STIHL 390, 290, 310 Instruction Manual

STIHL MS 290, 310, 390
STIH)
Instruction Manual Manual de instrucciones
MS 290
Warning!
To reduce the risk of kickback injury use STIHL reduced kickback bar and STIHL PM 1 (3/8" Picco) or RM 2 3/8" or RM 2 (0,325") chain depending on sprocket or other available low kickback components.
Advertencia!
Para reducir el riesgo de lesionarse como resultado de un culatazo, utilice la barra de contragolpe reducido y la cadena PM 1 (Picco de 3/8 pulg) o RM 2 (3/8 pulg) o RM 2 (0,325 pulg) de STIHL, dependiendo de la rueda dentada usada y de otros componentes reductores de contragolpe.
Read and follow all safety precautions in Instruction Manual – improper use can cause serious or fatal injury.
Lea y siga todas las precauciones de seguridad dadas en el manual de instrucciones – el uso incorrecto puede causar lesiones graves o mortales.
MS 310, 390
Warning!
This saw is capable of severe kickback which may cause serious or fatal injury. Only for users with extraordinary cutting needs and experience and training dealing with kickback. Chainsaws with significantly reduced kickback potential are available. STIHL recommends the use of STIHL reduced kickback bar and low kickback chain.
Advertencia! Esta sierra es capaz de causar contragolpes severos, los cuales pueden causar lesiones graves o mortales. Sólo es apta para usuarios con necesidades extraordinarias de corte y mucha experiencia y capacitación en el manejo de los contragolpes. Existen sierras con un potencial mucho menor de causar contragolpes. STIHL recomienda usar una barra y cadena de contragolpe reducido de STIHL.

Contents

English / USA
Guide to Using this Manual .............. 2
Some Important Safety
Precautions for Chain Saw Users ..... 3
Safety Precautions ........................... 5
Mounting the Bar and Chain ........... 26
Tensioning the Saw Chain .............. 28
Checking Chain Tension ................. 28
BA_SE_102_006_01_08.fmPrinted on chlorine-free paper.
Fuel ................................................ 28
Fueling ............................................ 29
Chain Lubricant .............................. 31
Filling Chain Oil Tank ...................... 31
Checking Chain Lubrication ........... 32
Chain Brake .................................... 32
Winter Operation ............................ 33
Information Before You Start .......... 35
Starting / Stopping the Engine ........ 35
Operating Instructions .................... 38
Oil Quantity Control * ...................... 39
Taking Care of Guide Bar ............... 40
Air Filter System ............................. 40
Cleaning Air Filter ........................... 41
Motor Management ........................ 41
Adjusting the Carburetor ................ 42
Spark Arresting Screen in Muffler* . 43
Checking the Spark Plug ................ 44
Replacing Starter Rope
Printing inks contain vegetable oils; paper can be recycled.
and Rewind Spring ......................... 45
Storing the Machine ........................ 47
Checking and Replacing
Chain Sprocket ............................... 47
Maintaining and Sharpening
Saw Chain ...................................... 49
Maintenance Chart ......................... 53
Parts and Controls .......................... 55
Specifications ................................. 57
Special Accessories ....................... 59
Ordering Spare Parts ..................... 59
Maintenance and Repairs .............. 59
STIHL Incorporated Federal Emission Control
Warranty Statement ........................ 60
Allow only persons who understand this Manual to operate your chainsaw.
To receive maximum performance and satisfaction from your STIHL chainsaw, it is important that you read and understand precautions, using your chainsaw.
Contact your STIHL dealer or the STIHL distributor for your area if you do not understand any of the instructions in this Manual.
the maintenance and safety
starting on page 3, before
!Warning!
Because a chainsaw is a high-speed wood-cutting tool, some special safety precautions must be observed as with any other power saw to reduce the risk of personal injury.
Careless or improper use may cause serious or even fatal injury.
STIHL's philosophy is to continually improve all of its products. As a result, engineering changes and improvements are made from time-to-time. If the operating characteristics or the appearance of your chainsaw differs from those described in this Manual, please contact your STIHL dealer for information and assistance.
* see “Guide to Using this Manual”
STIHl
© ANDREAS STIHL AG & Co. KG, 2004
0458 209 3021 A. M19. H4. PM. Printed in USA
1MS 290, 310, 390
English / USA

Guide to Using this Manual

Pictograms
All the pictograms attached to the machine are shown and explained in this manual.
The operating and handling instructions are supported by illustrations.
Symbols in text
The individual steps or procedures described in the manual may be marked in different ways:
: A bullit marks a step or procedure
without direct reference to an illustration.
A description of a step or procedure that refers directly to an illustration may contain item numbers that appear in the illustration. Example:
Loosen the screw (1)
Lever (2) ...
In addition to the operating instructions, this manual may contain paragraphs that require your special attention. Such paragraphs are marked with the symbols described below:
Warning where there is a risk of an accident or personal injury or serious damage to property.
Caution where there is a risk of damaging the machine or its individual components.
Note or hint which is not essential for using the machine, but may improve the operator’s under­standing of the situation and result in better use of the machine.
Note or hint on correct procedure in order to avoid damage to the environment.
Equipment and features
This instruction manual may refer to several models with different features. Components that are not installed on all models and related applications are marked with an asterisk (*). Such components may be available as special accessories from your STIHL dealer.
Engineering improvements
STIHL’s philosophy is to continually improve all of its products. As a result, engineering changes and improvements are made from time to time. If the operating characteristics or the appearance of your machine differ from those described in this manual, please contact your STIHL dealer for assistance.
Therefore some changes, modifications and improvements may not be covered in this manual.
2
MS 290, 310, 390

