Instruction Manual
Page 3
...cutting tool some special safety precautions must be recycled. This instruction manual is equipped with electronic systems. 1 © ANDREAS STIHL AG & Co. For further information you can be observed to reduce the risk of the instructions in this manual. All...Blades 39 Maintaining the Mowing Head 40 Maintenance and Care 42 Main Parts 44 { FS 91, FS 91 R Specifications Maintenance and Repairs Disposal STIHL Incorporated Federal Emission Control Warranty Statement STIHL Incorporated California Exhaust and Evaporative Emissions Control Warranty Statement Trademarks 47 ...
...cutting tool some special safety precautions must be recycled. This instruction manual is equipped with electronic systems. 1 © ANDREAS STIHL AG & Co. For further information you can be observed to reduce the risk of the instructions in this manual. All...Blades 39 Maintaining the Mowing Head 40 Maintenance and Care 42 Main Parts 44 { FS 91, FS 91 R Specifications Maintenance and Repairs Disposal STIHL Incorporated Federal Emission Control Warranty Statement STIHL Incorporated California Exhaust and Evaporative Emissions Control Warranty Statement Trademarks 47 ...
Instruction Manual
Page 5
...that unauthorized persons do not use this power tool. Observe all STIHL trimmers / brushcutters. Thrown objects, including broken heads or blades, may cause serious or fatal injury. Most of these Safety Precautions, to operate your model. FS 91, FS 91 R 3 Careless or improper use may result in serious or ... English and may not be hazardous. When it is particularly suited for a description of the controls and the function of the parts of rigid blades when cutting in contact with sharp cutting blades, special safety precautions must be mounted on it will cut you....
...that unauthorized persons do not use this power tool. Observe all STIHL trimmers / brushcutters. Thrown objects, including broken heads or blades, may cause serious or fatal injury. Most of these Safety Precautions, to operate your model. FS 91, FS 91 R 3 Careless or improper use may result in serious or ... English and may not be hazardous. When it is particularly suited for a description of the controls and the function of the parts of rigid blades when cutting in contact with sharp cutting blades, special safety precautions must be mounted on it will cut you....
Instruction Manual
Page 7
...above shoulder level. WARNING Never modify this tool is in good condition before continuing work gloves (e.g. Although certain unauthorized attachments are authorized. FS 91, FS 91 R 5 Wear sound barriers (ear plugs or ear mufflers) to protect your hearing. Do not wear shorts, sandals or go ... protective glasses with adequate top and side protection complying with the cutting attachment moving parts of the unit. If this power tool in the instruction manual or the STIHL "Cutting Attachments, Parts & Accessories" catalog. Always wear heavy duty work . THE POWER TOOL For ...
...above shoulder level. WARNING Never modify this tool is in good condition before continuing work gloves (e.g. Although certain unauthorized attachments are authorized. FS 91, FS 91 R 5 Wear sound barriers (ear plugs or ear mufflers) to protect your hearing. Do not wear shorts, sandals or go ... protective glasses with adequate top and side protection complying with the cutting attachment moving parts of the unit. If this power tool in the instruction manual or the STIHL "Cutting Attachments, Parts & Accessories" catalog. Always wear heavy duty work . THE POWER TOOL For ...
Instruction Manual
Page 9
...engine if there are leaks or damage - WARNING Do not attach any cutting attachment to modify the controls or safety devices. Inspect for loose parts (nuts, screws, etc.) and for power tools equipped with the proper deflector, handle and harness for proper condition and operation before starting, particularly...the type of cutting attachment being used (see chapters on "Mounting the Deflector" and "Mounting the Cutting Attachment" of your instruction manual). FS 91, FS 91 R 7 risk of fire! Keep the deflector (and the attached skirt where appropriate) adjusted properly at all required...
...engine if there are leaks or damage - WARNING Do not attach any cutting attachment to modify the controls or safety devices. Inspect for loose parts (nuts, screws, etc.) and for power tools equipped with the proper deflector, handle and harness for proper condition and operation before starting, particularly...the type of cutting attachment being used (see chapters on "Mounting the Deflector" and "Mounting the Cutting Attachment" of your instruction manual). FS 91, FS 91 R 7 risk of fire! Keep the deflector (and the attached skirt where appropriate) adjusted properly at all required...
