On June 10, 1997, at 2045 eastern daylight time, a homebuilt Kolb Mark III, N1144T, was substantially damaged as it impacted the terrain during a forced landing near Findlay, Ohio. The certificated private pilot/owner and builder received serious injuries. Visual meteorological conditions prevailed and no flight plan was filed for the flight conducted under 14 CFR Part 91. The flight originated from a private airport, Lutz Field, about 2030. The pilot termed the departure as a normal take off and climb out to 800 feet msl. At level off, the engine lost partial power, and then, lost complete power. The pilot stated that the carburetor had come off in flight and he attempted to return to the airstrip, but was forced to land in a corn field. A Federal Aviation Administration Inspector examined the wreckage and reported that the landing gear was bent upward and the fuselage contacted the ground. The attaching bolts to the aft fuselage tubing structure, which supported the vertical rudder and horizontal elevators, were broken. The Inspector stated that the propeller, mounted on the engine behind and on top of the cabin facing aft, was fractured. The aft fuselage tubing structure directly below the propeller contained dents and scratches. Inspection of the flight and powerplant controls verified continuity. Fuel quantity remaining in one of the two 5 gallon tanks was estimated to be 2 quarts with the second empty. The engine contained two carburetors. One carburetor was found on top of the wing with the throttle linkage still attached. The mounting clamp to the detached carburetor remained attached to the rubber bushing on the engine. The Inspector reported that he was unable to check for a torque value. The second carburetor remained on the engine. The pilot reported that he had not recently done any maintenance on the engine.