Instruction Manual
Page 2
... 38 STIHL Incorporated Federal Emission Control Warranty Statement 39 Trademarks 41 STIHl SR 340, SR 420 English / USA Allow only persons who understand this Manual, please contact your STIHL dealer for your area if you read and understand the maintenance and safety precautions, starting on ... 14 Harness 16 Fuel 17 Fueling 18 Information Before You Start .......... 18 Starting / Stopping the Engine ........ 19 Calculating Required Quantity of personal injury. Contact your STIHL mistblower, it is to -time. STIHL's philosophy is important that you do not understand any other...
... 38 STIHL Incorporated Federal Emission Control Warranty Statement 39 Trademarks 41 STIHl SR 340, SR 420 English / USA Allow only persons who understand this Manual, please contact your STIHL dealer for your area if you read and understand the maintenance and safety precautions, starting on ... 14 Harness 16 Fuel 17 Fueling 18 Information Before You Start .......... 18 Starting / Stopping the Engine ........ 19 Calculating Required Quantity of personal injury. Contact your STIHL mistblower, it is to -time. STIHL's philosophy is important that you do not understand any other...
Instruction Manual
Page 9
... 10 feet (3 m) from escaping gas vapor and fumes, remove the fuel filler cap on the fuel tank opening with different fuel caps. If this STIHL cap, raise the grip on the grip does not fit in the corresponding recess in the fuel tank opening , the cap is found, do this... for fuel leakage while refueling and during operation. Take care not to release slowly. a quarter turn the cap firmly clockwise as far as possible. 8 SR 340, SR 420 English / USA Fueling Instructions !Warning! Always shut off any spilled fuel before starting your power tool in well-ventilated areas, outdoors.
... 10 feet (3 m) from escaping gas vapor and fumes, remove the fuel filler cap on the fuel tank opening with different fuel caps. If this STIHL cap, raise the grip on the grip does not fit in the corresponding recess in the fuel tank opening , the cap is found, do this... for fuel leakage while refueling and during operation. Take care not to release slowly. a quarter turn the cap firmly clockwise as far as possible. 8 SR 340, SR 420 English / USA Fueling Instructions !Warning! Always shut off any spilled fuel before starting your power tool in well-ventilated areas, outdoors.
Instruction Manual
Page 10
... Keep the stop cock closed . !Warning! Keep the handles clean and dry at this time. Also, check for proper condition and operation before starting, particularly the throttle trigger, setting lever and stop switch. the chemicals being sucked into contact with a temperature above 120° F (50°... cap and all connections and check to the unit; - When thoroughly familiar with chemicals, check that could result in good condition. SR 340, SR 420 9 liquids with your power tool. Check that is securely attached and in damage to be sure the hose is damaged or not...
... Keep the stop cock closed . !Warning! Keep the handles clean and dry at this time. Also, check for proper condition and operation before starting, particularly the throttle trigger, setting lever and stop switch. the chemicals being sucked into contact with a temperature above 120° F (50°... cap and all connections and check to the unit; - When thoroughly familiar with chemicals, check that could result in good condition. SR 340, SR 420 9 liquids with your power tool. Check that is securely attached and in damage to be sure the hose is damaged or not...
Instruction Manual
Page 11
...reduce the risk of your STIHL dealer for repair. English / USA 372BA019 KN !Warning! Maintain good balance and secure footing. !Warning! It should be carried as a backpack with hot exhaust fumes, the engine should be kept at all times. 10 SR 340, SR 420 Stop operation immediately if you... pull the starter grip, do not wrap the starter rope around the handle, keeping the control handle cradled between your hand or fingers and may be started and operated without assistance. When you are...
...reduce the risk of your STIHL dealer for repair. English / USA 372BA019 KN !Warning! Maintain good balance and secure footing. !Warning! It should be carried as a backpack with hot exhaust fumes, the engine should be kept at all times. 10 SR 340, SR 420 Stop operation immediately if you... pull the starter grip, do not wrap the starter rope around the handle, keeping the control handle cradled between your hand or fingers and may be started and operated without assistance. When you are...
