What is the relationship between fuel temperature and vapor lock?

Higher temperatures can indeed lead to vapor lock, which is a situation where fuel vaporizes in the fuel lines or carburetor before it can reach the engine cylinder. This phenomenon occurs because as the temperature of the fuel rises, the likelihood of it forming vapor increases. When the fuel becomes vapor instead of liquid, it creates bubbles in the fuel system, which can obstruct the flow of liquid fuel to the engine.

Understanding this relationship is crucial for maintaining engine performance, particularly in small engines that may be exposed to varying environmental conditions or during high-temperature operation. Ensuring that fuel remains at a lower temperature helps maintain it in a liquid state, avoiding the problems associated with vapor lock, such as loss of engine power or difficulty starting the engine.

In context, while some may think that lower temperatures would contribute to vapor lock or that temperature has no effect at all, the direct correlation between higher fuel temperatures and the risk of vapor lock is critical knowledge for effectively managing engine performance.