Stihl FS 111 RX Instruction Manual page 9

How to Avoid Fuel Spraying
Removing the fuel cap on a pressurized
tank can result in gasoline, vapors and
fumes being forcefully sprayed out from
the fuel tank in all directions. To reduce
the risk of burns, serious injuries or
property damage from fuel spraying:
Follow the fueling instructions in this
–
chapter.
Always assume your fuel tank is
–
pressurized.
Allow the power tool to cool before
–
removing the fuel cap.
In hot environments, cooling will
–
take longer.
The engine is air cooled. When it is
–
shut off, cooling air is no longer
drawn across the cylinder and the
engine temperature will rise for
several minutes before starting to
cool.
After the power tool has cooled
appropriately, follow the safety
instructions in this chapter for removing
the cap.
Never remove the fuel filler cap by
turning it directly to the open position.
First check for residual pressure in the
tank by slowly turning the cap
approximately 1/2 turn counter-
clockwise. The cap should be held in
place by the threads while allowing
residual vapor/pressure to be relieved.
Once the fumes or vapor have been
relieved, turn the cap further until it can
be removed from the tank opening.
Use only good quality fuel that is
appropriate for the season (summer v.
winter blends). Some blends of
FS 111 RX
gasoline, particularly winter blends, are
more volatile and can contribute to fuel
spraying.
Removing the Threaded Fuel Filler Cap
WARNING
After allowing the power tool to cool,
remove the fuel filler cap slowly and
carefully to allow any remaining
pressure build-up in the tank to release:
While maintaining steady,
–
downward pressure, slowly turn the
cap approximately 1/2 turn counter-
clockwise.
If any significant venting occurs,
–
immediately re-seal the tank by
turning the cap clockwise to the
closed position. Allow the power
tool to cool further before
attempting to open the tank.
Turn the cap to the open position
–
only after the contents of the tank
are no longer under pressure.
Never remove the cap by turning it
–
directly to the open position. First
allow the power tool to cool
adequately and then release any
residual pressure by slowly turning it
approximately 1/2 turn counter-
clockwise.
Never attempt to remove the cap
–
while the engine is still hot or
running.
Installing the Threaded Fuel Filler Cap
WARNING
Unit vibrations can cause
an improperly tightened
fuel filler cap to loosen or
come off and spill quanti-
ties of fuel. To reduce the
risk of fuel spillage and
fire, tighten the fuel filler
cap by hand with as
much force as possible.
Damaged or Broken Cap
If your fuel cap does not tighten properly,
it may be damaged or broken. Stop
using the power tool and take it to your
authorized STIHL dealer for repair.
Vapor Lock
WARNING
Vapor lock occurs when fuel in the fuel
line or carburetor vaporizes, causing
bubbles to block the free flow of liquid
fuel into the carburetor. Vapor lock
cannot be relieved or affected by
opening the fuel tank. Removing the fuel
filler cap without first allowing the power
tool to cool adequately can result in fuel
spraying. Always follow the instructions
in this section when removing the fuel
cap.
English
7