Flite Dek 180 Tach operation

[Brianrv-4]

I have my tach wires as hooked per spec. They are hooked to my p leads on a 0320 lycoming.
I also installed the 30 k resistors as shown in book. I noticed when I was spinning up my motor for the first time to pre oil that my tach was junping from 0 to 5186 or something like that. I did not have plug wires or plugs in engine at the time, nowhere to discharge spark.I also have the the revelotion to 2 in set up .Is this what would happen?? . I havent cranked engine yet.

 

[dynonsupport]

Until the engine is actually running, this isn't totally surprising. You've got the impulse coupling firing at one time, the other mag firing at another time, etc. Not a normal situation. All you really proved is that the EMS is hooked to at least one mag.