On October 11, 1995, at 1825 central daylight time (cdt), a Roisum Team Mini-Max, N452BX, piloted by a private pilot, was substantially damaged after a forced landing on a road. The aircraft avoided hitting a semi trailer, but collided with a ditch. The pilot reported a total loss of engine power while on a cross country flight. Visual meteorological conditions prevailed at the time of the accident. The personal 14 CFR Part 91 flight was not operating on a flight plan. The pilot reported minor injuries. The flight departed Sturgeon Bay, Wisconsin, at 1650 cdt. An on scene investigation was conducted by an FAA Principal Maintenance Inspector (PMI). The PMI found a fuel filter retaining nut on the automotive type fuel filter had rotated, causing its inlet holes to become blocked. The fuel filter was purchased by the builder/pilot from a homebuilt aircraft supplier. The PMI said that the fuel filter nut could have been safetied to prevent rotation. During a phone conversation with the builder/pilot he agreed with the PMI as to the cause of the total power loss. The aircraft's fuel filter was also examined by the NTSB IIC. The IIC confirmed that the N452BX's fuel filter retaining nut could loosen causing complete blockage of the fuel inlet holes. A new fuel filter the same part number as the one on N452BX was obtained. The IIC found the new fuel filter's retaining nut was easily removed by hand. Investigation also revealed that complete blockage of the new fuel filter was not possible, due to the differences in shaft length between the accident aircraft's fuel filter and the new fuel filter. The reason for the differences in shaft length was not determined.