What's the difference between plunger carburetor and vacuum diaphragm carburetor? Who is more dominant?

The main difference is that the main types of "lifting" throttle are different. Plug carburetor lifts the throttle valve directly with the throttle pipe, while vacuum carburetor lifts the throttle valve indirectly with air pressure.

Plunger carburetor has the advantages of simple structure, small volume, low cost, slightly better acceleration than vacuum carburetor, but slightly worse fuel economy. On the contrary, the vacuum carburetor has complex structure, large volume and high cost. The acceleration is slightly lower than that of the plunger carburetor, but the fuel utilization rate is higher and the fuel economy is better. This is basically the case in theory, but in practice, especially for small-displacement vehicles, the difference between them is not obvious.