Product Instruction Manual
Page 3
... Metal Cutting Blades 43 Maintenance and Care 44 Main Parts 46 Specifications Special Accessories Maintenance and Repairs STIHL Incorporated Federal Emission Control Warranty Statement STIHL Incorporated California Exhaust and Evaporative Emissions Control Warranty Statement Trademarks { FS 90, FS 90 R English 48 Allow only persons who fully understand 49 this manual. Because a trimmer / brushcutter is a high-speed...
... Metal Cutting Blades 43 Maintenance and Care 44 Main Parts 46 Specifications Special Accessories Maintenance and Repairs STIHL Incorporated Federal Emission Control Warranty Statement STIHL Incorporated California Exhaust and Evaporative Emissions Control Warranty Statement Trademarks { FS 90, FS 90 R English 48 Allow only persons who fully understand 49 this manual. Because a trimmer / brushcutter is a high-speed...
Product Instruction Manual
Page 4
...numbers that require your special attention. In addition to the operating instructions, this manual may not be on your STIHL dealer for gear lubricant Air intake summer mode Warning! Such paragraphs are made from those described in the illustration....engineering changes and improvements are marked with the symbols and signal words described below: Engineering Improvements STIHL's philosophy is to continually improve all of its individual components. 2 FS 90, FS 90 R Therefore, some changes, modifications and improvements may contain paragraphs that appear in this manual...
...numbers that require your special attention. In addition to the operating instructions, this manual may not be on your STIHL dealer for gear lubricant Air intake summer mode Warning! Such paragraphs are made from those described in the illustration....engineering changes and improvements are marked with the symbols and signal words described below: Engineering Improvements STIHL's philosophy is to continually improve all of its individual components. 2 FS 90, FS 90 R Therefore, some changes, modifications and improvements may contain paragraphs that appear in this manual...
Product Instruction Manual
Page 5
...trimmer or a brushcutter - Have your STIHL dealer show you . English Warning! The use this power tool. Striking such objects could damage the cutting attachment and may cause blades to the machine. FS 90, FS 90 R 3 Many FS models may be used with a loop handle. FS models with your power tool. Warning!... serious or fatal injury. As more fully explained later in serious or fatal injury to reduce the risk of personal injury. STIHL does not recommend the use may result in these Safety Precautions, to the operator or bystanders. Read the instruction manual and the...
...trimmer or a brushcutter - Have your STIHL dealer show you . English Warning! The use this power tool. Striking such objects could damage the cutting attachment and may cause blades to the machine. FS 90, FS 90 R 3 Many FS models may be used with a loop handle. FS models with your power tool. Warning!... serious or fatal injury. As more fully explained later in serious or fatal injury to reduce the risk of personal injury. STIHL does not recommend the use may result in these Safety Precautions, to the operator or bystanders. Read the instruction manual and the...
Product Instruction Manual
Page 6
... and keep your model. A power tool with loose components or with your power tool run unattended. Maintain a firm grip at all STIHL trimmers / brushcutters. Therefore, continual and regular users should consult their hands and fingers. Warning! When it . Most of their physician ...damaged or worn AV elements will not sustain whitefinger disease or carpal tunnel syndrome. the power tool 3. Do not operate this tool. 4 FS 90, FS 90 R Tiredness may have higher vibration levels. - To reduce the risk of all times, but cold weather, smoking and diseases or physical conditions...
... and keep your model. A power tool with loose components or with your power tool run unattended. Maintain a firm grip at all STIHL trimmers / brushcutters. Therefore, continual and regular users should consult their hands and fingers. Warning! When it . Most of their physician ...damaged or worn AV elements will not sustain whitefinger disease or carpal tunnel syndrome. the power tool 3. Do not operate this tool. 4 FS 90, FS 90 R Tiredness may have higher vibration levels. - To reduce the risk of all times, but cold weather, smoking and diseases or physical conditions...
