I need an operation manual for scott's riding lawn mower model 42589x8

Have you tried Google or Bing yet?

Hi,
You may be able to find the manual, or not. You can have this link however to the parts breakdown. This is a Murray machine made in the newly acquired Noma factory, at that time, in Jackson, TN. Basically a Noma frame with mostly a Murray deck adapted to it. Try:
http://www.outdoordistributors.com/p...PARTS-LIST.pdf
Peace,
Clarke