mike mcs repair
Registered User
chugiak AK
for a bit we had some with 15 to 20 hours on them.. that failed/hard start because that...
Slick Magneto Internal Timing Issues
- Thread starter Steve Pierce
- Start date
nanook
MEMBER
northern alaska
I've seen excessive follower wear on both Bendix and Slicks. When the capacitor is not chopping off the arc at the points, the points and the arm that the follower is mounted on, gets heated up. The follower is plastic, when you heat plastic it gets soft...soft plastic followers don't last very long.
BES
Registered User
Esbjerg, Denmark
Steve,
Interesting topic. The Slicks on my A65 have some 600 hours on them (100 after servicing) with no issue whatsoever. The Slicks on my 0-320 have about 40 after rebuild and show a pretty large mag drop and lumpy idling. The timing to the engine has been checked and is spot on, but the issue of internal timing I hadn't thought about.
Could you be persuaded to make one of your excellent YouTube videos on how to check and set the E-gap??
Interesting topic. The Slicks on my A65 have some 600 hours on them (100 after servicing) with no issue whatsoever. The Slicks on my 0-320 have about 40 after rebuild and show a pretty large mag drop and lumpy idling. The timing to the engine has been checked and is spot on, but the issue of internal timing I hadn't thought about.
Could you be persuaded to make one of your excellent YouTube videos on how to check and set the E-gap??
Had to pull a new 4371 after only 9 hours of ops. Joe discussed the internal e-gap with me during my trouble shooting but that wasn't the problem. No explanation from Champion after warranty replacement. Another local aircraft got 25 hrs. Are we seeing a QC problem at the factory?
Steve Pierce
BENEFACTOR
Graham, TX
Spoke with Champion sales representative at Oshkosh. He said everything was fixed and no more problems. Not what I got from the Tech guy. Seems Champion engineers changed about 8 things in the magneto at one time and they still haven't quite got a handle on what is causing the point wear. Nothing official yet but this Service Letter helps I guess.
Steve Pierce
BENEFACTOR
Graham, TX
Well I got word that Champion went ahead and started making points like Unison did and the rapid point wear should be solved. Any points made after 9/21/2015 should be good. If you buy new points and they are made prior to that date send them back because you will have the magneto back off in 100 hours because it is hard to start and the E-gap will be off.
RaisedByWolves
FRIEND
Tx
I replaced my points before they figured out they had a problem. About 100-150 hours the engine was super hard to start. Pulled and re timed them internally.
Steve Pierce
BENEFACTOR
Graham, TX
Unison made everything in house. Champion out sourced things and made several changes at one time so they have no idea what caused the problem or at least that is what they told me. All I was told is that the problem was solved by going back to the way Unison did it.
hotrod180
FRIEND
Port Townsend, WA
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.
SC3CM
Registered User
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. "
"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. "
bob turner
Registered User
Does this mean that one can now buy Slicks and feel comfortable that they will go 800 hours?
behindpropellers
Registered User
NE Ohio
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
Steve Pierce
BENEFACTOR
Graham, TX
I would addjust them at 500 hrs Bob, by 700 hrs is when they seem to get hard to start for me.
WhiskeyMike
MEMBER
West Boxford MA
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.
Steve Pierce
BENEFACTOR
Graham, TX
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.
fancypants
FOUNDER
IL
Another update to the service bulletin for the distributor gear, separate from the points wear problem (SB15-4A):
View attachment 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.
View attachment 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.
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