As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OWNER COMPLAINED OF LT FUEL TANK SIPHONING FUEL EXCESSIVELY FROM VENT SYSTEM. FOUND WELDED TUBE TEE ASSEMBLY HAD NOT BEEN DRILLED AFTER WELDING. VENT AIR COULD NOT REACH ANTI-SIPHON CHECK VALVE. AFTER DRILLING HOLE INTO TUBE, VENT SYSTEM OPS CHECKED GOOD.