Suspect is the throw-out bearing. It is nearly impossible to put it in backwards without noticing. There are long and short throw-out bearings. If you put in a bearing that was shorter than the one intended for the clutch, you would have exactly the situation you described..
it took me a couple hundred miles to figure out where exactly it engages....maybe you are halfway in, halfway out? these clutches are soo much lighter than the termy cobras......
I have been having the same problem. I got it figured out now......it is just so much different than my termi. It engages way much later in the travel.
The clutch chatter is normal, and I believe they even state that in the owners manual. I have pretty much figured out a way to drive it so it doesn't chatter anymore though. I think with some more gear it would be almost non existant.