READ ENTIRE POST because I jump around a bit:
Try jump starting it or using a battery charger with a "Boost" setting (carefully). Sounds like a bad battery. If that doesn't work, move on to the starter solenoid. Also look for a burned fusable link or a blown fuse. That mower should have headlights, if they don't come on even faintly with a known good battery, it's not the solenoid and the problem is in the wiring somewhere before the solenoid. Then suspect the above fusable links or fuses or the ignition switch. Those types of ignition switches are prone to failure especially how they are mounted where corrosion can start to form. Easy to replace and you can find cheaper ones than the Craftsman/Poulan branded switches. If your headlights are bright, go with the solenoid AFTER you make sure the switch under the seat (the one that shuts it off if you get off of the seat while it's running) is working. They can fail quickly too but can be bypassed long enough to see if that is the problem (Don't operate the mower with this switch bypassed.) Any good parts store should be able to test the solenoid so, you'd only be out a bit of time if it tests good. Just take the whole starter out.
monte
April 2008