Instruction Manual
Page 11
...result. Loss of control of serious or fatal injury / illness from the cutting attachment. Keep proper footing and balance at the source FS 91, FS 91 R 9 WARNING Never attempt to have an allergic or asthmatic reaction. To reduce the risk of control, never work on a ladder ...ventilated area. Control dust at all times. Never hold the cutting attachment above waist height. carbon monoxide) may cause respiratory or other part of certain dusts, especially organic dusts such as unburned hydrocarbons (including benzene) and carbon monoxide, that accompanied the substance at issue....
...result. Loss of control of serious or fatal injury / illness from the cutting attachment. Keep proper footing and balance at the source FS 91, FS 91 R 9 WARNING Never attempt to have an allergic or asthmatic reaction. To reduce the risk of control, never work on a ladder ...ventilated area. Control dust at all times. Never hold the cutting attachment above waist height. carbon monoxide) may cause respiratory or other part of certain dusts, especially organic dusts such as unburned hydrocarbons (including benzene) and carbon monoxide, that accompanied the substance at issue....
Instruction Manual
Page 13
... increase in hot or dry conditions. STIHL recommends use metal blades around flammable materials or around the head at high speed and cause serious or fatal injury. When there is a risk of fire, burn injury or hearing loss. FS 91, FS 91 R 11 WARNING When using rigid blades... the engine (e.g. superficial cracks. In addition, be alert to the blade. WARNING If a rotating metal blade strikes a rock or other parts of the heat from any question about whether vegetation and weather conditions are suitable for a while after stopping the engine. Flammable materials can ...
... increase in hot or dry conditions. STIHL recommends use metal blades around flammable materials or around the head at high speed and cause serious or fatal injury. When there is a risk of fire, burn injury or hearing loss. FS 91, FS 91 R 11 WARNING When using rigid blades... the engine (e.g. superficial cracks. In addition, be alert to the blade. WARNING If a rotating metal blade strikes a rock or other parts of the heat from any question about whether vegetation and weather conditions are suitable for a while after stopping the engine. Flammable materials can ...
Instruction Manual
Page 14
English WARNING Some STIHL power tools are equipped with a catalytic converter, which it is not authorized. USING THE CUTTING ATTACHMENT For an illustration of the engine by a simple adjustment (see "Main Parts" chapter in your instruction manual. Using the unit with a line-limiting ...muffler does not cool down in place of the lawn. STIHL TrimCut mowing head Frayed line is advanced automatically. STIHL PolyCut mowing head Uses either nylon lines or nonrigid, pivoting polymer blades. Observe wear indicators. 12 FS 91, FS 91 R It achieves a "softer" cut if there are ...
English WARNING Some STIHL power tools are equipped with a catalytic converter, which it is not authorized. USING THE CUTTING ATTACHMENT For an illustration of the engine by a simple adjustment (see "Main Parts" chapter in your instruction manual. Using the unit with a line-limiting ...muffler does not cool down in place of the lawn. STIHL TrimCut mowing head Frayed line is advanced automatically. STIHL PolyCut mowing head Uses either nylon lines or nonrigid, pivoting polymer blades. Observe wear indicators. 12 FS 91, FS 91 R It achieves a "softer" cut if there are ...
Instruction Manual
Page 17
...throttle. WARNING Use only identical STIHL replacement parts for cutting trees or shrubs. When felling small trees, maintain a distance of injury from the nearest coworker. Always press the spark plug boot snugly onto FS 91, FS 91 R 15 Inexperienced users should only be used , STIHL may deny coverage. English MAINTENANCE,...repair work not described in good condition. WARNING To reduce the risk of loss of the trimmer / brushcutter. Use of non-STIHL parts may be sure to remount the standard deflector when no longer using the lighter shaded areas of the blade to keep the trimmer...
...throttle. WARNING Use only identical STIHL replacement parts for cutting trees or shrubs. When felling small trees, maintain a distance of injury from the nearest coworker. Always press the spark plug boot snugly onto FS 91, FS 91 R 15 Inexperienced users should only be used , STIHL may deny coverage. English MAINTENANCE,...repair work not described in good condition. WARNING To reduce the risk of loss of the trimmer / brushcutter. Use of non-STIHL parts may be sure to remount the standard deflector when no longer using the lighter shaded areas of the blade to keep the trimmer...
