Get the model number (generally in the format 917.xxxxxx).. the number is on a small plate usually located under the seat (if it is a fold-up seat) or it might be on the dash .
call Sears, give them the number, and ask for a replacement manual.
You could also try calling AYP at ! 800 659-5917 5am-5pm mon-sat. They may be able to send you a photocopy of the manual.
Russ Shade, June 2007