Gep - your procedure sounds like it's fine, and should be getting you where you need to be.
I'd contact your seller, and see if you can get a different complete CARB to try. Unless you want to dig into it and start troubleshooting the "pop off" pressure on the metering needle lever assembly.

Unless you are experienced with setting that lever, I don't recommend going there; you can end up with a carb that doesn't run at all, and risk the seller saying "you did it".

PM me.