What was found
THE NR 1 ENG POWER LEVER WAS DIFFICULT TO RETARD AFTER TAKEOFF FROM CLE. THE NR 1 ENG FIRE WARNING ACTIVATED 30 SECONDS AFTER SETTING CLIMB POWER. THE FIRE WARNING CEASED AFTER ENG POWER WAS REDUCED TO IDLE. THE A/C WAS RETURNED TO CLE WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND SUPPLY DUCT TO NR 1 ENG NOSE COWL ANTI-ICE VALVE RUPTURED. THE ANTI-ICE DUCT WAS REPLACED AND LEAK CHECKS WERE GOOD. IN ADDITION, THE NR 1 ENG POWER LEVER WAS LUBRICATED.