Spark Plug - Stihl BG 50 Instruction Manual

Engine stops while idling
Turn the idle speed screw (LA)
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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)
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carefully counterclockwise, no
further than stop, until the engine
runs smoothly and accelerates well.
Erratic idling behavior, engine speed
drops when swinging the machine
Idle setting is too rich
Turn the low speed screw (L) slowly
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clockwise until the engine runs and
accelerates smoothly.
BG 50
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 the engine does not run
satisfactorily:
Carry out the standard setting.
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Warm up the engine.
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Turn high speed screw (H) slightly
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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.

Spark Plug

If the engine is down on power, difficult
to start or runs poorly at idling speed,
first check the spark plug.
Install a new spark plug after approx.
100 operating hours or earlier if the
electrodes are badly eroded/corroded.
The wrong fuel mix (too much engine oil
in the gasoline), a dirty air filter and
unfavorable running conditions (mostly
at part throttle etc.) affect the condition
of the spark plug. These factors cause
deposits to form on the insulator nose
which may degrade performance.
Removing the Spark Plug
1
Pull off the spark plug boot (1).
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Unscrew the spark plug.
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English
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