Small Engines (Lawn Mowers, etc.): cub cadet brushcutter, fishing line, cub cadet

Question
I have a 4 cycle Cub Cadet string trimmer/brushcutter (model 4075), recently purchased.  Ran great for a few hours. Starts and idles fine, however when I give it some throttle, the end attachment (string or blade) does not move, and further throttle causes engine to die.  Apparently something is stuck or not engaging.  Thoughts?  

Answer
Is it still under warranty?

If not, I would start by removing the trimmer string shaft from the engine assembly.  Start the engine and see if it will run correctly.  If so then you know your problem is in the shaft and not the engine.  If is does not run correctly then the problem is in the engine and not the shaft.

About the only part that usually binds on the shaft is the head...usually something gets stuck, like grass or fishing line, and prevents the head from turning.

Let me know what you find.
Eric