Excuse me, what are the functions of the two holes under the choke valve of motorcycle carburetor?

One of these two holes is the idle air measuring hole, which leads to the idle measuring hole (vertical thin nozzle in the float chamber), and the other is the auxiliary air measuring hole, which leads to the main measuring hole. They basically work at low speed and idle speed. When the carburetor cleaner is sprayed through these two holes, you can see that they flow out from the corresponding position in the float chamber.

When the engine idle speed is very low, the throttle opening is very small, and then the air velocity at the carburetor throat is also very small. At this time, the air sucked by these two metering holes cooperates with the mixed gas screw to form a mixed gas with appropriate concentration for the engine to burn, and the general idea is similar.