As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) OIL SOAKED POINTS CAUSING THE ENG NOT INCREASING RPM MORE THAN 2 PERCENT WHILE THE ENGINE TACH NEEDLE WOULD BOUNCE FROM 100 PERCENT TO 110 PERCENT. UPON FURTHER REVIEW, DURING THE TEARDOWN, IT REVEALED ONE OF THE TACH LEAD WIRES HAD CHAFED THROUGH ON THE TACH POINTS OPPOSITE POST.