As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE OFF ENGINE BEGAN SURGING, AIRCRAFT WAS YAWING LEFT AND RIGHT, TORQUE WAS FLUCTUATING +/- 30 PERCENT. THROTTLE CONFIRMED OPEN, ENGINE BEEPED TO MAXIMUM N2 AND NR WOULD NOT GO ABOVE 94 PERCENT UPON LANDING THE MECHANIC REMOVED AND REPLACED THE GOVERNOR AND STARTER GENERATOR AND THE AIRCRAFT WAS RETURNED TO SERVICE.