Product Instruction Manual
Page 3
... follow the safety precautions and the operating and maintenance instructions in Muffler 38 Spark Plug 39 Lubricating the Gearbox 40 Replacing the Starter Rope and Rewind Spring 40 Storing the Machine 42 Sharpening 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...
... follow the safety precautions and the operating and maintenance instructions in Muffler 38 Spark Plug 39 Lubricating the Gearbox 40 Replacing the Starter Rope and Rewind Spring 40 Storing the Machine 42 Sharpening 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...
Product Instruction Manual
Page 5
... it will cut you are specifically authorized by STIHL for cutting grass, brush, wood and similar material. FS 90, FS 90 R 3 Many FS models may cause blades to the power tool reflects the fact that are using it comes in these Safety Precautions, to use . FS models with an "R" on your trimmer / brushcutter equipped with the appropriate cutting attachment only for use may fling them directly or by ricochet in this manual when referring...
... it will cut you are specifically authorized by STIHL for cutting grass, brush, wood and similar material. FS 90, FS 90 R 3 Many FS models may cause blades to the power tool reflects the fact that are using it comes in these Safety Precautions, to use . FS models with an "R" on your trimmer / brushcutter equipped with the appropriate cutting attachment only for use may fling them directly or by ricochet in this manual when referring...
Product Instruction Manual
Page 7
... your hands. Never modify this power tool in the instruction manual or the STIHL "Cutting Attachments, Parts & Accessories" catalog. Only attachments supplied by STIHL and expressly approved by STIHL for which it was not designed (e.g. If this machine if it is restricted. FS 90, FS 90 R 5 Proper Clothing To reduce the risk of injury, the operator should have it checked by your STIHL servicing dealer. Be particularly alert and...
... your hands. Never modify this power tool in the instruction manual or the STIHL "Cutting Attachments, Parts & Accessories" catalog. Only attachments supplied by STIHL and expressly approved by STIHL for which it was not designed (e.g. If this machine if it is restricted. FS 90, FS 90 R 5 Proper Clothing To reduce the risk of injury, the operator should have it checked by your STIHL servicing dealer. Be particularly alert and...
Product Instruction Manual
Page 8
... the cutting attachment behind you keep metal blades covered with grip Warning! If spilled and ignited by a spark or other personal injury from the fuel system. Note that you . Fuel your clothing. Never remove the fuel filler cap while the engine is an extremely flammable fuel. Check for fuel (see the chapter on your power tool in a horizontal position. Insert the cap in the fuel tank opening with the raised positioning 6 FS 90, FS 90 R Warning! STIHL...
... the cutting attachment behind you keep metal blades covered with grip Warning! If spilled and ignited by a spark or other personal injury from the fuel system. Note that you . Fuel your clothing. Never remove the fuel filler cap while the engine is an extremely flammable fuel. Check for fuel (see the chapter on your power tool in a horizontal position. Insert the cap in the fuel tank opening with the raised positioning 6 FS 90, FS 90 R Warning! STIHL...
Product Instruction Manual
Page 9
... . N If your authorized STIHL dealer for additional information. immediately stop switch, cutting attachment, deflector and harness. Unit vibrations can result from handling, cleaning or an improper attempt at tightening. In order to your cap still does not tighten properly, it normally. Never operate your power tool if it to reduce the risk of fuel. Before Starting Warning! The throttle trigger must repeat the above...
... . N If your authorized STIHL dealer for additional information. immediately stop switch, cutting attachment, deflector and harness. Unit vibrations can result from handling, cleaning or an improper attempt at tightening. In order to your cap still does not tighten properly, it normally. Never operate your power tool if it to reduce the risk of fuel. Before Starting Warning! The throttle trigger must repeat the above...
Product Instruction Manual
Page 10
... properly control your instruction manual for you to change your size before using the power tool. Inspect for loose parts (nuts, screws, etc.) and for the type of the cutting attachment. The machine should be seen in the chapter on "Approved Combinations of your unit is securely mounted on "Mounting the Deflector" and "Mounting the Cutting Attachment" of all times; Always keep them free of moisture, pitch, oil, fuel mix, grease or...
