On May 20, 1997, around 1415 central daylight time, a Piper PA-31-350, N4105Q, experienced an in-flight fire in the left engine which was first noticed by the pilot upon touchdown into Sparta, Tennessee. The airplane was operated by the pilot on a personal flight under the provisions of Title 14 CFR Part 91. The prevailing weather was visual meteorological conditions and an instrument flight plan was filed. The airplane sustained substantial damage. The commercial pilot and his five passengers were uninjured. The flight originated in Sarasota, Florida at 1215 eastern daylight time and was destined for Huntingburg, Indiana. During cruise, the pilot noted higher than normal fuel consumption on the left engine which prompted him to divert to Sparta. The pilot stated he made a normal landing. On the landing roll-out, he noticed the left engine compartment was on fire and stopped the airplane. He evacuated the airplane, and extinguished the fire using a hand-held fire extinguisher. Subsequently, an airworthiness inspector from the Nashville FSDO examined the airplane. He noted extensive damage, including melted fuel lines, throttle and propeller cables separated with concurrent evidence of heat damage, and a buckled firewall. Representatives from Textron Lycoming, the engine manufacturer, and Lear Romec, the fuel pump manufacturer, were involved in the subsequent examination of the engine. It was determined, after pressurizing the fuel pump, that there was a leak in the fuel pump precipitated by a possible problem with the gasket material. The screws around the gasket loosened, allowing the leak to start. This leak allowed fuel to have contact with the heated engine, and it provided the fuel for the in-flight fire. The fuel pump, part number RG9080J7A, was overhauled by D & G Fuel Supply in April. This overhaul shop was an approved facility which used the Lear Romec overhaul manual. Their last FAA audit was in March of 1997. There were no reports of problems with this facility. As per the overhaul manual, the torque on the fuel pump attaching screws was set, and then the pump was pressurized to 60 pounds per square inch (psi) to determine if there were any leaks. At this time, no leaks were noted. Currently, the fuel pump manufacturer, Lear Romec, has released a Service Bulletin, number 101SB020, which recommends inspections of the torque on the attaching screws every 50 hours or 6 months, whichever comes first. According to an engineer from Lear Romec, this measure is a safety precaution to prevent further in-flight fires while the company attempts to determine the reason the screws are loosening.