Table schema:
CREATE TABLE table_name_20 (displacement VARCHAR, model VARCHAR, fuel_system VARCHAR, power VARCHAR)

Question: What is the displacement when the fuel system is carburettor, and a power of ps (kw; hp), and also has a model of 2000?
SQL: SELECT displacement FROM table_name_20 WHERE fuel_system = "carburettor" AND power = "ps (kw; hp)" AND model = "2000"