What is the most common air-to-gasoline ratio for small gas engines?

The most common air-to-gasoline ratio for small gas engines is 14.7:1. This ratio represents the stoichiometric mix for gasoline, which means it is the ideal balance of air and fuel needed for complete combustion. At this ratio, all the fuel is burned efficiently, maximizing power output while minimizing harmful emissions.

In small gas engines, maintaining the proper air-to-fuel ratio is crucial for performance and efficiency. If the mixture is too rich (too much fuel), it can lead to incomplete combustion, increased emissions, and fouling of spark plugs. Conversely, a lean mixture (too much air) can cause overheating and potential engine damage. The 14.7:1 ratio provides a benchmark that engine manufacturers often design their systems to achieve under normal operating conditions.

Understanding this balance is vital for troubleshooting and maintaining small engines, as deviations from this ratio can result in performance issues. Thus, knowing the standard air-to-fuel ratio is essential for anyone involved in the operation or repair of small gas engines.