­ Unfavorable running conditions.
1
WARNING Arcing may occur if the adapter nut (1) is loose or missing. Working in an easily combustible or explosive atmosphere may cause a fire or an explosion. This can result result in serious inju- ries or damage to property. Use resistor type spark plugs with a properly
tightened adapter nut.
25.3 Installing the spark plug

000BA045 KN

2310BA006 KN

2310BA012 KN

Pull off the spark plug boot Unscrew spark plug
25.2 Checking the Spark Plug
A
Clean dirty spark plug. Check electrode gap (A) and readjust if neces-
sary ­ see “Specifications”. Rectify the problems which have caused foul-
ing of the spark plug. 32

000BA039 KN

Fit spark plug by hand Tighten the spark plug and press on the spark
plug boot firmly Fit the shroud ­ see “Shroud”
26 Storing the Machine
For periods of about 30 days or longer Drain and clean the fuel tank in a well-ventila-
ted area. Dispose of fuel properly in accordance with
local environmental requirements. If a manual fuel pump is fitted: Press the man-
ual fuel pump at least 5 times. Start the engine and run it at idling speed until
it stops.
0458-737-0121-C

27 Checking and Replacing the Chain Sprocket

Remove saw chain and guide bar; clean and

spray with protective oil Thoroughly clean the machine – pay special

5

attention to the cylinder fins and air filter

When using biological chain oil (e.g. STIHL

BioPlus), fill the lubricant oil tank

Store the machine in a dry and secure location

Keep out of the reach of children and other

unauthorized persons

27 Checking and Replacing

the Chain Sprocket

4

Remove chain sprocket cover, saw chain and

guide bar.

Release chain brake ­ pull hand guard against

the front handle

27.1 Fit new chain sprocket

English
62 1
3 62 1

001BA121 KN 001BA122 KN

­ after use of two saw chains or earlier ­ if the wear marks (arrows) are deeper than
0.5 mm ­ otherwise the service life of the saw chain is reduced ­ use check gauge (special accessory) to test
Using two saw chains in alternation helps pre- serve the chain sprocket.
STIHL recommends use of original STIHL chain sprockets in order to ensure optimal functioning of the chain brake.

Use a screwdriver to remove the E-clip (1) Remove the washer (2) Remove rim sprocket (3) Inspect transport profile on the clutch drum (4)
­ if there are also heavy signs of wear, also replace the clutch drum Remove clutch drum or spur chain sprocket (5) including needle cage (6) from the crankshaft ­ with QuickStop Super chain brake, press throttle trigger lockout before- hand
27.2 Install spur chain sprocket / rim sprocket
Clean crankshaft stub and needle cage and lubricate with STIHL lubricant (special acces- sory)
Slide needle cage onto the crankshaft stub After refitting, turn the clutch drum and/or spur
chain sprocket approx. 1 full turn so that the carrier for the oil pump drive engages ­ with QuickStop Super chain brake, press throttle trigger lockout beforehand Refit the rim sprocket ­ cavities toward the outside Refit washer and E-clip on the crankshaft

0458-737-0121-C

33

English
28 Maintaining and Sharpen- ing the Saw Chain
28.1 Sawing effortlessly with a prop- erly sharpened saw chain
A properly sharpened saw chain cuts through wood effortlessly even with very little pushing. Never use a dull or damaged saw chain ­ this leads to increased physical strain, increased vibration load, unsatisfactory cutting results and increased wear. Clean the saw chain Check the saw chain for cracks and damaged
rivets Replace damaged or worn chain components
and adapt these parts to the remaining parts in terms of shape and level of wear ­ rework accordingly Carbide-tipped (Duro) saw chains are especially wear-resistant. For an optimal sharpening result, STIHL recommends STIHL servicing dealers.
WARNING
Compliance with the angles and dimensions lis- ted below is absolutely necessary. An improperly sharpened saw chain ­ especially depth gauges that are too low ­ can lead to increased kickback tendency of the chain saw ­ risk of injury!
28.2 Chain pitch
a

28 Maintaining and Sharpening the Saw Chain
The diameter of file to be used depends on the chain pitch ­ see table “Sharpening tools”. The angles of the cutter must be maintained dur- ing resharpening.
28.3 Sharpening and side plate angles
A

689BA021 KN

B

A Sharpening angle

STIHL saw chains are sharpened with a 30° sharpening angle. Ripping chains, which are sharpened with a 10° sharpening angle, are exceptions. Ripping chains have an X in the des- ignation.
B Side plate angle

The correct side plate angle results automatically when the specified file holder and file diameter are used.

