Wiktionary
change horses in midstream
alt. (context idiomatic English) To change one's plan or approach when an effort is already underway or at another inopportune time. vb. (context idiomatic English) To change one's plan or approach when an effort is already underway or at another inopportune time.
Usage examples of "change horses in midstream".
Yet the community classified him as radical because in November 1944 he had voted for a fourth term for Franklin Roosevelt on the theory that you shouldnt change horses in midstream.
I used to represent the Common Europe Satelserv, but a year or two ago I managed to change horses in midstream.