addition on usual flodding issue:
sometimes your favourite setup of two carbs happens to be ruined by an unexpected flodding of one of the carbs
here is what i experienced:
suddenly the perfect iddle does not come steady anymore the engine stumbles and it dies
it is usually one of the carbs, not the two of them, you open the air filter box and you see one carb completely full of fuel
the culprit ? the floater gets stuck by the protruding paper gasket
this is the explanation:
the cardboard gasket that isolates the lower body from the intermediate tends to move and protrude a little, enough so that on some occasions the float is blocked by it, in this way the valve does not cut off the flow, and the gasoline overflows the tank and flood the carburetor
the proof:
when flodding happens, try hitting** the carburetor with a rubber mallet (in the area near the fuel reservoir of the carb), the vibration will cause the float to come loose and hence block the flow of fuel by means of the shutting valve, and the flooding will stop.
If when hitting with the hammer, the flood does not stop, the problem is elsewhere
**carburetor body is sort of aluminium/pot metal mix, i said a rubber mallet and i say hitting, but be careful, we do not want to break the carb body, i will hit only in the corners/edges of the body, lower section close to the place in which the floater si located
the solution:
If this is the problem, the solution is not too complex, but you must disassemble the carburetor again until you reach the float, place the gasket very carefully and cut any edge of it so that nothing protrudes from the inner wall of the tank.
and ensure that the float moves freely in place