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MS 290, MS 310, MS 390
English
34
If there is a noticeable loss of engine
power
N
Press the throttle trigger lockout and
move the Master Control lever to
cold start
k
N
Turn the knob above the rear handle
to the left – slot vertical
N
Pull off the carburetor box cover
toward the rear
N
Clean away loose dirt from around
the filter
Fouled air filters will impair engine
performance, increase fuel consumption
and make the machine more difficult to
start.
N
Pull off the prefilter (1) upward,
unscrew slotted nut (2) and remove
main filter (3)
N
Separate the halves of the filter from
one another
N
Knock out the filter or blow it clear
with compressed air from the inside
outwards.
In case of stubborn dirt:
N
Wash the filter in STIHL special-
purpose cleaner (special
accessories) or a clean, non-
flammable cleaning liquid (e.g.,
warm soapy water) and dry it.
Do not clean fleece filters with a brush!
N
Replace damaged filter
N
Reinstall filter
General Information
The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
Changing the setting of the high speed
screw alters the engine's power output
and the maximum off-load engine
speed.
Standard Setting
N
Shut off the engine.
N
Check the air filter and clean or
replace if necessary.
N
Check the spark arresting screen
(not in all models, country-specific)
in the muffler and clean or replace if
necessary.
Cleaning the Air Filter
139BA016 KN
139BA017 KN
3
2
1
2
Adjusting the Carburetor