On February 15, 2011, about 1130 mountain standard time, a Cessna 172H, N2561L, made an off field forced landing following a loss of engine power near Wikieup, Arizona. Sheble Aviation was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The certified flight instructor (CFI) and student pilot were not injured; the airplane sustained substantial damage to the firewall. The cross-country instructional flight departed Sun Valley, Arizona, at an undetermined time with a planned destination of Prescott, Arizona. Visual meteorological conditions prevailed, and no flight plan had been filed. The CFI reported that the airplane was in cruise flight at 9,500 feet mean sea level (msl) when the engine power became intermittent followed by a total loss of power. The CFI took command of the airplane, established best glide speed, and picked a landing site. Attempts to restart the engine were unsuccessful. Prior to landing, the CFI turned the mixture control and ignition switches to the OFF position, and unlatched the doors. On final approach, he added flaps, and turned the electrical master switch to the OFF position. The airplane was almost stopped when it contacted a rut, and the nose gear sheared off. A Federal Aviation Administration (FAA) inspector examined the wreckage on scene. He observed no obvious defects with the engine, and the fuel tanks exhibited sufficient fuel. The left fuel tank contained fuel up to the bottom of the filler neck. The right fuel tank contained fuel to within 3/4-inch of the filler neck. Maintenance personnel under his supervision drained fuel from the left and right wings sumps and fuel strainer. The left wing tank measured approximately 15 US gallons; the right wing tank measured approximately 17 US gallons. He observed no water or contaminants; the content was bluish in color and had an odor consistent with aviation gasoline. He noted that the throttle was at the 3/4 full forward position, the mixture was set to full rich, and carburetor heat was on. The fuel selector was in the off position. Maintenance personnel disassembled the airplane, and relocated it to Sheble’s facility at the Fort Mohave, Sun Valley Airport, Arizona. The FAA inspector supervised an inspection of the airplane at the operator’s facility. Prior to the inspection, the airplane was configured with an external fuel supply, and the engine was ground run. The engine would operate at idle power for a brief amount of time, but would not accelerate as the throttle was moved to the forward position. Inspection of the engine compartment with the engine running revealed fuel dripping from the main fuel supply line in the area between the fuel strainer and the carburetor inlet. Inspection of the fuel line revealed that approximately 6 inches of the 18-inch hose assembly had deteriorated and cracked, resulting in the leak. A replacement hose assembly was installed, and the engine ran normal under all perimeters. The data tag on the hose assembly identified it as being a Stratoflex P/N- 111417-8D0250, TSO C53A, A, OP2000PSI, A1/92, CD3QT91. The CD3QT91 indicated this hose assembly has been in services since the third quarter of 1991. The engine was installed in this airplane on June 2, 2008, with 1,155.2 continuing hours since major overhaul. The engine currently had 2,120.3 hours since major overhaul with no record or documentation of any hose assemblies being replaced or repaired.