Some Important Safety Precautions for Chain Saw Users

English / USA
A. A Summary of Warnings on kickback and other Selected Risks – Taken Primarily from ANSI B 175.1 (See also the “Safety Precautions“ section of this Owner’s Manual)
!Warning!
Kickback may occur when the nose or tip of the guide bar touches an object, or when the wood closes in and pinches the saw chain in the cut. Tip contact in some cases may cause a lightning fast reverse reaction, kicking the guide bar up and back towards the operator. Pinching the saw chain along the top of the guide bar may push the guide bar rapidly back towards the operator. Either of these reactions may cause you to lose control of the saw which could result in serious personal injury.
Section 5.11 of ANSI B 175.1-2000 sets certain performance and design criteria related to chainsaw kickback. STIHL has developed a color code system using green and yellow to help you select a powerhead, bar and chain combination that complies with the kickback requirements of the ANSI Standard. See the sections entitled "Safety Precautions" and "Specifications" of this manual.
Do not rely exclusively upon the safety devices built into your saw. As a chainsaw user, you should take several steps to keep your cutting jobs free from accident or injury.
1. With a basic understanding of kickback, you can reduce or eliminate the element of surprise. Sudden surprise contributes to accidents.
2. Keep a good firm grip on the saw with both hands, the right hand on the rear handle, and the left hand on the front handle, when the engine is running. Use a firm grip with thumbs and fingers encircling the chainsaw handles. A firm grip will help you reduce kickback and maintain control of the saw. Don't let go.
3. Make sure the area in which you are cutting is free from obstructions. Do not let the nose of the guide bar contact a log, branch, or any other obstruction that could be hit while you are operating the saw.
4. Cut at high engine speeds.
5. Do not overreach or cut above shoulder height.
6. Follow manufacturer's sharpening and maintenance instructions for the saw chain.
7. Only use replacement bars and chains specified by the manufacturer or the equivalent.
8. Reduced kickback bars and low kickback chains are designed to reduce the risk of kickback injury. Ask your STIHL dealer about these devices.
B. Other Safety Precautions
!Warning!
1. Do not operate a chainsaw with one hand! Serious injury to the operator, helpers, bystanders, or any combination of these persons may result from one-handed operation. A chainsaw is intended to be used with two hands.
2. Do not operate a chainsaw when you are fatigued.
3. Use safety footwear; snug-fitting clothing; protective gloves; and eye, hearing, and head protection devices.
3MS 290, 310, 390
English / USA
4. Use caution when handling fuel. Move the chainsaw at least 10 feet (3 m) from the fueling point before starting the engine.
5. Do not allow other persons to be near the chainsaw when starting or cutting with the chainsaw. Keep bystanders and animals out of the work area.
6. Do not start cutting until you have a clear work area, secure footing, and a planned retreat path from the falling tree.
7. Keep all parts of your body away from the saw chain when the engine is running.
8. Before you start the engine, make sure that the saw chain is not contacting anything.
9. Carry the chainsaw with the engine stopped, the guide bar and saw chain to the rear, and the muffler away from your body.
10. Do not operate a chainsaw that is damaged, improperly adjusted, or not completely and securely assembled. Be sure that the saw chain stops moving when the throttle trigger is released.
11. Shut off the engine before setting the chainsaw down.
12. Use extreme caution when cutting small size brush and saplings because slender material may catch the saw chain and be whipped toward you or pull you off balance.
13. When cutting a limb that is under tension be alert for springback so that you will not be struck when the tension in the wood fibers is released.
14. Keep the handles dry, clean, and free of oil or fuel mixture.
15. Operate the chainsaw only in well­ventilated areas.
16. Do not operate a chainsaw in a tree unless you have been specifically trained to do so.
17. All chainsaw service, other than the items listed in the Owner's Manual maintenance instructions, should be performed by competent chainsaw service personnel.(For example, if improper tools are used to remove the flywheel or if an improper tool is used to hold the flywheel in order to remove the clutch, structural damage to the flywheel could occur and could subsequently cause the flywheel to burst).
18. When transporting your chainsaw, use the appropriate chain guard (scabbard).
Other important safety precautions are contained in the body of the Owner's Manual, especially in the Safety Precautions.
Note:
When using a chainsaw for logging purposes, refer to the Code of Federal Regulations, Parts 1910 and 1928.
4
MS 290, 310, 390

