Stihl MS 261 Instruction Manual page 12

English
Allow the Saw to Cool Before Removing the Fuel Cap
WARNING
￭ Gasoline vapor pressure may build up inside the fuel tank.
The amount of pressure depends on a number of factors,
such as the fuel used, altitude, and temperature. To
reduce the risk of burns and other personal injury from
escaping gas, vapor and fumes:
– Always shut off the engine and allow it to cool before
removing the fuel cap.
￭ The engine is air cooled. When it is shut off, cooling air is
no longer drawn across the cylinder and engine
temperatures will rise for several minutes before starting
to cool. In hot environments, cooling will take longer. To
reduce the risk of burns and other personal injury from
escaping gas vapor and fumes:
– Allow the chain saw to cool. If you need to refuel
before completing a job, turn off the machine and
allow the engine to cool before opening the fuel tank.
Fuel Spraying or "Geysering"
WARNING
￭ Removing the cap on a pressurized fuel tank can result in
gasoline, vapors and fumes being forcefully sprayed out
from the fuel tank in all directions. The escaping gasoline,
vapors or fumes can cause serious personal injury,
including fire and burn injury, or property damage.
￭ Sometimes also referred to as "fuel geysering," fuel
spraying is an expulsion of fuel, vapors and fumes which
can occur in hot conditions, or when the engine is hot, and
the tank is opened without allowing the saw to cool
adequately. It is more likely to occur when the fuel tank is
half full or more.
￭ Pressure is caused by fuel and heat and can occur even if
the engine has not been running. When gasoline in the
fuel tank is heated (by ambient temperatures, heat from
the engine, or other sources), vapor pressure will increase
inside the fuel tank.
10
5 IMPORTANT SAFETY INSTRUCTIONS
￭ Some blends of gasoline, particularly winter blends, may
cause tanks to pressurize more quickly or create greater
pressure. At higher altitudes, fuel tank pressurization is
more likely.
How to Avoid Fuel Spraying
WARNING
￭ 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 chain saw to cool before removing the fuel
cap.
– If you need to refuel before completing a job, turn off
the machine and allow the engine 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 chain saw has cooled appropriately, follow the
safety instructions in this chapter for removing the cap.
– Never remove the cap by turning it directly to the
open position.
– First check for residual pressure by turning the cap
slowly to the vent position, approximately 1/8 turn
counter-clockwise.
– Use only good quality fuel that is appropriate for the
season (summer v. winter blends). Some blends of
gasoline, particularly winter blends, are more volatile
and can contribute to fuel spraying.
0458-573-8621-C