background image

► Carry out the following measures:

► Replace the air filter.

► Clean or replace the spark plug.

► Adjust saw for winter or summer operation.

► If the problem continues: Carry out the measured listed below.

Fault

Cause

Remedy

The engine does not

start.

There is not enough

fuel in the fuel tank.

► Prepare fuel mix and refuel the trimmer.

The carburetor is too

hot.

► Allow trimmer to cool down.

► Depress the manual fuel pump at least 10 times

before starting the engine.

The carburetor has

iced up.

► Allow trimmer to warm up to +10°C.

The engine idles

erratically.

The carburetor has

iced up.

► Allow trimmer to warm up to +10°C.

The engine stops

while idling.

The carburetor has

iced up.

► Allow trimmer to warm up to +10°C.

The engine does not

reach maximum

speed.

 

Trimmer is not cor‐

rectly tuned to ambi‐

ent conditions.

► Calibrate the brushcutter.

Throttle cable is not

correctly adjusted.

► Adjust the throttle cable.

The engine switches

off although there is

still fuel in the fuel

tank.

The pickup body is

not located in the

right place.

► Contact a STIHL servicing dealer.

18.2

Replacing air filter

The air filter cannot be cleaned. The air filter

must be replaced if it is damaged or there is a

loss of engine power.

► Shut off the engine.

► Move the choke lever to position  .

2

3

1

0000097407_001

► Take out the screws (1) and remove the filter

cover (2).

► Clean the area around the air filter (3) with a

damp cloth or a soft brush.

► Take out the air filter (3).

► Install the new air filter (3).

► Fit the filter cover (2).

► Insert screws (1) and tighten.

18.3

Cleaning the Spark Plug

► Shut off the engine.

► Allow trimmer to cool down.

2

1

4

3

0000097405_001

► Turn screw (1) counterclockwise.

► Lift the cover (2) and push it backwards.

► Pull off the spark plug boot (3).

► If the area around the spark plug (4) is soiled:

Clean the spark plug (4) with a cloth.

► Unscrew the spark plug (4).

► Clean the spark plug (4) with a cloth.

► If the spark plug (4) is corroded: Install a new

spark plug (4).

► Insert and tighten down the spark plug (4)

firmly.

► Press the spark plug boot (3) firmly home.

► Install cover (2) and tighten screw (1).

English

18 Troubleshooting

20

0458-844-0101-A

Summary of Contents for FS 491 C-M

Page 1: ...STIHL FS 491 C M Instruction Manual 2 23...

Page 2: ...themselves to a sus tainable and responsible handling of natural resources This user manual is intended to help you use your STIHL product safely and in an environmentally friendly manner over a long...

Page 3: ...er 14 Throttle trigger Controls the engine speed 15 Throttle trigger lockout Unlocks the throttle trigger 16 Stop switch Shuts off the engine 17 Wing screw The wing screw secures the handlebar to the...

Page 4: ...otects the user from contact with metal cutting attachments 3 3 Icons Meanings of symbols that may be on the trimmer and the deflector This icon denotes the fuel tank This symbol denotes the manual fu...

Page 5: ...des Do not use this deflector for circular saw blades 4 1 4 Guard for shredder blades Meanings of warning signs and labels on the deflector for shredder blades Do not sse this deflector for shredder b...

Page 6: ...ous injury to the user Tie up and confine long hair above your shoulders Objects can be thrown at high speed during operation This may result in injury to the user Wear close fitting safety glasses Su...

Page 7: ...t a STIHL dealer for assistance Close the fuel tank cap If the brushcutter is dirty Clean the brush cutter Never attempt to modify your brushcutter Exception Mounting one of the combina tions of cutti...

Page 8: ...r fatally injured and property may be damaged Protect fuel mixture and gasoline from heat and fire Do not spill fuel mixture or gasoline If fuel is spilled Wipe up fuel with a cloth and do not attempt...

Page 9: ...immer Operate the trimmer alone Keep the cutting attachment close to the ground Watch out for obstacles Work standing on the ground and keep your balance If you start feeling fatigue Take a break If y...

Page 10: ...or in the direction of the user black arrow The user can lose control of the trim mer This can result in serious or fatal injuries Hold the trimmer firmly with both hands Use the working techniques de...

Page 11: ...y to the user Wear work gloves made from resist ant material 5 Preparing Trimmer for Operation 5 1 Preparing the Brushcutter for Operation The following steps must be performed before commencing work...

Page 12: ...ar as stop and hold it depressed Rotate the mowing head until the stop pin engages in position The shaft is now blocked Unscrew the mowing head clockwise Remove the thrust plate Remove stop pin 6 4 Re...

Page 13: ...nsert the stop pin in the bore up to the limit stop and hold it depressed Rotate the metal cutting attachment clockwise until the stop pin engages in position The shaft is now blocked Unscrew the moun...

Page 14: ...Two stroke engine oil 1 l gasoline 60 ml Two stroke engine oil 3 l gasoline 100 ml Two stroke engine oil 5 l gasoline Pour two stroke engine oil into a clean approved fuel canister first and then add...

Page 15: ...again with the choke lever 2 in the position 9 2 Shut off the engine 2 3 1 0000097402_001 Release the throttle trigger 1 and throttle trig ger lockout 2 The cutting attachment comes to a standstill De...

Page 16: ...engine housing and an air filter with plastic webbing The accessories and User Manual are available from a STIHL servicing dealer 11 2 Summer Operation The shutter must be set to summer mode when wor...

Page 17: ...ceably C Release the throttle trigger The engine runs at idling speed The brushcut ter is calibrated and ready for use Shut off the engine 11 4 Holding and Controlling the Brushcutter 1 2 0000097031 0...

Page 18: ...ing attachment If a metal cutting attachment is mounted Fit the matching transport guard 13 Transporting 13 1 Transporting the Trimmer Shut off the engine If a metal cutting attachment is mounted Fit...

Page 19: ...grease can be seen on the end of the screw plug 2 Screw in the tube of STIHL gear lubri cant 1 Squeeze 5 g of STIHL gear grease into the gear housing Unscrew the tube of STIHL gear lubri cant 1 Refit...

Page 20: ...uel in the fuel tank The pickup body is not located in the right place Contact a STIHL servicing dealer 18 2 Replacing air filter The air filter cannot be cleaned The air filter must be replaced if it...

Page 21: ...A Sound power level Lw measured according to ISO 22868 112 dB A Vibration level ahv measured according to ISO 22867 Control handle 2 8 m s Left handle 3 4 m s For information on compliance with Employ...

Page 22: ...spare parts and accessories accordingly STIHL cannot warrant for the use of those parts Original STIHL spare parts and original STIHL accessories are available from STIHL dealers 22 Disposal 22 1 Disp...

Page 23: ...hi nery Safety Regulations 2008 Electromagnetic Compatibility Regulations 2016 and Noise Emis sion in the Environment by Equipment for use Outdoors Regulations 2001 and has been manu factured in compl...

Page 24: ...www stihl com 04588440101A 04588440101A 0458 844 0101 A 0458 844 0101 A...

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