What's a pilot stub?

[Paul Eastham]

The Sensenich Propeller installation instructions (http://www.sensenich.com/misc/mpinstal.htm) admonish you (repeatedly) to inspect and clean the pilot stub and pilot bore. What are they, and where do I find them?

[DanH]

Pilot bore is the big hole in the center of the prop. Pilot stub is the matching protrusion in the center of your engine flange.

[Hawkeye7A]

And here I thought the pilot stub was the main item of interest when you have to make that obligatory mad dash from your plane to the restroom during a fuel stop.