Why is fuel leaking out of the vent tube on carburetor of mercury outboard?

Fuel leaking from the vent tube on a carburetor of a Mercury outboard typically indicates an issue with the carburetor's float or needle valve. If the float is stuck or damaged, it can prevent the needle valve from sealing properly, allowing fuel to overflow and exit through the vent tube. Additionally, a clogged fuel line or a malfunctioning fuel pump may also contribute to excess fuel pressure, exacerbating the problem. Regular maintenance and inspection can help prevent these issues.