Cleaning The Air Filter; Motor Management - Stihl FS 90 Instruction Manual

: Unscrew and dry off the spark plug.
: Open the throttle wide.
: Crank the engine several times with
the starter to clear the combustion
chamber.
: Refit the spark plug. Connect the
spark plug boot (press it down
firmly).
: Move the slide control to START.
: Set the choke knob to e –
even if engine is cold.
: Now start the engine.
Throttle cable adjustment
: Check adjustment of throttle cable –
see "Adjusting the Throttle Cable".
Tank run until dry
: After refueling, press the fuel pump
bulb at least five times – even if bulb
is filled with fuel.
: Set choke knob according to engine
temperature.
: Now start the engine.
FS 90, FS 90 R

Cleaning the Air Filter

4
Dirty air filters reduce engine power,
increase fuel consumption and make
starting more difficult.
If there is a noticeable loss of engine
power:
: Set the choke knob to g.
: Take out the screw (1) and remove
the filter cover (2).
: Clean away loose dirt from around
the filter.
: Grip the filter element (3) at the
notch (arrow) in the filter housing (4)
and take it out.
: Fit a new filter element. As a
temporary measure you can knock it
out on the palm of your hand or blow
it out. Do not wash.
: Replace any damaged parts.
: Install filter element in the filter
housing.
: Refit the filter cover.
: Insert the screw and tighten it down
firmly.

Motor Management

Exhaust emissions are controlled by the
design of the fundamental engine
parameters and components (e.g.
carburation, ignition, timing and valve or
port timing) without the addition of any
1
major hardware.
2
English / USA
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