On May 19, 1998, approximately 0630 mountain daylight time, an Air Tractor AT-301, N4326S, nosed over during an aborted landing at an agricultural application airstrip about three miles northwest of Idaho Falls, Idaho. The airline transport pilot, who was the sole occupant, was not injured, but the aircraft, which was owned and operated by Lewis Flying Service, sustained substantial damage. The 14 CFR Part 91 repositioning flight, which departed Rigby-Jefferson County Airport, about 15 minutes earlier, was being operated in visual meteorological conditions at the time of the accident. According to the pilot, he elected to land with a tailwind because landing in that direction would allow him to come to a stop near the equipment that was going to be used to load chemicals into the aircraft. He said that after the aircraft touched down, he became uncomfortable with the downwind landing, and elected to execute a go-around. When he applied power, the engine coughed and did not accelerate, so he retarded the throttle and then applied power a second time. During the second power application, the engine again coughed and failed to accelerate, so the pilot retarded the power to idle and attempted to complete the landing. During the landing roll, the pilot brought the stick to the full-aft position, and the tailwheel settled onto the terrain. But, according to the pilot, as the aircraft slowed, the tailwind lifted the tail and the aircraft nosed over on the dirt airstrip. In a post-accident interview, the pilot, who had leaned the fuel mixture en route, said that the engine had been running fine prior to the attempted go-around, but that he had failed to adjust the mixture prior to the landing. He further stated that he felt that if the mixture would have been richer when he applied power for the go-around that the engine would have accelerated normally.