Air Filter System; Cleaning The Air Filter - Stihl MS 391 Safety Manual

If groove depth is less than specified:
N
Replace the guide bar.
The drive link tangs will otherwise
scrape along the bottom of the groove –
the cutters and tie straps will not ride on
the bar rails.
MS 311, MS 391

Air Filter System

The air filter system can be adapted to
different operating conditions by the
insertion of different air filters.
Retrofitting is simple.
Depending on equipment version, the
machine is equipped with a fleece filter,
a fleece filter with a felt prefilter or a
fabric filter.
Fleece filter
For normal or dry applications.
Fleece filter with felt prefilter
For very dusty operating environments.
Fabric filter
For extreme winter conditions (e.g.,
powdered or drifting snow or frost
formation).

Cleaning the Air Filter

If there is a noticeable loss of engine
power
Remove shroud
N
Move the Master Control Lever to
the stop position 0
N
Push the front hand guard forwards
– the saw chain is blocked
2
1
N
Loosen screws (1)
N
Remove the shroud (2)
Remove air filter
N
Clean away loose dirt from around
the filter
Do not use tools to remove and
install the air filter – the air filter
could be damaged in the process.
English
1
1
27