Carburet problems

I just bought a Zanella XX 125 (it is 2 times), that when starting it I cannot make carbure correctly .. I do not identify what the problem is, because when I give it accelerator, sometimes it runs out without a gasoline in high and other times it does not even have a way out ... if anyone knows how to tame these kiss, I would not get badly a hand ... from now on thank you ...