Operating Instructions; Replacing The Air Filter; Adjusting The Carburetor; Spark Plug - Stihl BR 800 Instruction Manual

11 Operating Instructions

► Set the choke knob according to engine tem‐
perature.
► Start the engine.
11 Operating Instructions
11.1 During Operation
After a long period of full throttle operation, allow
the engine to run for a short while at idle speed
so that engine heat can be dissipated by the flow
of cooling air. This helps protect engine-mounted
components (ignition, carburetor) from thermal
overload.
11.2 After Finishing Work
Storing for a short period: Wait for the engine to
cool down. Keep the machine in a dry place, well
away from sources of ignition, until you need it
again. For longer out-of-service periods – see
"Storing the Machine".

12 Replacing the Air Filter

Dirty air filters reduce engine power, increase
fuel consumption and make starting more diffi‐
cult.
12.1 If There is a Noticeable Loss of
Engine Power
1
2
► Loosen the screws (1).
► Remove the filter cover (2) together with the
air filter (3).
0458-490-8321-B
3
► Remove the air filter (3) from the filter cover.
► Replace a dirty or damaged air filter (3).
► Fit the new air filter (3) in the filter cover (2).
► Fit the filter cover (2) with air filter (3) in posi‐
tion.
► Insert the screws (1) and tighten them down
firmly.

13 Adjusting the Carburetor

13.1 Adjusting Idle Speed
Engine stops while idling:
► Turn the idle speed screw (LA) slowly clock‐
wise until the engine runs smoothly.

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".
14.1 Removing the Spark Plug
3
1
► Loosen the screw (1).
► Remove the cover (2).
► Pull off the spark plug boot (3).
► Unscrew the spark plug (4).
English
4
2
15