On July 11, 1998, about 1300 Alaska daylight time, an experimental/homebuilt Meeuwsen Wagabond airplane, N36GM, sustained substantial damage during a forced landing on a roadway, about 5 miles northeast of Wasilla, Alaska. The tailwheel equipped airplane was being operated as a visual flight rules (VFR) local area personal flight when the accident occurred. The airplane was registered to, and operated by, the pilot. The certificated airline transport pilot, the sole occupant, received minor injuries. Visual meteorological conditions prevailed. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on July 13, 1998, at 1105, the pilot reported the following: He recently completed a flight from California, through Canada, to Wasilla. During the trip through Canada, the pilot encountered rust deposits in the fuel supply. He drained the airplane fuel sump before each flight until no rust deposits were observed. The airplane has two, metal wing mounted fuel tanks. The tanks do not have an individual sump. The only fuel sump is an airframe gascolator. Prior to departing on the accident flight, the pilot said he drained about a quart of fuel from the sump, and did not notice any contamination. The pilot said he departed a private airstrip adjacent to Cottonwood Lake in Wasilla. The airplane climbed to about 50 feet above the lake, and suddenly began to run rough. The engine was producing popping and banging noises, and began losing rpm. The pilot said he applied carburetor heat, and leaned the fuel mixture. The engine speed recovered to about 2200 rpm, but continued to run rough. The pilot reported he attempted several carburetor heat and mixture combinations, but the airplane did not gain any altitude. After traveling about 1 mile over the lake, the airplane was approaching an area of trees and a roadway with adjacent electrical power lines. The pilot said he selected an emergency landing area on the roadway and dove the airplane toward the ground between several sets of power lines. The airplane landed on the roadway, and the right wing struck a stop sign. The pilot said he then applied right rudder to intentionally swerve the airplane into a ditch. A Federal Aviation Administration (FAA) airworthiness inspector, Anchorage Flight Standards District Office (FSDO), Anchorage, Alaska, examined the airplane wreckage after the pilot/owner recovered the airplane. The inspector indicated the pilot had fueled the airplane with automotive gasoline from gas cans. The carburetor and the airframe gascolator had been disassembled by the pilot. The inspector noted the gascolator appeared to be clean. The interior of the carburetor bowl exhibited evidence of rust.