Tooth shapes Micro = semi-chisel tooth, e. g., 63 PM3, 26 RM3, 36 RM Super = full chisel tooth, e. g., 63 PS3, 26 RS, 36 RS3 Ripping chain, e. g., 63 PMX, 36 RMX

Angle (°)

A

B

30 75

30 60

10 75

The angles must be identical for all cutters in the saw chain. Varying angles: Rough, uneven run- ning of the saw chain, increased wear ­ even to the point of saw chain breakage.

689BA027 KN

The chain pitch marking (a) is embossed in the area of the depth gauge of each cutter.

Marking (a) 7 1 or 1/4 6, P or PM 2 or 325 3 or 3/8 4 or 404

Chain pitch

Inches mm

1/4 P

6.35

1/4

6.35

3/8 P

9.32

0.325

8.25

3/8

9.32

0.404

10.26

34

0458-737-0121-C

28 Maintaining and Sharpening the Saw Chain
28.4 File holder

English

689BA018 KN

90°

689BA025 KN

689BA043 KN

Use a file holder Always use a file holder (special accessory, see table “Sharpening tools”) when sharpening saw chains by hand. File holders have markings for the sharpening angle. Use only special saw chain files! Other files are unsuitable in terms of shape and type of cutting.
28.5 To check the angles
STIHL filing gauge (special accessory, see table “Sharpening tools”) ­ a universal tool for check- ing sharpening and side plate angles, depth gauge setting, and tooth length, as well as clean- ing grooves and oil inlet holes.
28.6 Proper sharpening
Select sharpening tools in accordance with chain pitch
Clamp guide bar if necessary Block saw chain ­ push the hand guard for-
ward To advance the saw chain, pull the hand
guard toward the handlebar: The chain brake is disengaged. With the Quickstop Super chain brake system, additionally press the throttle trigger lockout Sharpen frequently, removing little material ­ two or three strokes of the file are usually suffi- cient for simple resharpening

001BA203 KN

Guide the file: horizontally (at a right angle to the side surface of the guide bar) in accord- ance with the specified angle ­ according to the markings on the file holder ­ rest the file holder on the tooth head and the depth gauge
File only from the inside outward The file only sharpens on the forward stroke ­
lift the file on the backstroke Do not file tie straps and drive links Rotate the file a little periodically in order to
avoid uneven wear To remove file burr, use a piece of hardwood Check angle with file gauge
All cutters must be equally long.
With varying cutter lengths, the cutter heights also vary and cause rough running of the saw chain and chain breakage. All cutters must be filed down equal to the
length of the shortest cutter ­ ideally, one should have this done by a servicing dealer using an electric sharpener

0458-737-0121-C

35

English
28.7 Depth gauge setting

28 Maintaining and Sharpening the Saw Chain

mark) is lowered at the same time as the depth gauge of the cutter.

WARNING

a

The rest of the humped drive link must not be

filed; otherwise, this could increase the tendency

of the chain saw to kick back.

689BA023 KN

The depth gauge determines the depth to which the cutter penetrates the wood and thus the chip thickness.
a Required distance between depth gauge and cutting edge

When cutting softwood outside of the frost sea- son, the distance can be increased by up to 0.2 mm (0.008″).

Chain pitch

Inches 1/4 P 1/4 3/8 P 0.325 3/8 0.404

(mm) (6.35) (6.35) (9.32) (8.25) (9.32) (10.26)

Depth gauge

Distance (a)

mm

(Inches)

0.45

(0.018)

0.65

(0.026)

0.65

(0.026)

0.65

(0.026)

0.65

(0.026)

0.80

(0.031)

28.8 Lowering the depth gauges

The depth gauge setting is lowered when the cutter is sharpened. Check the depth gauge setting after each
sharpening

1

2

Rework the depth gauge so that it is flush with the file gauge
Afterwards, dress the leading edge of the depth gauge parallel to the service mark (see arrow) ­ when doing this, be careful not to fur- ther lower the highest point of the depth gauge WARNING
Depth gauges that are too low increase the kick- back tendency of the chain saw.

