Husqvarna W 40P Operator's Manual page 37

STORAGE
Adding a Fuel Stabilizer to Extend Fuel Storage Life
Short Term Storage (30-90 days)
If your equipment will not be used for 30-90 days, we recommend the
following to prevent fuel-related problems:
Add fuel stabilizer following the manufacturer s instructions.
1. When adding a fuel stabilizer, fill the fuel tank with fresh gasoline. If
only partially filled, air in the tank will promote fuel deterioration during
storage. If you keep a container of gasoline for refueling, be sure that
it contains only fresh gasoline.
If it takes more than 3 months to use the fuel in your storage container,
we suggest adding a fuel stabilizer to the fuel when you full the
container.
2. After adding a fuel stabilizer, fill the pump chamber with water and run
the engine outdoors for 10 minutes to be sure that treated gasoline
has replaced the untreated gasoline in the carburetor.
NOTICE
Dry operation will damage the pump seal. Be sure the pump chamber is
filled with water before starting the engine.
3. Stop the engine, and move the fuel valve lever to the OFF position.
Drain the water from the pump chamber.
OFF
FUEL VALVE
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