Where can I find a starter bendicts for a sears model 502.255750 lawn mower?

I would start at sears.com, but since it is a briggs engine also try www.briggsandstratton.com. If you are talking about an electric starter and just need the gear the part # is 693059. You can get an Parts List and see the part and part number you need at http://shop.briggsandstratton.com/BShopProductListingPage.asp?MecID=100&CatalogID=56B2B9A7-283C-11D4-8886-00B0D0203414&SessionID=43C7B3A0-6A44-4EB2-B2CC-23B437198A68&SMSID=Smart+Search&ViewName=htsDIY&EngineModelNumber=253707&EngineType=0181# (no spaces)

cholbach
September 2005