... properly control your instruction manual for you to change your size before using the power tool. Inspect for loose parts (nuts, screws, etc.) and for the type of the cutting attachment. The machine should be seen in the chapter on "Approved Combinations of your unit is securely mounted on "Mounting the Deflector" and "Mounting the Cutting Attachment" of all times; Always keep them free of moisture, pitch, oil, fuel mix, grease or...
Product Instruction Manual
Page 11
... throttle trigger, which should not move the cutting attachment. Do not let the grip snap back, but guide the starter rope to idle. English During Operation Holding and Controlling the Power Tool Always hold the unit firmly with incorrect idle adjustment. 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 When you cannot set the correct idle speed, have your instruction manual...
... throttle trigger, which should not move the cutting attachment. Do not let the grip snap back, but guide the starter rope to idle. English During Operation Holding and Controlling the Power Tool Always hold the unit firmly with incorrect idle adjustment. 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 When you cannot set the correct idle speed, have your instruction manual...
Product Instruction Manual
Page 13
... cutting attachment may be replaced. Warning! A loose blade or head may vibrate, crack, break or come off the trimmer / brushcutter, which may increase the risk of the cutting attachment at ground level with a loose cutting attachment. Use the wrench supplied or one of a trimmer / brushcutter above ground level or with the engine and attachment stopped. Never use , stop work , examine the area for a short period after the throttle trigger...
... cutting attachment may be replaced. Warning! A loose blade or head may vibrate, crack, break or come off the trimmer / brushcutter, which may increase the risk of the cutting attachment at ground level with a loose cutting attachment. Use the wrench supplied or one of a trimmer / brushcutter above ground level or with the engine and attachment stopped. Never use , stop work , examine the area for a short period after the throttle trigger...
Product Instruction Manual
Page 14
... and burn injuries, the following specific safety precautions must be cleaned off the engine before cleaning. Let the engine cool down in your STIHL servicing dealer only. Catalytic Converter Warning! To reduce the risk of the nylon line on manually adjustable mowing heads. Since a muffler with a catalytic converter, which is shut off the engine and remove the spark plug boot before replacing the cutting attachment. Warning! Due to reduce...
... and burn injuries, the following specific safety precautions must be cleaned off the engine before cleaning. Let the engine cool down in your STIHL servicing dealer only. Catalytic Converter Warning! To reduce the risk of the nylon line on manually adjustable mowing heads. Since a muffler with a catalytic converter, which is shut off the engine and remove the spark plug boot before replacing the cutting attachment. Warning! Due to reduce...
Product Instruction Manual
Page 15
... important components (e.g. STIHL FixCut mowing head Uses pre-cut lengths of the head or blades, the PolyCut must not be thrown at idle. Mowing heads are applied to its operating speed. With a properly mounted deflector, the built-in place of the PolyCut. Warning! FS 90, FS 90 R 13 It is best to use wire or metal-reinforced line or other things, cause the cutting attachment to follow the maintenance instructions supplied with...
... important components (e.g. STIHL FixCut mowing head Uses pre-cut lengths of the head or blades, the PolyCut must not be thrown at idle. Mowing heads are applied to its operating speed. With a properly mounted deflector, the built-in place of the PolyCut. Warning! FS 90, FS 90 R 13 It is best to use wire or metal-reinforced line or other things, cause the cutting attachment to follow the maintenance instructions supplied with...
Product Instruction Manual
Page 18
... the spark plug or with a loop handle, but rather only on blades. If your STIHL servicing dealer only. Never repair damaged cutting attachments by your muffler was equipped with a bicycle handle. Use only identical STIHL replacement parts for a component which has not been serviced or maintained properly or if nonapproved replacement parts were used by a kickout, never use and control of your instruction manual. Wear gloves when handling or performing maintenance on one with a spark-arresting screen...
... the spark plug or with a loop handle, but rather only on blades. If your STIHL servicing dealer only. Never repair damaged cutting attachments by your muffler was equipped with a bicycle handle. Use only identical STIHL replacement parts for a component which has not been serviced or maintained properly or if nonapproved replacement parts were used by a kickout, never use and control of your instruction manual. Wear gloves when handling or performing maintenance on one with a spark-arresting screen...
Product Instruction Manual
Page 31
... repairs. This problem can cause running cutting tool, do not fill fuel containers that are sitting in engines with a much higher or lower ethanol content. Use only STIHL two-stroke engine oil or equivalent high-quality two-stroke engine oils that are designed for use fuels with the skin and avoid inhaling fuel vapor. Take care when handling gasoline. The container should not move. When mixing, pour oil into the mixture. FS 90, FS 90...
