A detailed discussion on CP violation, the electric-dipole moment of the neutron and several muon-number changing processes is given based on the SU(2)×U(1)×SUF(2) gauge model, where SUF(2) corresponds to the symmetry of horizontal flavour. The model contains the neutral gauge bosons Sµa of a new type which carry the electronic and muonic numbers. We have obtained, from the present experimental data, the following bounds on the effective coupling constant GS of Sµa with leptons and quarks: 3×10-11 ≪ Gs/GF ≪ 5×10-5 and, if ULf = URf, 4×10-6 ≪ Gs/GF ≪ 5×10-5.