Which component is typically NOT part of an outboard motor assembly?

The cooling system is generally not considered a core component of an outboard motor assembly in the same way as the lower unit, mid-section, and cylinder head.

In outboard motors, the lower unit is responsible for housing the propeller and gear mechanisms, while the mid-section connects the lower unit to the powerhead and supports various components like the steering system. The cylinder head is a crucial part of the powerhead, where the combustion process occurs. While cooling systems are essential for the operation of an engine, they tend to be integrated into other components rather than being a standalone part of the assembly. They often work in conjunction with the engine block and other components to manage engine temperature, but they are not classified as a distinct part of the outboard motor assembly itself.