Preheat the oven to 350°F, and prepare a 9" x 5" loaf pan with a light coating of grease and dusting of flour.
Sift the flour, baking powder, baking soda and salt together. Add the lemon zest, and blend well.
Add the oil, sugar, eggs, and yogourt to a second bowl, and beat together until smooth and well blended.
Add the wet ingredients to the dry ingredients. Mix until well combined, but do not over-mix.
Pour into the pan and bake for 60 to 75 minutes. The top should be a golden color, and a clean knife inserted in the middle should come out clean.
Remove from the oven, and allow the loaf to cool for about 20 minutes before removing from the pan.