689BA044 KN

689BA051 KN

689BA061 KN

Lay the appropriate file gauge (1) for the chain pitch on the saw chain and press it against the cutter to be checked ­ if the depth gauge pro- trudes past the file gauge, the depth gauge must be reworked
Saw chains with humped drive link (2) ­ upper part of the humped drive link (2) (with service
36

0458-737-0121-C

689BA052 KN

29 Maintenance and Care
Lay the file gauge on the saw chain ­ the high- est point of the depth gauge must be flush with the file gauge
After sharpening, clean the saw chain thor- oughly, removing any filings or grinding dust ­ lubricate the saw chain thoroughly
In the event of extended periods of disuse, store saw chains in cleaned and oiled condi- tion

English

Sharpening tools (special accessories)

Chain pitch

Round file Round file ^

File holder

File gauge

Taper square Sharpening

file

set1)

Inches (mm) mm (Inches Part number Part number Part number Part number Part number )

1/4P (6.35) 3.2 (1/8) 5605 771 3206

5605 750 4300

0000 893 4005

0814 252 3356

5605 007 1000

1/4 3/8 P

(6.35) 4.0 (5/32) 5605 772 40065605 750 43271110 893 40000814 252 33565605 007

1027

(9.32) 4.0 (5/32) 5605 772

5605 750

1110 893

0814 252

5605 007

4006

4327

4000

3356

1027

0.325 (8.25) 4.8 (3/16) 5605 772 4806

5605 750 4328

1110 893 4000

0814 252 3356

5605 007 1028

3/8

(9.32) 5.2 (13/64) 5605 772

5605 750

1110 893

0814 252

5605 007

5206

4329

4000

3356

1029

0.404 (10.26) 5.5 (7/32) 5605 772 5506

5605 750 4330

1106 893 4000

0814 252 3356

5605 007 1030

1)consisting of file holder with round file, taper square file and file gauge

29 Maintenance and Care

The following maintenance intervals apply for normal operat- ing conditions only. When working under difficult conditions (high accumulation of dust, highly resinous lumber, lumber from tropical trees, etc.) or longer than normal each day, the specified intervals must be shortened accordingly. If you only use the tool occasionally, extend the intervals accordingly.

Before starting work At the end of work and/or daily
Whenever tank is refilled Weekly Monthly
Annually If faulty
If damaged As required

Complete machine

Visual inspection (condition, X

X

leaks)

Clean

X

Throttle trigger, throttle trigger Function test lockout, choke lever, stop switch, master control lever (dependent on equipment)

X

X

Chain brake

Function test

X

X

Have checked by dealer1)

X

1. STIHL recommends STIHL servicing dealer

2. When using professional chainsaws (with a power output of 3.4 kW or more) for the first time, tighten the cylinder block screws after 10 to 20 hours of operation

0458-737-0121-C

37

Before starting work At the end of work and/or daily
Whenever tank is refilled Weekly Monthly
Annually If faulty
If damaged As required

English
The following maintenance intervals apply for normal operat- ing conditions only. When working under difficult conditions (high accumulation of dust, highly resinous lumber, lumber from tropical trees, etc.) or longer than normal each day, the specified intervals must be shortened accordingly. If you only use the tool occasionally, extend the intervals accordingly.

29 Maintenance and Care

Manual fuel pump (if present) check

X

Have repaired by a specialist

X

dealer1)

Fuel pick-up body / filter in fuel check

tank

Clean, replace filter insert

X

X

X

replace

X

XX

Fuel tank

Clean

X

Lubricating oil tank

Clean

X

Chain lubrication

check

X

Saw chain

Check, pay attention to

X

X

sharpness

Checking the chain tension X

X

sharpen

X

Guide bar

Check (wear, damage)

X

Clean and turn over

X

Deburr

X

replace

XX

Chain sprocket

check

X

Air filter

Clean

X

X

replace

X

Anti-vibration elements

check

X

X

Have replaced by servicing

X

dealer1)

