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Am I grounded? I Broke the metal braid on the #2 bottom plug wire that comes from the PowerUp ES4371.

tom paul

tom paul

Well Known Member
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I was doing the Savvy oil control ring flush today. On one cylinder, (#2) when I went to remove the bottom plug, I severed the outer braided metal on the ignition wire from the magneto. The inner and out ring of the ignition wire connector were stuck together so when I started to loosen the nut, the cable twisted, and I heard the snap of the braided wires. I don't know the condition of the inner wire, but I suspect that is OK. It didn't twist much at all, and the braid looks like it was ready to go, just hanging on by a few strands. The other cables look good. Do I need to replace the ignition harness before I fly? Can I do some surgery on the cable and restore the braided connection? I don't know how to take this double nut cable end apart.
Is that connection necessary for the spark to happen? I think this braid is only there as an RF shield. If that is the case, is it critical in my case?
Thanks all.
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IMG_0097.jpg
 
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I just checked the Air Power website and the harness for a 4 cylinder mag is close to $700 and is back-ordered. If I can fix this cable, I would like to do that. There is enough slack in the cable that I could potentially cut it and reconnect it to the threaded plug connector, if that is advisable. I don't know how to separate the two parts of the threaded connector. There is the small square piece around the cable, and the large 3/4" nut that threads onto the sparkplug. These don't seem to be threaded together, so maybe they are not removable, and the cable can not be repaired. Looking forward to some wisdom on this.
 
tom paul said:
I just checked the Air Power website and the harness for a 4 cylinder mag is close to $700 and is back-ordered. If I can fix this cable, I would like to do that. There is enough slack in the cable that I could potentially cut it and reconnect it to the threaded plug connector, if that is advisable. I don't know how to separate the two parts of the threaded connector. There is the small square piece around the cable, and the large 3/4" nut that threads onto the sparkplug. These don't seem to be threaded together, so maybe they are not removable, and the cable can not be repaired. Looking forward to some wisdom on this.
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o_O how can some wires cost so dang much. I bought some gum for $7 today. What is happening with the world?!
 
tom paul said:
I was doing the Savvy oil control ring flush today. On one cylinder, (#2) when I went to remove the bottom plug, I severed the outer braided metal on the ignition wire from the magneto. The inner and out ring of the ignition wire connector were stuck together so when I started to loosen the nut, the cable twisted, and I heard the snap of the braided wires. I don't know the condition of the inner wire, but I suspect that is OK. It didn't twist much at all, and the braid looks like it was ready to go, just hanging on by a few strands. The other cables look good. Do I need to replace the ignition harness before I fly? Can I do some surgery on the cable and restore the braided connection? I don't know how to take this double nut cable end apart.
Is that connection necessary for the spark to happen? I think this braid is only there as an RF shield. If that is the case, is it critical in my case?
Thanks all.
View attachment 81784
View attachment 81784
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Are you able to post a couple more pics of the end fitting? If you can take a pic of the end after moving the big nut out of the way that would help, and also of the spring in the core.
On my harness the sleeve around the shield is a press together fit and the two pieces can be prised apart with a thin blade. The spring contact in the end is a barbed fitting and will most likely need to be replaced with a new one after if it is pulled out.
The shield is to prevent RF interference in the comm and avionics. The core, if it is still intact, will still carry the spark to the plug, but obviously the cable is also physically weakened. Only if I was stranded somewhere without help would I consider flying it home, otherwise I would get it fixed before flying.
 
tom paul said:
I was doing the Savvy oil control ring flush today. On one cylinder, (#2) when I went to remove the bottom plug, I severed the outer braided metal on the ignition wire from the magneto. The inner and out ring of the ignition wire connector were stuck together so when I started to loosen the nut, the cable twisted, and I heard the snap of the braided wires. I don't know the condition of the inner wire, but I suspect that is OK. It didn't twist much at all, and the braid looks like it was ready to go, just hanging on by a few strands. The other cables look good. Do I need to replace the ignition harness before I fly? Can I do some surgery on the cable and restore the braided connection? I don't know how to take this double nut cable end apart.
Is that connection necessary for the spark to happen? I think this braid is only there as an RF shield. If that is the case, is it critical in my case?
Thanks all.
View attachment 81784
View attachment 81784
Click to expand...
Good Morning,
Depending on your "need to fly" - a broken shield at the spark plug does not render the aircraft unsafe, it does leave the aircraft susceptible to ignition noise getting into the VHF radios. I suggest you fix asap using techniques in the attached maintenance manual.... and be careful (use two wrenches) when removing or replacing these wires onto spark plugs.
 

