Spark Plug - Stihl MM 55 Manual De Instrucciones

Cutting attachment turns when idling
Turn the idle speed screw (LA)
N
counterclockwise until the working
tool stops running – then turn
another 1/2 to 1 turn in the same
direction
If the working tool continues to keep
moving in idle even after adjustment,
have the machine checked by a
servicing dealer.
Erratic idling behavior, engine stalls
despite correction of LA-setting, poor
acceleration
The idle setting is too lean –
Turn the low speed screw (L)
N
counterclockwise (approx. 1/4 turn)
until the engine runs and
accelerates smoothly
Erratic idling behavior
The idle setting is too rich –
Turn the low speed screw (L)
N
clockwise (approx. 1/4 turn) until the
engine runs and accelerates
smoothly
MM 55, MM 55 C

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.
Remove the spark plug
Move the slide control to STOP-0
N
1
Unplug spark plug boot (1)
N
Unscrew spark plug
N
Checking the Spark Plug
Clean dirty spark plug.
N
Check electrode gap (A) and
N
readjust if necessary – see
"Specifications".
Use only resistor type spark plugs of
N
the approved range.
Rectify problems which have caused
fouling of spark plug:
Too much oil in fuel mix.
–
Dirty air filter.
–
Unfavorable running conditions,
–
e.g. operating at part load.
English
A
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