MYALEROGL - hi, this is a test area and normally you won't get answers here. Your question would be seen by more folks if it were posted up in the Gardening or Miscellaneous areas. Anyway - I guessed your part number might be a Craftsman mower, so I checked a favorite site for parts and it says that 917 prefix means it was made by American Yard Products. I tried finding manuals and found 3 places that may have them - but you'll need to call them with the complete part number (should be under the seat). Here they are:
Bentley Supply Co. - 1-205-669-9752 (parts help); 1-866-669-0280 (ordering) - I tried searching on "manual" at their site in their AYP area and it returned 50 pages of hits; they claim to have numerous manuals. They're open 8 - 5 CDT.
Jack's Small Engines - 1-877-73-PARTS - I've used them before for parts (not manuals) and had excellent service from them; they're in nortern Maryland and open 8 - 5 EDT.
Outdoor Distributors - 1-877-70-PARTS - I've used them before for parts and had excellent service from them. Their site is how I made the Craftsman-AYP connection. They also state they have numerous manuals but I couldn't get a hit using the part number you supplied. They're in Alabama and they're open 8 - 5 CDT.