What was found
AIRCRAFT SUSPENDED TAKE OFF AND RETURNED TO PLATFORM, LOW POWER ON RT ENGINE. INLET AND OUTLET OF RT ENGINE WERE CHECKED, ALL CORRECT. FUEL CONTROL UNIT WAS REPLACED AND PT2, PT7 AND OIL FILTER WERE CHECKED. TRIM TO BOTH ENGINES WAS PERFORMED AND EGT REACHED 630 DEGREES, THEREFORE PYD AND PRBC VALVES WERE REPLACED. AFTER REPLACEMENT, EGT REACHED 640 DEGREES, SO PYD AND PRBC WERE REINSTALLED IN THE ORIGINAL POSITIONS. ENGINE WAS REPLACED IAW MM 71-00-00, TEST CORRECT.