What was found
IAD/SYR - FLT 6387 - DURING CRUISE ON 9-3-97 AT 2,155 HOURS, THE CREW EXPERIENCED A DISCREPANCY WITH THE LT ENGINE RPM INDICATION. AIRCRAFT RETURNED TO THE GATE WHERE MAINTENANCE TROUBLESHOT THE DISCREPANCY AND FOUND THE LT ENGINE TACH GENERATOR HAD FAILED. MAINTENANCE REMOVED AND REPLACED THE LT TACH GENERATOR IAW THE PROCEDURES AS OUTLINED IN THE MM. MAINTENANCE PERFORMED THE REQUIRED TESTS AS STATED IN THE MM. AIRCRAFT WAS THEN RELEASED FOR SERVICE. (X)