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Yes, you are still grounded and will spark. Many different grd return paths on a mag. However, the shielding is there to reduce electro magnetic emissions (i.e. interference) and that function will now be gone. Can't tell you how much of a problem that will cause for you.
 
tom paul said:
I just checked the Air Power website and the harness for a 4 cylinder mag is close to $700 and is back-ordered. If I can fix this cable, I would like to do that. There is enough slack in the cable that I could potentially cut it and reconnect it to the threaded plug connector, if that is advisable. I don't know how to separate the two parts of the threaded connector. There is the small square piece around the cable, and the large 3/4" nut that threads onto the sparkplug. These don't seem to be threaded together, so maybe they are not removable, and the cable can not be repaired. Looking forward to some wisdom on this.
Click to expand...
I just purchased a RS mag harness from Maggie (New Horizons) in California for $310 US. Much better wires than the ACS ones which are OK for mags but not so good for EI.
 
I have dealt with a lot of ignition noise in antique airplanes with old unshielded wires and new avionics. Any little bit of shielding can reduce ignition related radio "noise". You likely will not have a significant issue. I would wrap some electrical tape around it and try your radio with the engine running. See what you get. Likely you will be able to fly home just fine. As an aside I have purchase shielding in 10' length on Amazon and shielded un-shielded wires. Very effective.
 
To keep this from occurring: always us a wrench to hold the small nut on the wire still while you unscrew the big nut from the barrel of the sparkplug.
 
Tandem46 said:
Can you replace entire harness for
$200 from Spruce?
www.aircraftspruce.com

Shielded Ignition Harnesses - For Slick Mags | Aircraft Spruce ®

Shielded Ignition Harnesses - For Slick Mags New production ignition harnesses at remarkably low prices. Late type 5MM wire constructed of 16 strands of tightly braided copper wire impregnated with scuff resistant white silicone.
www.aircraftspruce.com www.aircraftspruce.com
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Thanks for this link. I will check with them to see if they have one that will fit my magneto.
 
tom paul said:
Interesting! Are there any cons to converting to automotive plugs on the bottom? My engine has automotive plugs and harness on the top. Is that normal or has this been converted?
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Thanks all! One more question: How can I safely confirm that the core wire has not been damaged and the plug is sparking? I would know how to do this in a car, but car doesn't have a deadly prop 12" away. My thought is this: I could disconnect or remove the other plugs so the engine won't start, put a plug in the damaged wire and rest in a place that grounds it and that I can see it from the cockpit, then crack the starter and look for a spark. That is logic from my automotive and motorcycle experience. Will this work in this case?
 
tom paul said:
I was doing the Savvy oil control ring flush today. On one cylinder, (#2) when I went to remove the bottom plug, I severed the outer braided metal on the ignition wire from the magneto. The inner and out ring of the ignition wire connector were stuck together so when I started to loosen the nut, the cable twisted, and I heard the snap of the braided wires. I don't know the condition of the inner wire, but I suspect that is OK. It didn't twist much at all, and the braid looks like it was ready to go, just hanging on by a few strands. The other cables look good. Do I need to replace the ignition harness before I fly? Can I do some surgery on the cable and restore the braided connection? I don't know how to take this double nut cable end apart.
Is that connection necessary for the spark to happen? I think this braid is only there as an RF shield. If that is the case, is it critical in my case?
Thanks all.
View attachment 81784
View attachment 81784
Click to expand...
Safe to fly but lots of ignition noise. Sorry in advance but you should always hold the shield nut with a wrench when removing the larger spark plug nut
 
If I do replace the cap and harness, does anyone know if I need special tools? Do I need to remove the magneto to replace the cap and wires?
Thanks
 
sansoneservices said:
Safe to fly but lots of ignition noise. Sorry in advance but you should always hold the shield nut with a wrench when removing the larger spark plug nut
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yup. I get that now. The other three rotated independently so there was no issue, but this one was nearly fused.
 
the harness for a 4 cylinder mag is close to $700
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In typical VAF fashion, for this kind of $$$ a small step would permit a time jump... e.g. from the 20th to the 21st century, by installing some EI system, at least on the damaged side.
 
