  We perform three-dimensional simulations of magnetorotational supernovae
using a $39\,M_{\odot}$ progenitor star with two different initial magnetic
field strengths of $10^{10}$ G and $10^{12}$ G in the core. Both models rapidly
undergo shock revival and their explosion energies asymptote within a few
hundred milliseconds to values of $\gtrsim 2\times10^{51}$ erg after
conservatively correcting for the binding energy of the envelope. Magnetically
collimated, non-relativistic jets form in both models, though the jets are
subject to non-axisymmetric instabilities. The jets do not appear crucial for
driving the explosion, as they only emerge once the shock has already expanded
considerably. Our simulations predict moderate neutron star kicks of about
$150\, \mathrm{km}\,\mathrm{s}^{-1}$, no spin-kick alignment, and rapid early
spin-down that would result in birth periods of about $20\, \mathrm{ms}$, too
slow to power an energetic gamma-ray burst jet. More than $0.2\,M_\odot$ of
iron-group material are ejected, but we estimate that the mass of ejected
$^{56}\mathrm{Ni}$ will be considerably smaller as the bulk of this material is
neutron-rich. Explosive burning does not contribute appreciable amounts of
$^{56}\mathrm{Ni}$ because the burned material originates from the slightly
neutron-rich silicon shell. The iron-group ejecta also show no pronounced
bipolar geometry by the end of the simulations. The models thus do not
immediately fit the characteristics of observed hypernovae, but may be
representative of other transients with moderately high explosion energies. The
gravitational-wave emission reaches high frequencies of up to 2000 Hz and
amplitudes of over 100 cm. The gravitational-wave emission is detectable out to
distances of $\sim4$ Mpc in the planned Cosmic Explorer detector.
