Considering the general form of the symmetry breaking Hamiltonian including isospin violation term u3 in the framework of chiral SU(4)×SU(4) model, and imposing smoothness assumption on certain three-point vertex functions, we estimate the symmetry breaking and vacuum asymmetry parameters, masses and weak decay constants of spin-zero charm mesons in terms of known meson masses and one input variable F=fK/fπ. Our kinematical method predicts mD(S)=3.3GeV, mF(S)=3.6GeV and the non-electromagnetic mass splittings, (mD+(P)-mD°(P))u3≃(mD+(S)-mD°(S))u3=1.5MeV for F=1.28. The weak decay constant ratios are obtained to be fD(P)/fK≈fF(P)/fK=1.03, fD(S)/fK≈fF(S)/fK=0.30, which are in general much lower than the values predicted by the linear σ-model calculations. The mixing angle between η′(958) and η′′(2750) is also obtained to be ∼40°, in agreement with the recent predictions.