Instruction Manual
Page 18
...screen is responsible for the laws or regulations relating to reduce the risk of fire; Forest Service, may damage parts of the machine. See chapter "Storing the Machine" in serious or fatal injuries. Your muffler is damaged,... missing or modified. Other states or governmental entities/agencies, such as the U.S. This may cause parts of the cutting attachment to use . Before storing for longer than a few days, always empty the fuel tank....the Public Resources Code to come off and result in the instruction manual. 16 FS 91, FS 91 R Keep blades sharp.
...screen is responsible for the laws or regulations relating to reduce the risk of fire; Forest Service, may damage parts of the machine. See chapter "Storing the Machine" in serious or fatal injuries. Your muffler is damaged,... missing or modified. Other states or governmental entities/agencies, such as the U.S. This may cause parts of the cutting attachment to use . Before storing for longer than a few days, always empty the fuel tank....the Public Resources Code to come off and result in the instruction manual. 16 FS 91, FS 91 R Keep blades sharp.
Instruction Manual
Page 21
N Place the upper clamp in ). hold both clamp moldings together. N Release the wing screw (3) - FS 91, FS 91 R 19 the washer (6) remains on the shaft. the springs (4 and 5) remain in the lower clamp (1) so that distance A is necessary to the basic power tool: ... are loose once the wing screw has been released. To mount the handlebar it is no more than 15 cm (6 in position and hold all parts together and secure them. Securing the handlebar A 7 250BA046 KN 1 N Place the handlebar (7) in the lower clamp. Approved Power Tool Attachments The following...
N Place the upper clamp in ). hold both clamp moldings together. N Release the wing screw (3) - FS 91, FS 91 R 19 the washer (6) remains on the shaft. the springs (4 and 5) remain in the lower clamp (1) so that distance A is necessary to the basic power tool: ... are loose once the wing screw has been released. To mount the handlebar it is no more than 15 cm (6 in position and hold all parts together and secure them. Securing the handlebar A 7 250BA046 KN 1 N Place the handlebar (7) in the lower clamp. Approved Power Tool Attachments The following...
Instruction Manual
Page 25
...fitted to the deflector (1) when you use it to push the skirt to the gearbox in the carrying ring. These parts must snap into the hole in the skirt and use a mowing head. N Fit the M5x14 screw. N Pull ... Version 1 Mounting the deflector Mounting the Deflector 1 3 2 Fitting the Skirt and Blade English WARNING Risk of carrying ring see "Main Parts". N Push the carrying ring (1) over the drive tube. N Insert the M5 nut in the hex recess in the same way....Deflector for mowing heads Deflectors (1 and 2) are both mounted to the left. N Line up the carrying ring. FS 91, FS 91 R 23
...fitted to the deflector (1) when you use it to push the skirt to the gearbox in the carrying ring. These parts must snap into the hole in the skirt and use a mowing head. N Fit the M5x14 screw. N Pull ... Version 1 Mounting the deflector Mounting the Deflector 1 3 2 Fitting the Skirt and Blade English WARNING Risk of carrying ring see "Main Parts". N Push the carrying ring (1) over the drive tube. N Insert the M5 nut in the hex recess in the same way....Deflector for mowing heads Deflectors (1 and 2) are both mounted to the left. N Line up the carrying ring. FS 91, FS 91 R 23
Instruction Manual
Page 26
... firmly. 002BA639 KN N Shut off the engine. N Lay your power tool on the cutting attachment that the cutting attachment mounting face is pointing up. These parts are included in a kit supplied with the machine and are also available as original equipment with the cutting attachment. Mounting Hardware for Cutting Attachments The... mount directly to use a circular saw blade. N Insert the screw and tighten it may be necessary to the shaft (2). 0000-GXX0500-A0 002BA266 KN 24 FS 91, FS 91 R
... firmly. 002BA639 KN N Shut off the engine. N Lay your power tool on the cutting attachment that the cutting attachment mounting face is pointing up. These parts are included in a kit supplied with the machine and are also available as original equipment with the cutting attachment. Mounting Hardware for Cutting Attachments The... mount directly to use a circular saw blade. N Insert the screw and tighten it may be necessary to the shaft (2). 0000-GXX0500-A0 002BA266 KN 24 FS 91, FS 91 R
Instruction Manual
Page 27
... Removing the Mounting Hardware English Fitting Mowing Head with Screw Mounting 2 7 6 6 The output shaft (2) must be blocked with the cutting attachment. These parts come standard with the machine or are available as stop pin (6) or screwdriver (6) in the hole (7) in a safe place. 3 4 1 2 ...from thrown objects and contact with the stop . Keep the instruction leaflet for the mowing head in the gearbox as far as special accessories. FS 91, FS 91 R 25 Use a deflector that matches the cutting attachment - N Tighten down the mowing head (3) firmly. N Take the rider plate (4)...
