Product Instruction Manual
Page 3
...Cutting Attachment 25 4-MIX Engine 28 Fuel 29 Fueling 30 Fitting the Harness 31 Balancing the Trimmer/Brushcutter 32 Starting / Stopping the Engine 33 Operating Instructions 36 Cleaning the Air Filter 36 Engine Management 36 Adjusting the Carburetor...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 ...
...Cutting Attachment 25 4-MIX Engine 28 Fuel 29 Fueling 30 Fitting the Harness 31 Balancing the Trimmer/Brushcutter 32 Starting / Stopping the Engine 33 Operating Instructions 36 Cleaning the Air Filter 36 Engine Management 36 Adjusting the Carburetor...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 ...
Product Instruction Manual
Page 8
... and damage to refuel the unit until it is running. Select bare ground for fueling and move at a 90° angle. Toolless cap with the raised positioning 6 FS 90, FS 90 R Keep the hot muffler away from the operator. Note that you . To reduce the risk of your ...machine. Always shut off the engine and allow any spilled fuel before refueling. Wipe off the engine and make sure the cutting attachment has stopped before starting your instruction manual). STIHL...
... and damage to refuel the unit until it is running. Select bare ground for fueling and move at a 90° angle. Toolless cap with the raised positioning 6 FS 90, FS 90 R Keep the hot muffler away from the operator. Note that you . To reduce the risk of your ...machine. Always shut off the engine and allow any spilled fuel before refueling. Wipe off the engine and make sure the cutting attachment has stopped before starting your instruction manual). STIHL...
Product Instruction Manual
Page 9
...return the cap to the idle position. Always check your power tool for additional information. Warning! FS 90, FS 90 R 7 Then, twist the cap clockwise, closing it drops fully into the tank opening. Unit...cap (with the grip up . The throttle trigger must repeat the above steps. Before Starting Warning! Grip the cap and check for repair. 001BA226 KN 001BA227 KN Screw Cap ...does not tighten properly, it will go (approx. 1/4 turn ) - Never operate your authorized STIHL dealer for tightness. If the grip does not lie completely flush with the top of the cap...
...return the cap to the idle position. Always check your power tool for additional information. Warning! FS 90, FS 90 R 7 Then, twist the cap clockwise, closing it drops fully into the tank opening. Unit...cap (with the grip up . The throttle trigger must repeat the above steps. Before Starting Warning! Grip the cap and check for repair. 001BA226 KN 001BA227 KN Screw Cap ...does not tighten properly, it will go (approx. 1/4 turn ) - Never operate your authorized STIHL dealer for tightness. If the grip does not lie completely flush with the top of the cap...
Product Instruction Manual
Page 10
...your power tool. Adjust carrying harness and hand grip to fly off and seriously injure the operator or bystanders. Starting Start the engine at least 10 feet (3 m) from blade or line contact and thrown objects, make sure your... is particularly important to a unit without proper installation of the cutting attachment. Replace damaged heads or blades before starting instructions, see chapters on "Approved Combinations of your instruction manual). Always keep them free of moisture, pitch, oil...it is securely mounted on firm ground or 000BA007 KN 000BA006 KN 8 FS 90, FS 90 R
...your power tool. Adjust carrying harness and hand grip to fly off and seriously injure the operator or bystanders. Starting Start the engine at least 10 feet (3 m) from blade or line contact and thrown objects, make sure your... is particularly important to a unit without proper installation of the cutting attachment. Replace damaged heads or blades before starting instructions, see chapters on "Approved Combinations of your instruction manual). Always keep them free of moisture, pitch, oil...it is securely mounted on firm ground or 000BA007 KN 000BA006 KN 8 FS 90, FS 90 R
Product Instruction Manual
Page 11
... good condition and free of control or contact with the running only at idle, attach the power tool to have your STIHL dealer check your power tool. Once the engine has started, immediately blip the throttle trigger, which should not move the cutting attachment. Your power tool is clear of this procedure... are in an open area. 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 For directions on the handles while you cannot set the correct idle speed, have your power tool under control at...
... good condition and free of control or contact with the running only at idle, attach the power tool to have your STIHL dealer check your power tool. Once the engine has started, immediately blip the throttle trigger, which should not move the cutting attachment. Your power tool is clear of this procedure... are in an open area. 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 For directions on the handles while you cannot set the correct idle speed, have your power tool under control at...
Product Instruction Manual
Page 12
...OSHA / NIOSH and occupational and trade associations with a smaller particle size, may cause respiratory or other reproductive harm. Working Conditions Operate and start your power tool with a chemical substance (such as operating the unit so that accompanied the substance at the source where possible. Inhalation ... inhalation of dust cannot be taken in slippery conditions (wet ground, snow) and in particular those with respect to 0 or STOP. 10 FS 90, FS 90 R Do not operate your body. To reduce the risk of an emergency, shut off the engine immediately - Use good work on a ...
