On March 13, 1994, at approximately 1520 Pacific standard time (PST), an amphibious Cessna 185, N4732E, impacted the water during a precautionary landing on American Lake, Tacoma, Washington. The commercial pilot, who was the sole occupant of the aircraft, was not injured, but the aircraft sustained substantial damage. The local personal pleasure flight was on its initial takeoff when the accident occurred. No flight plan had been filed, and the ELT, which was activated by the impact with the water, was turned off at the scene. The pilot said that after takeoff, the aircraft seemed to be producing substantially less power than he expected. He moved the throttle to full forward, and adjusted the propeller to maximum rpm, but felt that he would not be able to clear the trees at the end of the lake. He then made a steep turn back toward the center of the lake, and while he was rolling out of the turn, the aircraft impacted the water and flipped over. The fuel shutoff valve, Cessna part number 9851070-2, was found to be seized in a partially closed position, restricting fuel flow.