MT Governor and WW200RV prop
I have some more information to add to this old thread:
Just spoke with Kevin at American Propeller regards the pressure requirements of the Whirlwind 200RV prop. Someone told me the 200RV needs higher than standard pressure, and Kevin did confirm that on the call.
The 200RV needs 425 to 450 psi to operate correctly, and Kevin looked it up just to be sure. Pressure is used to increase pitch in this hub. Apparently, 450 psi is higher than standard and higher than the MT is set for out of the box. He advised to have the governor set for the high end of the range, 450 psi.
On another call to MT USA, Dave told me they'd update my governor (model P-420-3) to the latest "F" designation for the labor cost only. He quoted that at 2 hours, or $120 bucks. There are parts that get changed in the governor as part of the update. They also will adjust the pressure up to the 450 the 200RV prop requires.
I asked Dave about the surging problem - why was it happening. He said the "pilot valve wasn't settling correctly", so that's MT's explanation of the surging issue. I know there have been reports of the P-420-3's not holding RPM real well even after the update, but Dave told me this would definitely fix the problem. We'll see...
Keeping my fingers crossed on this one - I paid over a Grand to pry this off the shelf from Van.