Stihl FS 261 - Troubleshooting and Component Replacement; Replacing the Air Filter; Cleaning or Replacing the Spark Plug; Adjusting the Engine Idle Speed

Fault Cause Remedy
The engine has floo‐
ded.
►
Start the engine with the choke lever in the
position.
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 brushcutter to warm up to +10°C.
The engine idles
erratically.
The carburetor has
iced up.
► Allow brushcutter to warm up to +10°C.
The engine stops
while idling.
The carburetor has
iced up.
► Allow brushcutter to warm up to +10°C.
Cutting attachment
runs while engine is
idling.
Throttle cable adjust‐
ment is not correct.
► Adjust the throttle cable.
Idle speed adjust‐
ment is not correct.
► Adjust the idle speed.
The engine does not
reach maximum
speed.
Throttle cable adjust‐
ment is not correct.
► 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 authorized 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 the position.
3
2
1
0000099195_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
3
4
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► 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).
18.4 Adjust idle speed
► Start the engine.
► Warm up the engine by repeatedly opening
and closing the throttle for about 1 minute.
English 18 Troubleshooting
20 0458-837-0101-A