I'm not even sure how to ask this, but I'll try.
I have one of these earth augers (power post hole diggers).
It has a 2 cycle 3HP engine, under the engine is a Centrifical Clutch,
and under that is some gears (transmission), and the auger (drill)
goes below that.

The problem is the clutch is not disengaging. When I pull the starter
rope the drill already turns, and when it does start, I'm already
digging which makes it impossible to have enough hands to set the
choke lever and control the thing. Because of this, it got away from
me, but finally killed after bouncing around on the ground for a
minute.

I took this cent... clutch apart. It works sort of like the rear
brakes (drum brakes) in a car. The engine connects to a round piece
of steel, there are two dogs that fit around it with pivot points, and
a spring on each end to keep the two halves together. I understand
the principle. When the engine turns fast, the springs stretch and
the dogs contact the "drum" surrounding it. Pretty much the same as
the way drum brakes contact the drum, except this is centrifical.

On disassembly, I found the assembly attaches to the engine shaft with
a set screw, and there is a key to lock it to the shaft. Everything
was in working order, no rust, good springs, everything clean.
However, the set screw had fallen out, so the whole thing was floating
in there. I got a new set screw, and tightened it well. I pushed the
assembly tight against the washer spacers on the engine shaft. I
noticed the indent from the original set screw was in that same exact
spot, so I know that's correct.

I put the whole thing back together only to find that it still will
not disengage. As I said, everything appears in perfect working order
on that clutch. This leaves me puzzled. I just dont know what else
to do with it.

Has anyone worked on these sort of things? What can I do with it?

One other thing. I am wondering if the whole clutch could be upside
down. I bought this auger at an auction, and the last owner could
have tampered with it. When I removed the clutch assembly, I noticed
that the upper part which contacts the spacers under the engine was
very smooth, whereas the bottom side showed some wear marks from being
loose (with that set screw out). I reassembled it the same way. This
entire clutch assembly could be flipped over and installed upside
down. It will fit either way. How can I tell which way is right?
This is where I dont know how to word this question.... (here goes my
best try). In relation to the rotation of the motor, how can I tell
which is the correct way to install it to make the dogs fly outward
when the engine speeds up? I can easily tell the rotation direction
by pulling the rope a little, but after that, I'm lost......

Finally, if the clutch assembly were backwards, I would suspect it
would not engage at all, rather than engage all the time. Is this
correct thinking?????

(Unfortunately this thing has no brand name, no model number, so I
cant even get a diagram for it).

Sure could use some help.....

Mark