Instruction Manual
Page 3
..., 2020 0458-546-8621-D. VA8.K20. 0000001050_029_GB FS 40, FS 40 C, FS 50, FS 50 C This instruction manual is protected by Dealer 32 Maintenance and Care 33 Main Parts 35 Specifications 36 Maintenance and Repairs 37 Disposal 38 Limited Warranty 38 STIHL Incorporated Federal Emission Control Warranty Statement 38 STIHL Incorporated California Exhaust and Evaporative Emissions Control Warranty...
..., 2020 0458-546-8621-D. VA8.K20. 0000001050_029_GB FS 40, FS 40 C, FS 50, FS 50 C This instruction manual is protected by Dealer 32 Maintenance and Care 33 Main Parts 35 Specifications 36 Maintenance and Repairs 37 Disposal 38 Limited Warranty 38 STIHL Incorporated Federal Emission Control Warranty Statement 38 STIHL Incorporated California Exhaust and Evaporative Emissions Control Warranty...
Instruction Manual
Page 4
... of a step or procedure that refers directly to continually improve all of its individual components. Engineering Improvements STIHL's philosophy is to an illustration may contain item numbers that appear in the illustration. The individual steps or...gasoline and engine oil mixture Press to operate decompression valve Manual fuel pump Press to operate manual fuel pump Filler hole for assistance. 2 FS 40, FS 40 C, FS 50, FS 50 C As a result, engineering changes and improvements are supported by illustrations. Depending on your special attention. For example: N Remove ...
... of a step or procedure that refers directly to continually improve all of its individual components. Engineering Improvements STIHL's philosophy is to an illustration may contain item numbers that appear in the illustration. The individual steps or...gasoline and engine oil mixture Press to operate decompression valve Manual fuel pump Press to operate manual fuel pump Filler hole for assistance. 2 FS 40, FS 40 C, FS 50, FS 50 C As a result, engineering changes and improvements are supported by illustrations. Depending on your special attention. For example: N Remove ...
Instruction Manual
Page 5
...If the rotating line or blade comes in this machine. the power tool 3. Tiredness may cause serious or fatal injury. FS 40, FS 40 C, FS 50, FS 50 C 3 during a work , check with your FS model. If you . Safety Precautions and Working Techniques Because a trimmer is a high-speed, fast-cutting power tool,... in contact with the appropriate cutting attachment only for a description of the controls and the function of the parts of your STIHL dealer show you are specifically authorized by ricochet in use it for use of your power tool without the instruction manual. See...
...If the rotating line or blade comes in this machine. the power tool 3. Tiredness may cause serious or fatal injury. FS 40, FS 40 C, FS 50, FS 50 C 3 during a work , check with your FS model. If you . Safety Precautions and Working Techniques Because a trimmer is a high-speed, fast-cutting power tool,... in contact with the appropriate cutting attachment only for a description of the controls and the function of the parts of your STIHL dealer show you are specifically authorized by ricochet in use it for use of your power tool without the instruction manual. See...
Instruction Manual
Page 6
An AV system is restricted. 4 FS 40, FS 40 C, FS 50, FS 50 C A power tool with loose components or with damaged or worn AV ..."+" (or your hearing. Continual and regular users should wear proper protective apparel. WARNING The ignition system of the STIHL unit produces an electromagnetic field of a power tool (or other machines) exposing the operator to vibration are mentioned...to reduce the transmission of injury, the operator should have higher vibration levels. - Most STIHL power tools are not known, but do not guarantee that you also wear a face shield or face screen...
An AV system is restricted. 4 FS 40, FS 40 C, FS 50, FS 50 C A power tool with loose components or with damaged or worn AV ..."+" (or your hearing. Continual and regular users should wear proper protective apparel. WARNING The ignition system of the STIHL unit produces an electromagnetic field of a power tool (or other machines) exposing the operator to vibration are mentioned...to reduce the transmission of injury, the operator should have higher vibration levels. - Most STIHL power tools are not known, but do not guarantee that you also wear a face shield or face screen...
Instruction Manual
Page 7
...damaged. THE POWER TOOL For illustrations and definitions of movement. If this instruction manual). 389BA019 KN FS 40, FS 40 C, FS 50, FS 50 C 5 Only attachments supplied by STIHL and expressly approved by STIHL for your power tool with the cutting attachment moving parts of heavy material to help to the...scarfs, neckties, jewelry, flared or cuffed pants, unconfined long hair or anything that the controls and safety devices are useable with STIHL power tools, their use with nonslip soles. Steel-toed safety boots are authorized. use may be extremely dangerous. Do not continue...
