The 4N Yakubovsky equations have been solved precisely for different realistic 2N interactions acting in the states 1S 0 and 3S 1− 3D 1. The Bonn potential predictions come close to the experimental value. We also study the changes in the formalism to include charge-independence breaking and illustrate its effect due to the 2N force in the state 1S 0 by a few examples. The 3N and 4N binding energies turn out to be strongly correlated.