STIHL 029, 039
79
11.8
Fuel Pickup Body and
Fuel Hose
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.
- Remove the carburetor box cover –
- Remove the vent from the nipple on
the fuel tank and take it out of its seat
in the cover.
- Use a 3 mm (1/8") dia. drift to push
the grub screws out of the hose.
- Wash all parts in fresh white spirit
and blow out with compressed air.
Installation of the tank vent is a
reversal of the removal sequence.
Note:
Use a drift to position the
grub screws as shown in the
drawing.
Fit the tank vent on the nipple and
then push it into its seat in the cover.
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.
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 and drain the
tank.
- Pour a small amount of clean
gasoline into the tank.
- Close the tank and shake the saw
vigorously.
- Open the tank again and drain it.
11.7
Tank Vent
Removing tank vent
Top:
1 = Grub screw
2 = Vent hose
Bottom:
Correct positions of grub screws a =
approx. 18 mm (11 /16")
Assembly hook 5910 893 8800
