If you area is like ours here in the USA you won't be finding those main nozzles or any many of other check valves either for these cube carburetors. Many vendors simply won't try have parts even if Walbro or Zama even make them available. I had one Zama all I needed was the welch plug that covered the main nozzle on a C1Q version and had to end up buying a new cube.
I end up throwing this cubes in the recycle bin because I can not replace the parts that I know are bad. I do save more than I throw away thanks to my ultrasonic cleaner.
The good news here is the price of many these cubes have dropped quite a bit in the last year. Some are just a little above the rebuild kits especially when you add in your labor.
I know that knowing what wrong and not being able to get the parts are a little disheartening but this is the direction the industry has taken and is beyond the repair tech control.