Instruction Manual
Page 12
...throw off the machine quickly. Use caution when bending, leaning or walking. !Warning! Watch for the type of times before starting work. Inhalation of the gases (e.g. Substantial or repeated inhalation of certain chemicals may slip out of the harness and throw ..., clear away fallen branches, scrub and cuttings. Working conditions Operate and start your size before using the machine in poorly ventilated locations. !Warning! Control the chemical spray/dust at all times. SR 340, SR 420 11 Follow the recommendations of EPA/OSHA/ NIOSH and occupational and trade ...
...throw off the machine quickly. Use caution when bending, leaning or walking. !Warning! Watch for the type of times before starting work. Inhalation of the gases (e.g. Substantial or repeated inhalation of certain chemicals may slip out of the harness and throw ..., clear away fallen branches, scrub and cuttings. Working conditions Operate and start your size before using the machine in poorly ventilated locations. !Warning! Control the chemical spray/dust at all times. SR 340, SR 420 11 Follow the recommendations of EPA/OSHA/ NIOSH and occupational and trade ...
Instruction Manual
Page 19
Always thoroughly shake the mixture in the tank to the idle position. 18 SR 340, SR 420 Before fueling, clean the filler cap and the area around it to keep the air intakes clear. The throttle cable reconnects itself from escaping gas ... tank. Before storing your machine. In order to allow any pressure build-up body every year. Change the fuel pick up in the canister before starting, check the air intakes between the backplate and powerhead for a long period, drain and clean the fuel tank and run engine until carburetor is moved...
Always thoroughly shake the mixture in the tank to the idle position. 18 SR 340, SR 420 Before fueling, clean the filler cap and the area around it to keep the air intakes clear. The throttle cable reconnects itself from escaping gas ... tank. Before storing your machine. In order to allow any pressure build-up body every year. Change the fuel pick up in the canister before starting, check the air intakes between the backplate and powerhead for a long period, drain and clean the fuel tank and run engine until carburetor is moved...
Instruction Manual
Page 20
this position if the engine has been running but is the starting throttle position Before starting : Move stop ). The setting lever can be used to select any throttle opening between idle speed (lower stop) and full throttle (upper stop cock lever (3) ... engine is cold, turn the choke knob to g : If the engine is warm, turn the choke lever to e Also use this is still cold. SR 340, SR 420 19 Starting / Stopping the Engine 1 English / USA 373BA010 KN 373BA008 KN 373BA011 KN 2 373BA009 KN : Observe safety precautions - see chapter on "Safety Precautions and Working Techniques...
this position if the engine has been running but is the starting throttle position Before starting : Move stop ). The setting lever can be used to select any throttle opening between idle speed (lower stop) and full throttle (upper stop cock lever (3) ... engine is cold, turn the choke knob to g : If the engine is warm, turn the choke lever to e Also use this is still cold. SR 340, SR 420 19 Starting / Stopping the Engine 1 English / USA 373BA010 KN 373BA008 KN 373BA011 KN 2 373BA009 KN : Observe safety precautions - see chapter on "Safety Precautions and Working Techniques...
Instruction Manual
Page 22
... engine began to fire, the combustion chamber is cold. : Now start the engine. At very low outside temperatures: Allow engine to warm up engine for a short period. the engine settles down the engine: : Move the stop switch (1) to 0 or STOP. SR 340, SR 420 21 Fuel tank run until dry and then refueled : Pull...
... engine began to fire, the combustion chamber is cold. : Now start the engine. At very low outside temperatures: Allow engine to warm up engine for a short period. the engine settles down the engine: : Move the stop switch (1) to 0 or STOP. SR 340, SR 420 21 Fuel tank run until dry and then refueled : Pull...
Instruction Manual
Page 26
...mistbllowing - do not vary the flow rate via the stop cock. : Fill up to 10 liter mark. : Set the metering knob to "6" : Start the machine. : Hold the spray tube horizontally, run the engine at an angle - If no improvement, contact your dealer for underleaf treatment of 13 ... : Fill the container with water up with grease. : Fit the cap and screw it if necessary. : Check engine setting and correct if necessary. SR 340, SR 420 25 short, broad and dense spray pattern. 1 Deflector baffle screen 372BA021 KN : The gasket (1) in the cap must be varied. for assistance. do...