Air intake on fan housing

Clean

X

X

X

Cylinder fins

Clean

X

X

X

Carburetor

Check idle adjustment ­ saw X

X

chain must not rotate

Set the idle speed; if required

X

have the chainsaw repaired

by a specialist dealer1)

Spark plug

Adjust electrode gap

X

Replace after 100 hours of operation

1. STIHL recommends STIHL servicing dealer

2. When using professional chainsaws (with a power output of 3.4 kW or more) for the first time, tighten the cylinder block screws after 10 to 20 hours of operation

38

0458-737-0121-C

Before starting work At the end of work and/or daily
Whenever tank is refilled Weekly Monthly
Annually If faulty
If damaged As required

30 Minimize Wear and Avoid Damage
The following maintenance intervals apply for normal operat- ing conditions only. When working under difficult conditions (high accumulation of dust, highly resinous lumber, lumber from tropical trees, etc.) or longer than normal each day, the specified intervals must be shortened accordingly. If you only use the tool occasionally, extend the intervals accordingly.

English

Accessible screws and nuts (except adjusting screws) Chain catcher
Safety information label

Tighten2)
check replace replace

30 Minimize Wear and Avoid Damage
Observing the instructions in this manual helps reduce the risk of unnecessary wear and dam- age to the power tool.
The power tool must be operated, maintained and stored with the due care and attention described in this owner’s manual.
The user is responsible for all damage caused by non-observance of the safety precautions, oper- ating and maintenance instructions in this man- ual. This includes in particular: ­ Alterations or modifications to the product not
approved by STIHL. ­ Using tools or accessories which are neither
approved or suitable for the product or are of a poor quality. ­ Using the product for purposes for which it was not designed. ­ Using the product for sports or competitive events. ­ Consequential damage caused by continuing to use the product with defective components.

Maintenance Work

All the operations described in the “Maintenance Chart” must be performed on a regular basis. If these maintenance operations cannot be per- formed by the owner, they should be performed by a servicing dealer.

X
X
X
X
STIHL recommends that you have servicing and repair work carried out exclusively by an author- ized STIHL servicing dealer. STIHL dealers are regularly given the opportunity to attend training courses and are supplied with the necessary technical information.
If these maintenance operations are not carried out as specified, the user assumes responsibility for any damage that may occur. Among other parts, this includes: ­ Damage to the engine due to neglect or defi-
cient maintenance (e.g. air and fuel filters), incorrect carburetor adjustment or inadequate cleaning of cooling air inlets (intake ports, cyl- inder fins). ­ Corrosion and other consequential damage resulting from improper storage. ­ Damage to the machine resulting from the use of poor quality replacement parts.
30.2 Parts Subject to Wear and Tear
Some parts of the power tool are subject to nor- mal wear and tear even during regular operation in accordance with instructions and, depending on the type and duration of use, have to be replaced in good time. Among other parts, this includes: ­ Saw chain, guide bar ­ Drive components (clutch, clutch drum, chain
sprocket) ­ Filters (air, oil, fuel)

1. STIHL recommends STIHL servicing dealer

2. When using professional chainsaws (with a power output of 3.4 kW or more) for the first time, tighten the cylinder block screws after 10 to 20 hours of operation

0458-737-0121-C

39

English
­ Starter mechanism ­ Spark plug ­ Components of antivibration system
31 Main Parts

7 17

13 14 3 24 1 6 7
18

5

9 8

10 11 12

1 20 19

16

1 22

24

25

15

21 23

26

1 Shroud lock 2 Carburetor adjusting screws 3 Fuel pump1) 4 Shutter (summer and winter operation) 5 Chain brake 6 Chain sprocket 7 Chain sprocket cover 8 Chain catcher 9 Side chain tensioner1) 10 Spiked bumper 11 Guide bar 12 Oilomatic chain 13 Adjusting wheel1) (quick chain adjuster) 14 Handle of wingnut1) (quick chain adjuster) 15 Oil filler cap 16 Muffler 17 Front hand guard

