The pilot was preparing to depart on a private flight from Cobden Vic. to Moorabbin. The Piper Cherokee aircraft was parked in front of the club house when the pilot found that the starter motor would not engage. After various attempts to get the starter motor to engage were unsuccesssful the pilot decided to hand swing the propeller. The pilot advised that he applied the parking brake, set the throttle to approximately half power and turned the magneto switches on. When he swung the propeller the engine started and ran at high RPM. The parking brakes did not stop the aircraft from rolling forward. The pilot grabbed the wing to try to arrest the aircraft's progress, however it continued to gather speed. When the pilot could no longer hang onto the wing he grabbed the tail plane. The pilot was carried 300 metres before he relinquished his grip and the aircraft sped away. The aircraft coninued south past the wind sock and broke through the perimeter fence into a paddock. It ran across the paddock and through another fence and across the airfield access road. On the far side of the road it demolished a gate before colliding with a shed and toilet, coming to rest against a farm plough. The aircraft had travelled in excess of 1 1/2 km. The low time pilot had not been trained in hand starting aircraft engines. He said that he was not aware of the regulatory requirements surrounding the starting of aircraft engines, and did not ask a nearby pilot to sit on the brakes while he attempted the hand start. He stated was not aware that the operator from whom he rented the aircraft specifically banned unauthorised attempts to rectify defects when away from Moorabbin, including the hand starting of aircraft engines.