The private single-engine pilot had a student helicopter certificate. He took off to hover and check that the helicopter was in good condition. He stated that before takeoff, the helicopter was fueled with a 5 gallon can that had been painted red. Before refueling, he rinsed the can and then used a spout strainer to add about 10 gallons of fuel. After warming the engine and taking off, the helicopter flew about 50 seconds and then the engine coughed and lost power. An autorotation was initiated from about 50 ft and 35 mph. Subsequently, the helicopter landed hard, the rotor blades flexed downward and severed the tail boom, a fuel tank ruptured and the helicopter burned. Disassembly of the carburetor revealed that the main jet was blocked. Particles of red paint (that matched the paint on the fuel can) were found near the blockage. Also, the helicopter had little or no use in recent years. Reportedly, residual gum may have accumulated during the years and/or the fuel may have gummed the red paint.