This chapter shall not be construed to prevent any occupant of premises within the city from repairing his own motor vehicles or vehicle or machinery on his premises even though exposed to public view, so long as the person pursues the work to completion with reasonable diligence; provided, however, that any vehicle which remains out of running condition with any wheel, tire, engine, body or other major part removed therefrom for a period in excess of twenty days, while remaining exposed to public public view, shall be deemed to be prima facie evidence that such vehicle or motor vehicle is not being diligently repaired and constitutes a violation of this chapter. (Ord. 463 § 3, 1985)