What is a likely cause if a float-type carburetor leaks fuel when the engine is stopped?

A float-type carburetor leaking fuel when the engine is stopped is typically due to the float needle valve being worn or not seated properly. The float needle valve controls the flow of fuel into the carburetor's float chamber. When the engine is off and the demand for fuel ceases, the needle valve should effectively seal off the flow. If the valve is worn, it may not create a proper seal, allowing fuel to leak into the carburetor and subsequently spill out. Additionally, if the needle valve is not seated properly, it can also fail to stop the flow of fuel, resulting in leakage.

The other factors, while they may contribute to different issues within the fuel system, do not directly correlate with the specific scenario of fuel leakage when the engine is not running. A damaged carburetor gasket might cause fuel to leak under pressure when the engine is running but is less likely to cause a leak when the engine is stopped. A pinched fuel line may restrict fuel flow rather than causing a leak. Similarly, if the throttle plate is not closed properly, it could lead to other performance issues during operation but would not typically cause leakage when the engine is off. Thus, the condition of the float needle valve is the most pertinent explanation