![background image](http://html1.mh-extra.com/html/stihl/fc-75/fc-75_user-manual_1378585039.webp)
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! The tank vent must
always be checked and cleaned
as well if any faults develop in the
carburetor or fuel supply.
Both functions are checked by
performing pressure and vacuum
tests on the tank via the fuel hose.
Equalization of tank pressures
from the outside inwards takes
place through the bore in the fuel
filler cap, the sintered filter, the
valve and the bores in the cap.
Equalization of tank pressures
from the inside outwards takes
place through the bores in the cap
and valve body, the sintered filter
and the bore in the fuel filler cap.
Cleaning
- Unscrew fuel filler cap.
•
Prise cap (1) off valve body (2).
•
Lever valve body out of fuel filler
cap (3).
•
Lever sintered filter (4) out of fuel
filler cap.
- Clean valve body with fresh
petrol.
•
Draw valve (5) with damaged
diaphragm out of valve body and
fit a new one.
•
Press new sintered filter (4) into
fuel filler cap.
•
Fit O-ring (6) over valve body.
- Insert valve body in fuel filler cap
and press until it is heard to
engage.
- Place cap on valve body and
press until it is heard to engage.
- Screw on fuel filler cap.
The diaphragm pump draws fuel
out of the tank and into the carbu-
retor via the fuel hose. Any impuri-
ties in 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! The fuel tank and
pickup body must always be
checked first if any faults develop
in the fuel supply system. Clean
the fuel tank if necessary.
Cleaning the fuel tank
•
Unscrew fuel filler cap and drain
fuel tank.
- Fill with a little fresh petrol.
- Tightly close fuel filler cap and
vigorously shake brushcutter.
- Unscrew fuel filler cap again and
drain tank.
Note: Ensure that the fuel is
disposed of in accordance with
regulations!
366RA189
VA
392RA120
VA
366RA190
VA
1
6
2
4
5
3
366RA191
VA
39