Replacing The Air Filter; Adjusting The Carburetor; Spark Plug - Stihl BT 131 Instruction Manual

English
A
► Engage the auger brake by moving the acti‐
vating lever to position A.
► Rotate the whole machine counterclockwise to
unwind the auger from the ground.
► After releasing the trapped auger, check oper‐
ation of the auger brake – see "Auger Brake".

12 Replacing the Air Filter

Filters have an average life of more than a year.
Do not remove the filter cover or replace the air
filter as long as there is no noticeable loss of
power.
12.1 If there is a noticeable loss of
engine power.
► Remove padding from the handle frame.
4
► Turn the choke knob to g.
► Take out the screws (1).
► Remove the filter cover (2).
► Clean away loose dirt from around the filter.
14
3
2
1
► Remove the filter element (3).
► Replace dirty or damaged filter.
► Replace any damaged parts.
12.2 Installing the Filter Element
► Install the filter element in the filter housing
and fit the cover.
► Fit the screws and tighten them down firmly.
► Fit the padding – see "Assembling the Unit".

13 Adjusting the Carburetor

The carburetor has been set at the factory to pro‐
vide an optimum fuel-air mixture under most
operating conditions.
13.1 Adjusting Idle Speed
Engine stops while idling
► Warm up the engine for about 3 minutes.
► Turn the idle speed screw (LA) slowly clock‐
wise until the engine runs smoothly – the
auger must not rotate.
Auger rotates when engine is idling
► Turn the idle speed screw (LA) slowly counter‐
clockwise until the auger stops rotating and
then turn the screw about another 1/2 to 3/4
turn in the same direction.
WARNING
If the auger continues to rotate when the engine
is idling, have your machine checked and
repaired by your servicing dealer.
1

14 Spark Plug

► If the engine is down on power, difficult to start
or runs poorly at idle speed, first check the
spark plug.
► Fit a new spark plug after about 100 operating
hours – or sooner if the electrodes are badly
eroded. Install only suppressed spark plugs of
the type approved by STIHL – see "Specifica‐
tions".
12 Replacing the Air Filter
0458-529-8321-B