Catalytic Converter - Stihl BG 55 Instruction Manual

Adjustment for operation at high
altitude or at sea level
A slight correction of the setting may be
necessary if engine power is not
satisfactory when operating at high
altitude or at sea level:
: Check the air filter and clean it if
necessary.
: Warm up the engine.
At high altitude
: Rotate the high speed screw (H)
clockwise (leaner) no further than
stop.
At sea level
: Rotate the high speed screw (H)
counterclockwise (richer) no further
than stop.
BG 55, BG 65, BG 85, SH 55, SH 85
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Adjusting idle speed
L
Engine stops while idling
: Set low speed screw (L) to one full
turn open.
: Turn idle speed screw (LA) slowly
clockwise until the engine runs
smoothly – then back it off
from that position.
Erratic idling behavior; poor
acceleration
(even though low speed screw is open
one full turn)
Idle setting is too lean:
: Turn low speed screw (L)
counterclockwise until the engine
runs and accelerates smoothly.
It is usually necessary to change the
setting of the idle speed screw (LA)
after every correction to the low speed
screw (L).

Catalytic Converter*

Power tools with a catalytic converter*
may only be operated with unleaded
gasoline and STIHL two-stroke
engine oils in a mix ratio of 50:1
(see chapter "Fuel").
LA
The catalytic converter in the muffler
reduces noxious emissions in the
exhaust gas.
Correct adjustment of the carburetor
(if adjustable) and observance of the
specified mix ratio of gasoline and two-
stroke engine oil are essential to
minimize harmful exhaust emissions
and ensure a long catalyst service life.
1
/ turn
4
* see "Guide to Using this Manual"
English
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