It is possible to make some basic carburetor adjustments without the vehicle running, but it is generally not recommended. Carburetors work by mixing air and fuel in the correct ratio to create a combustible mixture for the engine. The amount of air and fuel that is mixed is determined by the position of various valves and jets in the carburetor. When the engine is running, the vacuum created by the engine draws fuel through the carburetor and mixes it with air. This creates a fine mist of fuel that is then mixed with the engine’s air supply to create a combustible mixture.
When the engine is not running, there is no vacuum to draw fuel through the carburetor, so it is difficult to make precise adjustments. Additionally, some of the carburetor adjustments require the engine to be running in order to be effective.
For these reasons, it is generally recommended to only make carburetor adjustments when the engine is running.
