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Old 08-08-2020, 08:32 PM
ChrisMcC ChrisMcC is offline
Join Date: Mar 2014
Location: Colorado Springs
Posts: 7
Default PMag Leads are Loose

My PMag leads (at the mag) are not confidence-inspiring. They slip on, but do not have the comforting "snap" fitting like at the plugs. On take-off roll today, one came loose, the engine began sputtering, and I aborted the takeoff.

Is there a way to more securely attach the leads to the mag?

Thank you!
Chris McClernon
Colorado Springs, CO (KFLY)
RV-7 N174FM

Last edited by ChrisMcC : 08-08-2020 at 08:39 PM.
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Old 08-08-2020, 09:18 PM
Scott Hersha Scott Hersha is offline
Join Date: Jan 2005
Location: Cincinnati, OH
Posts: 1,539

I agree, its a weak connector that is used on the Pmags. Do yourself a favor and tin the ends of the wires that slip into the connector. The screw clamps on the connector squishes the stranded wire, and tinning the end first prevents that and makes a more secure connection. You can really crank down tightly on those screws if you do it this way, without breaking any of the ends of the strands.
RV6/2001 built/sold 2005
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RV8/2018 built/Sold(sadly)
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Old 08-08-2020, 10:30 PM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
Join Date: Jul 2009
Location: Mojave
Posts: 4,613

I think the OP is talking about the spark plugs leads on the coil tower. A bit of vasaline on the boot and a conscious effort to seat the boot as far as possible on the tower (rather than the terminal) will help. There are millions and millions of cars with this coil/wire connection and they don't fall off.

If not, and he's talking about the primary wiring connector, then crimping a brass tube/ferrule on the end of the wire gives the screw something to bite onto without creating the brittle segment of wire solder can cause.
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
Harmon Rocket II -SDS EFI
1940 Taylorcraft BL-65
1984 L39C
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Old 08-09-2020, 05:20 AM
Kyle Boatright Kyle Boatright is offline
Join Date: Aug 2005
Location: Atlanta, GA
Posts: 4,187

If the wires easily slide on/off the coil, you've got wear in the system. Either the wire ends, the coil posts, or both. I don't exactly remember the tactile feel you should get (maybe two light clicks as a wire goes into place), but I noticed this issue on my the last condition inspection and replaced both the wires and coil to correct the situation.
Kyle Boatright
Marietta, GA
2001 RV-6 N46KB
2019(?) RV-10
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Old 08-17-2020, 02:43 PM
isosceles isosceles is offline
Join Date: Jan 2018
Location: Fremont
Posts: 59
Default emagair service notes

Did you check emag air service notes?

Plug Wire Terminal Coil Connection

Importance High.

Background: We have recent reports of certain ignition leads having reduced retention force at the coil termination on the back of the ignition...
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Old 08-17-2020, 03:10 PM
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Carlos151 Carlos151 is offline
Join Date: Jan 2008
Location: Lebanon, TN
Posts: 270
Default +1 for checking with Emag

Last year I ordered a new pMag with a wire set. Then I received a notice from them that some of the wire sets were shipped out with weak connectors that would not snap into place on the pMag or the plugs. After calling them, they had me send my set back in and I soon received a new set of plug wires at no cost. Give 'em a call, they're great to work with.
Karl Richcreek
N151TK "La Otra Chica"
Flying as of August 14, 2015
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Old 08-17-2020, 03:35 PM
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DanH DanH is offline
Join Date: Oct 2005
Location: 08A
Posts: 9,433

Be cautious about using a lubricant on plug boots. Although it tends to make them air tight and moisture proof, it can also allow the boot/connector assembly to rotate slightly on the coil post due to vibration...the boot doesn't grip the tower or plug as dry silicone would. I've seen some really worn connectors, as well as things like spark plug caps with grooves cut in them.

The p-mag coil is a Ford part. E-mag owners are unlikely to change it for the previous style, which is electrically equivalent, but for those going with an EDIS-base system, the early coil uses wire caps with positive retention.
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Dan Horton
Barrett IO-390
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Old 08-17-2020, 04:25 PM
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Larry DeCamp Larry DeCamp is offline
Join Date: Apr 2010
Location: Clinton, Indiana
Posts: 983
Default Just something to consider

Based on past input from the forum, I use Fuel Lube as a dielectric lubricant for Pmag plug boots and it is very hard to get them off and they are clearly moisture occlusive, just a thought.
Larry DeCamp
RV-3B flying w/7:1 0320 / carb / Pmags / Catto 3b / digital steam
RV-4 fastback w/ Superior roller 360/AFP/G3X/CPI/Catto3b
Clinton, IN
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Old 08-17-2020, 07:28 PM
Doug Rohrer Doug Rohrer is offline
Join Date: May 2009
Location: Bowling Green, KY
Posts: 292
Default Another Loose Lead

To add another data point, I had a Pmag lead fall off at the mag end on my new engine. Did not notice it because misfire was masked by the other Pmag firing the other plug. I also found a loose, but not disconnected lead on the other Pmag. I will be calling Emag about this. I believe my leads were made in the suspect time period.
Doug Rohrer
Bowling Green, KY
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Old 08-21-2020, 01:18 PM
Doug Rohrer Doug Rohrer is offline
Join Date: May 2009
Location: Bowling Green, KY
Posts: 292
Default Update

I contacted Brad at Emagair and explained my problem. He quickly agreed to send me two replacement wire sets at no cost. Because the coil ran for a while with the wire disconnected, he said the coil is now suspect and he is sending a replacement coil as well. Great customer service.
Doug Rohrer
Bowling Green, KY
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