Dan 57 said:
In typical VAF fashion, for this kind of $$$ a small step would permit a time jump... e.g. from the 20th to the 21st century, by installing some EI system, at least on the damaged side.
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I have a lightspeed on the top plugs. The "slick" is on the bottom plugs
 
tom paul said:
Thanks all! One more question: How can I safely confirm that the core wire has not been damaged and the plug is sparking?
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Ohm out the lead from end to end. Look for the proper reading (per foot). If it looks good, make sure to articulate the wire at the damage and look for an intermittent “open”.
 
tom paul said:
If I do replace the cap and harness, does anyone know if I need special tools? Do I need to remove the magneto to replace the cap and wires?
Thanks
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No special tools required if you buy the complete harness set. Magneto remains in place. It's a very easy procedure and your wires look like crap anyway. Remember the wire "set" includes both magnetos
 
sansoneservices said:
No special tools required if you buy the complete harness set. Magneto remains in place. It's a very easy procedure and your wires look like crap anyway. Remember the wire "set" includes both magnetos
Click to expand...
Did you look at Maintenance Manual posted in post #8, very comprehensive, answers your questions.
 
tom paul said:
Interesting! Are there any cons to converting to automotive plugs on the bottom? My engine has automotive plugs and harness on the top. Is that normal or has this been converted?
Click to expand...
In my opinion there is no drawback. With the kit from G3i, you can make the conversion in a couple hours at most. I too have Lightspeed on top with NGK BR8ES plugs and a Slick mag on the bottom. Now with the G3i harness I’m also running the NGKs on the bottom as well. I’ve noticed no change in performance but my 8 NGK plugs are barely the price of one aviation spark plug and you can get NGKs at most auto part stores.
 
tom paul said:
If I do replace the cap and harness, does anyone know if I need special tools? Do I need to remove the magneto to replace the cap and wires?
Thanks
Click to expand...
Slick mags have three screws holding the cap to the mag. Depends on how old it is, you have TORX or Allen head screws. Some also have slots. May need a short stubby driver to match the fastener in the cap. The cap will only go on ONE way. Many of the new harnesses will be numbered for the cylinder and Top / Bottom. Since you have EI on the top, the lead that would go to the top would be used on the bottom of the same cylinder.
 
RV7 To Go said:
I just purchased a RS mag harness from Maggie (New Horizons) in California for $310 US. Much better wires than the ACS ones which are OK for mags but not so good for EI.
Click to expand...
I am getting a quote from Maggie. I did order the one from Spruce for $199, but that is a set of two. I only need one. It just makes me wonder about the quality, since those are basically $100 each whereas the correct one from Air Power is $800. I certainly don't want an inferior product on such a critical system. I will see what Maggie says. Do you all like that one better than the cheap one from Spruce? Also, the one available at Spruce is spec'd for an O-360, not an IO-360 which I have, so the salesperson wasn't sure it would fit my engine in terms of lead length.
It will be here Monday and I can try it, but again, I'd like to understand better the difference in quality.
I would also consider the G3i switch to automotive plugs, but I am slightly spooked by the notion that there may be less quality control in them than in aviation plugs. Is that something people feel comfortable with? And...I actually just installed new bottom aviation plugs when diagnosing a rough running engine about 25 hours ago. (it turned out to be a clogged injector nozzle)
thanks all
 
tom paul said:
I would also consider the G3i switch to automotive plugs, but I am slightly spooked by the notion that there may be less quality control in them than in aviation plugs. Is that something people feel comfortable with?
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Tom, the G3i is a kit, you build it yourself. The components are high-quality…for example, the leads are MSD. Think of it this way, if you are already running Lightspeed on the top, the G3i components are as good if not better than what Klaus sells at LSE. As for the plugs, if you went the G3i route, use whatever plugs in the bottom that you’re already using in the top. Everyone on this site running electronic ignition (Emag/Pmag, LSE, etc) are using automotive plugs… Probably thousands of RVs. Denso and NGK are prevalent, but many others too.
Not trying to sway you one way or the other…Do what makes you comfortable.
 