Safety Precautions

English / USA
The use of any chainsaw may be hazardous. The saw chain has many sharp cutters. If the cutters contact your flesh,
they will cut you, even if the chain is not moving. At full throttle, the chain speed can reach 45 mph (20 m/s). It is important that you read, fully understand and observe the following safety precautions and warnings. Read the Owner's Manual and the Safety Precautions periodically.
Pay special attention to the section on reactive forces.
!Warning!
Reactive forces, including kickback, can be dangerous. Careless or improper use of any chainsaw may cause serious or fatal injury.
All safety precautions that are generally observed when working with an axe or a hand saw also apply to the operation of chainsaws. However, because a chainsaw is a high-speed, fast-cutting power tool, special safety precautions must be observed to reduce the risk of personal injury.
Have your STIHL dealer show you how to operate your chainsaw. Observe all applicable local safety regulations, standards and ordinances.
!Warning!
Minors should never be allowed to use a chainsaw. Bystanders, especially children, and animals should not be allowed in the area where a chainsaw is in use. Never let the saw run unattended. Store it in a locked place away from children and empty the fuel tank before storing for longer than a few days.
Do not lend or rent your chainsaw without the Owner`s Manual. Be sure that anyone using your saw reads and understands the
information contained in this manual.
These safety precautions and warnings apply to the use of all STIHL chainsaws. Different models may have different parts and controls. See the appropriate section of your Owner's Manual for a description of the controls and function of the parts of your model saw.
Safe use of a chainsaw involves
1. the operator
2. the saw
3. the use of the saw.
THE OPERATOR
Physical Condition
You must be in good physical condition and mental health and not under the influence of any substance (drugs, alcohol) which might impair vision, dexterity or judgement.
Do not operate a chainsaw when you are fatigued. Be alert - If you get tired while operating your chainsaw, take a break. Tiredness may result in loss of control. Working with any chainsaw can be strenuous. If you have any condition that might be aggravated by strenuous work, check with your doctor before operating a chainsaw.
!Warning!
Prolonged use of chainsaws (or other machines) exposing the operator to vibrations may produce whitefinger disease (Raynaud's phenomenon) or carpal tunnel syndrome.
5MS 290, 310, 390
English / USA
These conditions reduce the hand's ability to feel and regulate temperature, produce numbness and burning sensations and may cause nerve and circulation damage and tissue necrosis.
All factors which contribute to whitefinger disease are not known, but cold weather, smoking and diseases or physical conditions that affect blood vessels and blood transport, as well as high vibration levels and long periods of exposure to vibration are mentioned as factors in the development of whitefinger disease. In order to reduce the risk of whitefinger disease and carpal tunnel syndrome, please note the following:
Many STIHL models are available
with an anti-vibration (AV) system designed to reduce the transmission of vibrations created by the engine and cutting attachment to the operator's hands. An AV system is recommended for those persons using chainsaws on a regular or sustained basis.
Wear gloves and keep your hands
warm. Heated handles, which are available on most STIHL power­heads, are recommended for cold weather use.
Keep the saw chain sharp and the
saw, including the AV system, well maintained. A dull chain will in­crease cutting time, and pressing a dull chain through wood will in­crease the vibrations transmitted to your hands. A saw with loose components or with damaged or worn AV buffers will also tend to have higher vibration levels.
Maintain a firm grip at all times, but
do not squeeze the handles with constant, excessive pressures. Take frequent breaks.
All the above mentioned precautions do not guarantee that you will not sustain whitefinger disease or carpal tunnel syndrome. Therefore, continual and regular users should monitor closely the condition of their hands and fingers. If any of the above symptoms appear, seek medical advice immediately.
!Warning!
The ignition system of your unit produces an electromagnetic field of a very low intensity. This field may inter­fere with some pacemakers. To reduce the risk of serious or fatal injury, persons with pacemaker should consult their physician and the pacemaker manu­facturer before operating this tool.
Proper Clothing
!Warning!
To reduce the risk of injury, the operator should wear proper protective apparel.
Clothing must be sturdy and snug-fitting, but allow complete freedom of movement. Avoid loose­fitting jackets, scarfs,
neckties, jewelry, flared or cuffed pants, unconfined long hair or anything that could become entangled with the saw or brush. Wear overalls or jeans with a reinforced cut retardant insert or cut retardant chaps.
Protect your hands with
gloves when handling
saw and saw chain.
Heavy-duty, nonslip
gloves improve your grip
and protect your hands.
Good footing is most
important in chainsaw
work. Wear sturdy boots
with nonslip soles. Steel-
toed safety boots are
recommended.
Never operate a chainsaw unless wearing goggles or properly fitted safety glasses with adequate top and side protection complying with your national standard.
6
MS 290, 310, 390
English / USA
Wear an approved safety hard hat to protect your head. Chainsaw noise may damage your hearing. Always wear
sound barriers (ear plugs or ear mufflers) to protect your hearing. Continual and regular users should have their hearing checked regularly.
THE SAW
Parts of the chainsaw; for illustrations and definitions of the parts see the chapter on "Main Parts of Saw".
!Warning!
Never modify a chainsaw in any way. Only attachments and parts supplied by STIHL or expressly approved by STIHL for use with the specific STIHL saw models are authorized. Although certain unauthorized attachments are usable with the STIHL powerhead, their use may, in fact, be extremely dangerous.
THE USE OF THE SAW
Transporting the chainsaw
!Warning!
Always stop the engine before putting a chainsaw down or carrying it. Carrying a chainsaw with the engine running is extremely dangerous.
Accidental acceleration of the engine can cause the chain to rotate. During operation, the powerhead muffler and the material around it reach extremely high temperatures. Avoid touching the hot muffler, you could receive serious burns.
By hand: When carrying your saw by hand, the engine must be stopped and the saw must be in the proper position.
Grip the front handle and place the muffler away from the body.
001BA115 KN
The chain guard (scabbard) should be over the chain and the guide bar, which should point backwards. When carrying your saw, the bar should be behind you.
By vehicle: When transporting in a vehicle, keep chain and bar covered with the chain guard. Properly secure your saw to prevent turnover, fuel spillage and damage to the saw or vehicle.
Preparation for the use of the saw
Take off the chain guard and inspect for safety in operation. For assembly, follow the procedure described in the chapter "Mounting the Bar and Chain" of your Owner's Manual. STIHL Oilomatic chain, guide bar and sprocket must match each other in gauge and pitch. Before replacing any bar and chain, see the sections on "Specifications", "Kickback" and the "ANSI B 175.1-2000 chainsaw kickback standard" in this manual.
7MS 290, 310, 390
English / USA
!Warning!
Proper tension of the chain is extremely important. In order to avoid improper setting, the tensioning procedure must be followed as described in your manual. Always make sure the hexagonal nut(s) for the sprocket cover is (are) tightened securely after tensioning the chain. Never start the saw with the sprocket cover loose. Check chain tension once more after having tightened the nut(s) and thereafter at regular intervals (whenever the saw is shut off). If the chain becomes loose while cutting, shut off the engine and then tighten. Never try to adjust the chain while the engine is running!
Fueling
Your STIHL chainsaw uses an oil-gaso­line mixture for fuel (see chapter "Fuel" of your Owner's Manual).
!Warning!
Gasoline is an extremely flammable fuel. If spilled or ignited by a spark or other ignition source, it can cause fire and serious burn injury or property damage. Use extreme caution when handling gasoline or fuel mix.
Do not smoke or bring any fire or flame near the fuel or the chainsaw. Note that combustible fuel vapors may be vented from the fuel system.
Fueling Instructions
!Warning!
Fuel your chainsaw in well-ventilated areas, outdoors only. Always shut off the engine and allow it to cool before refueling. Gasoline vapor pressure may build up inside the gas tank depending on the fuel used, the weather conditions, and the venting system of the tank. In order to reduce the risk of burns or other personal injury from escaping gas vapor and fumes, remove the fuel filler cap on the STIHL product carefully so as to allow any pressure build-up in the tank to release slowly. Never remove fuel filler cap while engine is running.
Select bare ground for fueling and move at least 10 feet (3 m) from fueling spot before starting the engine. Wipe off any spilled fuel before starting your saw, and check for leakage.
!Warning!
