Adjusting The Carburetor - Stihl BR 380 Instruction Manual

3
4
Remove the main filter (3) from the
N
cover and inspect it – if it is dirty or
damaged, fit a new one.
Always install a new prefilter together
with the new main filter.
Take the prefilter (4) out of the filter
N
cover.
If prefilter is wet, dry it – then knock
N
it out on the palm of your hand or
blow it out with compressed air.
Always replace a damaged prefilter.
Clean loose dirt from the filter cover
N
and filter chamber.
Install the main filter (3) and
N
prefilter (4) in the filter cover.
Fit the cover on the filter base (5)
N
and tighten it down firmly.
BR 380

Adjusting the Carburetor

The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
With this carburetor it is only possible to
5
adjust the high speed and low speed
screws within fine limits.
Standard Setting
Stopping the engine
N
Check the air filter and clean or
N
replace as necessary.
Check the spark arresting screen
N
(not in all versions) in the muffler
and clean or replace as necessary.
Carefully turn both adjusting screws
N
counterclockwise as far as stop.
The high speed screw (H) is 1/4 turn
N
open.
The low speed screw (L) is 1/4 turn
N
open.
Start and warm up the engine.
N
Adjusting Idle Speed
Engine stops while idling
N
L
H
Erratic idling behavior, engine stops
even though setting of LA screw has
been corrected, poor acceleration
Idle setting is too lean:
N
Erratic idling behavior
Idle setting is too rich
N
It is usually necessary to change the
setting of the idle speed screw (LA) after
every correction to the low speed
screw (L).
L
LA
Turn the idle speed screw (LA)
slowly clockwise until the engine
runs smoothly.
Turn the low speed screw (L)
counterclockwise, no further than
stop, until the engine runs and
accelerates smoothly.
Turn the low speed screw (L)
clockwise, no further than stop, until
the engine runs and accelerates
smoothly.
English
15