The pilot of an experimental homebuilt aircraft landed on a city street following an engine failure. Cause determined to have been the inadvertent application of the cold start pump which over-richened the engine mixture.

Narrative

Aircraft is an experimental amateur built. Ignition and fuel injection system is all electric. While recording a GPS waypoint for future use; the pilot inadvertently and unknowingly activated a micro-switch which turned on the 'cold start' function which doubled fuel flow into engine. This function is normally only used to start engine in extremely cold temperatures. The engine was unable to provide sufficient power and the aircraft quickly lost altitude. Due to the low height AGL; there was insufficient time to troubleshoot and rectify the situation. The aircraft was successfully landed on a city street without injury or damage. Engine later ran normally when switch was returned to normal position. Root design issues contributing to the incident include previously unrecognized poor ergonomics; placing the switch near the GPS where it could be inadvertently activated. Preferably; a switch securing device should also be used and will be installed. Contributing factor was the low altitude.