1. Depending on model
2. to ISO 11681 +/- 50 rpm 40

2310BA029 ST

18 Front handle (handlebar) 19 Spark plug boot 20 Starter grip 21 Fuel filler cap 22 Master Control lever 23 Throttle trigger 24 Throttle trigger lockout 25 Rear handle 26 Rear hand guard # Serial number

31 Main Parts

32 Specifications

32.1 Engine

STIHL single cylinder two-stroke engine

32.1.1 MS 231, MS 231 C

Displacement:

42.6 cc

Bore:

42.5 mm

Stroke:

30 mm

Engine power to ISO 7293: 2.0 kW (2.7 bhp) at

10,000 rpm

Idle speed:1)

2,800 rpm

32.1.2 MS 251, MS 251 C

Displacement:

45.6 cc

Bore:

44 mm

Stroke:

30 mm

Engine power to ISO 7293: 2.2 kW (3.0 bhp) at

10,000 rpm

Idle speed:1)

2,800 rpm

32.2 Ignition System

Electronic magneto ignition

Spark plug (resistor type): Electrode gap:

NGK CMR6H, BOSCH USR 4 AC 0.5 mm

32.3 Fuel System

All position diaphragm carburetor with integral fuel pump

Fuel tank capacity:

390 cc (0.39 l)

32.4 Chain Lubrication

Fully automatic, speed-controlled oil pump with rotary piston

0458-737-0121-C

33 Ordering Spare Parts

Oil tank capacity:

200 cc (0.2 l)

32.5 Weight
dry, without bar and chain MS 231: MS 231 C with ErgoStart and quick chain tensioner: MS 251: MS 251 C with ErgoStart and quick chain tensioner:

4.8 kg 5.1 kg 4.8 kg 5.1 kg

32.6 Cutting Attachment

Actual cutting length may be less than the speci- fied length

32.6.1 .325″ Rollomatic E guide bars

Cutting lengths: Pitch: Groove width: Nose sprocket:

35, 40, 45 cm .325″ (8.25 mm) 1.6 mm 11-tooth

32.6.2 3/8″ P Rollomatic E guide bars

Cutting lengths: Pitch: Groove width: Nose sprocket:

30, 35, 40, 45 cm 3/8″ P (9.32 mm) 1.3 mm 9-tooth

32.6.3 .325″ chain

Rapid Micro 3 (26 RM3) Type 3634

Rapid Duro 3 (26 RD3) Type 3667

Pitch:

.325″ (8.25 mm)

Drive link gauge:

1.6 mm

32.6.4 3/8″ P chain

Picco Micro 3 (63 PM3) Type 3636

Picco Super 3 (63 PS3) Type 3616

Picco Duro 3 (63 PD3) Type 3612

Pitch:

3/8″ P (9.32 mm)

Drive link gauge:

1.3 mm

32.6.5 Chain sprocket 7-tooth for .325″ Max. chain velocity to ISO 11681: 25.6 m/s Chain speed at maximum power 19.3 m/s output:

6-tooth for 3/8″ P Max. chain velocity to ISO 11681: 24.8 m/s Chain speed at maximum power 18.6 m/s output:

32.7 Noise and Vibration Data

For further details on compliance with Vibration Directive 2002/44/EC see www.stihl.com/vib.

32.7.1 Sound pressure level Lp to ISO 22868

MS 231: MS 231 C: MS 251: MS 251 C:

103 dB(A) 103 dB(A) 103 dB(A) 103 dB(A)

0458-737-0121-C

English

32.7.2 Sound power level Lw to ISO 22868

MS 231: MS 231 C: MS 251: MS 251 C:

114 dB(A) 114 dB(A) 114 dB(A) 114 dB(A)

32.7.3

Vibration measurement ahv, eq to ISO 22867

MS 231: MS 231 C: MS 251: MS 251 C:

Handle, left 3.9 m/s2 3.9 m/s2 3.9 m/s2 3.9 m/s2

Handle, right 3.9 m/s2 3.9 m/s2 3.9 m/s2 3.9 m/s2

The Kfactor in accordance with Directive 2006/42/EC is 2.0 dB(A) for the sound pressure level and sound power level; the Kfactor in accordance with Directive 2006/42/EC is 2.0 m/s2 for the vibration level.

