carb problems

[Dave Mann]

    With any new (to me) carburetor after a check that everything is there in the right place I connect it up to a lawnmower petrol tank and check the fuel level which should be just below the main jet cap. This can be a protracted affair if the needle valve is leaking, this is cured by mounting the needle in a pedestal drill and running in it's seat with some T cut. DO NOT USE GRINDING PASTE.     The petrol level is adjusted by sliding the collar up the needle valve to lower the fuel level and vice versa. The collar is sometimes secured with solder and it only needs a very small movement.

[AustinWood]

The up-draught carburetors are not sealed and the fuel evaporates from the float chamber. As it's gravity feed this is constantly replenished from the tank.
We always turn off the fuel when the car is not being used.
This also prevents the fuel level rising because of a poor seating of the valve.

[Vancevr]

so in your last picture what part should i adjust?