What is the standard timing on the IO-390 engine?
I ask because you want to make sure the P-mags are configured correctly, which can be done with either the EICAD program available on the Emag website or with our
EICommander.
The P-mag w/o the jumper in is set to a little over 30 degrees, which is great if you are flying behind a Continental A65 but not so good for a Lycoming O-320 or larger.
With the jumper in, they fire at 26 degrees before TDC, which works for most standard parallel engines. However, if you have high compression pistons, you might want to think about moving it down a few degrees and if you have an angle valve engine, it should be set to 20 degrees.
If you are buying new P-mags, they will have firmware version 40 (or higher) and should be set to TDC when timing them. There is no need to clock them as some have done with light props and earlier firmware versions.
PS. I will be demonstrating the P-mags and the EICommander at OSH again this summer. Watch the forums for the date, time, and location.