...damaged. THE POWER TOOL For illustrations and definitions of movement. If this instruction manual). 389BA019 KN FS 40, FS 40 C, FS 50, FS 50 C 5 Only attachments supplied by STIHL and expressly approved by STIHL for your power tool with the cutting attachment moving parts of heavy material to help to the...scarfs, neckties, jewelry, flared or cuffed pants, unconfined long hair or anything that the controls and safety devices are useable with STIHL power tools, their use with nonslip soles. Steel-toed safety boots are authorized. use may be extremely dangerous. Do not continue...
Instruction Manual
Page 9
...fuel spraying. Once the fumes or vapor have been relieved, turn counterclockwise. winter blends). Damaged or Broken Cap If your authorized STIHL dealer for several minutes before attempting to the closed position. Vapor Lock WARNING Vapor lock occurs when fuel in this section when removing...temperature will take it may be relieved or affected by turning it is shut off and spill quantities of liquid fuel into the carburetor. FS 40, FS 40 C, FS 50, FS 50 C 7 - In hot environments, cooling will rise for repair. Never remove the fuel filler cap by slowly turning the cap...
...fuel spraying. Once the fumes or vapor have been relieved, turn counterclockwise. winter blends). Damaged or Broken Cap If your authorized STIHL dealer for several minutes before attempting to the closed position. Vapor Lock WARNING Vapor lock occurs when fuel in this section when removing...temperature will take it may be relieved or affected by turning it is shut off and spill quantities of liquid fuel into the carburetor. FS 40, FS 40 C, FS 50, FS 50 C 7 - In hot environments, cooling will rise for repair. Never remove the fuel filler cap by slowly turning the cap...
Instruction Manual
Page 10
English To relieve vapor lock: - If the manual fuel pump bulb will not be filled, place the Choke Lever to clear the vapor and send liquid fuel into the carburetor. to the cold start position g, place the Choke Lever to 30 times - Press the manual fuel pump bulb at least 20 to the warm start position < and start the engine in the cold start position g and pull the starter cord until the engine runs. even if the bulb is already filled with fuel - Then start position For specific starting instructions, see the appropriate section of your instruction manual. - If the engine ...
English To relieve vapor lock: - If the manual fuel pump bulb will not be filled, place the Choke Lever to clear the vapor and send liquid fuel into the carburetor. to the cold start position g, place the Choke Lever to 30 times - Press the manual fuel pump bulb at least 20 to the warm start position < and start the engine in the cold start position g and pull the starter cord until the engine runs. even if the bulb is already filled with fuel - Then start position For specific starting instructions, see the appropriate section of your instruction manual. - If the engine ...
Instruction Manual
Page 12
...stop switch is used to stop the engine, it by simply pulling the starter rope, with both hands on how to have your STIHL dealer check your power tool and make proper adjustments and repairs. Keep your hands in this procedure may result in injury to keep hands... or on slopes or uneven ground. Make sure your trimmer handles and grips are working on any other insecure support. Work carefully. 10 FS 40, FS 40 C, FS 50, FS 50 C WARNING This unit is equipped with one hand. If the engine is normally in operational readiness. Wrap your fingers and thumbs around...
...stop switch is used to stop the engine, it by simply pulling the starter rope, with both hands on how to have your STIHL dealer check your power tool and make proper adjustments and repairs. Keep your hands in this procedure may result in injury to keep hands... or on slopes or uneven ground. Make sure your trimmer handles and grips are working on any other insecure support. Work carefully. 10 FS 40, FS 40 C, FS 50, FS 50 C WARNING This unit is equipped with one hand. If the engine is normally in operational readiness. Wrap your fingers and thumbs around...
Instruction Manual
Page 14
...Never operate your muffler. Make sure that the risk of a brush or forest fire is greater in hot or dry conditions. 12 FS 40, FS 40 C, FS 50, FS 50 C WARNING To reduce the risk of unintentional rotation of the cutting attachment and injury, always shut off the trimmer, which may .... Any modification could cause an increase in serious or fatal injury. Have your muffler serviced and repaired by your muffler maintained by a STIHL servicing dealer. Your muffler is furnished with a spark arresting screen designed to superficial cracks. WARNING If the head, blade or deflector becomes...
