Cream margarine with 1/2 cup sugar, then with the remaining sugar, ginger and nutmeg. Beat at high speed for 4 minutes scraping bowl often. Add eggs two at a time scraping bowl occasionally. At low speed, add flour until blended. Stir in kumquat puree. Turn into greased and floured 10' tube pan. Cover with foil and bake 1 hour and 15 minutes. Invert and remove from pan and cool.