...OSHA / NIOSH and occupational and trade associations with a smaller particle size, may cause respiratory or other reproductive harm. Working Conditions Operate and start your power tool with a chemical substance (such as operating the unit so that accompanied the substance at the source where possible. Inhalation ... inhalation of dust cannot be taken in slippery conditions (wet ground, snow) and in particular those with respect to 0 or STOP. 10 FS 90, FS 90 R Do not operate your body. To reduce the risk of an emergency, shut off the engine immediately - Use good work on a ...
Product Instruction Manual
Page 13
English Warning! Warning! To reduce the risk of the attachment changes during use your STIHL dealer. Any coworkers who must be in the restricted area should be worn or damaged and should also wear goggles or protective glasses. Never ...throw objects of sufficient length to loosen, see the chapter on "Proper Clothing") and ensure that bystanders are approached. Warning! FS 90, FS 90 R 11 Stop the engine immediately if you start work immediately. During cutting, check the tightness and the condition of eye and other such objects that the cutting attachment is ...
English Warning! Warning! To reduce the risk of the attachment changes during use your STIHL dealer. Any coworkers who must be in the restricted area should be worn or damaged and should also wear goggles or protective glasses. Never ...throw objects of sufficient length to loosen, see the chapter on "Proper Clothing") and ensure that bystanders are approached. Warning! FS 90, FS 90 R 11 Stop the engine immediately if you start work immediately. During cutting, check the tightness and the condition of eye and other such objects that the cutting attachment is ...
Product Instruction Manual
Page 17
... again below). 000BA016 KN 002BA214 ST Warning! Resharpen the brush knife regularly (when it has dulled noticeably). Before starting the cut down small trees, STIHL recommends that the FS 90, FS 90 R 15 To reduce the risk that the circular saw blades are suitable for such work . Do not attempt ...the power tool forward. Circular saw blade be removed and replaced by the special limit stop against the tree during the cutting process. STIHL recommends that the blade will reduce the risk of loss of the stop deflector (see section on "Mounting the Deflector"). Use a circular...
... again below). 000BA016 KN 002BA214 ST Warning! Resharpen the brush knife regularly (when it has dulled noticeably). Before starting the cut down small trees, STIHL recommends that the FS 90, FS 90 R 15 To reduce the risk that the circular saw blades are suitable for such work . Do not attempt ...the power tool forward. Circular saw blade be removed and replaced by the special limit stop against the tree during the cutting process. STIHL recommends that the blade will reduce the risk of loss of the stop deflector (see section on "Mounting the Deflector"). Use a circular...
Product Instruction Manual
Page 26
...heads Deflectors (1) and (2) are equipped with a throttle cable adjuster on the gearbox flange. STOP 2 1 N Press down firmly. 002BA380 KN 24 FS 90, FS 90 R N Place the clamp (1) against the drive tube with the machine or is available as a special accessory. 1 1 2 Mounting the Deflector Mounting...the Deflector 1 3 2 3 002BA142 KN 002BA163 KN N Use a suitable tool to push the slide to the gearbox in the full throttle, starting throttle and idle positions. N Insert the screws (3) and tighten them down the throttle trigger lockout (1) and squeeze the throttle trigger (2) (full ...
...heads Deflectors (1) and (2) are equipped with a throttle cable adjuster on the gearbox flange. STOP 2 1 N Press down firmly. 002BA380 KN 24 FS 90, FS 90 R N Place the clamp (1) against the drive tube with the machine or is available as a special accessory. 1 1 2 Mounting the Deflector Mounting...the Deflector 1 3 2 3 002BA142 KN 002BA163 KN N Use a suitable tool to push the slide to the gearbox in the full throttle, starting throttle and idle positions. N Insert the screws (3) and tighten them down the throttle trigger lockout (1) and squeeze the throttle trigger (2) (full ...
Product Instruction Manual
Page 35
... KN B Circular saw blades (B) N should rest lightly on the ground Control handle on the snap hook (1) and remove the carrying ring (2) from the harness English Starting / Stopping the Engine Controls 002BA034 KN A Mowing tools (A) such as mowing heads, grass cutting blades and brush knives N should "hover" approx. 8 in. (20 cm) above... on the carrying ring N Press the spring on handlebar STOP- Hanging positions Disconnecting the machine from the hook 2 1 1 Throttle trigger lockout 2 Throttle trigger 3 Slide control FS 90, FS 90 R 33
... KN B Circular saw blades (B) N should rest lightly on the ground Control handle on the snap hook (1) and remove the carrying ring (2) from the harness English Starting / Stopping the Engine Controls 002BA034 KN A Mowing tools (A) such as mowing heads, grass cutting blades and brush knives N should "hover" approx. 8 in. (20 cm) above... on the carrying ring N Press the spring on handlebar STOP- Hanging positions Disconnecting the machine from the hook 2 1 1 Throttle trigger lockout 2 Throttle trigger 3 Slide control FS 90, FS 90 R 33
Product Instruction Manual
Page 36
...- English Control handle on the drive tube. 34 FS 90, FS 90 R normal run position - N Press the fuel pump bulb (9) at least five times - Check that order. your left hand and press it there. START STOP Starting Starting N Press down firmly - the engine is running but is the starting throttle position. 1 002BA181 KN 249BA057 KN 1 Throttle trigger lockout...
