The answer depends on the type of boat motor you're referring to.
Inboard Engines
Inboard boat motors, which are typically found in larger boats, do use coolant to regulate their operating temperature. Similar to car engines, these motors have a closed cooling system where coolant circulates through the engine block and cylinder heads, absorbing heat and transferring it to a radiator where it's released.
Outboard Engines
Outboard boat motors, commonly found on smaller boats, typically use a different cooling system. These motors rely on water-cooling, where water is drawn from the surrounding lake or ocean and pumped through the engine block to dissipate heat. However, some newer outboard motors might also use a closed-loop cooling system with a dedicated coolant.
Other Types of Boat Motors
Some specialized boat motors, such as jet drives or sterndrives, might also have different cooling systems. However, most of these motors use either water-cooling or a closed-loop cooling system with coolant.
Conclusion
Whether a boat motor uses coolant depends on its type and design. Inboard motors typically use coolant, while outboard motors often rely on water-cooling. However, newer outboard motors might utilize a closed-loop cooling system with coolant.