Product Instruction Manual
Page 7
...doubt, have their use with your power tool will not protect the operator from loss of heavy material to help to protect your legs. FS 90, FS 90 R 5 Always wear gloves when handling the machine and metal blades. Wear long pants made of control and blade or line contact, ... If this power tool in particular that the fuel system is subjected to unusually high loads for use may, in the instruction manual or the STIHL "Cutting Attachments, Parts & Accessories" catalog. heavy impact or a fall), always check that the controls and safety devices are recommended. To reduce...
...doubt, have their use with your power tool will not protect the operator from loss of heavy material to help to protect your legs. FS 90, FS 90 R 5 Always wear gloves when handling the machine and metal blades. Wear long pants made of control and blade or line contact, ... If this power tool in particular that the fuel system is subjected to unusually high loads for use may, in the instruction manual or the STIHL "Cutting Attachments, Parts & Accessories" catalog. heavy impact or a fall), always check that the controls and safety devices are recommended. To reduce...
Product Instruction Manual
Page 8
... a trimmer / brushcutter down. Fueling Instructions Warning! Fuel your power tool in a horizontal position. Toolless cap with the raised positioning 6 FS 90, FS 90 R Keep the hot muffler away from an improperly tightened fuel cap, correctly position and tighten the fuel cap in the fuel tank opening ...leakage is found, do this with different fuel caps. Use extreme caution when handling gasoline or fuel mix. Warning! Warning! STIHL recommends that combustible fuel vapor may escape from the fueling spot before refueling. In order to reduce the risk of fuel spillage ...
... a trimmer / brushcutter down. Fueling Instructions Warning! Fuel your power tool in a horizontal position. Toolless cap with the raised positioning 6 FS 90, FS 90 R Keep the hot muffler away from an improperly tightened fuel cap, correctly position and tighten the fuel cap in the fuel tank opening ...leakage is found, do this with different fuel caps. Use extreme caution when handling gasoline or fuel mix. Warning! Warning! STIHL recommends that combustible fuel vapor may escape from the fueling spot before refueling. In order to reduce the risk of fuel spillage ...
Product Instruction Manual
Page 9
... off and spill quantities of fuel. immediately stop switch, cutting attachment, deflector and harness. See also the "Fueling" chapter in your authorized STIHL dealer for proper condition and operation before starting, particularly the throttle trigger, throttle trigger lockout, slide control / stop use of the unit and... take it will twist the base of the cap into the tank opening when the positioning marks line up . FS 90, FS 90 R 7 Using the grip, press the cap down firmly while turning it clockwise as far as it to your Instruction Manual for tightness. ...
... off and spill quantities of fuel. immediately stop switch, cutting attachment, deflector and harness. See also the "Fueling" chapter in your authorized STIHL dealer for proper condition and operation before starting, particularly the throttle trigger, throttle trigger lockout, slide control / stop use of the unit and... take it will twist the base of the cap into the tank opening when the positioning marks line up . FS 90, FS 90 R 7 Using the grip, press the cap down firmly while turning it clockwise as far as it to your Instruction Manual for tightness. ...
Product Instruction Manual
Page 11
... and grips are working. To reduce the risk of injury from loss of moisture, pitch, oil, fuel mix or grease. 002BA054 KN 002BA055 KN FS 90, FS 90 R 9 Important Adjustments Warning! For directions on the handles while you cannot set the correct idle speed, have your power tool under control at starting..., engine speed will be absolutely sure that the cutting attachment is a one-person machine. other solid surface in this position to have your STIHL dealer check your hands in an open area. To reduce the risk of personal injury from loss of your hand. Wrap your fingers and ...
... and grips are working. To reduce the risk of injury from loss of moisture, pitch, oil, fuel mix or grease. 002BA054 KN 002BA055 KN FS 90, FS 90 R 9 Important Adjustments Warning! For directions on the handles while you cannot set the correct idle speed, have your power tool under control at starting..., engine speed will be absolutely sure that the cutting attachment is a one-person machine. other solid surface in this position to have your STIHL dealer check your hands in an open area. To reduce the risk of personal injury from loss of your hand. Wrap your fingers and ...
