Gravely Pro-Turn 400 Series Operator's Manual page 13

Storage
NEVER store unit with fuel in fuel tank,
inside a building where any ignition sources
are present.
Keep machine free of grass, leaves, or other
debris build-up. Clean up oil or fuel spillage
and remove any fuel-soaked debris. Allow
machine to cool before storing.
For extended storage, shut off fuel and
clean unit thoroughly. See engine manual for
proper storage.
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