On several official websites, it is reported that partially opening the fuel valve has no effect on petrol usage.

https://www.nairaland.com/6641394/does-keeping-generator-fuel-tap

This made sense since engineers claim that the carburetor determines fuel consumption based on load.

Therefore I decided to verify this claim's accuracy.
Before starting my generator, I opened the fuel valve for 15 minutes with the generator switched off.

Even though a considerable quantity of petrol had already poured into the carburetor, the generator turned on but died instantly.

However, as soon as I opened the fuel valve, the generator started up and ran smoothly. This indicated to me that the fuel valve, not the carburetor, was responsible for gasoline use.

To further demonstrate my concept, I partially opened the fuel valve and observed that my 2.5KVA generator operating on a refrigerator and several home appliances used far less fuel than usual.

In my opinion, halfway opening of fuel valve saves fuel significantly.

Nor mind them, it's safe alot, something that is very experimental and most people have done it, u see the people saying know are mostly those people that sell fuel and Thier cronnis

Lol…. use AC with your Gen and you'll know that opening valve half way is a waste of time.