The aircraft was on a positioning flight and being flown at a height of 1,200 ft, to remain clear of cloud, when the engine lost power. The pilot carried out a forced landing in a field during which the tailwheel detached, resulting in minor damage to the lower rear fuselage and rudder. There were no injuries. The engine was subsequently inspected and a ground run was carried out; no anomalies were identified. The pilot reported that the ambient conditions were conducive to serious carburettor icing and he candidly commented that operating the aircraft at a relatively low height meant that the application of full carburettor heat after the power loss was too late to rectify the situation.