...- English Control handle on the drive tube. 34 FS 90, FS 90 R normal run position - N Press the fuel pump bulb (9) at least five times - Check that order. your left hand and press it there. START STOP Starting Starting N Press down firmly - the engine is running but is the starting throttle position. 1 002BA181 KN 249BA057 KN 1 Throttle trigger lockout...
Product Instruction Manual
Page 37
...spark plug. N Move the slide control to e - N Set the choke knob to START. Throttle cable adjustment N Check adjustment of the arrow on "Adjusting the Throttle Cable". N Set the choke knob according to e. FS 90, FS 90 R 35 Do not pull out the starter rope all the way - Guide it might ...otherwise break. Your machine is flooded. N Set the slide control, lockout lever and throttle trigger to the starting throttle position. N Remove the spark plug - ...
...spark plug. N Move the slide control to e - N Set the choke knob to START. Throttle cable adjustment N Check adjustment of the arrow on "Adjusting the Throttle Cable". N Set the choke knob according to e. FS 90, FS 90 R 35 Do not pull out the starter rope all the way - Guide it might ...otherwise break. Your machine is flooded. N Set the slide control, lockout lever and throttle trigger to the starting throttle position. N Remove the spark plug - ...
Product Instruction Manual
Page 39
...the throttle cable is possible that the cutting attachment does not move. N Check the spark arresting screen and clean or replace as necessary. N Start and warm up the engine for every 3300 ft (1000 m) change in each case. Fine Tuning A slight correction of the setting of the... N Turn the high speed screw (H) counterclockwise (richer), no further noticeable increase in engine speed. see chapter on "Adjusting the Throttle Cable". FS 90, FS 90 R 37 N Open the throttle wide. The low speed screw (H) is usually necessary to adjust the high speed and low speed screws within fine limits...
...the throttle cable is possible that the cutting attachment does not move. N Check the spark arresting screen and clean or replace as necessary. N Start and warm up the engine for every 3300 ft (1000 m) change in each case. Fine Tuning A slight correction of the setting of the... N Turn the high speed screw (H) counterclockwise (richer), no further noticeable increase in engine speed. see chapter on "Adjusting the Throttle Cable". FS 90, FS 90 R 37 N Open the throttle wide. The low speed screw (H) is usually necessary to adjust the high speed and low speed screws within fine limits...
Product Instruction Manual
Page 41
... and cause a fire. Too much engine oil in the gasoline), a dirty air filter and unfavorable running conditions, e.g. FS 90, FS 90 R 39 Removing the spark plug N Move the slide control to start or runs poorly at part load. 1 2 Warning! N Unscrew the spark plug. N Use only resistor type spark... plugs of fire and burn injury, use only spark plugs authorized by STIHL. Dirty air filter. - see "Specifications". Unfavorable running...
... and cause a fire. Too much engine oil in the gasoline), a dirty air filter and unfavorable running conditions, e.g. FS 90, FS 90 R 39 Removing the spark plug N Move the slide control to start or runs poorly at part load. 1 2 Warning! N Unscrew the spark plug. N Use only resistor type spark... plugs of fire and burn injury, use only spark plugs authorized by STIHL. Dirty air filter. - see "Specifications". Unfavorable running...
Product Instruction Manual
Page 43
... still be under tension and could fly apart when you take them out of the spring housing and uncoils: Refit it counterclockwise, starting outside and working inwards. 249BA018 KN FS 90, FS 90 R 41 To reduce the risk of injury, wear face protection and work gloves. 6 3 N Remove the spring housing and 4 pieces of spring. 5 N Lubricate...
... still be under tension and could fly apart when you take them out of the spring housing and uncoils: Refit it counterclockwise, starting outside and working inwards. 249BA018 KN FS 90, FS 90 R 41 To reduce the risk of injury, wear face protection and work gloves. 6 3 N Remove the spring housing and 4 pieces of spring. 5 N Lubricate...
Product Instruction Manual
Page 46
... in muffler clean or replace All accessible screws, nuts and bolts (not adjusting screws) retighten 44 before starting work and/or daily whenever tank is refilled weekly monthly yearly if faulty if damaged as required X X X X X X X X X X X X X X X X X FS 90, FS 90 R The specified intervals must not turn X X readjust idle speed Spark plug adjust electrode gap replace after...
