Originally Posted by mmcelrea
The rpm is sensed by the g3x from the digital tach signal output on the pmag. you can hear that the rpm is fluctuating and garmin pilot shows the fluctuations. I will probably change the restrictor or add a smaller one to try and damp out the fluctuations.
Could a resonance be caused in the vacuum tube to the mags causing the timing to go out at both 1150 and 2300rpm?
Are pmags more sensitive to vacuum?
The quick way to check that theory is to disconnect the vacuum line from the pMag.
Retired Firmware Guy and Airplane Builder
2018 RV-7 QB -- Built, Flying
2007 RV-7 QB -- Built, Drowned
1998 RV-8 QB -- Started, Sold
Aided and abetted building a number of other RV's.