Engine Running Behavior - Stihl FS 500 Instruction Manual

Checking the spark plug
N
Clean dirty spark plug.
N Check electrode gap (A) and
readjust if necessary – see
"Specifications".
N
Rectify the problems which have
caused fouling of the spark plug.
Possible causes are:
– Too much oil in fuel mix.
– Dirty air filter.
– Unfavorable running conditions.
If the spark plug comes with a
detachable adapter nut (1), screw
the adapter onto the thread and
tighten it down firmly to reduce
the risk of arcing and fire.
FS 500, FS 550
Installing the Spark Plug
A
N Screw the spark plug (3) into the
cylinder and fit the boot (2) (press it
down firmly).
N Fit the cover.
1

Engine Running Behavior

If engine running behavior is
unsatisfactory even though the air filter
is clean and the carburetor and throttle
cable are properly adjusted, the cause
may be the muffler.
2
Have the muffler checked by a servicing
dealer for contamination
(carbonization).
STIHL recommends that you have
servicing and repair work carried out
exclusively by an authorized STIHL
servicing dealer.
3
English
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