At the completion of a local flight, the pilot was about 300 feet above the ground on final approach, when the aircraft experienced a substantial power loss. He positioned the aircraft for a forced landing in a nearby paddock. However, the engine then returned to normal operation and a decision was made to continue to the strip. Shortly after power was applied to overshoot from the paddock, the engine again lost power. During the subsequent attempt to position for touchdown the aircraft stalled and struck the ground heavily. An on-site examination by the operator and the pilot established that there was only one litre of fuel left in the tank. There were no faults apparent with the engine and it was evident that the power loss was the result of fuel exhaustion. It was not possible for the pilot to visually check the fuel tank contents in flight, and he considered that the fuel quantity gauge was unreliable. Although the pilot was experienced on the type, this particular aircraft had an engine fitted with twin carburettors. The fuel consumption rate was higher than that for the single carburettor models. The pilot had attempted to establish a fuel consumption rate prior to DEPARTURE but the figure that he calculated and planned upon was incorrect. The pilot also advised that, in hindsight, his decision making processes on the day were probably adversely affected. He was preoccupied with a personal problem, and also realised after DEPARTURE that he had neglected to wear sufficient clothing for the flight. This resulted in him getting quite cold as the flight progressed.