32.8 REACH

REACH is an EC regulation and stands for the Registration, Evaluation, Authorisation and Restriction of Chemical substances.

For information on compliance with the REACH regulation (EC) No. 1907/2006 see www.stihl.com/reach.

32.9 Exhaust Emissions

The CO2value measured in the EU type approval procedure is specified at www.stihl.com/co2.

The measured CO2value was determined on a representative engine in accordance with a standardized test procedure under laboratory conditions and does not represent either an explicit or implied guarantee of the performance of a specific engine.

The applicable exhaust emission requirements are fulfilled by the intended usage and mainte- nance described in this instruction manual. The type approval expires if the engine is modified in any way.

33 Ordering Spare Parts
Please enter your saw model, serial number as well as the part numbers of the guide bar and saw chain in the spaces provided. This will make re-ordering simpler.
The guide bar and saw chain are subject to nor- mal wear and tear. When purchasing these parts, always quote the saw model, the part numbers and names of the parts.

41

English

Maintenance and Repairs

Model
Serial number
Guide bar part number
Chain part number
34 Maintenance and Repairs
Users of this machine may only carry out the maintenance and service work described in this user manual. All other repairs must be carried out by a servicing dealer. STIHL recommends that you have servicing and repair work carried out exclusively by an author- ized STIHL servicing dealer. STIHL dealers are regularly given the opportunity to attend training courses and are supplied with the necessary technical information. When repairing the machine, only use replace- ment parts which have been approved by STIHL for this power tool or are technically identical. Only use high-quality replacement parts in order to avoid the risk of accidents and damage to the machine. STIHL recommends the use of original STIHL replacement parts. Original STIHL parts can be identified by the STIHL part number, the { logo and the STIHL parts symbol K (the symbol may appear alone on small parts).
35 Disposal
Observe all country-specific waste disposal rules and regulations.
STIHL products must not be thrown in the gar- bage can. Take the product, accessories and packaging to an approved disposal site for envi- ronment- friendly recycling.

000BA073 KN

Contact your STIHL servicing dealer for the lat- est information on waste disposal.

36 EC Declaration of Con- formity
ANDREAS STIHL AG & Co. KG Badstr. 115 D-71336 Waiblingen

Germany

declare in exclusive responsibility that the prod- uct

Category: Make: Model:
Serial identification: Displacement all versions of MS 231: all versions of MS 251:

Chainsaw STIHL MS 231 MS 231 C MS 231 C-BE MS 251 MS 251 C MS 251 C-BE 1143 42.6 cm3 45.6 cm3

conforms to the provisions of Directives 2011/65/EU, 2006/42/EC, 2014/30/EU and 2000/14/EC and has been developed and manu- factured in compliance with the following stand- ards in the versions valid at the time of produc- tion:

EN ISO 116811, EN 55012, EN 6100061

The measured and guaranteed sound power lev- els were determined according to Directive 2000/14/EC, Annex V, using the ISO 9207 standard.

Measured sound power level

all versions of MS 231: all versions of MS 251:

114 dB(A) 114 dB(A)

Guaranteed sound power level

all versions of MS 231: all versions of MS 251:

116 dB(A) 116 dB(A)

The EC type examination was carried out by
DPLF Deutsche Prüf- und Zertifizierungsstelle für Landund Forsttechnik (NB 0363) Max-Eyth-Weg 1 D-64823 Gross-Umstadt
Certification No. all versions of MS 231: K-EG-2010/5603 all versions of MS 251: K-EG-2010/5605
Technical documents deposited at:

42

0458-737-0121-C

36 EC Declaration of Conformity ANDREAS STIHL AG & Co. KG Produktzulassung (Product Licensing) The year of manufacture and serial number are applied to the product. Done at Waiblingen, 03.02.2020 ANDREAS STIHL AG & Co. KG p p.
Dr. Jürgen Hoffmann Director Product Certification & Regulatory Affairs

English

0458-737-0121-C

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www.stihl.com

04587370121C
0458-737-0121-C

04587370121C
0458-737-0121-C

References

• CO2 Values of our Products according to EURO V | STIHL | STIHL
• Information on Physical Agents Directive Vibration | STIHL | STIHL

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