The aircraft lost power during takeoff and a forced landing was made from 400 ft AGL to a slag dump about 1 mile south of the airport. The right wing was substantially damaged by the initial impact as the aircraft was turning right at touchdown. The nose gear separated as did the left main gear. The pilot was seriously injured. The passenger was not injured. During preflight the pilot noted the left tank was almost empty and the right tank contained about 15 gallons of fuel. The tank selector indicated that the right tank was being used. After the accident it was discovered that the selector was installed 90 degrees out of phase. When it indicated right tank it was on left tank. The selector would have to be positioned to off to use fuel from the right tank. The aircraft had been flown 3 times since the annual inspection about one half hour each time and always with selector on the right tank position. If left tank position had been used the engine would have quit as this would have been off.