Erratic tach readings

While flying yesterday, my tach readout on my Dynon Skyview started going crazy…. rpm were jumping all over the place between 2600 to 4000rpm!
It did this for about 10 minutes and then returned to normal for the last 10 min of the flight. The Dynon EMS is connected to the right mag only,( Have SureFly on left side). I checked the leads connections on the mag and they were tight…..
Any thoughts/ advice is appreciated!

Walt

Engine is a AeroSports Power O-375 . SureFly EIS / Slick mag
Dynon Skyview Classic EFIS

Sounds like you need a new plane!

Ha Ha

Bad Connector

I don't have a Dynon Skyview but a GRT EIS 4000. I experienced similar behavior too from my Slick mag. I chased it down to a bad connector and/or crimp. Replaced that, problem solved.

Doug
RV-7 Flying!

I had a similar issue with a pmag, it was wiring related, the set screw on the tach wire.backed out and the wire would intermittently break continuity.