On January 23, 2007, at 1345 central standard time, a homebuilt Lancair 360, N117BG, registered to and operated by a private individual, as a 14 CFR Part 91 test flight, experienced an engine fire while taxiing following a landing at the Guntersville Municipal-Joe Starnes Field Airport, in Guntersville, Alabama. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. The commercial pilot reported no injuries and the airplane sustained substantial damage. The flight originated from the Guntersville Municipal airport at 1300. According to the pilot, while taxiing following a normal landing he smelled fiberglass and then observed smoke and fire coming from the engine cowling. He immediately stopped the airplane, and egressed. He said the airplane continued to burn. Examination of the airplane by an FAA Inspector found the airplane partially consumed by fire. Examination of the engine revealed that the fuel line from the fuel servo to the flow divider had melted from the connection at the fuel servo to the cylinder baffling. The hose was still connected to the flow divider and retained torque on the fitting. The hose was removed and examination provided that the approximately half of its original length had been burnt away or melted. Examination revealed that the hose was of non-aviation automotive origin and identified as SAE. The construction of the hose was of plastic with a vinyl outer coating. Examination of the fuel line fitting still attached to the fuel servo revealed threads in the socket were clean with no residual hose material present in the threads. There was a light amount of melted plastic on the outer end of the socket. The hose had not been properly assembled, thus allowing fuel to escape into the engine compartment.