  We provide a detailed analysis of the decays of doubly-charged bilepton gauge
bosons $Y^{\pm\pm}$, as predicted in models based on a $SU(3)_C\times
SU(3)_L\times U(1)_X$ symmetry. In addition to the decay modes into same-sign
lepton pairs, which were already investigated in scenarios wherein each
branching ratio was about one third, there are, depending on the mass spectrum,
possible non-leptonic decays which reduce the leptonic rates. These
non-leptonic decays are typically into a light quark (antiquark) and a heavy
TeV-scale antiquark (quark), which carries double lepton number and decays via
virtual bileptons. We choose two benchmark points to represent the particle
spectrum and present a phenomenological analysis of such decays. We find that,
while the LHC statistics are too low, even in the high-luminosity phase, they
can lead to a visible signal at a future 100 TeV hadron collider (FCC-$hh$). A
more exhaustive exploration with a rigorous inclusion of tagging efficiencies,
detector simulations and higher-order corrections to the partonic cross
section, aiming at assessing the reach of LHC and FCC-$hh$ for bileptons as a
function of the model parameters, as well as a recast of four-top searches in
terms of the bilepton model, are deferred to future work.
