When you say "lost oil pressure",how did you come to that conclusion?Did the engine suddenly become a mess of noise and clattering and stop running or did the oil pressure gauge say zero?We need more info please.
Ok, but throw us a bone here...where, when, how...??? Were you riding, any recent mods, was bike in storage, any reasons for possible cause...? Something b/c otherwise you're going to get a slew of responses & then you're better off getting bike hauled to dealer for their assessment.