What was found
REJECTED TAKEOFF, NO AIRSPEED ON F/O'S PFD (60KTS). REMOVED LINE AT F/O'S PITOT PROBE AND PRESSURIZED WITH NITROGEN. THERE WAS A BLOCKAGE AT FIRST THEN IT CLEARED, WAS NOT ABLE TO DETERMINE WHAT THE BLOCKAGE WAS, BUT F/O'S PITOT PROBE IS NOW CLEAR. RECONNECTED LINE. SYSTEM OPS CHECKS NORMAL PER M/M 34-11-34-4. PERFORMED LEAK CHECK OF F/O'S PITOT SYSTEM, LEAK WAS GOOD PER M/M 34-10-10-501.