While on a local flight, the pilot of the experimental amateur built airplane experienced a total loss of power. When public safety personnel asked the pilot how the accident occurred he advised that he was circling a field when the engine stopped running. He then executed a forced landing to the field which was not uniformly level. During the landing the right wing hit the ground; the airplane cartwheeled, and then came to rest upside down. When the pilot was asked how the loss of power had occurred, he advised public safety personnel that he believed that water got into the gasoline which caused the engine to stop running. Examination of the airplane by Federal Aviation Administration (FAA) inspectors revealed the wing was substantially damaged. No registration number was present on the airplane, and no data plate was present on either the airplane or the engine. Review of FAA records revealed the airplane was not registered, and the pilot was not certificated. The FAA also advised the NTSB that no maintenance records were recovered. Despite multiple attempts by NTSB investigators to contact the pilot, no phone calls were returned, correspondence from the NTSB went unanswered, and no NTSB Form 6120.1 Pilot/Operator Aircraft Accident/Incident Report was received.