As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING WILDLIFE SURVEY, ENGINE BECAME ROUGH AND WAS SHUT DOWN. AIRCRAFT LANDED ON RIVER LEVEE. CARBURETOR TO MANIFOLD TUBE HAD BECOME DISLODGED. REPLACED TUBE, ENGINE FUNCTIONED NORMALLY. THIS AIRCRAFT FUEL SYSTEM IS GRAVITY FLOW AND IS PLACARDED TO TURN ON ELECTRIC FUEL PUMP FOR MANEUVERING. SUSPECT BACKFIRE DUE TO DISRUPTED FUEL FLOW CAUSED TUBE TO BECOME DISLODGED.