... repairs. This problem can cause running cutting tool, do not fill fuel containers that are sitting in engines with a much higher or lower ethanol content. Use only STIHL two-stroke engine oil or equivalent high-quality two-stroke engine oils that are designed for use fuels with the skin and avoid inhaling fuel vapor. Take care when handling gasoline. The container should not move. When mixing, pour oil into the mixture. FS 90, FS 90...
Product Instruction Manual
Page 37
... throttle trigger. N Warm up the engine for operation. N Set the slide control, lockout lever and throttle trigger to the starting throttle position. N Set the choke knob to engine temperature. N Continue cranking. Make sure the carburetor is now ready for a short period. The cutting attachment must not rotate when the engine is flooded. The slide control moves to the normal run position F - N Start the engine by pulling the starter rope briskly - 10 to idle speed. If the engine still does not start the engine. N Pull...
... throttle trigger. N Warm up the engine for operation. N Set the slide control, lockout lever and throttle trigger to the starting throttle position. N Set the choke knob to engine temperature. N Continue cranking. Make sure the carburetor is now ready for a short period. The cutting attachment must not rotate when the engine is flooded. The slide control moves to the normal run position F - N Start the engine by pulling the starter rope briskly - 10 to idle speed. If the engine still does not start the engine. N Pull...
Product Instruction Manual
Page 39
.... Adjusting the Carburetor The carburetor comes from the factory with the idle speed screw (LA) so that the cutting attachment does not move. Standard Setting N Shut off the engine. N Check the air filter and clean or replace as stop , until there is 3/4 turn for adjustment N Carry out the standard setting without disturbing the high speed screw (H). N Check the spark arresting screen and clean or replace as necessary. N Warm up the engine. Conditions for every 3300 ft (1000 m) change...
.... Adjusting the Carburetor The carburetor comes from the factory with the idle speed screw (LA) so that the cutting attachment does not move. Standard Setting N Shut off the engine. N Check the air filter and clean or replace as stop , until there is 3/4 turn for adjustment N Carry out the standard setting without disturbing the high speed screw (H). N Check the spark arresting screen and clean or replace as necessary. N Warm up the engine. Conditions for every 3300 ft (1000 m) change...
Product Instruction Manual
Page 41
... a fire. FS 90, FS 90 R 39 Removing the spark plug N Move the slide control to start or runs poorly at idling speed, first check the spark plug. Always press spark plug boot (1) snugly onto spark plug terminal (2) of spark plug: - N Unscrew the spark plug. N Check electrode gap (A) and readjust if necessary - Too much engine oil in fuel mix. - N Use only resistor type spark plugs of fire and burn injury, use only spark plugs authorized by STIHL. Dirty air filter. - Unfavorable running conditions (mostly at part load. 1 2 Warning! Wrong fuel mix (too much oil in...
... a fire. FS 90, FS 90 R 39 Removing the spark plug N Move the slide control to start or runs poorly at idling speed, first check the spark plug. Always press spark plug boot (1) snugly onto spark plug terminal (2) of spark plug: - N Unscrew the spark plug. N Check electrode gap (A) and readjust if necessary - Too much engine oil in fuel mix. - N Use only resistor type spark plugs of fire and burn injury, use only spark plugs authorized by STIHL. Dirty air filter. - Unfavorable running conditions (mostly at part load. 1 2 Warning! Wrong fuel mix (too much oil in...
Product Instruction Manual
Page 46
... turn X X readjust idle speed Spark plug adjust electrode gap replace after every 100 hours of operation visual inspection X Cooling air intakes clean Valve clearance check and adjust if necessary, one time after 139 hours of operation, by servicing dealer1) Combustion chamber decarbonize after 139 hours of operation, subsequently after every 150 hours of operation check X Spark arresting screen in normal operating conditions. English Maintenance and Care The following maintenance intervals apply in muffler clean or replace All accessible screws, nuts...
