I have a Craftmans 46 inch Model 917.272140 mower. When mowing for a few minutes, the blades just stop. Usually it happens if a hit a small dip in the yard. Just like the switch has been turned off, but it hasn't been. I turn the mower off for a while, then go back to it. It works fine. What could be causing that?

Hi,
I broke your post free of where you put it. Since you gave the model number, I was able to look up the manual and it contained the schematic of the electrical system. This machine has an electric PTO with a relay attached. The problem you describe is the result of an overly sensitive seat switch which deactivates the relay which causes the PTO switch to disengage the PTO clutch. You should not have to let the mower sit to restart the deck; just push the PTO switch in and pull it back out to reset things.
Your manual is at this link:
http://www.managemylife.com/mmh/lis_pdf/OWNM/99030709.pdf
And the schematic is page 33, but I post it below ,also.
Peace,
Clarke