Check for fuel leakage while refueling and during operation. If fuel or oil leakage is found, do not start or run the engine until leak is fixed and spilled fuel has been wiped away. Take care not to get fuel on your clothing. If this happens, change your clothing immediately. Different models may have different fuel caps.
Cap with Grip
!Warning!
In order to reduce the risk of fuel spillage and fire from an improperly tightened fuel cap, correctly position and tighten the fuel cap in the fuel tank opening.
To do this with this STIHL cap, raise the grip on the top of the cap until it is upright at a 90° angle. Insert the cap in the fuel
tank opening with the triangular marks on the grip of the cap and on the fuel tank opening lining up. Using the grip, turn the cap firmly clockwise as far as it will go (approx. a quarter turn).
8
MS 290, 310, 390
Fold the grip flush with the top of the cap. If the grip does not lie completely flush with the cap and the detent on the grip does
not fit in the corresponding recess in the filler neck, the cap is not properly seated and tightened and you must repeat the above steps.
Slotted Cap
!Warning!
Unit vibrations can cause an improperly tightened fuel filler cap to loosen or come off and spill quantities of fuel. In order to reduce the risk of fuel spillage and fire, tighten fuel filler cap by hand with as much force as possible.
The screwdriver end of
the STIHL combination
wrench or other similar
tool can be used as an aid
in tightening slotted fuel
filler caps.
See "Fueling" chapter in your Owner's Manual.
Starting
The chain brake must be engaged when starting the saw.
!Warning!
Your chainsaw is a one-person saw. Do not allow other persons to be near the running chainsaw. Start and operate your saw without assistance. For specific starting instructions, see the appropriate section of the Owner's Manual. Proper starting methods reduce the risk of injury. Do not drop start. This method is very dangerous because you may lose control of the saw.
There are two recommended methods for starting your chainsaw.
With the first recommended method, the chainsaw is started on the ground. Make sure the chain brake is engaged (see "Chain Brake" chapter in your Owner's Manual) and place the chainsaw on firm ground or other solid surface in an open area. Maintain good balance and secure footing.
English / USA
001BA113 KN
Grip the front handlebar of the saw firmly with your left hand and press down. For saws with a rear handle level with the ground, put the toe of your right foot into the rear handle and press down. With your right hand pull out the starter grip slowly until you feel a definite resistance and then give it a brisk, strong pull.
The second recommended method for starting your chainsaw allows you to start the saw without placing it on the ground. Make sure the chain brake is engaged, grip the front handle of the chainsaw firmly with your left hand. Keep your arm on the front handle in a locked (straight) position. Hold the rear handle of the saw tightly between your legs just above the knees. Maintain good balance and secure footing. Pull the starting grip slowly with your right hand until you feel a definite resistance and then give it a brisk, strong pull.
001BA114 KN
9MS 290, 310, 390
English / USA
!Warning!
Be sure that the guide bar and chain are clear of you and all other obstructions and objects, including the ground. When the engine is started, the engine speed with the starting throttle lock engaged will be fast enough for the clutch to engage the sprocket and, if the chain brake is not activated, turn the chain. If the upper quadrant of the tip of the bar touches any object, it may cause kick­back to occur (see section on reactive forces). To reduce this risk, always engage the chain brake before starting. Never attempt to start the chainsaw when the guide bar is in a cut or kerf.
!Warning!
When you pull the starter grip, do not wrap the starting rope around your hands. Do not allow the grip to snap back, but guide the starter rope slowly back to permit the rope to rewind properly. Failure to follow this procedure may result in injury to hand or fingers and may damage the starter mechanism.
Important adjustments
!Warning!
To reduce the risk of personal injury from loss of control or contact with the running chain, do not use a saw with incorrect idle adjustment. At correct idle speed, the chain should not rotate. For directions to adjust idle speed, see the appropriate section of your Owner's Manual. If you cannot set the correct idle speed, have your STIHL dealer check your saw and make proper adjustments or repairs. After adjusting a chain, start the saw, let the engine run for a while, then switch engine off and recheck chain tension. Proper chain tension is very important at all times.
Catalytic converter
!Warning!
Some STIHL chainsaw models are equipped with a catalytic converter, which is designed to reduce the exhaust emissions of the engine by a chemical process in the muffler. Due to this process, the muffler does not cool down as rapidly as conventional mufflers when the engine returns to idle or is shut off. To reduce the risk of fire and burn injuries, specific safety precautions must be observed.
!Warning!
Since a muffler with a catalytic converter cools down less rapidly than conventional mufflers, never set your chainsaw
down on or near dry brush, grass, wood chips or other combustible materials while it is still hot. Let the engine cool down sitting on concrete, metal, bare ground or solid wood (e.g. the trunk of a felled tree) away from any combustible substances.
!Warning!
To reduce the risk of fire or burn injury, let the unit cool down before refueling your chainsaw after use.
!Warning!
Never disassemble or modify your muffler. The muffler could be damaged and cause an increase in heat radiation or sparks, thereby increasing the risk of fire or burn injury. You may also permanently damage the engine. Have your muffler serviced and repaired by your STIHL Servicing Dealer only.
10
MS 290, 310, 390
English / USA
!Warning!
To reduce the risk of fire or burn injury, keep the area around the muffler clean. Remove all debris such as pine needles, branches or leaves.
!Warning!
An improperly mounted or damaged cylinder housing or a damaged/ deformed muffler shell may interfere with the cooling effect of the catalytic converter. To reduce the risk of fire or burn injury, do not continue work with a damaged or improperly mounted cylinder housing or a damaged/ deformed muffler shell. Your catalytic converter is furnished with screens designed to reduce the risk of fire from the emission of hot particles. Due to the heat from the catalytic reaction, these screens will normally stay clean and need no service or maintenance. If you experience loss of performance and you suspect a clogged screen, have your muffler maintained by a STIHL Servicing Dealer.
Working Conditions
Operate the chainsaw under good visibility and daylight conditions only.
!Warning!
Your chainsaw produces poisonous exhaust fumes as soon as the combustible engine is running. These gases
(e.g. carbon monoxide) may be colorless and odorless. To reduce the risk of serious or fatal injury from breathing toxic fumes, never run the chainsaw indoors or in poorly ventilated locations. Ensure proper ventilation when working in trenches or other confined areas.
!Warning!
Use of this product (including sharpen­ing the saw chain) can generate dust, mists and fumes containing chemicals known to cause respiratory disease, cancer, birth defects, or other reproductive harm. If you are unfamiliar with the risks associated with the particular dust, mist or fume at issue, consult your employer, governmental agencies such as OSHA and NIOSH and other sources on hazardous materials. California and some other authorities, for instance, have published lists of substances known to cause cancer, reproductive toxicity, etc. Control dust (such as sawdust), mists (such as oil mist from chain lubrication) and fumes at the source where possible.
In this regard use good work practices and follow the recommendations of OSHA / NIOSH and occupational and trade associations. When the inhalation of toxic dust, mists and fumes cannot be eliminated, the operator and any bystanders should always wear a respirator approved by NIOSH / MSHA for the type substance at issue.
!Warning!
Breathing asbestos dust is dangerous and can cause severe or fatal injury, respiratory illness or cancer. The use and disposal of asbestos containing products have been strictly regulated by OSHA and the Environmental Protection Agency. Do not cut or disturb asbestos, asbestos containing products (e.g. asbestos containing drywall or other construction products), or products such as pipes which are wrapped or covered with asbestos insulation. If you have any reason to believe that you might be cutting asbestos, immediately contact your employer or a local OSHA representative.
11MS 290, 310, 390
English / USA
The muffler and other parts of the engine (e.g. fins of the cylinder, spark plug) become hot during operation and remain hot for a while after stopping the engine. To reduce risk of burns do not touch the muffler and other parts while they are hot. Don't work alone. Keep within calling distance of others in case help is needed.
Your chainsaw is equipped with a chain catcher. It is designed to reduce the risk of personal injury in the event of a thrown or broken chain. From time to time the catcher may be damaged or removed.
