Txbyker Posted February 3, 2016 Report Share Posted February 3, 2016 Just returned from KGGG with my plane last week, 2005 GX. On run up the right mag was giving me fits. Turned out to be a bad spark plug wire #5 near the mag. Maxwell put another harness on that he had available which was used and a different color. Anal as I am I want to replace all spark plug harness with "new" to keep them consistent and in fear of another weak one. Can't imagine how that would happen but I would have not liked it if it was in the air. Can anyone tell me what the best harness may be for the IO-550-G? Kelly, Champion? Russ Quote Link to comment Share on other sites More sharing options...
kortopates Posted February 3, 2016 Report Share Posted February 3, 2016 You do realize that you can replace a single wire lead on a harness? It requires some special tooling but they sell spare wires in different lengths to do the job. If you still have your original set it my be an option for you. If your harness was not old and just one wire got damaged, such as chaffed, that is the thing to do. If its an old harness then I'd replace both mag harnesses which are sold as a kit. Aircraftspruce has a big selection and your current magneto type and plug type (i.e. Bendix vs Slick mags; not engine model) will direct you to your kit options available pre-fab'd for your mag, plug type and engine model. It really comes down if you want to pay more for a nice colored leads (as I did). 2 Quote Link to comment Share on other sites More sharing options...
Guest Posted February 3, 2016 Report Share Posted February 3, 2016 (edited) 8 hours ago, Txbyker said: Just returned from KGGG with my plane last week, 2005 GX. On run up the right mag was giving me fits. Turned out to be a bad spark plug wire #5 near the mag. Maxwell put another harness on that he had available which was used and a different color. Anal as I am I want to replace all spark plug harness with "new" to keep them consistent and in fear of another weak one. Can't imagine how that would happen but I would have not liked it if it was in the air. Can anyone tell me what the best harness may be for the IO-550-G? Kelly, Champion? Russ If it the original, it will be a TCM harness to go along with the TCM engine and magnetos. I'm not sure if TCM sells individual wires but you can certainly buy one harness. You can search their site for harness part numbers, or call their tech help line. Clarence Edited February 4, 2016 by M20Doc Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted February 4, 2016 Report Share Posted February 4, 2016 I put on a TCM harness last year. It was very well made, the best one I've ever had. 1 Quote Link to comment Share on other sites More sharing options...
N601RX Posted February 4, 2016 Report Share Posted February 4, 2016 I purchased a new set a few years ago that had 90 deg brass boots on the plug ends. The 90 deg bend lets the wire exit without a sharp bend. They have held up very well. At the time they were manufactured by a small company called skytronics. They have since been purchased by Kelley. 2 Quote Link to comment Share on other sites More sharing options...
cliffy Posted February 8, 2016 Report Share Posted February 8, 2016 In my mind its a toss up. They're all pretty good. I've used several different mfgs. Just found 8 of 12 not working correctly on an IO520 this week. No issues from the owner but not checking good with lead tester Could actually hear the spark jumping inside the shielding to ground Quote Link to comment Share on other sites More sharing options...
N601RX Posted February 8, 2016 Report Share Posted February 8, 2016 I think the useful life of them depends a lot on how well they are routed and supported. Also if you have a spark plug that opens up with high resistance the voltage is going to increase to the point that it can spark to something. It can either spark through the insulation on the wire to the shield or spark through the adjacent windings on the mag coil damaging them. 2 Quote Link to comment Share on other sites More sharing options...
StevenL757 Posted February 8, 2016 Report Share Posted February 8, 2016 On 2/3/2016 at 11:42 AM, Txbyker said: Just returned from KGGG with my plane last week, 2005 GX. On run up the right mag was giving me fits. Turned out to be a bad spark plug wire #5 near the mag. Maxwell put another harness on that he had available which was used and a different color. Anal as I am I want to replace all spark plug harness with "new" to keep them consistent and in fear of another weak one. Can't imagine how that would happen but I would have not liked it if it was in the air. Can anyone tell me what the best harness may be for the IO-550-G? Kelly, Champion? Russ Russ, did this get resolved? If not, call John Bodenmann at the CMI service center in Mobile. 251-436-8670. He has new harnesses in stock (the Gold Seal ignition harnesses are around ~$400'ish), can take your payment and ship out immediately. Needed one replacing on my former IO-550G several years ago (before I bought my IO-550N8B through them). I've purchased consistently with them for over 6 years, and have always received top quality service and professionalism. Personally, even if they do supply individual wires, spend the additional money and get the full harness. Sleep better at night. 1 Quote Link to comment Share on other sites More sharing options...
Txbyker Posted February 8, 2016 Author Report Share Posted February 8, 2016 4 hours ago, StevenL757 said: Russ, did this get resolved? If not, call John Bodenmann at the CMI service center in Mobile. 251-436-8670. He has new harnesses in stock (the Gold Seal ignition harnesses are around ~$400'ish), can take your payment and ship out immediately. Needed one replacing on my former IO-550G several years ago (before I bought my IO-550N8B through them). I've purchased consistently with them for over 6 years, and have always received top quality service and professionalism. Personally, even if they do supply individual wires, spend the additional money and get the full harness. Sleep better at night. Steven, thanks, I am with you, replace them all. I appreciate the lead but ordered a new set of TCM from Spruce last week and they will probably ship this week. Russ Quote Link to comment Share on other sites More sharing options...
StevenL757 Posted February 9, 2016 Report Share Posted February 9, 2016 On February 3, 2016 at 11:42 AM, Txbyker said: Just returned from KGGG with my plane last week, 2005 GX. On run up the right mag was giving me fits. Turned out to be a bad spark plug wire #5 near the mag. Maxwell put another harness on that he had available which was used and a different color. Anal as I am I want to replace all spark plug harness with "new" to keep them consistent and in fear of another weak one. Can't imagine how that would happen but I would have not liked it if it was in the air. Can anyone tell me what the best harness may be for the IO-550-G? Kelly, Champion? Russ Excellent. Quote Link to comment Share on other sites More sharing options...
Txbyker Posted February 27, 2016 Author Report Share Posted February 27, 2016 I got my new TCM plug wires. Had my local A&P install. He is an anal A&P. Calls me and tells me he is going to reseat all of the induction pipes with new gaskets, some bolts on one cylinder finger tight and surely leaking air. I watch you guys post your speeds in cruise with envy. I could never bust 173 kts with my heavy plane with A/C, oxy, etc. Well now it is pretty smooth. Saw 181kts tas at 21.9", 2550 rpm, 9000 feet yesterday. Had the plane 3 years and never had it this smooth. Russ 1 Quote Link to comment Share on other sites More sharing options...
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