The pilot stated he crossed over the destination airport at mid field and entered a right downwind for landing to runway 36 when the engine lost power. Another airplane was on base leg for landing. The pilot elected to make a forced landing in the grass next to runway 36. He immediately switched the fuel tank from the left main fuel tank to the right fuel tank and attempted an engine restart without success. The pilot stated he misjudged his landing distance by about 150 feet and failed to maintain airspeed on final. The airplane stalled and collided with the ground on the nose gear. Examination of the airplane after the accident revealed the left fuel quantity indicator indicated empty. The fuel tank was not ruptured and no fuel was present in the fuel tank. The pilot's Operating Handbook states the airplane has three gallons of unusable fuel in each fuel tank. Three gallons of fuel was drained from the left main fuel tank. The fuel line was disconnected at the fuel flow divider, and the fuel line to the inlet side of the engine driven fuel pump was disconnected. No fuel was present. The nose section of the airplane was positioned in a brace and the airplane was tied down with a cargo strap. The engine was started and ran smoothly with the fuel selector selected on the right main fuel tank.