12.3.5 Accelerator Pump - Stihl MS 270 User Manual

12.3.5 Accelerator Pump

– Remove the carburetor
– see 12.2.1.
Use a suitable pointed tool to
remove the sealing plug.
1
Take the screw (1) out of the
throttle shutter.
MS 270, MS 280
– Set the throttle shaft to the full
throttle position.
Carefully pull the throttle shutter
out of the shaft.
Remove the snap ring (1) from
the throttle shaft.
Hold accelerator pump bore closed
with one finger so that the parts of
the accelerator pump do not pop out
of the carburetor when the throttle
shaft is removed.
Wear safety glasses.
– Pull the throttle shaft out of the
carburetor body.
1
2
3
4
Remove ball (1), pump piston (2)
with sealing ring (3) and
spring (4) from the carburetor
body.
– Inspect parts for damage and
wear and replace if necessary.
Install in the reverse sequence.
1
Wear safety glasses while
installing the accelerator pump/
throttle shaft to protect your eyes
from injury if parts suddenly pop out
of the carburetor body.
Note correct installed sequence of
the individual parts of the
accelerator pump: First fit the
spring (4), then the pump piston (2),
with the ball seat (arrow) facing you,
and the ball (1).
Use a suitable tool to press the
ball (1) down and fit the throttle
shaft.
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