...mistbllowing - do not vary the flow rate via the stop cock. : Fill up to 10 liter mark. : Set the metering knob to "6" : Start the machine. : Hold the spray tube horizontally, run the engine at an angle - If no improvement, contact your dealer for underleaf treatment of 13 ... : Fill the container with water up with grease. : Fit the cap and screw it if necessary. : Check engine setting and correct if necessary. SR 340, SR 420 25 short, broad and dense spray pattern. 1 Deflector baffle screen 372BA021 KN : The gasket (1) in the cap must be varied. for assistance. do...
Instruction Manual
Page 27
... be treated simultaneously. 1 2 1 43 5 372BA008 KN 373BA017 KN 373BA018 KN Dirty air filters reduce engine power increase fuel consumption and make starting more difficult. then knock it - English / USA Cleaning the Air Filter Dual deflector baffle screen Splits the spray jet in two - if ...filter cover. : If the prefilter is a noticeable loss of your hand or blow out with compressed air. : Always replace a damaged prefilter. 26 SR 340, SR 420 allows two closely planted rows to g : Release the screws (1) and pull off the filter cover (2). : Remove the main filter (3) from the ...
... be treated simultaneously. 1 2 1 43 5 372BA008 KN 373BA017 KN 373BA018 KN Dirty air filters reduce engine power increase fuel consumption and make starting more difficult. then knock it - English / USA Cleaning the Air Filter Dual deflector baffle screen Splits the spray jet in two - if ...filter cover. : If the prefilter is a noticeable loss of your hand or blow out with compressed air. : Always replace a damaged prefilter. 26 SR 340, SR 420 allows two closely planted rows to g : Release the screws (1) and pull off the filter cover (2). : Remove the main filter (3) from the ...
Instruction Manual
Page 29
... setting is too lean: : Turn low speed screw (L) counterclockwise - no further than stop : High speed screw (H) is now open 1/4 turn : Start and warm up the engine. : Turn the high speed screw (H) clockwise (leaner) - If the setting is too lean, there is a risk of... both adjusting screws counterclockwise as far as stop - Erratic idling behavior, engine stalls even after every correction to insufficient lubrication and overheating. 28 SR 340, SR 420 no further than stop - no further than stop . Erratic idling behavior Idle setting is now open 1/4 turn Low speed screw (L) is...
... setting is too lean: : Turn low speed screw (L) counterclockwise - no further than stop : High speed screw (H) is now open 1/4 turn : Start and warm up the engine. : Turn the high speed screw (H) clockwise (leaner) - If the setting is too lean, there is a risk of... both adjusting screws counterclockwise as far as stop - Erratic idling behavior, engine stalls even after every correction to insufficient lubrication and overheating. 28 SR 340, SR 420 no further than stop - no further than stop . Erratic idling behavior Idle setting is now open 1/4 turn Low speed screw (L) is...
Instruction Manual
Page 30
... of the approved range. operating at idling speed, first check the spark plug. : Remove spark plug - SR 340, SR 420 29 If engine is down on power, difficult to start or runs poorly at part load. These factors cause deposits to squeeze ends of clip (1) together and then ...fuel mix. : Dirty air filter. : Unfavorable running conditions (mostly at maximum RPM, check the spark arresting screen (if fitted) in the muffler. see "Starting / Stopping the Engine". : Clean dirty spark plug. : Check electrode gap (A) and readjust if necessary - Fit a new spark plug after approx. 100 operating...
... of the approved range. operating at idling speed, first check the spark plug. : Remove spark plug - SR 340, SR 420 29 If engine is down on power, difficult to start or runs poorly at part load. These factors cause deposits to squeeze ends of clip (1) together and then ...fuel mix. : Dirty air filter. : Unfavorable running conditions (mostly at maximum RPM, check the spark arresting screen (if fitted) in the muffler. see "Starting / Stopping the Engine". : Clean dirty spark plug. : Check electrode gap (A) and readjust if necessary - Fit a new spark plug after approx. 100 operating...
