As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RUNNING FUEL LEAK AFER REPLACEMENT OF O-RING ON DRAIN VALVE. ORIGINAL LEAKAGE WAS MINOR FROM AROUND ELONGATED RIVET HOLE ON RETAINING NUT INSTALLATION. HOSE FOR DRAIN VALVE WAS .50 INCH INSTEAD OF .4375 INCH AND NUT WAS OFFSET FROM HOLE BY .1250 INCH DUE TO MISALIGNMENT OF HOLE AND NUT. SUBMITTER STATED THE INSTRUCTIONS OF MOONEY SB M20-188 WERE NOT ENETRED IN LOG BOOK.