Harry Lime
Practitioner
Others have already warned you of having the lens fall off. But you can also affect the rangefinder focus accuracy, as you would have altered the angular orientation of the lens cam, and thus, the detected focus movement.
Bottom line, click the lens in firmly.
And the flange focal distance could be off. If the distance from the rear element to the film plane is incorrect, your pictures can be out of focus.
The easiest solution is to just send it to Yye for a CLA. It probably hasn't been serviced in decades.