To reduce the risk of personal injury, do not operate a chainsaw with a damaged or missing catcher.
Inspect buffers periodically. Replace damaged, broken or excessively worn buffers immediately, since they may result in loss of control of the saw.
A "sponginess" in the feel of the saw, increased vibration or increased "bottoming" during normal operation may indicate damage, breakage or excessive wear. Buffers should always be replaced in sets. If you have any questions as to whether the buffers should be replaced, consult your STIHL servicing dealer.
!Warning!
Take extreme care in wet and freezing weather (rain, snow, ice). Put off the work when the weather is windy, stormy or rainfall is heavy.
!Warning!
Avoid stumbling on obstacles such as stumps, roots or rocks and watch out for holes or ditches. Clear the area where you are working. Be extremely cautious when working on slopes or uneven ground. There is increased danger of slipping on freshly debarked logs.
!Warning!
To reduce the risk of serious or fatal injury to the operator or bystanders, never
use the saw with one hand.
You cannot control reactive forces and you may lose control of the saw, which can result in the skating or bouncing of the bar and chain along the limb or log.
Even for those compact saws designed for use in confined spaces, one-handed operation is dangerous because the operator may lose control.
001BA087 LÄ
Cutting Instructions
Grip: Always hold the saw firmly with both hands when the engine is running. Place your left hand on front handle bar and your right hand on rear handle and throttle trigger. Left-handers should follow these instructions too. Wrap your fingers tightly around the handles, keeping the handles cradled between your thumb and forefinger. With your hands in this position, you can best oppose and absorb the push, pull and kickback forces of your saw without losing control (see section on reactive forces). Make sure your chainsaw handles and grip are in good condition and free of moisture, pitch, oil or grease.
!Warning!
Do not operate your chainsaw with the starting throttle lock engaged. Cutting with the starting throttle lock engaged does not permit the operator proper control of the saw or chain speed.
12
MS 290, 310, 390
English / USA
!Warning!
Never touch a chain with your hand or any part of your body when the engine is running, even when the chain is not rotating. The chain continues to rotate for a short period after the throttle trigger is released.
!Warning!
Do not cut any material other than wood or wooden objects. Use your saw for chainsawing only. It is not designed for prying or shoveling away limbs, roots or other objects. When sawing, make sure that the saw chain does not touch any foreign materials such as rocks, fences, nails and the like. Such objects may be flung off, damage the saw chain or cause the saw to kickback.
!Warning!
In order to keep control of your saw, always maintain a firm foothold.
001BA018 LA
Never work on a ladder, or on any other insecure support. Never use the saw above shoulder height.
!Warning!
Never work in a tree unless you have received specific, professional training for such work, are properly secured (such as tackle and harness system or a lift bucket), have both hands free for operating the chainsaw in a cramped environment and have taken proper precautions to avoid injury from falling limbs or branches.
Position the chainsaw in such a way that your body is clear of the cutting attachment whenever the engine is running. Stand to the left of cut while bucking.
Don't put pressure on the saw when reaching the end of a cut. The pressure may cause the bar and rotating chain to
001BA031 KN
pop out of the cut or kerf, go out of control and strike the operator or some other object. If the rotating chain strikes some other object, a reactive force may cause the moving chain to strike the operator.
Reactive forces including kickback
!Warning!
Reactive forces may occur any time the chain is rotating. Reactive forces can be dangerous! In any chainsaw,
001BA082 KN
13MS 290, 310, 390
English / USA
the powerful force used to cut wood can be reversed (and work against the operator). If the rotating chain is suddenly stopped by contact with any solid object like a log or branch or is pinched, there active forces may occur instantly. These reactive forces may result in loss of control which may, in turn, cause serious or fatal injury. An understanding of the causes of these reactive forces may help you avoid loss of control.
The most common reactive forces are
–kickback,
pushback,
–pull-in.
Kickback:
Kickback may occur when the moving saw chain near the upper quadrant of the bar nose contacts a solid object or is pinched.
001BA093 LÄ
The reaction of the cutting force of the chain causes a rotational force on the chainsaw in the direction opposite to the chain movement. This may fling the bar up and back in an uncontrolled arc mainly in the plane of the bar. Under some cutting circumstances the bar moves towards the operator, who may suffer severe or fatal injury.
Kickback may occur, for example, when the chain near the upper quadrant of the bar nose contacts the wood or is pinched during limbing or when it is incorrectly used to begin a plunge or boring cut.
The greater the force of the kickback reaction, the more difficult it becomes for the operator to control the saw. Many factors influence the occurrence and force of the kickback reaction. These include chain speed, the speed at which the bar and chain contact the object, the angle of contact, the condition of the chain and other factors.
The type of bar and saw chain you use is an important factor in the occurrence and force of the kickback reaction. Some STIHL bar and chain types are designed to reduce kickback forces. STIHL recommends the use of reduced kickback bars and low kickback chains.
001BA035 KN
ANSI B 175.1-2000 chainsaw kickback standard
Section 5.11 of ANSI standard B 175.1-2000, sets certain performance and design criteria related to chainsaw kickback.
To comply with section 5.11 of ANSI B 175.1-2000:
14
MS 290, 310, 390
English / USA
a) saws with a displacement of less
than 3.8 cubic inches (62 cm³).
must, in their original condition,
meet a 45° computer derived kickback angle when equipped with certain cutting attachments.
and must be equipped with at least
two devices to reduce the risk of kickback injury, such as a chain brake, low kickback chain, reduced kickback bar, etc.
b) saws with a displacement of
3.8 cubic inches (62 cm³) and above
must be equipped with at least one
device designed to reduce the risk of kickback injury such as a chain brake, low kickback chain, reduced kickback bar, etc.
The computer derived angles for saws below 3.8 cubic inch (62 cm³) displacement are measured by applying a computer program to test results from a kickback test machine.
!Warning!
The computer derived angles of § 5.11 of ANSI B 175.1-2000 may bear no relationship to actual kickback bar rotation angles that may occur in real life cutting situations.
In addition, features designed to reduce kickback injuries may lose some of their effectiveness when they are no longer in their original condition, especially if they have been improperly maintained. Compliance with § 5.11 of ANSI B 175.1­2000 does not automatic-ally mean that in a real life kickback the bar and chain will rotate at most 45°.
!Warning!
In order for powerheads below 3.8 cubic inch (62 cm³) displacement to comply with the computed kickback angle requirements of § 5.11 of ANSI B 175.1­2000 use only the following cutting attachments:
bar and chain combinations listed
as complying in the "Specifications" section of the Owner's Manual or
other replacement bar and chain
combinations marked in accordance with the standard for use on the powerhead or
replacement chain designated
"low kickback saw chain''.
See the section on "Low kickback saw chain and reduced kickback bars"
Devices for reducing the risk of kickback injury
STIHL recommends the use of the STIHL Quickstop chain brake on your power-head with green labeled reduced kickback bars and low kickback chains.
!Warning!
To reduce the risk of injury, stop using the saw immediately if the chain brake does not function properly. Take the saw to your local STIHL Service Center! Do not use the saw until the problem has been rectified (see the section "Chain Brake").
Quickstop chain brake
STIHL has developed a chain stopping system designed to reduce the risk of injury in certain kickback situations. It is called a Quickstop chain brake. The Quickstop is available as standard equipment on your STIHL chainsaw and is available for installation on most older STIHL saws. Ask your dealer to retrofit your older model saw with a chain brake.
15MS 290, 310, 390
English / USA
When a kickback occurs, the guide bar may rotate around the front handle. If the cutting position is such that the operator's left hand is gripping the front handle behind the hand guard, and if the left hand rotates around the front handle and makes a sufficiently forceful contact with the front hand guard, which is the Quickstop activating lever, this contact will activate the Quickstop. The chain brake on most new model STIHL chainsaws can also be activated by inertia. See the chapter entitled "Chain Brake" of your Owner's Manual.
!Warning!
Never operate your chainsaw without a front hand guard. In a kickback situation this guard helps protect your left hand or other parts of your body. In addition, removal of the hand guard on a saw equipped with a chain brake will deactivate the chain brake.
!Warning!
