Good day, I have a relatively old motorcycle and am getting it back in shape. However, I can’t get it on for a long time. The motorcycle only has a kick starter. It’s a Dellorto VHBZ 25 B S carburetor. The carburetor has been overhauled. However, when starting it comes out of the golden vent tube in the air intake (picture follows) petrol sprayed out. I assume that the carburetor overflows, as the spark plugs are always wet. I have b ereits tries to turn the mixing screw completely for the fuel supply, but even then petrol from the tube sprayed. Does someone have a tip ? Thank you very much! Addition: The whole thing only occurs with a carburetor on a cylinder.