I helped a friend put his clutch in a little while back and the pedal vibrates.
He has about 400 miles on it and it still does it. I was thinking the flywheel wasn't surfaced correctly but I was going to post on this board and see if anyone else agrees with me before he buys a new flywheel. Does anyone else have any other ideas of what it might be?
It does not vibrate with the clutch engaged. BTW

 

Does the pedal vibrates when it is out, and doesn't vibrates when you push it down? If so, did you replace or did you put in the pilot bearing?

 

That is correct. However I did replace the pilot berring. (with a brass one)