Tank Vent; Pickup Body - Stihl 4141 Series Manual

Back off the low speed screw
(stop screw) until the end of the
screw (arrow) is no longer visible,
then turn it six full turns
clockwise.
Adjusting idle speed
– Carry out standard setting.
– Start engine and warm it up to
normal operating temperature.
– If the engine stops while idling:
Turn low speed screw slowly
clockwise until the engine runs
smoothly. The cutting attachment
must not rotate.
– If the cutting attachment rotates
while engine is idling: Turn low
speed screw counterclockwise
until cutting attachment stops
rotating. Then turn screw another
two turns in the same direction.
38
9.6

Tank Vent

Correct operation of the carburetor
is only possible if atmospheric
pressure and internal fuel tank
pressure are equal at all times. This
is ensured by the tank vent.
Important:
In the event of trouble with the
carburetor or the fuel supply
system, always check and clean the
tank vent. Check functions by
performing pressure and vacuum
tests on the fuel tank via the fuel
hoses.
1
– Disconnect both fuel hoses from
the carburetor.
– Seal one fuel hose with a suitable
plug. Perform pressure or
vacuum test on tank via the other
fuel hose.
Equalization of pressure from the
outside inwards takes place via
the valve (1). There must be no
build up of pressure or vacuum in
the tank. In case of malfunction,
install a new valve.
9.7

Pickup Body

The diaphragm pump draws fuel out
of the tank and into the carburetor
via the fuel hose. Any impurities
mixed with the fuel are retained by
the pickup body (filter). The fine
pores of the filter eventually become
clogged with minute particles of dirt.
This restricts the passage of fuel
and results in fuel starvation.
1
Important:
In the event of trouble with the fuel
supply system, always check the
fuel tank and the pickup body first.
Clean the fuel tank if necessary.
Cleaning the fuel tank
Unscrew the filler cap (1) and
drain the tank.
– Pour a small amount of clean
gasoline into the tank.Close the
tank and shake the powerhead
vigorously.
– Open the tank again and drain it.
Note:
Dispose of old fuel at approved
disposal site.
Series 4141 Powerhead