No Quickstop or other chain brake device prevents kickback. These devices are designed to reduce the risk of kickback injury, if activated, in certain kickback situations. In order for the Quickstop to reduce the risk of kickback injury, it must be properly maintained
001BA036 KN
and in good working order. See the chapter entitled "Chain Brake" and "Maintenance, Repair and Storing" of your Owner's Manual. In addition, there must be enough distance between the bar and the operator to ensure that the Quickstop has sufficient time to activate and stop the chain before potential contact with the operator.
!Warning!
An improperly maintained chain brake may increase the time needed to stop the chain after activation, or may not activate at all.
!Warning!
Never run the chainsaw above idle speed for more than 3 seconds when the chain brake is engaged or the chain is pinched or otherwise caught in the cut. Clutch slippage can cause excessive heat, leading to severe damage of the motor housing, clutch and oiler component and may interfere with the operation of the chain brake. If clutch slippage in excess of 3 seconds has occurred, allow the motor housing to cool before proceeding and check the operation of your chain brake as described in the chapter entitled "Chain Brake". Also make sure that the chain is not turning at idle speed (see above "Important Adjustments").
Low kickback saw chain and reduced kickback bars
STIHL offers a variety of bars and chains. STIHL reduced kickback bars and low kickback chains are designed to
16
MS 290, 310, 390
English / USA
reduce the risk of kickback injury. Other chains are designed to obtain higher cutting efficiency or sharpening ease but may result in higher kickback tendency.
STIHL has developed a color codesystem to help you identify the STIHL reduced kickback bars and low kickback chains. Cutting attachments with green warning decals or green labels on the packaging are designed to reduce the risk of kickback injury. The matching of green decaled powerheads under 3.8 cubic inch (62 cm³) displacement with green labeled bars and green labeled chains gives compliance with the computed kickback angle requirements of ANSI B 175.1-2000 when the products are in their original condition. Products with yellow decals or labels are for users with extraordinary cutting needs and experience and specialized training for dealing with kickback.
STIHL recommends the use of its green labeled reduced kickback bars, green labeled low kickback chains and a STIHL Quickstop chain brake for both experienced and inexperienced chainsaw users.
Please ask your STIHL dealer to properly match your powerhead with the appropriate bar/chain combinations to reduce the risk of kickback injury. Green labeled bars and chains are recommended for all powerheads. See your "STIHL Bar and Chain Information" leaflet for details.
!Warning!
Use of other, non-listed bar/chain combinations may increase kickback forces and increase the risk of kickback injury. New bar/chain combinations may be developed after publication of this literature, which will, in combination with certain powerheads, comply with
§ 5.11 of ANSI B 175.1-2000. Check with your STIHL dealer for such combinations.
!Warning!
Reduced kickback bars and low kickback chains do not prevent kickback, but they are designed to reduce the risk of kickback injury. They are available from your STIHL dealer.
!Warning!
Even if your saw is equipped with a Quickstop, a reduced kickback bar and/ or low kickback chain, this does not eliminate the risk of injury by kickback. Therefore, always observe all safety precautions to avoid kickback situations.
Low kickback chain
Some types of saw chain have specially designed components to reduce the force of nose contact kickback. STIHL has developed low kickback chain for your powerhead.
"Low kickback saw chain" is a chain which has met the kickback performance requirements of § 5.11.2.4 of ANSI B 175.1-2000 (Safety Requirements for Gasoline-Powered ChainSaws) when tested in its original condition on a selected representative sample of chainsaws below 3.8 cubic inch (62 cm³) displacement specified in ANSI B 175.1-2000.
!Warning!
There are potential powerhead and bar combinations with which low kickback saw chains can be used which have not been specifically certified to comply with the 45° computer derived kickback angle of § 5.11 of ANSI B 175.1-2000. Some low kickback chains have not been tested with all powerhead and bar combinations.
!Warning!
A dull or improperly sharpened chain may reduce or negate the effects of the design features intended to reduce kickback energy. Improper lowering or sharpening of the depth gauges or shaping of the cutters may increase the chance and the potential energy of a kickback. Always cut with a properly sharpened chain.
17MS 290, 310, 390
English / USA
Reduced kickback bar
STIHL green labeled reduced kickback bars are designed to reduce the risk of kickback injury when used with STIHL green labeled low kickback chains.
!Warning!
When used with other, more aggressive chains, these bars may be less effective in reducing kickback, and may result in higher kickback forces.
Bow Guides
!Warning!
Do not mount a bow guide on any STIHL chainsaw. Any chainsaw equipped with a bowguide is potentially very dangerous. The risk of kickback is increased with a bow guide because of the increased kickback contact area. Low kickback chain will not significantly reduce the risk of kickback injury when used on a bow guide.
To avoid kickback
The best protection from personal injury that may result from kickback is to avoid kickback situations:
1. Hold the chainsaw firmly with both
hands and maintain a secure grip.
2. Be aware of the location of the guide
bar nose at all times.
3. Never let the nose of the guide bar
contact any object. Do not cut limbs with the nose of the guide bar. Be especially careful when cutting small, tough limbs, small size brush and saplings which may easily catch the chain.
4 Don't overreach.
5. Don't cut above shoulder height.
6. Begin cutting and continue at full
throttle.
7. Cut only one log at a time.
8. Use extreme caution when
reentering a previous cut.
9. Do not attempt to plunge cut if you
are not experienced with these cutting techniques.
10. Be alert for shifting of the log or
other forces that may cause the cut to close and pinch the chain.
11. Maintain saw chain properly. Cut
with a correctly sharpened, properly tensioned chain at all times.
12. Stand to the side of the cutting path
of the chainsaw.
A
A = Pull-in:
Pull-in occurs when the chain on the bottom of the bar is suddenly stopped when it is pinched, caught or encounters a foreign object in the wood. The reaction of the chain pulls the saw forward and may cause the operator to lose control.
Pull-in frequently occurs when the bumper spike of the saw is not held securely against the tree or limb and when the chain is not rotating at full speed before it contacts the wood.
!Warning!
Use extreme caution when cutting small size brush and saplings which may easily catch the chain and pull you off balance.
To avoid pull-in
1. Always start a cut with the chain rotating at full speed and the bumper spike in contact with the wood.
2. Pull-in may also be prevented by using wedges to open the kerf or cut.
001BA037 KN
18
MS 290, 310, 390
B
B = Pushback:
Pushback occurs when the chain on the top of the bar is suddenly stopped when it is pinched, caught or encounters a foreign object in the wood. The reaction of the chain drives the saw straight back toward the operator and may cause loss of saw control. Pushback frequently occurs when the top of the bar is used for cutting.
To avoid pushback
1. Be alert to forces or situations that may cause material to pinch the top of the chain.
2. Do not cut more than one log at a time.
3. Do not twist the saw when withdrawing the bar from a plunge cut or underbuck cut because the chain can pinch.
Cutting Techniques
Felling
Felling is cutting down a tree.
Before felling a tree, consider carefully all conditions which may affect the direction of fall, including:
001BA038 KN
The intended direction of the fall.
The natural lean of the tree.
Any unusually heavy limb structure.
Surrounding trees and obstacles.
The wind direction and speed.
!Warning!
Always observe the general condition of the tree. Inexperienced users should never attempt to cut trees which are decayed or rotted inside or which are leaning or otherwise under tension. There is an increased risk that such trees could snap or split while being cut and cause serious or fatal injury to the operator or bystanders. Also look for broken or dead branches which could vibrate loose and fall on the operator. When felling on a slope, the operator should stand on the uphill side if possible.
English / USA
1
1 1
Felling Instructions:
When felling, maintain a distance of at least 21/2 tree lengths from the nearest person.
When felling in the vicinity of roads, railways and power lines, etc., take extra precautions. Inform the police, utility company or railway authority before beginning to cut.
/
2
1
/
2
2
!Warning!
The noise of your engine may drown any warning call.
!Warning!
There are a number of factors that may affect and change the intended direction of fall, e.g. wind, lean of tree, sloping ground, one-sided limb structure, wood structure, decay, snow load, etc. To reduce the risk of severe or fatal injury to yourself or others, look for these conditions prior to beginning the cut, and be alert for a change in direction while the tree is falling.
