Print quality worse after installing MK2S upgrade kit
I'm stumped. A year ago I got a MK2S upgrade kit and I finally installed it two weeks ago in preparation of getting the 2.5 upgrade. I printed all of the MK2S parts in PETG and during assembly I found that the holes for the bearings in the x-axis parts were too big because they were designed for ABS shrinkage. So I used the original x-idler and x-motor parts. Since then prints are not as good as they used to be. There are pronounced lines where the geometry changes. It looks like for one layer the perimeter is slightly larger or smaller. You can see this at the bottom of a hole and then again at the top of a hole and so on. I have tried tightening belts, loosening belts, reducing speed, and I put almost all of the original parts back on. The only new parts left on are the rambo box, rods and bearings, the y-motor mount, and part of the extruder body. In the pictures below "Old Bad MKS" are parts that were printed before the upgrade and the parts with no text I printed last night for comparison. One picture shows both new parts together so that you can see a problem on one part affects the other part. The arrow is just so I know how they were oriented on the build plate.
All of these parts are printed with the same gcode and I did not change the firmware. Any suggestions?