I have a sears craftsman tractor model #917275751 Won't start. Starter, solenoid , safety switches are good. Tested the ignition switch. Turn the key and nothing. Any ideas?

Battery?

Hi,
The manual is here:
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0521925.pdf
And the schematic on page 33 shows that you have a continuously "hot" solenoid and there must be a ground created through the switches to trigger it. This is not the most common practice, but it still happens in the industry.
Conclusion, one of those switches is bad! My guess is ignition switch, but only a guess. Use the info provided to prevent wholsale substitution.
Peace,
Clarke