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Even though I did have a P-Mag malfunction, which I’m told is rare, I’m still glad I have them. Since I had all the spark plugs out, I decided to buy a new set. Not a big deal when you have electronic ignitions w/ automotive spark plugs. My set of 8 cost me less than one aircraft spark plug—$18.32 at Napa. ;-) They recommend you replace every 100 hours, so in 800 hours I will have replaced with new all the plugs 8 times and still have spent less than a set of 8 aircraft plugs! Also when I get my P-Mag back and reinstall, timing will be a breeze—just a puff of air!! So if your contemplating electronic or bendix/slicks, this is stuff to think about. D.
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Can you tell us more about how your pmag failed? -
Flygirl, that sounds like a reply to a question which I can't see...?
Incidentally, I am also about the change over to electronic ignition. We are going for the Surefly SIM mag replacement system at this stage, just waiting to hear about availability.
Emag / Pmag would be nice because you don't need the (very small) back-up battery, but they aren't available for 6-cylinder engines.
I would like to know more about your Pmag failure too.Comment
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During cruise flight, out of the blue the Tachometer started fluctuating wildly between 2300 and 2800. Nothing else seemed out of the ordinary, meaning the prop was acting normal. It continued for the rest of the flight. A mag check on the ground showed something was really wrong. We took the tach wire out of the R-Mag to start trouble shooting, flew the plane and the tach was fine--so Rt-P Mag it is. Also upon further inspection we were not getting any spark to any plugs connected to that mag, but the spark plugs themselves said only the #3 & #4 cyl showed no spark--covered in a white powder. P-Mag folks said to switch the P-mag green plugs ( right to left and visa versa) to make sure it wasn't our wiring. We did that and at some point ended up getting back spark to the #1 & #2 plugs, but it was weak and still nothing in the 3 & 4 plugs. All my plugs to the Rt P-Mag are on the bottom. It all sounds very confusing I know, and the P-mag technician mentioned he has seen this before, send it back. We questioned him how the mag would cause the tach to mess up and he said it has something to do with the upper and lower signals being sent to the Dynon Skyview and how the Skyview is interpreting it. Above my pay grade so if your needing more info than that I bet they would explain it better.
I certainly hope this is the problem, otherwise we have no idea why the tach would do what it did or why there isn't any spark to #3 & #4. He thinks it's either the coil, or a circuit board issue. I did notice two quick disturbances in the headset just before this happened. Part of it?? Who knows. Another point to make here is that at lower tach setting on the ground,nothing showed up as abnormal. Only the higher RPM in flight and during take off it shot up to over 3000.
Jared, I see you have the P-mags now. We have 4 and after 53 hrs, only one has acted up, if it is the problem. I have not heard of the Surefly Sim mags. The P-Mag web site has a set for a 6 cyl for $1600 each, but they are not in production yet. Another point to make for the P-Mag--much lighter than a regular mag. Not sure how they compare to the Surefly. I see that one looks like a regular mag. If it makes any difference to anybody, the P-Mag is prettier.
Donna P.S. I expect to have it back next week. I'll update when I know more.
Last edited by Flygirl1; 05-14-2017, 11:18 PM.Comment
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Interesting. So whatever happened happened after a good pre-takeoff mag check?
I have been running one pmag for over a year, completely trouble free. After about two hours on the second, all is still well. I figure there are enough in service these days to have good confidence in them. Anything can fail, mags included.Comment
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Donna, I'm curious about the in-flight problem: Did you notice a loss of power, or a difference in engine sound? I know the Pmag has a much hotter spark than mags and wondering about the loss of one even being noticed.
BillComment
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Bill, I did not notice a thing. If the Manifold pressure changed, I didn't notice it. After testing the spark plugs the entire top set were sparking normally and the bottom, (all Rt P-Mag) were not. Why they all were not working one moment and only the back two not working the next is a mystery. Even then the forward two were weak sparks. When we took the tach wire off the Rt mag and flew it, it seemed to be creating normal power. Shame on me, but I don't believe I did a Mag check at that time. I am also curious as to what all the white powder was on the rear two plugs. It seemed to be a fair amount for the 15 min flight the tach was acting up. I'm assuming that is when the plugs quit working. My search on the net said either too hot or two cold or both. OK, whatever, but what is the white powder?? D.You do not have permission to view this gallery.
This gallery has 1 photos.Last edited by Flygirl1; 05-15-2017, 11:33 AM.Comment
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The white powder might be lead deposits, which would be normal. Running very lean in cruise, as I usually do, grounding one p-mag is immediately obvious.Comment
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I'm with Jared about the lead deposits. A plug that's firing nice and hot, looks like the ones with the white haze. I'm quite puzzled, though. Your bottom plugs look pretty good, but the top plug, not so much. If the right Pmag (which failed) fires the bottom plugs, I'd have expected the bottom plugs to look more like the one in the "top" hole. I'm puzzled..... Which is pretty normal!
BillComment
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The word from E-Mag is that two pins in the coil plug, (small green one) broke at the circuit board. The units come with adels clamp to help stop the wires from moving. We had used them, so not sure why they would break. They have seen this in a few mags, so I guess this could happen to the other mag. They replaced those parts and epoxied them for extra reinforcement and I believe all new mags off the assembly line will have this reinforcement installed. Unfortunately I will not receive my mag until next Monday, so I cannot report if it actually fixed my issue, but I suspect it will.
We asked about the P-Mag for the 6 cyl and were told they would be in production by the end of May, first of June. (Yea, right) He also said there will be a 6 month waiting period after that as they have deposits for 200 units. The connector on these mags is different than ours and we were told that it is a military style for TSO purposes, which might be the big hold up in getting these on the assembly line.
Another thing I noticed is on their web site they offer a after-hours and weekend phone number, which is a good thing/ bad thing. Good it's available for emergency on the road issues and bad that it's necessary??Last edited by Flygirl1; 05-17-2017, 08:59 PM.Comment
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Mag back on and all is back to normal. So the fix worked. ;-) Now, do I send in the other one ( and Dennis' too)or hope it doesn't happen--one of those $65 questions. D.Comment
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Does Brad have any input on whether the defect is likely to be present in the other mag? In other words, was the problem systemic in that production range, or was yours just a single error?Comment
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I think Trent is who we talked with. We were told that it has happened to a few, lucky me, but is not a wide spread problem. We did read in the service notes on their web site about the mag wire to the coil (small green plug)should be bent into an S shape to help stability in that wire. That is how my repaired one came back. None of the other ones are like that, so that is something we can do.Comment
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