  As experimental constraints on the parameter space of the MSSM and close
variations thereof become stronger, the motivation to explore supersymmetric
models that challenge some of the standard assumptions of the MSSM also become
stronger. For example, models where the gauginos are Dirac instead of Majorana
have recently received more attention. Beside allowing for a supersoft SUSY
breaking mechanism where the gauginos only provide finite threshold corrections
to scalar masses, the cross section for the production of a squark pairs is
reduced. In addition, Dirac gauginos can be used to build models that possess a
U(1)R symmetry. This symmetry can then be identified with a lepton number,
leading to models that are quite different from conventional scenarios. The
sneutrinos in these models can acquire a vev and give mass to the leptons and
the down-type squark. The phenomenology is novel, combining signatures that are
typical of R-parity violating scenarios with signatures arising from
leptoquarks. Correspondingly the constraints from electroweak precision data
are also different. In these models, one of the leptons mixes with gauginos and
superpotential Yukawa couplings can contribute to EWPM at tree level. In
addition, lepton universality is broken. In this paper we adapt the operators
analysis of Han and Skiba [1] to include the relevant violation of lepton
universality, and do a global fit of the model to electroweak precision data,
including all relevant tree-level and loop-level effects. We obtain bounds on
the vev of the sneutrino and on the superpotential couplings of the model.
