  An electroweak model of SU(3) $\times$ U(1) gauge group is studied. {}From
the group theoretical constraint, the symmetry breaking of this model to the
standard model occurs at 1.7~TeV or lower. Hence the mass of the new neutral
gauge boson is less than 1.7 TeV. The $Y^\pm$ and $Y^{\pm\pm}$ masses are found
to be less than half of the $Z_2$ mass. Thus, the decays $Z_2 \to Y^{++}
Y^{--}$ with $Y^{++} \to 2\ell^+ \: (\ell \!=\! e,\mu,\tau)$ is allowed,
providing spectacular signatures at future colliders. {}From the
flavor-changing neutral current processes, the representations of quarks can be
uniquely determined. The neutrino-isoscalar scattering experiments are also
considered.