Why don't you just take the end apart and fix it? Usually, you can take the lead off, trim the shielding back leaving enough to catch the center piece, press back together and reassemble. No special tools needed. Not hard to do if yours comes apart. Pretty sure it does.
 
tom paul said:
I am getting a quote from Maggie. I did order the one from Spruce for $199, but that is a set of two. I only need one. It just makes me wonder about the quality, since those are basically $100 each whereas the correct one from Air Power is $800. I certainly don't want an inferior product on such a critical system. I will see what Maggie says. Do you all like that one better than the cheap one from Spruce?
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I don't know what the difference between the harness' is. What I know is the ACS harness will work fine on a mag but not on a Surefly EI. Initially when I installed a new ACS harness on the Surefly it ran very rough but is working fine on the mag. I put a used Champion harness on the Surefly and it was fine. After researching online I found many people had the same issue with the ACS when using the Surefly and all said the Maggie harness worked great, although any of the big name harness' (Champion, Unison, Kelly) also work ok. After looking at the pricing, the Maggie harness was the least expensive of the ones that worked ok on the Surefly so I ordered one. Will see how it works once installed.
 
Jcurry said:
Why don't you just take the end apart and fix it? Usually, you can take the lead off, trim the shielding back leaving enough to catch the center piece, press back together and reassemble. No special tools needed. Not hard to do if yours comes apart. Pretty sure it does.
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I will have a look. the other leads look fine, so if I can fix this one, I don't need a harness. I do have enough slack to loose an inch to this process. Do the parts potentially just pull apart? Do i cut the cable first to release them or something?
 
RV7 To Go said:
I don't know what the difference between the harness' is. What I know is the ACS harness will work fine on a mag but not on a Surefly EI. Initially when I installed a new ACS harness on the Surefly it ran very rough but is working fine on the mag. I put a used Champion harness on the Surefly and it was fine. After researching online I found many people had the same issue with the ACS when using the Surefly and all said the Maggie harness worked great, although any of the big name harness' (Champion, Unison, Kelly) also work ok. After looking at the pricing, the Maggie harness was the least expensive of the ones that worked ok on the Surefly so I ordered one. Will see how it works once installed.
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I heard back from Maggie and they have an 8 week lead time at the moment, so I will either be fixing the lead that i have, or installing the one I ordered from Spruce. It is a mag, not an EI, so it should be ok, from what I am learning.
 
Cut the Ignition lead with a pair of wire cutters where it is frayed. Disassemble by prying apart the drive ferrule and ferrule with some sharp wire cutters.
Unscrew the spark plug contact spring and pull out the electrode screw.
Copy the trim dimensions from a undamaged spark plug lead.
Slide spark plug attach nut onto wire.
Squeeze the ferrules together on good shield with 2 pliers. Remove silicone from center conductor with a needle and insert electrode screw and spring.
 

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SPB W10 said:
Cut the Ignition lead with a pair of wire cutters where it is frayed. Disassemble by prying apart the drive ferrule and ferrule with some sharp wire cutters.
Unscrew the spark plug contact spring and pull out the electrode screw.
Copy the trim dimensions from a undamaged spark plug lead.
Slide spark plug attach nut onto wire.
Squeeze the ferrules together on good shield with 2 pliers. Remove silicone from center conductor with a needle and insert electrode screw and spring.
Click to expand...
Thanks for this. The rest of the harness didn't look great, so decided to replace it with the one from Spruce. It isn't the quality of the Maggie one for sure, that one looks amazing, but i didn't want to wait 2 months. I put everything back together yesterday and went for a short flight. Runs great. 75 RPM drop from both the EI and the mag to just the mag on runup. It seems I put it on correctly!
I appreciate the incredible resource that this community is!
 
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