What to do when co-authors want to submit manuscript for publication and you think it still has problems?
I wanted to add a fourth possibility to @artalexan's nice answer that might be more diplomatic:


Make the paper technically correct with the results you have (even if preliminary) and submit to the current venue. 


The major problem with submitting the paper is that it is dishonest, not that it is preliminary.

If the paper can be made technically correct and honest -- even if the results are preliminary -- it would be fine to at least submit it and let the reviewers judge if it is mature enough.

If you are a co-author, you should have the power to edit the misleading text. If the main author is stopping your efforts to do that, then ask to be removed from the paper.

Of course if the results themselves are incorrect (rather than preliminary) there may be no saving the paper.



On a side note, the attitude of the senior researcher in question towards publishing may be productive in the short term (getting some initial papers published quickly by misleading reviewers), but it is utterly counter-productive in the long run. Having a reputation for sloppy results/writing will seriously harm the trust that reviews/readers have in your paper ... and reputation is so important in research! I don't know your situation, but if the researcher shows no inclination to change their attitude, try to put distance between yourself and them.