Catalytic Converter - Stihl BG 55 Instruction Manual

Engine stops while idling
Turn the idle speed screw (LA)
N
clockwise until the engine runs
smoothly – then back it off a 1/4 turn
from that position.
Erratic idling behavior, poor acceleration
(despite correction to setting of LA
screw).
Idle setting is too lean
Turn the low speed screw (L)
N
counterclockwise, no further than
stop, until the engine runs and
accelerates smoothly.
Erratic idling behavior, engine speed
drops when swinging the machine
Idle setting is too rich
Turn the low speed screw (L) slowly
N
clockwise until the engine runs and
accelerates smoothly.
BG 55, BG 65, BG 85, SH 55, SH 85
It is usually necessary to change the
setting of the idle speed screw (LA) after
every correction to the low speed
screw (L).
Fine Tuning for Operation at High
Altitude
A slight correction of the setting may be
necessary if engine does not run
satisfactorily:
Carry out the standard setting.
N
Warm up the engine.
N
Turn high speed screw (H) slightly
N
clockwise (leaner) – no further than
stop.
NOTICE
After returning from high altitude, reset
the carburetor to the standard setting.
If the setting is too lean there is a risk of
engine damage due to insufficient
lubrication and overheating.

Catalytic Converter

Power tools with a catalytic converter
(depending on model) must be run on a
50 : 1 mixture of unleaded gasoline and
STIHL two-stroke engine oil or
equivalent two-stroke engine oil – see
chapter on "Fuel".
The catayltic converter integrated in the
muffler reduces the harmful emissions in
the exhaust gas.
The correct carburetor setting (if
adjustable) and strict observance of the
prescribed mix ratio of gasoline and two-
stroke engine oil are essential to
minimize harmful emissions and ensure
a long catalytic converter service life.
English
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