How to tactfully request removal of my name from co-authorship? I wrote a mathematics manuscript (see Extremely mild punishments for academic misconduct), and sent it to a professor, who then attempted to have it published after adding coauthors to the paper. His misconduct is not my concern. My concern is that the manuscript is not of publication quality, and I would prefer that my name not be attached to it. Virtually all of the manuscript is written by me, and all the work was done by me, so I can't claim that it is not my product.

My question is: What excuse do I use to have him take my name off the manuscript?

I would prefer to remain on good terms with this professor. I would also prefer not to mention in any way that the manuscript is worthless, because it solves a problem that he had been attempting unsuccessfully for quite a while, and such a statement would be deeply challenging to his pride.
You have a third choice:

Do not forget that all the authors should sign a contract before publishing a paper.
I am not telling you not to sign it.
However, it would be a good approach if you told your professor


  I am sure that huge improvements can still be made on this paper.
  Could you please delay the submission and let me work on the paper for
  another period of time?


This way, you told that paper is not of publication quality and implicated that you're not comfortable with your name on it.
If the professor still insists on publishing, only then you may say


  It's not like I'm not trusting your judgmental skills but when I know
  that I can do better, I cannot do with less. So please do not
  misunderstand me but I don't want to be a coauthor of a work that is
  less than my potential.


If your professor is professional enough, he will hear what you say.

Maybe not the best solution, but I would go with this one.