Product Instruction Manual
Page 13
... length to fences, sides of eye and other solid objects. When using rigid blades, avoid cutting close to obtain the proper torque. FS 90, FS 90 R 11 If the behavior of ricochets in serious or fatal injury. Warning! Stop the engine immediately if you start work immediately. Warning... to property, also maintain this kind. Warning! To reduce the risk of the nylon line heads for cracks, wear and damage. Warning! STIHL recommends use , stop work , examine the area for stones, glass, fence wire, metal, trash or other injury always wear proper eye ...
... length to fences, sides of eye and other solid objects. When using rigid blades, avoid cutting close to obtain the proper torque. FS 90, FS 90 R 11 If the behavior of ricochets in serious or fatal injury. Warning! Stop the engine immediately if you start work immediately. Warning... to property, also maintain this kind. Warning! To reduce the risk of the nylon line heads for cracks, wear and damage. Warning! STIHL recommends use , stop work , examine the area for stones, glass, fence wire, metal, trash or other injury always wear proper eye ...
Product Instruction Manual
Page 14
..., weeds, etc. Catalytic Converter Warning! Due to this process, the muffler does not cool down in your instruction manual. 12 FS 90, FS 90 R USING THE CUTTING ATTACHMENT For an illustration of burns do not touch the muffler and other parts of fire and burn injuries,...do not continue work with a catalytic converter cools down less rapidly than conventional mufflers, always set your muffler serviced and repaired by a STIHL servicing dealer. To reduce the risk of the cylinder, spark plug) become hot during operation. Have your power tool down as rapidly ...
..., weeds, etc. Catalytic Converter Warning! Due to this process, the muffler does not cool down in your instruction manual. 12 FS 90, FS 90 R USING THE CUTTING ATTACHMENT For an illustration of burns do not touch the muffler and other parts of fire and burn injuries,...do not continue work with a catalytic converter cools down less rapidly than conventional mufflers, always set your muffler serviced and repaired by a STIHL servicing dealer. To reduce the risk of the cylinder, spark plug) become hot during operation. Have your power tool down as rapidly ...
Product Instruction Manual
Page 15
... the edge of the nylon cutting lines. Observe wear indicators. Warning! Using the unit with mowing head). Frayed line is not authorized. FS 90, FS 90 R 13 Using the Mowing Heads Do not use a nylon line head. English Warning! To reduce the risk of severe or fatal injury...to the base (periphery) of these marks. clutch, polymer housing components). Mowing heads are missing or worn - However, the polymer-bladed STIHL PolyCut produces a better cut lengths of damaging tree bark etc. Sharpening is best to rotate at the proper length (see instruction sheet supplied...
... the edge of the nylon cutting lines. Observe wear indicators. Warning! Using the unit with mowing head). Frayed line is not authorized. FS 90, FS 90 R 13 Using the Mowing Heads Do not use a nylon line head. English Warning! To reduce the risk of severe or fatal injury...to the base (periphery) of these marks. clutch, polymer housing components). Mowing heads are missing or worn - However, the polymer-bladed STIHL PolyCut produces a better cut lengths of damaging tree bark etc. Sharpening is best to rotate at the proper length (see instruction sheet supplied...
Product Instruction Manual
Page 17
...crack and / or break, avoid all rigid cutting blades"). Use a chain saw blade for such work . Perform cut down small trees, STIHL recommends that the circular saw blades are suitable for signs of the blade to crack or shatter. When a trimmer / brushcutter with a circular... pressure. This will reduce the risk of loss of kickout (blade thrust) with all contact with a damaged brush knife. STIHL recommends that the FS 90, FS 90 R 15 Using the Circular Saw Blade English standard deflector be applied to full throttle. Resharpen the brush knife regularly (when ...
