As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COMPONENT HAS A HISTORY OF CAUSING ENG TO MOMENTARILY DECELERATE AS THROTTLE IS ADVANCED PAST THE IDLE STOP TO FLIGHT. DECELERATION CAN BE OVERCOME BY CONTINUING TO ADVANCE THROTTLE THROUGH THE DECELERATION. ONCE THROUGH DECELERATION A MAXIMUM OF ONLY 90 PERCENT OF MAIN ROTOR RPM COULD BE ACHIEVED. ALL ENGINE INDICATING INSTRUMENTS ARE WITH IN LIMITS AT FULL OPEN THROTTLE AS WELL AS AT IDLE ABOVE AND BELOW IDLE STOP.