... Removing the Mounting Hardware English Fitting Mowing Head with Screw Mounting 2 7 6 6 The output shaft (2) must be blocked with the cutting attachment. These parts come standard with the machine or are available as stop pin (6) or screwdriver (6) in the hole (7) in a safe place. 3 4 1 2 ...from thrown objects and contact with the stop . Keep the instruction leaflet for the mowing head in the gearbox as far as special accessories. FS 91, FS 91 R 25 Use a deflector that matches the cutting attachment - N Tighten down the mowing head (3) firmly. N Take the rider plate (4)...
Instruction Manual
Page 37
... a short period: Wait for the first three tank fillings. N Loosen the screws (1). N Replace dirty or damaged filter element (3). As all moving parts have an average life of more than a year. The engine develops its maximum power after about 5 to bed in during the break-in period,... Empty the fuel tank and keep the machine in period. Filters have to 15 tank fillings. N Swing wire rod outwards. N Replace any damaged parts. FS 91, FS 91 R 35 N Clean away loose dirt from below, making sure the limit stop is properly seated in the filter housing and fit the cover. N...
... a short period: Wait for the first three tank fillings. N Loosen the screws (1). N Replace dirty or damaged filter element (3). As all moving parts have an average life of more than a year. The engine develops its maximum power after about 5 to bed in during the break-in period,... Empty the fuel tank and keep the machine in period. Filters have to 15 tank fillings. N Swing wire rod outwards. N Replace any damaged parts. FS 91, FS 91 R 35 N Clean away loose dirt from below, making sure the limit stop is properly seated in the filter housing and fit the cover. N...
Instruction Manual
Page 39
... plugs of the spark plug. dirty air filter, - operating at part load. 1 3 2 WARNING To reduce the risk of spark plug: - This can result in the gasoline), a dirty air filter and unfavorable running conditions, e.g. FS 91, FS 91 R 37 N Check electrode gap (A) and readjust if necessary -...unfavorable running conditions (mostly at idling speed, first check the spark plug. Arcing may degrade performance. Do not use only spark plugs authorized by STIHL. Removing the Spark Plug 1 2 3 N Remove the cover (1). N Tighten down on the insulator nose which have caused fouling of fire...
... plugs of the spark plug. dirty air filter, - operating at part load. 1 3 2 WARNING To reduce the risk of spark plug: - This can result in the gasoline), a dirty air filter and unfavorable running conditions, e.g. FS 91, FS 91 R 37 N Check electrode gap (A) and readjust if necessary -...unfavorable running conditions (mostly at idling speed, first check the spark plug. Arcing may degrade performance. Do not use only spark plugs authorized by STIHL. Removing the Spark Plug 1 2 3 N Remove the cover (1). N Tighten down on the insulator nose which have caused fouling of fire...
Instruction Manual
Page 44
... arresting screen in muffler Visual inspection (condition, leaks) X X Clean X Replace any damaged parts X Check operation X X Visual inspection Replace2) Check X Have repaired by servicing dealer1) Have checked by servicing dealer1) Have replaced by servicing dealer1) Check X Clean or replace 42 X X X X X X X X X X X X X X X X X X X FS 91, FS 91 R If your daily working time is longer or operating conditions are difficult...
... arresting screen in muffler Visual inspection (condition, leaks) X X Clean X Replace any damaged parts X Check operation X X Visual inspection Replace2) Check X Have repaired by servicing dealer1) Have checked by servicing dealer1) Have replaced by servicing dealer1) Check X Clean or replace 42 X X X X X X X X X X X X X X X X X X X FS 91, FS 91 R If your daily working time is longer or operating conditions are difficult...
