2nd Chat. No reply. RE: Craftsman Power Washer, Model # 508.988400 S/N #1020 6767 28. This data has been verified 3 times. Have photos. Problem: There is no such model number listed in your web site. Previous Chat Rep asked to to confirm these numbers. I need a manual which requires a valid model number. Or a model number equivalent to mine. Purchase from ACE Hrdware, Sept 2013.