...Never operate your muffler. Make sure that the risk of a brush or forest fire is greater in hot or dry conditions. 12 FS 40, FS 40 C, FS 50, FS 50 C WARNING To reduce the risk of unintentional rotation of the cutting attachment and injury, always shut off the trimmer, which may .... Any modification could cause an increase in serious or fatal injury. Have your muffler serviced and repaired by your muffler maintained by a STIHL servicing dealer. Your muffler is furnished with a spark arresting screen designed to superficial cracks. WARNING If the head, blade or deflector becomes...
Instruction Manual
Page 15
...STIHL PolyCut mowing head Uses nonrigid, pivoting polymer blades. 2 Do not continue using the PolyCut if one blade, always replace all blades. WARNING To reduce the risk of accidents from blade contact and / or loss of control, never attempt to use a metal blade on this trimmer. FS 40, FS 40 C, FS 50, FS... To reduce the risk of severe or fatal injury from shattered blades, avoid contact with stones, metal and similar solid objects. STIHL AutoCut mowing head Nylon cutting cord advances automatically when tapped against the ground (TapAction). arrow) has worn away. clutch, polymer...
...STIHL PolyCut mowing head Uses nonrigid, pivoting polymer blades. 2 Do not continue using the PolyCut if one blade, always replace all blades. WARNING To reduce the risk of accidents from blade contact and / or loss of control, never attempt to use a metal blade on this trimmer. FS 40, FS 40 C, FS 50, FS... To reduce the risk of severe or fatal injury from shattered blades, avoid contact with stones, metal and similar solid objects. STIHL AutoCut mowing head Nylon cutting cord advances automatically when tapped against the ground (TapAction). arrow) has worn away. clutch, polymer...
Instruction Manual
Page 16
...control devices and systems may be securely attached). Strictly follow the maintenance and repair instructions in the instruction manual. 14 FS 40, FS 40 C, FS 50, FS 50 C An improperly maintained muffler will increase the risk of children. The owner/operator of your instruction manual. This... is equipped with a complying spark arrester that could result in injury to fire protection requirements. WARNING Use only identical STIHL replacement parts for properly maintaining the spark arrester. Always press the spark plug boot snugly onto the spark plug terminal of...
...control devices and systems may be securely attached). Strictly follow the maintenance and repair instructions in the instruction manual. 14 FS 40, FS 40 C, FS 50, FS 50 C An improperly maintained muffler will increase the risk of children. The owner/operator of your instruction manual. This... is equipped with a complying spark arrester that could result in injury to fire protection requirements. WARNING Use only identical STIHL replacement parts for properly maintaining the spark arrester. Always press the spark plug boot snugly onto the spark plug terminal of...
Instruction Manual
Page 17
... order to reduce the risk of injury from loss of injury, no other combinations are permitted. Do not use . Cutting Attachments Mowing heads 1 STIHL AutoCut C 6-2 2 STIHL DuroCut 5-2 3 STIHL PolyCut 7-3 FS 40, FS 40 C, FS 50, FS 50 C 4 STIHL PolyCut 6-2 Deflector 5 Deflector with blade, for mowing heads Handle 6 Loop handle Harness 7 Shoulder strap may be used WARNING Based on the cutting...
... order to reduce the risk of injury from loss of injury, no other combinations are permitted. Do not use . Cutting Attachments Mowing heads 1 STIHL AutoCut C 6-2 2 STIHL DuroCut 5-2 3 STIHL PolyCut 7-3 FS 40, FS 40 C, FS 50, FS 50 C 4 STIHL PolyCut 6-2 Deflector 5 Deflector with blade, for mowing heads Handle 6 Loop handle Harness 7 Shoulder strap may be used WARNING Based on the cutting...
Instruction Manual
Page 19
It is shipped with screw mounting Keep the supplement sheet for these mowing heads. STIHL PolyCut 5-2 mowing head, STIHL FixCut 6-3 mowing head N Slip the thrust plate (1) over the shaft (2) and engage the hex recess (3) on the ground Thrust Plate 1 3... KN 2 4 N Switch off the shaft (2). turn the thrust plate back and forth if necessary. STIHL AutoCut 5-2 mowing head, STIHL AutoCut C 5-2 mowing head N Pull the thrust plate (1), if fitted, off the engine. FS 40, FS 40 C, FS 50, FS 50 C 17 Mounting the Cutting Attachment Placing power tool on the external hexagon (4). 6 5 N To...
