What maintenance practice can help prevent gum and varnish buildup in the carburetor?

Using a fuel stabilizer is an effective maintenance practice to prevent gum and varnish buildup in the carburetor. Fuel stabilizers work by slowing down the oxidation process of fuel, which helps maintain the fuel's chemical composition over time. This is particularly important for small engines that may not be used frequently, as gasoline can deteriorate and form deposits that clog carburetors, fuel lines, and other components. When fuel goes stale, it can lead to varnish and gum buildup, which disrupts the flow of fuel and can cause performance issues or starting difficulties.

In contrast, regularly changing the oil, cleaning the air filter, and changing the spark plug are important maintenance tasks for overall engine health, but they do not directly address the preservation of fuel quality or the prevention of buildup specifically in the carburetor. These practices contribute to engine efficiency and longevity, but they do not prevent fuel deterioration in the same way that a fuel stabilizer does.