I have a new-to-me RV-4 that I did not build. I tried to pick up flight following on a post MX flight after my recent conditional, but was unreadable by ATC. After chatting with someone at the home airport and a bit of testing, it was determined that transmissions were fine at idle, but mostly static at high RPM. This was confirmed in the air, as I can throttle down and talk to ATC.
The plane has an AEIO-320 with dual P-Mags. Radio is a Flightline FL-760. I also have an old PM1000 intercom that I found to be INOP as I began the process of troubleshooting the COMM issue. I emailed PS and they do not believe that would cause the TX issues. I have a used PM1000II coming to replace the old unit though.
The relation to RPM has me thinking ignition. I sent an email to Hartzell about the P-Mags, but have not heard back. I did find the FAQ on the old P-Mag website and it mentioned spark plug wires not being seated as a potential cause. I pressed on all the wires and found one wire on the spark plug side that clicked once when pressed, and one wire on the P-Mag side that clicked twice when I pushed it in. I fired up the engine and tested the radio on the ground. It was still sending a fair bit of static at 1800 RPM when running up and transmitting on the ground. Have not had a chance to try pickup up flight following at cruise RPM though.
Does anyone have suggestions for troubleshooting steps, or past experience with anything similar?
The plane has an AEIO-320 with dual P-Mags. Radio is a Flightline FL-760. I also have an old PM1000 intercom that I found to be INOP as I began the process of troubleshooting the COMM issue. I emailed PS and they do not believe that would cause the TX issues. I have a used PM1000II coming to replace the old unit though.
The relation to RPM has me thinking ignition. I sent an email to Hartzell about the P-Mags, but have not heard back. I did find the FAQ on the old P-Mag website and it mentioned spark plug wires not being seated as a potential cause. I pressed on all the wires and found one wire on the spark plug side that clicked once when pressed, and one wire on the P-Mag side that clicked twice when I pushed it in. I fired up the engine and tested the radio on the ground. It was still sending a fair bit of static at 1800 RPM when running up and transmitting on the ground. Have not had a chance to try pickup up flight following at cruise RPM though.
Does anyone have suggestions for troubleshooting steps, or past experience with anything similar?