It is shipped with screw mounting Keep the supplement sheet for these mowing heads. STIHL PolyCut 5-2 mowing head, STIHL FixCut 6-3 mowing head N Slip the thrust plate (1) over the shaft (2) and engage the hex recess (3) on the ground Thrust Plate 1 3... KN 2 4 N Switch off the shaft (2). turn the thrust plate back and forth if necessary. STIHL AutoCut 5-2 mowing head, STIHL AutoCut C 5-2 mowing head N Pull the thrust plate (1), if fitted, off the engine. FS 40, FS 40 C, FS 50, FS 50 C 17 Mounting the Cutting Attachment Placing power tool on the external hexagon (4). 6 5 N To...
Instruction Manual
Page 20
... shaft N Turn the mowing head clockwise Fitting Mowing Head without Screw Mounting Keep the instruction leaflet for the mowing head in the mowing head (2). English STIHL AutoCut 5-2 8 4 2 1 7 2 3 5 6 1 002BA385 KN 232BA054 KN 232BA053 KN N Fit the thrust plate N Turn the mowing head anticlockwise on the shaft (1) as far as stop and tighten... that was used to block the shaft. screw it clockwise on the mowing head - Removing the Mowing Head 3 N Fit the spring (1) in a safe place. 18 FS 40, FS 40 C, FS 50, FS 50 C
... shaft N Turn the mowing head clockwise Fitting Mowing Head without Screw Mounting Keep the instruction leaflet for the mowing head in the mowing head (2). English STIHL AutoCut 5-2 8 4 2 1 7 2 3 5 6 1 002BA385 KN 232BA054 KN 232BA053 KN N Fit the thrust plate N Turn the mowing head anticlockwise on the shaft (1) as far as stop and tighten... that was used to block the shaft. screw it clockwise on the mowing head - Removing the Mowing Head 3 N Fit the spring (1) in a safe place. 18 FS 40, FS 40 C, FS 50, FS 50 C
Instruction Manual
Page 21
...down firmly by hand. STIHL PolyCut N Block the shaft. N Turn the spool (9) clockwise until you feel resistance and then tighten it down the mowing head firmly. N Fit the thrust plate on to the shaft - N Screw the mowing head (11) clockwise on to block the shaft. FS 40, FS 40 C, FS 50, FS 50 C 19 N ...Insert the cap (8) in the spool, press it clockwise at the same time. NOTICE Remove the tool used to the shaft (5) as far as stop and turn it down as far as stop. English STIHL AutoCut N Hold the mowing head...
...down firmly by hand. STIHL PolyCut N Block the shaft. N Turn the spool (9) clockwise until you feel resistance and then tighten it down the mowing head firmly. N Fit the thrust plate on to the shaft - N Screw the mowing head (11) clockwise on to block the shaft. FS 40, FS 40 C, FS 50, FS 50 C 19 N ...Insert the cap (8) in the spool, press it clockwise at the same time. NOTICE Remove the tool used to the shaft (5) as far as stop and turn it down as far as stop. English STIHL AutoCut N Hold the mowing head...
Instruction Manual
Page 22
... a winter blend during the summer will increase pressure in the fuel tank during operation. STIHL MotoMix has a high octane rating and ensures that gets into the mixture. 20 FS 40, FS 40 C, FS 50, FS 50 C For further details, see www.STIHLusa.com/ethanol The ethanol content in order ...cooled engines (e.g., outboard motors, snowmobiles, chain saws, mopeds, etc.). This problem can cause running problems or damage the engine. STIHL MotoMix uses STIHL HP Ultra two-stroke engine oil suited for use NMMA or TCW rated (twostroke water cooled) mix oils or other environmental factors...
... a winter blend during the summer will increase pressure in the fuel tank during operation. STIHL MotoMix has a high octane rating and ensures that gets into the mixture. 20 FS 40, FS 40 C, FS 50, FS 50 C For further details, see www.STIHLusa.com/ethanol The ethanol content in order ...cooled engines (e.g., outboard motors, snowmobiles, chain saws, mopeds, etc.). This problem can cause running problems or damage the engine. STIHL MotoMix uses STIHL HP Ultra two-stroke engine oil suited for use NMMA or TCW rated (twostroke water cooled) mix oils or other environmental factors...