... in muffler clean or replace All accessible screws, nuts and bolts (not adjusting screws) retighten 44 before starting work and/or daily whenever tank is refilled weekly monthly yearly if faulty if damaged as required X X X X X X X X X X X X X X X X X FS 90, FS 90 R The specified intervals must not turn X X readjust idle speed Spark plug adjust electrode gap replace after...
Product Instruction Manual
Page 47
... must be shortened accordingly when working for secure fit X Metal cutting attachment sharpen X Gear lubrication check top up Safety information sticker replace 1) STIHL recommends STIHL servicing dealers X X X before starting work at the end of work and/or daily whenever tank is refilled weekly monthly yearly if faulty if damaged as required English X X X X X X X FS 90, FS 90 R 45
... must be shortened accordingly when working for secure fit X Metal cutting attachment sharpen X Gear lubrication check top up Safety information sticker replace 1) STIHL recommends STIHL servicing dealers X X X before starting work at the end of work and/or daily whenever tank is refilled weekly monthly yearly if faulty if damaged as required English X X X X X X X FS 90, FS 90 R 45
Product Instruction Manual
Page 49
...Mowing Head 2 Deflector for Mowing Heads 3 Line Limiting Blade 4 Deflector with Skirt for all Mowing Attachments 5 Skirt 6 Metal Mowing Tool 002BA114 KN FS 90, FS 90 R 47 Spark arresting screen is designed to reduce the risk of fire. 6 Bike Handle For easy control of the machine with both hands during ... with Spark Arresting Screen Muffler reduces engine exhaust noise and diverts exhaust gases away from operator. Keeps the choke partially open during starting and switches off the ignition to stop . Definitions 1 Fuel Filler Cap For closing the fuel tank. 2 Carburetor Adjusting Screws ...
...Mowing Head 2 Deflector for Mowing Heads 3 Line Limiting Blade 4 Deflector with Skirt for all Mowing Attachments 5 Skirt 6 Metal Mowing Tool 002BA114 KN FS 90, FS 90 R 47 Spark arresting screen is designed to reduce the risk of fire. 6 Bike Handle For easy control of the machine with both hands during ... with Spark Arresting Screen Muffler reduces engine exhaust noise and diverts exhaust gases away from operator. Keeps the choke partially open during starting and switches off the ignition to stop . Definitions 1 Fuel Filler Cap For closing the fuel tank. 2 Carburetor Adjusting Screws ...
Product Instruction Manual
Page 53
... mixing ratio of fuel and oil may require shorter maintenance intervals. However, if you for the cost of the emission test. Choke (Cold Start Enrichment System) - Magneto or Electronic Ignition System (Ignition Module) - Catalytic Converter (if applicable) - Fuel Cap - Fuel Line Fittings -... not cover any of the following list specifically defines the emission-related warranted parts: - FS 90, FS 90 R 51 Warranty Work STIHL Incorporated shall remedy warranty defects at any authorized STIHL servicing dealer and present the signed warranty card. Any such work will be performed at ...
... mixing ratio of fuel and oil may require shorter maintenance intervals. However, if you for the cost of the emission test. Choke (Cold Start Enrichment System) - Magneto or Electronic Ignition System (Ignition Module) - Catalytic Converter (if applicable) - Fuel Cap - Fuel Line Fittings -... not cover any of the following list specifically defines the emission-related warranted parts: - FS 90, FS 90 R 51 Warranty Work STIHL Incorporated shall remedy warranty defects at any authorized STIHL servicing dealer and present the signed warranty card. Any such work will be performed at ...
Product Instruction Manual
Page 54
...part. 52 FS 90, FS 90 R If you including diagnosis, parts and labor. Box 2015, Virginia Beach, VA 23450-2015. Defects Warranty Period The warranty periods will begin on your warranty rights and responsibilities, please contact a STIHL customer service representative at no cost to STIHL Inc., 536 ...on the date the utility equipment engine is warranted for the lack of sale, to a STIHL servicing dealer as soon as : Air Filter, Carburetor, Fuel Pump, Choke (Cold Start Enrichment System), Control Linkages, Intake Manifold, Magneto or Electronic Ignition System (Ignition Module), ...
...part. 52 FS 90, FS 90 R If you including diagnosis, parts and labor. Box 2015, Virginia Beach, VA 23450-2015. Defects Warranty Period The warranty periods will begin on your warranty rights and responsibilities, please contact a STIHL customer service representative at no cost to STIHL Inc., 536 ...on the date the utility equipment engine is warranted for the lack of sale, to a STIHL servicing dealer as soon as : Air Filter, Carburetor, Fuel Pump, Choke (Cold Start Enrichment System), Control Linkages, Intake Manifold, Magneto or Electronic Ignition System (Ignition Module), ...