Vapour lock is a term used to describe a mechanical problem that occurs in engines. Essentially, vapour lock occurs when the fuel within the engine turns into a vapour and fails to flow through the fuel lines and into the engine. There are some synonyms that can be used to describe this problem, including fuel evaporation, fuel starvation, and engine stalling. These terms are all used to describe the same issue where the engine fails to receive the required fuel, leading to a loss of power and even engine failure if left unchecked. Some of the common causes of vapour lock include high temperatures, low fuel pressure, and fuel leaks.