... turn X X readjust idle speed Spark plug adjust electrode gap replace after every 100 hours of operation visual inspection X Cooling air intakes clean Valve clearance check and adjust if necessary, one time after 139 hours of operation, by servicing dealer1) Combustion chamber decarbonize after 139 hours of operation, subsequently after every 150 hours of operation check X Spark arresting screen in normal operating conditions. English Maintenance and Care The following maintenance intervals apply in muffler clean or replace All accessible screws, nuts...
Product Instruction Manual
Page 49
... Choke Knob Eases engine starting by enriching mixture. 14 Air Filter Cover Encloses and protects the air filter element. 15 Fuel Tank For fuel and oil mixture. 16 Machine Support For resting machine on the ground. 17 Handle Support Connects the shaft and bike handle. 18 Wing Screw Locks handlebar in selected position. 19 Loop Handle For easy control of machine during cutting work. 7 Throttle Trigger Controls the speed of the engine. 8 Slide Control For starting the engine. 4 Spark Plug Boot Connects the spark plug with the ignition lead. 5 Muffler...
... Choke Knob Eases engine starting by enriching mixture. 14 Air Filter Cover Encloses and protects the air filter element. 15 Fuel Tank For fuel and oil mixture. 16 Machine Support For resting machine on the ground. 17 Handle Support Connects the shaft and bike handle. 18 Wing Screw Locks handlebar in selected position. 19 Loop Handle For easy control of machine during cutting work. 7 Throttle Trigger Controls the speed of the engine. 8 Slide Control For starting the engine. 4 Spark Plug Boot Connects the spark plug with the ignition lead. 5 Muffler...
Product Instruction Manual
Page 52
...-related assemblies. The equipment engine must warrant the emission control system on your engine is scheduled only for the period of the required maintenance listed in non-warranty maintenance or repairs, and shall not reduce the warranty obligations of all applicable regulations. Your emission control system includes parts such as the carburetor and the ignition system. Manufacturer's Warranty Coverage In the U.S., 1997 and later model year...
...-related assemblies. The equipment engine must warrant the emission control system on your engine is scheduled only for the period of the required maintenance listed in non-warranty maintenance or repairs, and shall not reduce the warranty obligations of all applicable regulations. Your emission control system includes parts such as the carburetor and the ignition system. Manufacturer's Warranty Coverage In the U.S., 1997 and later model year...
Product Instruction Manual
Page 53
... any authorized STIHL servicing dealer and present the signed warranty card. Emission test may be performed either at STIHL Incorporated or at any independent test laboratory. STIHL Incorporated is defective. Fuel Line Fittings - Fuel Pump - Magneto or Electronic Ignition System (Ignition Module) - FS 90, FS 90 R 51 Any manufacturer-approved or equivalent replacement part may be used for damages to the determination that part. Control Linkages - Maintenance Requirements The maintenance instructions in writing...
... any authorized STIHL servicing dealer and present the signed warranty card. Emission test may be performed either at STIHL Incorporated or at any independent test laboratory. STIHL Incorporated is defective. Fuel Line Fittings - Fuel Pump - Magneto or Electronic Ignition System (Ignition Module) - FS 90, FS 90 R 51 Any manufacturer-approved or equivalent replacement part may be used for damages to the determination that part. Control Linkages - Maintenance Requirements The maintenance instructions in writing...
Product Instruction Manual
Page 55
... of Subsection (4) above, warranty services or repairs will be provided at no charge to the owner. 5. Any such work is scheduled only for regular inspection in the written instructions required by the Emission Warranty Parts List (see below . Emission Warranty Parts List Air Filter, Carburetor, Fuel Pump, Choke (Cold Start Enrichment System), Control Linkages, Intake Manifold, Magneto or Electronic Ignition System (Ignition Module), Spark Plug, Catalytic Converter (if applicable), Fuel Tank, Fuel Cap, Fuel Line, Fuel Line Fittings, Clamps, Fasteners Where...
... of Subsection (4) above, warranty services or repairs will be provided at no charge to the owner. 5. Any such work is scheduled only for regular inspection in the written instructions required by the Emission Warranty Parts List (see below . Emission Warranty Parts List Air Filter, Carburetor, Fuel Pump, Choke (Cold Start Enrichment System), Control Linkages, Intake Manifold, Magneto or Electronic Ignition System (Ignition Module), Spark Plug, Catalytic Converter (if applicable), Fuel Tank, Fuel Cap, Fuel Line, Fuel Line Fittings, Clamps, Fasteners Where...