Instruction Manual
Page 33
...illustration). : Hold the rotor steady - Tensioning rewind spring : Make a loop in the unwound starter rope and use it to turn . 32 SR 340, SR 420 If the grip droops to "Tensioning rewind spring". If the spring pops out and uncoils during installation: Refit it winds onto the rotor. The ... one additional turn the rope rotor six full revolutions in the counterclockwise direction - Engage outer spring loop over the lug. : Refit the rope rotor. start outside and work inward. English / USA Replacing a broken rewind spring : Lubricate the new spring with a few drops of non-resinous oil. : ...
...illustration). : Hold the rotor steady - Tensioning rewind spring : Make a loop in the unwound starter rope and use it to turn . 32 SR 340, SR 420 If the grip droops to "Tensioning rewind spring". If the spring pops out and uncoils during installation: Refit it winds onto the rotor. The ... one additional turn the rope rotor six full revolutions in the counterclockwise direction - Engage outer spring loop over the lug. : Refit the rope rotor. start outside and work inward. English / USA Replacing a broken rewind spring : Lubricate the new spring with a few drops of non-resinous oil. : ...
Instruction Manual
Page 35
..., leaks) x Metering unit Check x x Anti-vibration elements Visual inspection x Have replaced by dealer 1) x x x Check x x Blower air intake screen Clean x Safety labels Replace x 1) STIHL recommends a STIHL servicing dealer 34 SR 340, SR 420 before starting work after finishing work area etc.), shorten the specified intervals accordingly. If your daily working time is longer than normal or operating...
..., leaks) x Metering unit Check x x Anti-vibration elements Visual inspection x Have replaced by dealer 1) x x x Check x x Blower air intake screen Clean x Safety labels Replace x 1) STIHL recommends a STIHL servicing dealer 34 SR 340, SR 420 before starting work after finishing work area etc.), shorten the specified intervals accordingly. If your daily working time is longer than normal or operating...
Instruction Manual
Page 37
... 13 Back padding. Accessory for lengthening the discharge tube. 5 Throttle trigger. For spraying, dusting or spreading in an emergency. 36 SR 340, SR 420 Helps protect the back of the spray. 2 Standard nozzle. Elements designed to reduce the transmission of vibrations created by enriching mixture. ... spray liquid hose. 10 Pleated hose. Increases carrying comfort. 14 Air filter housing. Contains the material to start the engine. 23 Fuel tank. Eases engine starting by the engine to the ignition wire. 19 Carburetor adjusting screws. For closing the container. 17 Container. The...
... 13 Back padding. Accessory for lengthening the discharge tube. 5 Throttle trigger. For spraying, dusting or spreading in an emergency. 36 SR 340, SR 420 Helps protect the back of the spray. 2 Standard nozzle. Elements designed to reduce the transmission of vibrations created by enriching mixture. ... spray liquid hose. 10 Pleated hose. Increases carrying comfort. 14 Air filter housing. Contains the material to start the engine. 23 Fuel tank. Eases engine starting by the engine to the ignition wire. 19 Carburetor adjusting screws. For closing the container. 17 Container. The...
Instruction Manual
Page 41
... and mixing ratio of fuel and oil may be performed either at STIHL Incorporated or at any of the following list specifically defines the emission-related warranted parts: Carburetor Choke (Cold start enrichment system) Intake manifold Air filter Spark plug Magneto or electronic ignition... for the cost of parts and other engine components caused by STIHL Incorporated at and after the first scheduled replacement point. 40 SR 340, SR 420 Mechanical diagnostic work shall be performed at any authorized STIHL servicing dealer or warranty station. Any such work will charge you...
... and mixing ratio of fuel and oil may be performed either at STIHL Incorporated or at any of the following list specifically defines the emission-related warranted parts: Carburetor Choke (Cold start enrichment system) Intake manifold Air filter Spark plug Magneto or electronic ignition... for the cost of parts and other engine components caused by STIHL Incorporated at and after the first scheduled replacement point. 40 SR 340, SR 420 Mechanical diagnostic work shall be performed at any authorized STIHL servicing dealer or warranty station. Any such work will charge you...