While taxiing after landing, the engine lost power and the pilot turned the airplane off the runway. The pilot exited the airplane and noticed smoke at the rear of the airplane near the engine. The pilot attempted to extinguish the fire; however, his efforts were unsuccessful and the airplane was consumed by the fire. At the time of the accident, the airplane had accumulated 4.9 flight hours. Post accident examination of the airplane showed loose B-nuts on two fuel lines and one oil line. An oil streak was noted on the runway surface and no oil was found in the engine.