On September 17, 1998, approximately 1120 Pacific daylight time, an experimental Kelly Kolb Mark III, N62691, collided with a tree during an attempted forced landing in an open field in a residential area of Cashmere, Washington. The private pilot, who was the sole occupant, received serious injuries, and the aircraft, which was owned by the pilot, sustained substantial damage. The 14 CFR Part 91 local personal pleasure flight had departed Cashmere-Dryden Airport about three minutes prior to the accident. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, after completing a touch-and-go landing at the Cashmere-Dryden Airport, he was in a full-power climb when the engine suddenly quit and the propeller stopped rotating as he passed through 1,800 feet above ground level (AGL). He then attempted to land in an open field in a residential area, but collided with a tree as he began the landing flare. During the investigation it was discovered that there was fuel in the lines between the fuel tank and engine-driven fuel pump, but the float bowls in both carburetors were almost empty. Inspection of the fuel pump revealed that its front cover was misaligned by 60 degrees, partially restricting the flow of fuel through the pump to the carburetors. In an interview with an FAA inspector who viewed the aircraft after the accident, the pilot said that he had disassembled and reassembled the fuel pump while attempting to fit it to the aircraft during the construction process. He said that he did not remember being aware of the alignment index marks on the surface of the pump. According to the FAA inspector who inspected the aircraft after the accident, after the post-accident fuel pump inspection was completed, the pump was reassembled with the front cover properly aligned. Then a sparkplug was removed from each cylinder, and the propeller was turned rapidly by hand. During this test, the fuel pump produced an unrestricted flow of fuel. Although the aircraft had experienced no engine problems during approximately 40 hours of flight since construction, the spark plug coloration indicated the engine had been running very lean. It was also noted that the starvation/failure occurred during a full-power climb.