On October 9, 1994, at 1530 central daylight time, a Cessna 172H, N8181L, was destroyed while taxiing at a private airstrip near Moro, Arkansas. The private pilot and passenger were not injured. Visual meteorological conditions prevailed for the personal cross country flight. The pilot reported the following information. After a normal landing, when power was applied during taxiing to turn the airplane around, the engine made a sound and died. The pilot attempted to restart the engine, again a sound was heard, and then smoke and flames were observed coming out of the engine cowling. The airplane burned in less than 10 minutes. The pilot recalled smelling gas in the cockpit on the day of the accident. Examination of the airplane by a Federal Aviation Administration inspector revealed that the area forward of the firewall received very little thermal damage, and there was evidence of heat in the airbox. The cabin heat was on, and it appeared that flames traveled through the heater ducting into the cabin. The source of the fire could not be determined.