According to the pilot, he had recently purchased the airplane and noted that the fuel tanks were contaminated with water when it was purchased. He purchased and a mechanic installed new fuel tank sumps, fuel cap gaskets, and several other parts. Three days prior to the accident, he inspected the airplane, that was tied down outside, and sumped the fuel tanks, which initially revealed about 1 tablespoon of water. He continued to sump the fuel tanks until only fuel came out, and then performed an engine run-up without any anomalies. On the day of the accident, he performed a preflight inspection of the airplane and observed about 1 tablespoon of water in the strainer from the left tank. He continued sumping the left tank until only fuel was visible in the strainer. He started the engine, taxied, and performed an engine run-up for several minutes with no anomalies noted. He performed a normal take-off and while turning the airplane on course to the destination airport the engine experienced a total loss of power. The pilot elected to perform a forced landing to a field, and during the landing, the airplane struck a tree resulting in substantial damage to the fuselage, wings, and empennage. Postaccident examination of the wreckage revealed that the gascolator and carburetor contained water. The carburetor was drained, reinstalled, and an engine run was performed without any anomalies.