On February 23, 1995, about 1545 central standard time, a Mooney M20E, N7142U, registered to Charles B. Young Jr., operating as a 14 CFR Part 91 personal flight, experienced a total loss of engine power in cruise flight in the vicinity of Mclain, Mississippi. A forced landing was made on a highway, and the airplane collided with a sign. Visual meteorological conditions prevailed and no flight plan was filed. The airplane sustained substantial damage. The private pilot was not injured. The flight originated from Hattiesburg, Mississippi, about 15 minutes before the accident. The pilot stated he was in cruise flight at 3,500 feet agl when the airplane experienced a total loss of engine power. A forced landing was made to a highway that had been blocked off to vehicle traffic. On landing rollout the left wing of the airplane collided with a sign, the airplane veered to the left, collided with a ditch, and the nose gear collapsed. Examination of the crash site was conducted by the FAA. The FAA Aviation Safety Inspector stated, Mr. Young was forced to make an engine out landing on the highway. "There is no suitable landing area, approved or unapproved, other than Highway-98 in this location. The landing area was unsuitable, but it was the only alternative Mr. Young had." Temporary repairs were made to the airplane by personnel employed by Gulf Coast Aircraft, Mobile, Alabama, under the supervision of the FAA. An engine start was attempted, but with negative results. Examination of the engine assembly and accessories revealed no fuel was passing through the servo fuel injector. The servo fuel injector was removed from the airplane, and forwarded to the NTSB Southeast Regional Office, Miami, Florida. It was forwarded on March 9, 1995, to FAA, Transport Airplane Aircraft Certification, Renton, Washington, for further analysis by personnel of Precision Airmotive Corporation. Examination of the servo fuel injector, revealed the outer self locking nut on the fuel diaphragm stem was not attached to the fuel regulator, and the fuel regulator traveled to the no fuel flow setting. The outer nut on the fuel diaphragm stem was replaced and a functional test was successfully performed. Examination of logbook records for N7142U, revealed the servo fuel injector was overhauled and inspected by T. W. Smith Engine Co., Inc., Cincinnati, Ohio, on January 31, 1995. The fuel servo was released to Mr. kelly Bare, Aviation Claims Administrators Inc., Birmingham, Alabama, on April 6, 1995.