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Thread: Slick Magneto Internal Timing Issues

  1. #41
    hotrod180's Avatar
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    My experience is that with Slicks, you will be replacing spark plugs at 500-600 hours due to high resistance through them. But Bendix mags will spark them OK, even with the same high resistance, often until the center electrodes are worn down to a nub. Bottom line is that Bendix mags throw a lot hotter spark. I exchanged a set of Bendix mags for Slicks at engine overhaul time once, 14 years ago, but would never do so again.
    Cessna Skywagon-- accept no substitute!

  2. #42
    SC3CM's Avatar
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    Direct from Champion when asked about this specific issue:

    "I'll start with the fact that we have had a timing drift issue on a small percentage of mags for some time and have tried different remedies to minimize this effect. I will also emphasize that all Slick mags have timing drift by design, as the points erode timing advances and as the cam erodes timing retards, each of these must happen for the mag to remain in the area of e-gap over it's 500 hour expected service run. Champion released SL 74-20-001 (attached) in Feb 2015 because we have had excessive advanced timing drift happen on some of our mags . I have also released SB1-15 (attached) which deals with premature failure of the distributor gear finger in 4 cylinder mags and yes, some 4 cylinder mags could be impacted with both issues.

    The timing drift SL does state that more than 4 degrees timing drift in 100 hours or less must be investigated and resolved (meaning warranty if it happens during our warranty period). The SB requires all distributor gears within the s/n range to be replaced, regardless as to whether they are working perfectly or not and as one option we are replacing these at the factory at no-charge, please see all possible options called out in the bulletin.

    Champion did revert to the Unison design M3081 points on Sept 1, 2015 because we were never able to fully control the amount of timing drift that was happening with our M3081 design of the last few years. Any mag manufactured after Sept 1st 2015 and any M3081 points packaged dated after Sept 1st 2015 will have the "Unison" style M3081 point design incorporated. "

  3. #43
    nanook's Avatar
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    Translation: We tried to cut cost by using cheaper, inferior parts and it has bit us in the A$$...we'll call it bean counter drift.

  4. #44

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    Does this mean that one can now buy Slicks and feel comfortable that they will go 800 hours?

  5. #45
    behindpropellers's Avatar
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    Quote Originally Posted by SC3CM View Post
    Direct from Champion when asked about this specific issue:

    "I'll start with the fact that we have had a timing drift issue on a small percentage of mags for some time and have tried different remedies to minimize this effect. I will also emphasize that all Slick mags have timing drift by design, as the points erode timing advances and as the cam erodes timing retards, each of these must happen for the mag to remain in the area of e-gap over it's 500 hour expected service run. Champion released SL 74-20-001 (attached) in Feb 2015 because we have had excessive advanced timing drift happen on some of our mags . I have also released SB1-15 (attached) which deals with premature failure of the distributor gear finger in 4 cylinder mags and yes, some 4 cylinder mags could be impacted with both issues.

    The timing drift SL does state that more than 4 degrees timing drift in 100 hours or less must be investigated and resolved (meaning warranty if it happens during our warranty period). The SB requires all distributor gears within the s/n range to be replaced, regardless as to whether they are working perfectly or not and as one option we are replacing these at the factory at no-charge, please see all possible options called out in the bulletin.

    Champion did revert to the Unison design M3081 points on Sept 1, 2015 because we were never able to fully control the amount of timing drift that was happening with our M3081 design of the last few years. Any mag manufactured after Sept 1st 2015 and any M3081 points packaged dated after Sept 1st 2015 will have the "Unison" style M3081 point design incorporated. "
    Thanks Rene. I have one mag I need to rebuild and will make sure I have the last revision of parts when I order.

    Tim

  6. #46
    Steve Pierce's Avatar
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    I would addjust them at 500 hrs Bob, by 700 hrs is when they seem to get hard to start for me.
    Steve Pierce

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    Will Rogers

  7. #47
    WhiskeyMike's Avatar
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    How come Bendix mags worked great for many hours, with moderate service required; and now we have to pull mags constantly to repair and replace? Why not go back to Bendix? Price? Any opinions. Used to be buy Slicks - cheap, run em, throw em away. Now they cost twice as much and don't last. Why aren't people going back to Bendix? BTW I haven't checked the price.

  8. #48
    Steve Pierce's Avatar
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    Ha, just had this conversation with Ken at LyCon today. Slick mags are now about $3600 for a 4 cylinder kit. I was telling him about my findings with Slick mags a monto or zother ago. I had just shipped him an engine I pulled off of an Extra 300 that burned a hole in a piston a few weeks ago at the US Aerobatic Championship. He got the engine and after thinking about the timing issues and the fact that this engine had 140 hours since he built it and 20 hours since the owner replaced the mags he checked the timing. One was dead on 20 degrees which it should be and the other was at 30 degrees. In a high compression engine that is going to detonate severely. It had a hole in #4 and 3 other cylinders were seizing. Champion/Slick is claiming they pay for parts only, no labor. This is going to get interesting when the repair bill is probably gonna be $25K.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  9. #49
    fancypants's Avatar
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    Another update to the service bulletin for the distributor gear, separate from the points wear problem (SB15-4A):

    Based on process and component improvements following the initial release of this service bulletin, the serial number range is being extended in this revision. Magnetos previously returned for compliance to SB1-15 must be returned or inspected for compliance to this revision SB1-15A.
    ...
    If it is not possible to confirm the version of the distributor gear that is installed in a given magneto from maintenance records, the magneto may be removed from the engine in order to have the housing and distributor block removed to allow visual inspection of the distributor gear. Distributor gears with Copper electrodes must be replaced with distributor gears with Monel electrodes.
    ...
    Champion Aerospace has made further improvements to the K3008 distributor gear assembly with the final change being the change from a Copper to a Monel distributor gear electrode as of August 2016
    SB15-4A.pdf

    Not sure what the forum software is doing to this PDF, but the attachment looks janky. Probably better to just download it straight from Continental.
    Last edited by fancypants; 12-19-2018 at 10:35 AM.
    Thanks Steve Pierce thanked for this post

  10. #50

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    when looking at the pdf, just zoom it out it clears up.

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