The private pilot was conducting a local area round-robin flight to various lakes practicing water landings under Title 14, CFR Part 91. According to the pilot, while in cruise flight, the engine lost power. The pilot said he activated the boost pump, the engine produced power again for a few seconds, and then quit completely. He reported that during the forced landing to a small lake, the airplane struck trees and landed short of the lake. The airplane's wings received structural damage. During interviews, the mechanic who removed the airplane's wings for transport, told the NTSB investigator-in-charge (IIC) he didn't find any fuel in the wing fuel tanks. Another mechanic who removed the airplane's engine told the IIC the fuel system, including the gascolator, was intact with no signs of fuel leakage. The mechanic also said he removed less than 1 gallon of fuel from the airplane's header tank. The mechanic further stated that a visual inspection of the engine compartment did not disclose any evidence of a fuel leak. A visual examination of the airplane's exterior by the IIC did not disclose any evidence of fuel staining. In a written statement to the NTSB dated June 22, the pilot indicated that according to his fuel consumption calculations, there should have been enough fuel onboard for the proposed flight. The pilot also wrote that after recovering the airplane, he saw "fuel staining on the belly indicating fuel leaking from the gascolator."