This is ancient history, but my tendency now would go with the ain't broke advice - with the exception of the diaphragm and other more fragile parts. When I did my overhaul in the old days, the first attempt at a test flight resulted in a very rough running engine with fuel all over the place below the vent tubes. I learned that they had sent another needle version that didn't stop fuel flow into the already "full" float bowls. I replaced with the old needles.and put another 600 hours on the airplane. A note on ultrasonic cleaning. What is being used as the fluid in the ultrasonic bath. The reason I ask is that there are numerous chemicals that can be used that would not harm epoxy but would loosen sediments for rinsing. Is the fluid prescribed by Rotax?