001BA088 LÄ
19MS 290, 310, 390
English / USA
A
B
45°
45°
B
Escape path
First clear the tree base and work area from interfering limbs and brush and clean its lower portion with an ax.
Then, establish two paths of escape (B) and remove all obstacles. These paths should be generally opposite to the planned direction of the fall of the tree (A) and about at a 45° angle. Place all tools and equipment a safe distance away from the tree, but not on the escape paths.
20
001BA040 KN
Buttress roots
If the tree has large buttress roots, cut into the largest buttress vertically first (horizontally next) and remove the resulting piece.
001BA041 KN
Gunning sight
When making the felling notch, use the gunning sight on the shroud and housing to check the required direction of fall:
: Position the saw so that the gunning
sight points exactly in the direction you want the tree to fall.
MS 290, 310, 390
001BA019 KN
A
English / USA
Conventional cut
A = felling notch - determines the
direction of the fall
For a conventional cut:
: Properly place felling notch
perpendicular to the line of fall, close to the ground
: Cut down at app. 45-degree angle
to a depth of about 1/5 to 1/4 of the trunk diameter
: Make second cut horizontal : Remove resulting 45-degree piece
001BA052 KN
Open-face technique
A = felling notch - determines the
direction of the fall
For an open-face cut:
: Properly place felling notch
perpendicular to the line of fall, close to the ground
: Cut down at app. 50-degree angle
to a depth of app.1/5 to 1/4 of the trunk diameter
: Make second cut from below at app.
40 degree angle
: Remove resulting 90-degree piece
001BA042 LÄ
Making sapwood cuts
: For medium sized or larger trees
make cuts at both sides of the trunk,
: at same height as subsequent
felling cut.
: Cut to no more than width of guide
bar.
This is especially important in softwood in summer - it helps prevent sapwood splintering when the tree falls.
001BA043 KN
21MS 290, 310, 390
English / USA
C
B
B
B = Felling cut
Conventional and open-face technique:
: Begin 1 to 2 inches (2,5 to 5 cm)
higher than centre of felling notch
: Cut horizontally towards the felling
notch
: Leave approx.1/10 of diameter
uncut. This is the hinge
: Do not cut through the hinge - you
could lose control of the direction of the fall
Drive wedges into the felling cut where necessary to control the fall.
!Warning!
If the tip of the bar contacts a wedge, it may cause kickback. Wedges should be of wood or plastic - never steel, which can damage the chain.
C
001BA044 KN
C = Hinge
: Helps control the falling tree : Do not cut through the hinge -you
could lose control of the direction of the fall
!Warning!
In order to reduce the risk of personal injury, never stand directly behind the tree when it is about to fall, since part of the trunk may split and come back towards the operator (barber-chairing), or the tree may jump backwards off the stump. Always keep to the side of the falling tree. When the tree starts to fall, withdraw the bar, shut off the engine and walk away on the preplanned escape path. Watch out for falling limbs.
001BA045 KN
!Warning!
Be extremely careful with partially fallen trees which are poorly supported. When the tree hangs or for some other reason does not fall completely, set the saw aside and pull the tree down with a cable winch, block and tackle or tractor. If you try to cut it down with your saw, you may be injured.
Felling cut for small diameter trees: simple fan cut
Engage the bumper spikes of the chainsaw directly behind the location of the intended hinge and pivot the saw around this point only as far as the hinge. The bumper spike rolls against the trunk.
001BA046 KN
22
MS 290, 310, 390
1
3
2
Felling cut for large diameter trees:
!Warning!
Felling a tree that has a diameter greater than the length of the guide bar requires use of either the sectioning felling cut or plunge-cut method. These methods are extremely dangerous because they involve the use of the nose of the guide bar and can result in kickback. Only properly trained professionals should attempt these techniques.
Sectioning method
For the sectioning method make the first part of the felling cut with the guide bar fanning in toward the hinge. Then, using the bumper spike as a pivot, reposition the saw for the next cut.
1
001BA047 KN
Avoid repositioning the saw more than necessary. When repositioning for the next cut, keep the guide bar fully engaged in the kerf to keep the felling cut straight. If the saw begins to pinch, insert a wedge to open the cut. On the last cut, do not cut the hinge.
Plunge-cut method
Timber having a diameter more than twice the length of the guide bar requires the use of the plunge-cut method before making the felling cut.
English / USA
3
001BA089 LÄ
2
First, cut a large, wide felling notch. Make a plunge cut in the centre of the notch.
The plunge cut is made with the guide bar nose. Begin the plunge cut by applying the lower portion of the guide bar nose to the tree at an angle. Cut until the depth of the kerf is about the same
001BA048 KN
as the width of the guide bar. Next, align the saw in the direction in which the recess is to be cut.
With the saw at full throttle, insert the guide bar in the trunk.
Enlarge the plunge cut as shown in the illustration.
!Warning!
There is an extreme danger of kickback at this point. Extra caution must be taken to maintain control of the saw. To make the felling cut, follow the sectioning method described previously.
23MS 290, 310, 390
English / USA
0
If you are inexperienced with a chainsaw, plunge-cutting should not be attempted. Seek the help of a professional.
Limbing
Limbing is removing the branches from a fallen tree.
!Warning!
There is an extreme danger of kickback during the limbing operation. Do not work with the nose of the bar. Be extremely cautious and avoid contacting the log or other limbs with the nose of the guide bar.
Do not stand on a log while limbing it ­you may slip or the log may roll.
Start limbing by leaving the lower limbs to support the log off the ground. When underbucking freely hanging limbs, a pinch may result or the limb may fall, causing loss of control. If a pinch occurs, stop the engine and remove the saw, by lifting the limb.
!Warning!
Be extremely cautious when cutting limbs or logs under tension (spring poles). The limbs or logs could spring back toward the operator and cause loss of control of the saw and severe or fatal injury to the operator.
Bucking
Bucking is cutting a log into sections.
!Warning!
1. When bucking, do not stand on the log. Make sure the log will not roll downhill. If on a slope, stand on the uphill side of the log. Watch out for rolling logs.
001BA033 KN
2. Cut only one log at a time.
3. Shattered wood should be cut very carefully. Sharp slivers of wood may be caught and flung in the direction of the operator of the saw.
4. When cutting small logs, place log through "V" - shaped supports on top of a sawhorse. Never permit another person to hold the log. Never hold the log with your leg or foot.
01BA051 LÄ
24
MS 290, 310, 390
English / USA
0
5. Logs under strain: Risk of pinching! Always start relieving cut (1) at compression side (A).Then make bucking cut (2) at tension side (B). If the saw pinches, stop the engine and remove it from the log.
6. Only properly trained professionals should work in an area where the logs, limbs and roots are tangled. Working in blow down areas is extremely hazardous.
7. Drag the logs into a clear area before cutting. Pull out exposed and cleared logs first.
MAINTENANCE, REPAIR AND STORING
Maintenance, replacement, or repair of the emission control devices and systems may be performed by any nonroad engine repair establishment or individual. However if you claim warranty for a component which has not been serviced or maintained properly or if nonapproved replacement parts were used, STIHL may deny warranty.
Never operate a chainsaw that is damaged, improperly adjusted or not completely or securely assembled. Follow the maintenance and repair instructions in the appropriate section of
01BA050 LÄ
your Owner's Manual, especially those in the chapters "Mounting the Bar and Chain", "Maintaining and Sharpening" and "Chain Brake".
!Warning!
Use only STIHL replacement parts for maintenance and repair. Use of parts manufactured by others may cause serious or fatal injury.
!Warning!
Always stop the engine and ensure that the chain is stopped before making any adjustments, maintenance or repair work,
changing the saw chain or cleaning the saw. Do not attempt any maintenance or repair work not described in your Owner's Manual. Have such work performed at your STIHL service shop only.
!Warning!
Never test the ignition system with ignition wire terminal removed from sparkplug or with unseated spark plug, since uncontained sparking may cause a fire.
!Warning!
To reduce the risk of fire and burn injury, use only spark plugs authorized by STIHL. Always press spark plug boot snugly onto spark plug terminal of the proper size. (Note: If terminal has detachable SAE adapter nut, it must be attached.) A loose connection between spark plug terminal and ignition wire connector in the boot may create arcing that could ignite combustible fumes and cause a fire. Keep spark plug clean, and make sure ignition lead is in good condition.
!Warning!
Do not operate your chainsaw if the muffler is damaged, missing or modified. An improperly maintained muffler will increase the risk of fire and hearing loss. Never touch a hot muffler or burn will
25MS 290, 310, 390
English / USA

