Specifications - Stihl MS 651 Instruction Manual

English
► Turn the high speed screw H 1 1/2 turns coun‐
terclockwise.
► Turn the low speed screw L clockwise as far
as stop.
► Turn the low speed screw L one full turn
counterclockwise.
18.3 Adjusting Idle Speed
Engine stops while idling
► Carry out the standard setting.
► Start the engine and disengage the chain
brake.
► Warm up the engine by opening and closing
the throttle for about 1 minute.
► If the engine continues to stop while idling:
Turn the idle speed screw (LA) half a turn
clockwise and restart the engine.
► Turn the idle speed screw (LA) clockwise until
the chain begins to run.
► Turn the idle speed screw (LA) one full turn
counterclockwise.
Saw chain runs continuously while engine is
idling
► Carry out the standard setting.
► Start the engine and disengage the chain
brake.
► Warm up the engine by opening and closing
the throttle for about 1 minute.
► Turn the idle speed screw (LA) counterclock‐
wise until the saw chain stops running.
► Turn the idle speed screw (LA) one full turn
counterclockwise.
18.4 Clearing the Combustion
Chamber
► Engage the chain brake.
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► Remove the filter cover (1).
► Pull off the spark plug boot (2).
► Unscrew the spark plug.
► Dry the spark plug.
WARNING
■ Unconfined sparks may occur if the starter grip
is pulled after the spark plug boot has been
removed. Sparks may cause a fire or an
explosion in an easily combustible or explo‐
sive environment. This can result in serious or
fatal injuries and damage to property.
► Move the Master Control lever to posi‐
tion and hold it there before pulling the
starter grip.
► Move the Master Control lever to position
and hold it there.
► Pull the starter grip and guide it back several
times.
The combustion chamber is cleared.
► Insert and tighten down the spark plug.
► Press the spark plug boot (2) firmly home.
► Fit the filter cover (1).

19 Specifications

19.1 STIHL MS 651 Chainsaw
– Displacement: 91.1 cm³
– Engine power to ISO 7293: 5.0 kW (6.8 bhp)
– Idle speed according to ISO 11681:
2800 ± 50 rpm
– Approved spark plugs: NGK BPMR7A from
STIHL, BOSCH WSR 6 F
– Electrode gap of the spark plug: 0.5 mm
19 Specifications
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0458-784-0121-C