Honda F220 Owner's Manual page 43

The Distributor's Limited Warranty does not cover fuel system damage
or engine performance problems resulting from neglected storage
preparation.
You can extend fuel storage life by adding a gasoline stabilizer that is
formulated for that purpose, or you can avoid fuel deterioration
problems by draining the fuel tank and carburetor.
Adding a Gasoline Stabilizer to Extend Fuel Storage Life
When adding a gasoline 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.
1.Add gasoline stabilizer following manufacturer's instructions.
2.After adding a gasoline stabilizer, run the engine outdoors for 10
minutes to be sure that treated gasoline has replaced the untreated
gasoline in the carburetor.
3.Stop the engine, and turn the fuel valve to the OFF position.
STORAGE
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