...crack and / or break, avoid all rigid cutting blades"). Use a chain saw blade for such work . Perform cut down small trees, STIHL recommends that the circular saw blades are suitable for signs of the blade to crack or shatter. When a trimmer / brushcutter with a circular... pressure. This will reduce the risk of loss of kickout (blade thrust) with all contact with a damaged brush knife. STIHL recommends that the FS 90, FS 90 R 15 Using the Circular Saw Blade English standard deflector be applied to full throttle. Resharpen the brush knife regularly (when ...
Product Instruction Manual
Page 18
...good condition. Warning! Do not attempt any maintenance or repair work or cleaning the power tool. Warning! Do not operate your STIHL servicing dealer only. If your instruction manual. Warning! An improperly maintained muffler will increase the risk of your muffler was equipped with...when cutting in the boot may cause serious or fatal injury. Have such work not described in serious or fatal injuries. 16 FS 90, FS 90 R Never test the ignition system with the spark plug boot removed from thrown objects or operator contact with a bicycle handle. Warning...
...good condition. Warning! Do not attempt any maintenance or repair work or cleaning the power tool. Warning! Do not operate your STIHL servicing dealer only. If your instruction manual. Warning! An improperly maintained muffler will increase the risk of your muffler was equipped with...when cutting in the boot may cause serious or fatal injury. Have such work not described in serious or fatal injuries. 16 FS 90, FS 90 R Never test the ignition system with the spark plug boot removed from thrown objects or operator contact with a bicycle handle. Warning...
Product Instruction Manual
Page 21
Permissible combinations The complete equipment comprises: - Handle - Cutting attachments Mowing heads 1 STIHL SuperCut 20-2 2 STIHL AutoCut C 25-2 3 STIHL AutoCut 25-2 4 STIHL TrimCut 31-2 5 STIHL FixCut 25-2 6 STIHL PolyCut 20-3 Metal cutting attachments 7 Grass cutting blade 230-4 8 Grass cutting blade 230-8 9 Brush knife 250...Full harness must not be used . Deflector - Do not use rigid plastic blades on this unit only if equipped with FS 90, FS 90 R 19 Cutting attachment - Use circular saw blades Handles 17 Loop handle 18 Loop handle with the proper handle and harness in...
Permissible combinations The complete equipment comprises: - Handle - Cutting attachments Mowing heads 1 STIHL SuperCut 20-2 2 STIHL AutoCut C 25-2 3 STIHL AutoCut 25-2 4 STIHL TrimCut 31-2 5 STIHL FixCut 25-2 6 STIHL PolyCut 20-3 Metal cutting attachments 7 Grass cutting blade 230-4 8 Grass cutting blade 230-8 9 Brush knife 250...Full harness must not be used . Deflector - Do not use rigid plastic blades on this unit only if equipped with FS 90, FS 90 R 19 Cutting attachment - Use circular saw blades Handles 17 Loop handle 18 Loop handle with the proper handle and harness in...
Product Instruction Manual
Page 22
... KN N hold onto the lower (1) and upper clamps (2) N Unscrew the tommy screw (3) - FS 90, FS 90 R after the tommy screw has been unscrewed, the parts are loose and are pressed apart by the two springs (4, 5)! English Approved Power Tool Attachments The following STIHL interchangeable attachments may be mounted on the basic machine: FH HT Interchangeable...
... KN N hold onto the lower (1) and upper clamps (2) N Unscrew the tommy screw (3) - FS 90, FS 90 R after the tommy screw has been unscrewed, the parts are loose and are pressed apart by the two springs (4, 5)! English Approved Power Tool Attachments The following STIHL interchangeable attachments may be mounted on the basic machine: FH HT Interchangeable...
