Spark Plug - Stihl BR 500 Manual De Instrucciones

Standard Setting
Shut off the engine.
N
Check the air filter and clean or
N
replace if necessary.
Check that the throttle cable is
N
properly adjusted – readjust if
necessary – see chapter on
"Adjusting the Throttle Cable".
Check the spark arresting screen
N
(not in all models, country-specific)
in the muffler and clean or replace if
necessary.
H
Carefully turn both adjusting screws
N
counterclockwise as far as stop:
The high speed screw (H) is 3/4 turn
N
open.
The low speed screw (L) is 3/4 turn
N
open.
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
slowly clockwise until the engine
runs smoothly.
BR 500, BR 550, BR 600
Erratic idling behavior, engine stops
even though setting of LA screw has
been corrected, poor acceleration
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
Idle setting is too rich
Turn the low speed screw (L)
N
clockwise, no further than stop, 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).
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.

Spark Plug

If engine is down on power, difficult to
start or runs poorly at idling speed, first
check the spark plug.
Fit a new spark plug after approx. 100
operating hours or earlier if the
electrodes are badly eroded.
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 result in trouble in operation.
Removing the Spark Plug
2
Pull off the spark plug boot (1).
N
Unscrew the spark plug (2).
N
English
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