Engine Management; Adjusting The Carburetor - Stihl HS 46 Instruction Manual

English

Engine Management

Exhaust emissions are controlled by the
design of the fundamental engine
parameters and components (e.g.
carburation, ignition, timing and valve or
port timing) without the addition of any
major hardware.
18

Adjusting the Carburetor

General Information
The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
Standard Setting
Shut off the engine.
N
Inspect cutting blades and clean if
N
necessary (clean, move freely, not
warped).
Check the air filter and clean or
N
replace if necessary.
Check the spark arresting screen
N
(not in all models, country-specific)
in the muffler and clean or replace if
necessary.
L H
LA
Turn high speed screw (H)
N
counterclockwise as far as stop (no
more than 3/4 turn).
Turn the low speed screw (L)
N
carefully clockwise as far as stop,
then turn it back 3/4 turn.
Adjusting Idle Speed
Carry out the standard setting.
N
Start and warm up the engine.
N
Engine stops while idling
Turn the idle speed screw (LA)
N
clockwise until the cutting blades
begin to run – then back it off
about 1 full turn.
Cutting blades run when engine is idling
Turn the idle speed screw (LA)
N
counterclockwise until the cutting
blades stop moving – then turn it
another 1 full turn in the same
direction.
WARNING
If the cutting blades continue moving
when the engine is idling, have your
hedge trimmer checked and repaired by
your servicing dealer.
Erratic idling behavior, poor acceleration
(despite correction to setting of LA
screw).
Idle setting is too lean
Rotate the low speed screw (L)
N
about 1/4 turn counterclockwise, no
further than stop, until the engine
runs and accelerates smoothly.
Machine stops when it is swung at idle
speed
Idle setting is too rich
Rotate the low speed screw (L)
N
about 1/4 turn clockwise until the
engine idles smoothly.
HS 46, HS 46 C, HS 56 C