In the part below (Sketch of Revolve 1) I have the flange diameter in the sketch at 1.09375 which rounds off to 1.0938 for the radius of the flange, that should make a diameter of 2.1875, yet when I measure the part (Tools, Evaluate, Measure) I get a diameter of 1.6395. Do not understand what causes this discrepancy.
That's because you added a scale feature to the part. Scaled at .75:1, 2.186 works out to 1.6395.