On May 15, 1994, about 2000 central daylight time, a Stinson 108- 2, N9761K, experienced a loss of engine power during takeoff from a private airstrip near Kettle River, Minnesota. The airplane sustained substantial damage when it struck some trees in the forced landing. The private pilot was not injured. No flight plan was filed for the personal flight, and visual meteorological conditions prevailed at the time. The pilot stated the engine rpm dropped about 10-12 seconds after lift off, then the engine started sputtering and stopped. Federal Aviation Administration Inspectors who examined the wreckage reported the carburetor and intake manifold were damaged by ground impact. They were not able to determine if the fuel contained any contaminates. The Inspectors stated they were not able to find any engine malfunctions. The temperature was 51 degrees F., and the dew point was 43 degrees F. The pilot stated he checked the operation of the carburetor heat during his pre- takeoff engine run-up. The FAA inspector who examined the wreckage reported the carburetor heat was in the OFF position.