Black carb 3.5cc OB

[Liquimoly F1]

Hi,
I have bought a used liquimoly F1 boat with a used K&B OB engine (3.5cc) with black carb.
I wonder if these different holes are normals:

First: The bilobed holes in the barrel


Second: This hole in the carb


Third : What is the purpose of these holes?

Thanks and regards,
and sorry about my english :oops:
Cyril from France.

[MECOA]

Both "holes" are for air bleed at idle. The notch in the barrel is to make the opening at both sides of the barrel meter the correct amount of air. The small hole on the body is an air bleed in allow air into the barrel.

[Liquimoly F1]

Thanks a lot
I was wondering if the owner made the notch in the barrel,
Best regards and thanks again,
Cyril.