Spark Plug - Stihl PC 70 Instruction Manual

English
Cutting attachment runs when engine is
idling
Turn the idle speed screw (LA)
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counterclockwise until the cutting
attachment stops moving and then
rotate the screw another 1/2 to 1
turn in the same direction.
WARNING
If the cutting attachment continues to run
when the engine is idling, have your
machine checked and repaired by your
servicing dealer.
Erratic idling behavior, engine stops
even though setting of LA screw has
been corrected, poor acceleration
Idle setting is too lean
Idle setting is too lean: Rotate the
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low speed screw (L) about 1/4 turn
counterclockwise until the engine
runs and accelerates smoothly.
Erratic idling behavior
Idle setting is too rich:
Rotate the low speed screw (L)
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about 1/4 turn clockwise until the
engine runs and accelerates
smoothly.
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Spark Plug

If the engine is down on power,
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difficult to start or runs poorly at idle
speed, first check the spark plug.
Fit a new spark plug after about 100
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operating hours – or sooner if the
electrodes are badly eroded. Install
only suppressed spark plugs of the
type approved by STIHL – see
"Specifications".
Removing the Spark Plug
Move the slide control to STOP-0.
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1
Pull off the spark plug boot (1).
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Unscrew the spark plug.
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Checking the Spark Plug
Clean dirty spark plug.
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Check electrode gap (A) and
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readjust if necessary – see
"Specifications".
Rectify the problems which have
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caused fouling of the spark plug.
Possible causes are:
Too much oil in fuel mix.
–
Dirty air filter.
–
Unfavorable running conditions.
–
WARNING
Arcing may occur if the adapter nut (1) is
loose or missing. Working in an easily
combustible or explosive atmosphere
may cause a fire or an explosion. This
can result result in serious injuries or
damage to property.
PC 70, PC 75
A
1