Stormin Mormon wrote, on Sat, 13 Dec 2014 09:22:12 -0500:

Oddly, I have an old Champion catalog. No
such plug that I could find. Wish I was
more help.

Thanks for checking that out.
I have the newer manual from Generac (rev 1 instead of rev 0),
which corrects two of the three errors - but still specifies
the non-existent spark plug.

I'm pretty sure that the plug designation is a typo, but,
when I pull the old one, I'll know for sure so I'll let you
know.

Thanks for looking it up for me.