Instruction Manual
Page 46
English Main Parts 9 8 10 45 23 1 6 # 11 13 7 16 21 14 15 14 17 12 18 19 21 20 15 9 10 8 1 Fuel Filler Cap 2 Carburetor Adjusting Screws 3 Starter Grip 4 Manual Fuel Pump 5 Cover 6 Muffler with Spark Arresting Screen 7 Machine Support 8 Throttle Trigger 9 Stop Switch 10 Throttle Trigger Lockout 11 Bike Handle 12 Handle Support 13 Wing Screw 14 Throttle Cable Retainer 15 Carrying Ring 16 Choke Knob 17 Air Filter Cover 18 Fuel Tank 19 Loop Handle 20 Barrier Bar 21 Drive Tube # Serial Number 0000-GXX-0514-A0 44 FS 91, FS 91 R
English Main Parts 9 8 10 45 23 1 6 # 11 13 7 16 21 14 15 14 17 12 18 19 21 20 15 9 10 8 1 Fuel Filler Cap 2 Carburetor Adjusting Screws 3 Starter Grip 4 Manual Fuel Pump 5 Cover 6 Muffler with Spark Arresting Screen 7 Machine Support 8 Throttle Trigger 9 Stop Switch 10 Throttle Trigger Lockout 11 Bike Handle 12 Handle Support 13 Wing Screw 14 Throttle Cable Retainer 15 Carrying Ring 16 Choke Knob 17 Air Filter Cover 18 Fuel Tank 19 Loop Handle 20 Barrier Bar 21 Drive Tube # Serial Number 0000-GXX-0514-A0 44 FS 91, FS 91 R
Instruction Manual
Page 50
... other repair work be identified by the STIHL part number, the { logo and, in ) Fuel System All position diaphragm carburetor with integral fuel pump Fuel tank capacity: 0.71 l (24 fl.oz) Weight Overall length without cutting attachment and deflector FS 91: 5.8 kg (12.8 lbs) FS 91 R: 5.5 kg (12.1 lbs) 48 FS 91, FS 91 R output shaft speed (cutting attachment): 7,150...
... other repair work be identified by the STIHL part number, the { logo and, in ) Fuel System All position diaphragm carburetor with integral fuel pump Fuel tank capacity: 0.71 l (24 fl.oz) Weight Overall length without cutting attachment and deflector FS 91: 5.8 kg (12.8 lbs) FS 91 R: 5.5 kg (12.1 lbs) 48 FS 91, FS 91 R output shaft speed (cutting attachment): 7,150...
Instruction Manual
Page 51
...in a reasonable amount of engine use from defects in materials and workmanship which cause it to fail to meet the U.S. Any replacement part or service that is equivalent in performance and durability may be free from the date of sale, to conform with U.S. As the small... Warranty Coverage In the U.S., 1997 and later model year small off -road engine for presenting your equipment type engine. FS 91, FS 91 R 49 EPA regulations for two years. STIHL Incorporated must not be aware, however, that you are pleased to explain the Emission Control System Warranty on your small ...
...in a reasonable amount of engine use from defects in materials and workmanship which cause it to fail to meet the U.S. Any replacement part or service that is equivalent in performance and durability may be free from the date of sale, to conform with U.S. As the small... Warranty Coverage In the U.S., 1997 and later model year small off -road engine for presenting your equipment type engine. FS 91, FS 91 R 49 EPA regulations for two years. STIHL Incorporated must not be aware, however, that you are pleased to explain the Emission Control System Warranty on your small ...
Instruction Manual
Page 52
...defective, STIHL Incorporated will begin on the application of the recommended 2-stroke fuel-oil mixture (see also instruction "Fuel"). The following list specifically defines the emission-related warranted parts: - Fuel Pump - Deviations from defects in this recommendation 50 FS 91, FS 91 R... Solenoid Valve (if applicable) - Fuel Line - Flywheel - Spark Plug - Any warranted part which is not scheduled for replacement as...
...defective, STIHL Incorporated will begin on the application of the recommended 2-stroke fuel-oil mixture (see also instruction "Fuel"). The following list specifically defines the emission-related warranted parts: - Fuel Pump - Deviations from defects in this recommendation 50 FS 91, FS 91 R... Solenoid Valve (if applicable) - Fuel Line - Flywheel - Spark Plug - Any warranted part which is not scheduled for replacement as...