I have a newly purchased Delta 14-651 hollow-chisel mortiser, and I am
using the included bit set.

No matter where I set the bit clearance, no matter how fast/slow I feed
the bit, and no matter how deep I go per pass, my bit clogs with
material almost instantly.

I'm using well-dried cherry, and the 5/16" bit seems to do okay. But
as soon as I step up to the 3/8" bit, it clogs. Same with the 1/2".

I know the included bit sets aren't the highest quality, but I'd like
to investigate technique mistakes before I go blaming my tools. (And
sending more $$ to LV for their Japanese set!)

Any help would be mondo appreciated!!

BTW, thanks to charlieb web page about clearance setting!