I am seeing an RPM display that is useable but it oscillates +/- 50 RPM in cruise. I have the constant speed prop set to 2350 confirmed by an optical tach on the glare shield and the RPM display varies between 2300 and 2400 three or four cycles in a 2 minute period.

Looking at the same 2 minutes of data, EGT and CHT are +/- 5.

A probably unrelated symptom is, "No GPS". The GPS talks to the Trio autopilot reliably but the AFS only gets the signal once in a while. Strangely, the data file shows Latitude, Longitude, and Ground Speed consistently.

I am saving the .ALD files for each flight and it is an amazing amount of detail.

Any help is greatly appreciated.

John Morgensen
RV9A