Re: Four Wheel Bicycles.... Anyone ever?
Most states will see four wheels as a motor vehicle, not a bicycle and will require all of the things required on any car. Lights, horn, brake and turn signal lights, etc. Not to mention registration, insurance and possibly emmision and/or safety inspections.
To answer your question, yes, several people have motorized the four wheeled vehicles that were originally designed for pedal power.
Check your state laws before investing in a project that might be unusable.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"