On May 28, 2000, at 0930 central daylight time, a Cessna 195 tailwheel equipped airplane, N9876A, was substantially damaged during a precautionary landing following a partial loss of engine power near Kaufman, Texas. The airline transport rated pilot, who was the registered owner and sole occupant of the airplane, sustained minor injuries. Visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 91 personal flight and no flight plan was filed. The cross-country flight originated from the Aero Country Airport, McKinney, Texas, at 0900 and was destined for Galveston, Texas. The pilot reported that 20 minutes after departure, while in cruise flight, the engine began to "run rough" and vibrate. He reduced power in attempts to dampen the vibration. He initiated a precautionary landing to the Hall Airport, Kaufman, Texas. The pilot stated that as he landed on runway 17 he noticed a dirt embankment that was approximately 2 feet high running along the runway centerline. Subsequently, the airplane contacted the embankment and departed the left side of the runway. The airplane impacted trees and a fence, and came to a stop upright. The pilot stated that there was an "X" made out of PVC pipe at the end of the runway; however, he did not see the "X" prior to landing as it was obscured by tall grass. An FAA inspector, who examined the airplane, stated that the main landing gear were collapsed, and the fuselage sustained structural damage. The 300-horsepower Jacobs radial engine was test run in the presence of an FAA inspector. It took three attempts to start the engine. The engine ran rough with the ignition switch in the BOTH position, and when the ignition was switched to the LEFT position, the engine began to lose power. The ignition was switched back to BOTH, and the engine continued to run rough. The ignition switch was switched a second time to the LEFT position, and the engine started to lose power again. A continuity check was performed on the left magneto and it did not meet the manufacturer's specifications (resistance was less than the required 16,000 ohms). Additionally, the number 3, 4, and 5 rear spark plugs exhibited oil and lead deposits.