I have been stuck in India for a few weeks dealing with some parental health issues so a friend flew my RV-10 to an A&P to get the annual Condition Inspection done. On the return flight, he noticed that the tach was reading high (normal max is around 2660 and it was showing ~2900) and when I looked at the flight log data, I could also see that it was extremely noisy (as were the CHT readings).
Here's the logs from the last flight before the CI - https://apps.savvyaviation.com/flights/shared/flight/10748770/deee3737-054f-4e4e-864d-f350d4a24437
Here are the logs for the return flight f - https://apps.savvyaviation.com/flights/shared/flight/10748773/97d194f4-b5e3-4df8-b3f3-197aa8ab0ac7
The plane has dual Emags/Pmags with 2xAFS 5600. The Emag 12V output is connected to the AFS 12V tach input. The A&P indicated that he didn't make any changes there.
I had a similar issue about 6-9 months ago and it finally turned out that an ignition wire (from the Emag/Pmag) was not properly seated at the spark plug end which was causing the spark to jump causing significant EMI. The strange RPM behavior didn't show up when it was running on one of the ignitions (during a ground run-up) so it was obvious that it was being caused by an ignition wire on the other ignition.
I had the friend check the ignition wires and they seem to be seated ok though he did mention that the wires at the Emag end didn't look very good (photos attached). He also did a run-up on the ground but the behavior was the same on each ignition and seemed "normal" as best as he could tell but when he flew it again, it showed similar behavior again though this time the tach reading was not as noisy (though it was still high) - https://apps.savvyaviation.com/flights/shared/flight/10755869/480eb122-4f64-47a6-b29b-1ac6622c73b7 . Interestingly enough, some of the CHTs readings are still quite noisy.
It seems like an EMI related issue based on past experience but if anyone has any other ideas on what could be causing it, I would appreciate some input.
I am thinking of replacing all the plugs and the ignition wires after I get back next week.
Speaking of ignition wires, it looks like Spruce has a 60-90 day lead time for the Emag 6 lead ignition kit. I don't see anything on the Emag site that allows anything to be ordered. Does anyone know of an alternate source for the ignition lead kit? If anyone has built a set from parts available at an auto parts store, please send me the part numbers.
Thanks!
Here's the logs from the last flight before the CI - https://apps.savvyaviation.com/flights/shared/flight/10748770/deee3737-054f-4e4e-864d-f350d4a24437
Here are the logs for the return flight f - https://apps.savvyaviation.com/flights/shared/flight/10748773/97d194f4-b5e3-4df8-b3f3-197aa8ab0ac7
The plane has dual Emags/Pmags with 2xAFS 5600. The Emag 12V output is connected to the AFS 12V tach input. The A&P indicated that he didn't make any changes there.
I had a similar issue about 6-9 months ago and it finally turned out that an ignition wire (from the Emag/Pmag) was not properly seated at the spark plug end which was causing the spark to jump causing significant EMI. The strange RPM behavior didn't show up when it was running on one of the ignitions (during a ground run-up) so it was obvious that it was being caused by an ignition wire on the other ignition.
I had the friend check the ignition wires and they seem to be seated ok though he did mention that the wires at the Emag end didn't look very good (photos attached). He also did a run-up on the ground but the behavior was the same on each ignition and seemed "normal" as best as he could tell but when he flew it again, it showed similar behavior again though this time the tach reading was not as noisy (though it was still high) - https://apps.savvyaviation.com/flights/shared/flight/10755869/480eb122-4f64-47a6-b29b-1ac6622c73b7 . Interestingly enough, some of the CHTs readings are still quite noisy.
It seems like an EMI related issue based on past experience but if anyone has any other ideas on what could be causing it, I would appreciate some input.
I am thinking of replacing all the plugs and the ignition wires after I get back next week.
Speaking of ignition wires, it looks like Spruce has a 60-90 day lead time for the Emag 6 lead ignition kit. I don't see anything on the Emag site that allows anything to be ordered. Does anyone know of an alternate source for the ignition lead kit? If anyone has built a set from parts available at an auto parts store, please send me the part numbers.
Thanks!
