What happened
Following an uneventful approach and landing, the pilot was taxiing back up the runway when the right engine quit. The right seat passenger immediately noted flames coming from the engine and notified the pilot, who swung the aircraft into position for wind to keep flames from the wing while securing both engine fuel shut-off valves, heater fuel shut-off and the aircraft electrical system. Pilot ordered evacuation and attempted to extinguish fire with hand-held extinguisher. Fire continued to burn for about 15 minutes until local fire dept put out flames.
The investigation
Damage precluded determination of fire source, believed to be a broken line or separated fitting in the engine fuel system which allows a quantity of fuel to collect in the nacelle before engine quit from fuel starvation, fire ignited, and pilot closed shut-off valve.