Cleaning The Air Filter; Engine Management; Adjusting The Carburetor - Stihl MS 311 Instruction Manual

20 Cleaning the Air Filter

Rapid 1/4"
Picco 3/8" P
Rapid 3/8"; 0.325"
Rapid 0.404"
If groove depth is less than specified:
► 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.
20 Cleaning the Air Filter
20.1 If there is a noticeable loss of
engine power
20.1.1 Removing the shroud
► Move the Master Control lever to the stop
position (0).
► Push the hand guard forward – the chain is
locked.
1
► Open the twist locks (1) by turning them 1/4
turn counterclockwise with the combination
wrench.
► Remove the shroud (2).
20.1.2 Removing the air filter
► Clean away loose dirt from around the filter.
NOTICE
To avoid damaging the filter, do not use tools for
removing and installing the air filter.
1.
2.
0458-542-8221-D
4.0 mm
5.0 mm
6.0 mm
7.0 mm
1
2
1
► Rotate the air filter a 1/4 turn counterclockwise
and lift it away in the direction of the rear han‐
dle.
► Always replace a damaged filter.
20.1.3 Cleaning the air filter
► Wash the filter in STIHL special cleaner (spe‐
cial accessory) or a clean, non-flammable sol‐
ution (e.g. warm soapy water). Rinse the filter
from the inside outwards under a jet of water –
do not use a pressure washer.
► Dry the filter components – do not expose to
high temperatures.
► Do not impregnate the filter with oil.
► Reinstall the air filter.
20.1.4 Installing the air filter
1.
2.
► Place the air filter in position.
► Push the air filter in the direction of the filter
housing and turn it clockwise at the same time
until it engages – the "STIHL" name must be
horizontal.
► Install the shroud.

21 Engine Management

Exhaust emissions are controlled by the design
of the engine and components (e.g. carburation,
ignition, timing and valve or port timing).

22 Adjusting the Carburetor

22.1 General Information
The carburetor comes from the factory with a
standard setting.
This setting provides an optimum fuel-air mixture
under most operating conditions.
With this carburetor it is only possible to correct
the adjusting screws within fine limits.
22.2 Standard Setting
► Shut off the engine.
► Check the air filter and clean or replace if nec‐
essary.
English
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