Product Instruction Manual
Page 28
... far as stop pin slips into position and blocks the shaft. Attaching the mowing head Keep the information sheet for shipping) off the shaft (2). STIHL SuperCut 20-2, STIHL AutoCut 25-2, STIHL AutoCut C 25-2, 26 FS 90, FS 90 R If the parts are available as special accessory - N Rotate the nut or cutting attachment on "Blocking the output shaft".
... far as stop pin slips into position and blocks the shaft. Attaching the mowing head Keep the information sheet for shipping) off the shaft (2). STIHL SuperCut 20-2, STIHL AutoCut 25-2, STIHL AutoCut C 25-2, 26 FS 90, FS 90 R If the parts are available as special accessory - N Rotate the nut or cutting attachment on "Blocking the output shaft".
Product Instruction Manual
Page 29
... at least 1 in . (3 cm) of the lawn - the blade on the deflector for circular saw blades 200 (4, 5) - FS 90, FS 90 R 27 Removing the mowing head N Block the shaft STIHL SuperCut 20-2, STIHL AutoCut 25-2, STIHL AutoCut C 25-2, 002BA081 KN STIHL SuperCut Line is fed out automatically if the mowing line is fed out The blade on the...
... at least 1 in . (3 cm) of the lawn - the blade on the deflector for circular saw blades 200 (4, 5) - FS 90, FS 90 R 27 Removing the mowing head N Block the shaft STIHL SuperCut 20-2, STIHL AutoCut 25-2, STIHL AutoCut C 25-2, 002BA081 KN STIHL SuperCut Line is fed out automatically if the mowing line is fed out The blade on the...
Product Instruction Manual
Page 30
... and tighten it down firmly. N Take the parts off the shaft - If the mounting nut turns too freely, fit a new one. 28 FS 90, FS 90 R It operates otherwise on the shaft (10). English Removing the metal cutting attachment N Block the drive shaft. do not remove the thrust plate ...(7). 4-MIX Engine The STIHL 4-MIX engine features mixture lubrication and must engage the mowing head's mounting hole. Collar (see arrow) must be run on a fuel mixture ...
... and tighten it down firmly. N Take the parts off the shaft - If the mounting nut turns too freely, fit a new one. 28 FS 90, FS 90 R It operates otherwise on the shaft (10). English Removing the metal cutting attachment N Block the drive shaft. do not remove the thrust plate ...(7). 4-MIX Engine The STIHL 4-MIX engine features mixture lubrication and must engage the mowing head's mounting hole. Collar (see arrow) must be run on a fuel mixture ...
Product Instruction Manual
Page 31
... oils that are designed for use in or on unleaded gasoline and the STIHL twostroke engine oil at a mix ratio of the engine change if you use fuels with the running problems or even damage the engine. FS 90, FS 90 R 29 The idle speed and maximum speed of 50:1. The machine's ...fuel tank should not be kept tightly closed in order to operate on a vehicle or trailer. Fuel This engine is also important. For this reason STIHL recommends that gets into the container...
... oils that are designed for use in or on unleaded gasoline and the STIHL twostroke engine oil at a mix ratio of the engine change if you use fuels with the running problems or even damage the engine. FS 90, FS 90 R 29 The idle speed and maximum speed of 50:1. The machine's ...fuel tank should not be kept tightly closed in order to operate on a vehicle or trailer. Fuel This engine is also important. For this reason STIHL recommends that gets into the container...
Product Instruction Manual
Page 32
... Opening the toolless filler cap 002BA419 KN Refueling Take care not to spill fuel while fueling, and do not overfill the tank. One of the STIHL filling system (special accessory). N Turn cap clockwise as far as it is facing upwards. N Remove the filler cap. If the grip is not flush with...
... Opening the toolless filler cap 002BA419 KN Refueling Take care not to spill fuel while fueling, and do not overfill the tank. One of the STIHL filling system (special accessory). N Turn cap clockwise as far as it is facing upwards. N Remove the filler cap. If the grip is not flush with...
