Grate potatoes finely into a bowl. (Mom uses a box grater, I use the food processor)
Drain potatoes by squeezing out excess liquid. Grate onion and add to potatoes with onion juice. Beat in eggs, flour and salt.
Heat oil about 1/2 inch deep in a skillet. Spoon batter into oil, spreading pancake batter into cakes about 3 inches in diameter. To prevent oil from splattering when you spoon batter into pan, sprinkle salt into oil just before first pancake is spooned into oil. Drain pancakes on paper towel.