Watch The Yum Yums: The Day Things Went Sour (1990) : Full Movie Online Free It's almost opening day at Yum Yum Fun Park - but something terrible has happened! Those mean and yucky Sourpusses have set out to spoil the big day. Come join the fun as those yummy-smelling Yums Yums meet scary sewer rats, trick a ferocious sewer gator and match wits with the Sourpusses. Will they be able to rescue their magic toolbox and complete repairs in time to make Yum Yum Fun Park... once again... the sweetest and most fantastic amusement park on earth?