When I start moving the trottle, the tail motor comes on full speed (it does not track the throttle). I can push the stick all the way to the left and make it turn off, but I can't seem to get it to have more than two speeds, either on or off. I checked all the structures I could think of including gears and wires. Any idea how to fix or test for my solution? I replaced the tail motor, given the common problems they seem to have but the same behavior exist. What can I test or replace to solve the issue.

Did you crash? Mine did that after PCB and / or Gyro damage.

Here is where I have been getting my PCB's, under $16.00 shipped.

http://www.ebay.com/itm/300782014737...84.m1439.l2649

First one took 2 days to get, still waiting for the tha last one I ordered.
Going on 4 days now, I should get it tomorrow.

This seller is in Cali, so you might be able to find something closer.

If you were running without the canopy, you don't even have
to crash to lunch your PCB.

All it takes is for the flybar to nick the PCB, and it's toast.

Those surface mount components are no match for a hunk of steel
spinning at 1000+ RPM.

I had the canopy on but I did smack into a tree limb. I think that the PCB seems to be the most likely cause as the controller didn't change any settings. I also noticed that the tail motor replacement from HK did not have a plug for the flashing tail light but the tail light is there.... but not on when the heli is started. Not the end of the world but I wonder why the put a light in with no plug?

Either the plug is stuck inside the boom, or it is a factory defect.
All 3 tails I ordered from 2 different sellers have LED's and plugs.

The light, wires and plug from the old boom will swap in fine.

If you don't fly at night, I would remove them altogether.

Removing the pair of wires and plug will save you 3 grams.