Air compressor help

A buddy had an old gas powered compressor from his roofing days. Decent size tank, think it was 80 gallons. Had a 14 horse Briggs & Stratton on it. with a v4 compressor. Would go from empty to 175 psi in under a minute. Had to watch it as it had a tendency to walk around.....When we got it running in my driveway in AZ we went inside for a minute, came out to find it had taken off and was in front of a neighbors house.....He put casters with brakes in it afterwards.....