PMAG Problem

[Aggie78]

I got a call today and learned I have one of the P-mags in the "build window" of problem units...

Not happy, since the thing hasn't even been installed 2 months yet...

I've got a call into EmagAir to discuss my options, but it looks like it will be coming back out again!

[Whitman]

For those considering pmag. Realize it isn't maintained free like Slick magnetos can be before the required 500 hr service that traditional mags sometimes require. I certainly thought I could get more than 60hrs on my pmag without maintenance but not checking the service notes (AD) bit me in the backside.

From the e mag 114 manual:

Maintenance: Annual or 100 Hr. Inspection (whichever comes first):

1. Check E-MAG web site for most recent Service Notes (www.emagair.com page ?Service Notes?) and verify equipment is current with all updates.

2. Ignitions come with a (one-time trigger) thermal sticker that will trip (turn from light ash color to gray or gray/black) if case temperatures exceed 200 degrees (F). If tripped, review blast cooling and/or other ventilation issues that affect ignition cooling. Keep ignition temperatures below 200 degrees.

3. Ohm check plug wires (see ?Ohm Check? above), and examine spark plugs for signs of unusual wear or build-up. Gap plugs per instructions above. Replace auto style plugs with new ones after 100 to 125 hours. When reinstalling auto style plugs with auto plug adapters, review plug/adapter installation guidelines above.

4. Remove ignition and examine shaft and drive gear condition. Note: Ignition disassembly is not necessary (and if done may void your warranty). Look for excessive play (lateral and axial). Shaft rotation should be free, with no catching, flat spots, or grinding. The shaft on ?P? models (with internal alternator) will have a push-pull rippling effect as the shaft turns and the permanent magnets pass the rotor poles. This is normal and expected. If a P model ignition does not have this magnetic ripple, the unit requires additional (shop) service.

5. Replace older 1/16? cotter pins with larger 5/64? cotter pin. Inspect and secure the ends to prevent movement. The smaller pins have been in service for some time, but we?ve have occasional reports of pins coming loose and/or breaking.

6. Examine control plug and coil plug connections. Tighten to 4-5 inch pounds. Verify there are no stray wire strands. Verify all control wires use the Adel clamp strain relief.

7. Reinstall the ignition, and verify proper operation. Review Setting Ignition Timing instructions above. For P models, re-verify minimum operating speeds when running on internal power (see Minimum Operating Speed test above.)

[N941WR]

Originally Posted by Raymo

For the benefit of future readers and me:

Did the PMAG have the latest software (40) that *should* have precluded this issue?

Dual PMAGS in my future...

Based on my conversation with the OP, his P-mag was purchased just prior to the release of the V40 Service Bulliten.

Originally Posted by Jesse

It is my understanding that Pmags always use ship's power until it loses it and then reverts to the internal alternator.

As the others have stated, the early versions 113 series and prior, ran on Ship's power and only switched to internal power when ship's power is lost. 114 P-mags switch to internal power as the engine speed comes up. At around 800 RPM the internal generator produces enough power to be self sustaining.

[Bavafa]

Originally Posted by Aggie78

I got a call today and learned I have one of the P-mags in the "build window" of problem units...

Not happy, since the thing hasn't even been installed 2 months yet...

I've got a call into EmagAir to discuss my options, but it looks like it will be coming back out again!

How is that PMAG does not send notifications to those owners with the effected S/N. They have all of our info, including e-mails and they know which S/N went to which customer.

[ChiefPilot]

Originally Posted by Bavafa

How is that PMAG does not send notifications to those owners with the effected S/N. They have all of our info, including e-mails and they know which S/N went to which customer.

They address that right on their site in the section for the case bolts and state that they have contacted those they have records for. They do not have records for all, for example when purchased through an engine builder or other middleman.

[Whitman]

Update your records with e mag y'all!

[N941WR]

I spoke with Brad at Emag this evening. He is aware of this thread and said he has received a number of calls from concerned customers regarding the V40 upgrade.

Those who do not have V40 and have a key switch to control the grounding of the P-mags are highly unlikely to have a lost timing issue.

However, if you have toggle switches and for whatever reason leave one P-mag grounded during the starting sequence, you do run a good risk of loosing your timing mark.

It is still unknown why the OP lost his timing mark on a running engine. It is possible that the arcing described by the OP caused the P-mag to lose its timing mark but Emag is still looking into the reason. V40 may or may not have prevented the OP's issue. Once Emag understands the cause, they will fix it and they will issue a service bulletin.

The good thing for those of us running P-mags, as long as you understand this failure mode, you can test for it on the ground. Should it happen in the air, I would perform a mag check in the air, knowing I may get a nasty backfire, if I shut off the wrong ignition. (Sorry, the EICommander can tell you have a timing issue but it cannot tell you which P-mag is out of time and it needs two P-mags to run the comparison. It would not have helped the OP.)

If you are uncomfortable turning off one ignition in flight, throttle back, go to full rich, and find a place to land ASAP.

[Aggie78]

With a little help from a buddy, and since I'm local to the folks who made it, I shot over there with it in my hot little hands to drop it off for the fix.

The fix ended up happening "right now" and being about 10 minutes of bench time to disassemble, then re-assemble the mag with the thread locker installed.

In my case, I had no noticeable issues when I pulled the mag, and during the tear down it was found that I'd had one properly put together in the first place-thread locker was installed in all 4 locations where it was needed.

Comfort factor-we put it on the test bench and took it for a spin after re-assembly and she worked like a champ, and I plan on re-hanging it back on the engine tomorrow.

Brad and the folks at his company were apologetic about the the entire affair and the inconvenience folks were being put through.

Stuff happens when humans are involved...this is just one of those instances highlighting that fact.

[gbusterguy]

I talked to Brad at Emagair about the evaluation of my Pmag. This is what I learned.

The inspection of my Pmag did not reveal any damage or discrepancies.

My Pmag did not have the V40 update installed.

As stated on the Emag website V40 is not a mandatory update.

He said there is no reason to believe that the V40 update would have prevented my loss of timing issue anymore than the V37 that was installed at the time of the event.

Brad said they do not have enough definitive information at this point to know why this inflight timing event happened.

[johnbright]

Post #1:

Originally Posted by gbusterguy

... We found the connector on the end of the power wire coming off of the alternator had broken after 10 years of vibration and had been arching between the wire and the alternator,...

Post #49:

Originally Posted by gbusterguy

I talked to Brad at Emagair about the evaluation of my Pmag... He said there is no reason to believe that the V40 update would have prevented my loss of timing issue anymore than the V37 that was installed at the time of the event. Brad said they do not have enough definitive information at this point to know why this inflight timing event happened.

Hi Loel... do you have specifics on the broken connector and preventative measures to keep it from breaking?