On November 8, 1997, at 1600 central standard time, a Reid Capella XS experimental airplane, N89FW, executed a forced landing, following a loss of engine power, near Leander, Texas. The aircraft, owned and operated by a private individual, was flown by a private pilot, the sole occupant, under Title 14 CFR Part 91. The private pilot was not injured and the airplane sustained substantial damage. Visual meteorological conditions prevailed for the local test flight and a flight plan was not filed. The flight was originating at the time of the accident. During a personal interview, conducted by the investigator-in-charge (IIC), and on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the private pilot reported that the airplane was built in 1989. The current owner bought the airplane about 2 years prior and had completed several modifications on the wings, wing spars, and engine cowling. An overhauled Rotax 582 engine was installed during the modifications. The private pilot had completed 10 hours of test flights since the engine installation and the airframe modifications of the airplane. During the current test flight, the engine lost power at the downwind to base position for the runway. When the pilot realized that the airplane was not going to glide to the runway, the forced landing was executed to a field. During the landing flare/touchdown the airplane struck a fence and the ground resulting in structural damage to the right wing, horizontal stabilizer, nose gear and propeller. During a personal interview, conducted by the IIC, and on the Pilot/Operator Aircraft Accident Report(NTSB Form 6120.1/2), the owner reported that the fuel system and ignition system operated properly. Upon disassembly of the cylinders, the rear cylinder exhibited scoring, evidence of overheating, and a seized piston ring. The owner reported sending the components for inspection by a Rotax authorized technician; who, according to the owner confirmed that the engine had seized and that the oil injector was the cause. During a personal interview, conducted by the IIC, the person to whom the engine was sent for examination, stated that he "did not confirm that the oil injector was the cause." He further stated that a differential air flow to the engine, an improper fuel air ratio, an improper fuel oil mixture, and/or overheating could have contributed to the loss of engine power. During a personal interview, conducted by the IIC, the engine manufacturer stated that the person to whom the engine was sent for examination is not an authorized Rotax representative. The engine manufacturer further stated that he has no factual data to support failure of the oil injector device when operated according to the manufacturer's guidelines. The operator's manual for the Rotax 582 engine states in part: This is not a certified aircraft engine. It has not received any safety or durability testing, and conforms to no aircraft standards. It is for use in experimental, uncertificated aircraft and vehicles only in which an engine failure will not compromise safety.