As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT REPORTED A LOSS OF ENGINE RPM INDICATION. WHEN THE TACH CABLE WAS REMOVED FROM THE ENGINE THE END WAS FOUND TO BE STRIPPED AND THE INSIDE CABLE WAS VERY HARD TO TURN AND CORRODED. THE CABLE WAS REPLACED AND ENGINE RUN CARRIED OUT WITH NO FAULTS. (TC# 20130604009)