Honda F501 Owner's Manual page 43

3. Sediment cup cleaning
Gasoline is extremely flammable and is explosive under certain
conditions. Do not smoke or allow flames or sparks in the area.
Turn the fuel valve to the OFF position and remove the sediment cup
and the O-ring.
Wash the sediment cup in solvent, dry it thoroughly.
Place the O-ring in the fuel valve, and install the sediment cup. Tighten
the sediment cup securely.
Turn the fuel valve ON and check for leaks.
O-RING
SEDIMENT CUP
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