Instruction Manual
Page 23
... injury, including fire and burn injury, or property damage. Close the container and shake it by turning it is facing up. 547BA045 KN FS 40, FS 40 C, FS 50, FS 50 C 21 Preparations N Before fueling, clean the filler cap and the area around it first approximately 1/2 of fire and severe personal injury... fuel tank can occur when the engine is hot and the tank is more . - Always follow all directions. Gasoline US gal. 1 2 1/2 5 Oil (STIHL 50:1 or equivalent high-quality oils) US fl.oz. 2.6 6.4 12.8 Dispose of oil and gasoline. Never open the fuel tank or re-fuel the power...
... injury, including fire and burn injury, or property damage. Close the container and shake it by turning it is facing up. 547BA045 KN FS 40, FS 40 C, FS 50, FS 50 C 21 Preparations N Before fueling, clean the filler cap and the area around it first approximately 1/2 of fire and severe personal injury... fuel tank can occur when the engine is hot and the tank is more . - Always follow all directions. Gasoline US gal. 1 2 1/2 5 Oil (STIHL 50:1 or equivalent high-quality oils) US fl.oz. 2.6 6.4 12.8 Dispose of oil and gasoline. Never open the fuel tank or re-fuel the power...
Instruction Manual
Page 24
... from escaping gas vapor and fumes, remove the fuel filler cap slowly and carefully so as possible: 22 FS 40, FS 40 C, FS 50, FS 50 C N Turn the cap to the open the tank. Refueling N If your authorized STIHL dealer for repair or replacement. Take care not to remove the cap while the engine is still hot...
... from escaping gas vapor and fumes, remove the fuel filler cap slowly and carefully so as possible: 22 FS 40, FS 40 C, FS 50, FS 50 C N Turn the cap to the open the tank. Refueling N If your authorized STIHL dealer for repair or replacement. Take care not to remove the cap while the engine is still hot...
Instruction Manual
Page 29
... plug with solid, non-threaded terminals Installing the Spark Plug If engine running conditions, e.g. N Only use only spark plugs authorized by STIHL. See the chapter "Specifications" in this instruction manual Correct the problems that you have caused fouling of the spark plug: - Always ...Clean the spark plug if it is properly adjusted, the cause may occur that could ignite combustible fumes and cause a fire. or - FS 40, FS 40 C, FS 50, FS 50 C 27 see "Specifications" N Use only resistor type spark plugs of fire and burn injury, use resistor type spark plugs with a...
... plug with solid, non-threaded terminals Installing the Spark Plug If engine running conditions, e.g. N Only use only spark plugs authorized by STIHL. See the chapter "Specifications" in this instruction manual Correct the problems that you have caused fouling of the spark plug: - Always ...Clean the spark plug if it is properly adjusted, the cause may occur that could ignite combustible fumes and cause a fire. or - FS 40, FS 40 C, FS 50, FS 50 C 27 see "Specifications" N Use only resistor type spark plugs of fire and burn injury, use resistor type spark plugs with a...
Instruction Manual
Page 30
...this helps prevent the carburetor diaphragms sticking together. Keep the instructions for signs of wear before adjusting the nylon mowing line by hand. 28 FS 40, FS 40 C, FS 50, FS 50 C N Dispose of 2.5 cm (1 in). N Run the engine until the carburetor is supplied with corrosion inhibitor. The mowing ...head is dry - N If necessary, remove the mowing head. 546BA016 KN 232BA007 KN Adjusting Nylon Line STIHL AutoCut 2 1 N Hold the rotating mowing head above...
...this helps prevent the carburetor diaphragms sticking together. Keep the instructions for signs of wear before adjusting the nylon mowing line by hand. 28 FS 40, FS 40 C, FS 50, FS 50 C N Dispose of 2.5 cm (1 in). N Run the engine until the carburetor is supplied with corrosion inhibitor. The mowing ...head is dry - N If necessary, remove the mowing head. 546BA016 KN 232BA007 KN Adjusting Nylon Line STIHL AutoCut 2 1 N Hold the rotating mowing head above...
