No person shall adjust or repair any automobile or motorcycle or race the motor of same while standing on the public streets or alleys of the City, except in case of breakdown or other emergency requiring same, and no person or employee connected with the garage or repair shop shall use streets or alleys in the vicinity of such garage or shop for the purpose of working on or upon automobiles or motor drawn vehicles of any description.
No vehicle shall be stopped, parked or permitted to stand with the engine running on any street unattended, and when any vehicle is stopped, parked or permitted to stand unattended with motor off upon a street having a perceptible grade, the brakes shall be set and the front wheels of such vehicle shall be turned into the right side of the street.