As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOTS REPORTED THAT EXPERIENCED A DROP IN THE RIGHT HAND PROPELLER RPM AND THAT IT HAD DROOPED TO 1620 RPM ON TAKEOFF. MAINTENANCE CLEANED THE CONNECTOR ON THE RIGHT HAND PROPELLER TACH GENERATOR AND RE-INSTALLED. REFERENCE BEECH 1900 MM 77-10-00.