What Causes the Engine to Stall When the Choke Valve is Opened?

[JoshuaLynn]

When the gasoline engine stalls immediately after opening the choke valve, it indicates that the engine temperature is too low to rise properly. In such cases, the choke valve should be partially closed to increase the fuel-air mixture concentration. If the engine stalls upon opening the choke valve, it suggests that the cylinder cannot heat up or that components are not operating smoothly, requiring a very rich fuel-air mixture to forcibly sustain operation. If excessively low ambient temperature is ruled out, check the lubricating oil and replace it if it has deteriorated. Below is an extended explanation: The function of the choke valve: Starting the engine in winter can feel very difficult. Especially in the morning, it can be quite perplexing. In fact, winter starting difficulties mainly occur in carburetor-equipped engines. During the design of such engines, consideration was given to the fact that gasoline does not evaporate easily in winter, making starting difficult. Hence, the choke valve was specifically designed. The choke valve reduces the amount of air entering the carburetor intake, increases the fuel pressure at the nozzle, and enriches the air-fuel mixture. This makes starting the engine easier.