Mounting the Bar and Chain

result. If your muffler was equipped with a spark-arresting screen to reduce the risk of fire (e. g. in the USA, Canada and Australia), never operate your saw if the screen is missing or damaged. Remember that the risk of forest fires is greater in hot or dry weather. Keep the chain, bar and sprocket clean; replace worn sprockets or chains. Keep the chain sharp. You can spot a dull chain when easy-to­cut wood becomes hard to cut and burn marks appear on the wood. Keep the chain at proper tension. Tighten all nuts, bolts and screws except the carburetor adjustment screws after each use.
!Warning!
In order for the chain brake on your STIHL chainsaw to properly perform its function of reducing the risk of kickback and other injuries, it must be properly maintained. Like an automobile brake, a chainsaw chain brake incurs wear each time it is engaged.
The amount of wear will vary depending upon usage, conditions under which the saw is used and other factors. Excessive wear will reduce the effectiveness of the chain brake and can render it inoperable.
For the proper and effective operation of the chain brake the brake band and clutch drum must be kept free of dirt, grease and other foreign matter which may reduce friction of the band on the drum.
For these reasons, each STIHL chainsaw should be returned to trained personnel such as your STIHL servicing dealer for periodic inspection and servicing of the brake system according to the following schedule: Heavy usage - every three months, Moderate usage - twice a year, Occasional usage - annually.
The chainsaw should also be returned immediately for maintenance whenever the brake system cannot be thoroughly cleaned or there is a change in its operating characteristics.
For any maintenance please refer to the maintenance chart and to the warranty statement near the end of this manual.
Additionally, the daily maintenance schedule for your chainsaw set forth in your STIHL Owner's Manual should be strictly followed.
Store chainsaw in a dry place and away from children. Before storing for longer than a few days, always empty the fuel tank (see chapter "Storing the Machine" in this manual).
1
a
t = a : 2
You can run chains of different pitches on this chainsaw – depending on the chain sprocket (see “Specifications”):
The chain pitch (1) must match the pitch of the sprocket and the guide bar (for Rollomatic). The drive link gauge (2) must match the bar groove width (3).
The pitch is marked on the chain sprocket and guide bar in inches (e.g. 3/8 or .325). The groove width is marked on the guide bar in millimeters (e.g. 1.6).
If non-matching components of the wrong pitch or drive link gauge are run together on the same machine they may be damaged beyond repair after a short period of operation.
2
3
001BA105 KN
26
MS 290, 310, 390
English / USA
6
9
7
7
10
8
: Unscrew the nuts and take off the
chain sprocket cover.
4
5
: Turn screw (4) counterclockwise
until the tensioner slide (5) butts against left end of housing slot.
143BA034 KN
: Disengage the chain brake: Pull
hand guard (6) toward front handle.
001BA107 KN
Wear work gloves to protect your hands from the sharp cutters.
: Fit the chain – start at the bar nose.
001BA108 KN
: Fit the guide bar over the studs (7) –
cutting edges on top of bar must point to right – and engage the peg of the tensioner slide in locating hole (8) – place the chain over sprocket (9) at the same time.
: Now turn tensioning screw (10)
clockwise until there is very little chain sag on the underside of the bar – and the drive link tangs are
143BA003 KN
located in the bar groove.
: Refit the sprocket cover –
and screw on the nuts only finger­tight.
: Go to “Tensioning the Saw Chain”.
001BA109 KN
27MS 290, 310, 390
English / USA

Tensioning the Saw Chain

1
Retensioning during cutting work:
: Shut off the engine first –
and then loosen the nuts.
: Hold the bar nose up and use
screwdriver to turn tensioning screw (1) clockwise until chain fits snugly against the underside of the bar.
: While still holding the bar nose up,
tighten down the nuts firmly.
: Go to chapter “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 "Operating Instructions".

Checking Chain Tension

133BA024 KN
: Shut off the engine.
: Wear work gloves.
: Chain must fit snugly against the
underside of the bar – and, with the chain brake disengaged, it must still be possible to pull the chain along the bar by hand.
: 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 "Operating Instructions".

Fuel

This engine is certified to operate on unleaded gasoline and the STIHL two­stroke engine oil at a mix ratio of 50:1.
Your two-stroke engine requires a mixture of high-quality gasoline and quality two-stroke air cooled engine oil.
Use mid-grade unleaded gasoline with a
143BA007 KN
minimum octane rating of 89 (R+M/2). If the octane rating of the mid-grade gasoline in your area is lower, use premium unleaded fuel.
Fuel with a lower octane rating may increase engine temperatures. This, in turn, increases the risk of piston seizure and damage to the engine.
The chemical composition of the fuel is also important. Some fuel additives not only detrimentally affect elastomers (carburetor diaphragms, oil seals, fuel lines, etc.), but magnesium castings and catalytic converters as well. This could cause running problems or even damage the engine. For this reason STIHL recommends that you use only nationally recognized high-quality unleaded gasoline!
28
MS 290, 310, 390

Fueling

English / USA
Use only STIHL two-stroke engine oil or equivalent high-quality two-stroke engine oils that are designed for use only in air cooled two-cycle engines.
We recommend STIHL 50:1 two-stroke engine oil since it is specially formulated for use in STlHL engines.
Do not use BIA or TCW rated (two­stroke water cooled) mix oils or other mix oils that state they are for use in both water cooled and air cooled engines (e.g., outboard motors, snowmobiles, chainsaws, mopeds, etc.).
Take care when handling gasoline. Avoid direct contact with the skin and avoid inhaling fuel vapor. When filling at the pump, first remove the canister from your vehicle and place the canister on the ground before filling. Do not fill fuel canisters that are sitting in or on a vehicle.
The canister should be kept tightly closed in order to avoid any moisture getting into the mixture.
The machine‘s fuel tank and the canister in which fuel mix is stored should be cleaned as necessary.
Fuel mix ages
Only mix sufficient fuel for a few days work, not to exceed 3 months of storage. Store in approved fuel-canisters only. When mixing, pour oil into the canister first, and then add gasoline. Close the canister and shake it vigorously by hand to ensure proper mixing of the oil with the fuel.
Gaso­line
Oil (STIHL 50:1 or equivalent high-quality oils)
US gal. US fl.oz
12.6 2 1/2 6.4 5 12.8
Dispose of empty mixing-oil canisters only at authorized disposal locations.
001BA159 KN
Before fueling, clean the filler cap and the area around it to ensure that no dirt falls into the tank.
Always position the machine so that the filler cap points upwards.
Always thoroughly shake the mixture in the canister before fueling your machine.
In order to reduce the risk of burns or other personal injury from escaping gas vapor and fumes, remove the fuel filler cap carefully so as to allow any pressure build-up in the tank to release slowly.
29MS 290, 310, 390
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