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Slick Magneto Internal Timing Issues

Steve Pierce

BENEFACTOR
Graham, TX
Helped a friend of a friend buy a Super Cub in California recently with a little over 100 hours on the engine with new Slick mags. They got it to Louisiana and were having a hard time starting it. Lots of ideas were floating around but checking the e-gap (internal timing) fixed it. Got a call yesterday from Fairbanks, same issue, same time on new Slick mags except it was when the engine was hot and something was said about temps being 20 below. A call to Joe Logie at Champion revealed that they have a problem. They don't know what is causing it (I have an idea) but the internal timing is advancing prematurely and once the e gap is set no problem. Just a heads up before you start throwing serious money at this problem that an hour and a $5 tool can remedy.
 
You know when I had the low temp starting problem at 525 hours you had me bring my mags to Texas for the E gap.The adjustment was so minor I thought for sure there was a new mag in my future. I was shocked that a minute adjustment could do so much. I have never had the issue since. MY IA swore that he had never heard of it but was willing to let me do my thing. After seeing what happened to me I got a call from him about 3 months later on a mutual friends PA12 with the same problem. Once again the E gap at 500 or so hours was the problem.
Great Information Steve....a lot for a little.
 
http://www.aircraftspruce.com/catalog/eppages/tool-gauge-gap1.php?clickkey=30478

The price went up though. $14.

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Great post Steve. Thank you for sharing your knowledge and experience. You make our world a better place.

Bill
 
2 years ago at their booth at Kosh Joe was doing a little mag clinic every half hour on how to set the E gap if you showed an interest in learning it. And you went home with a free tool.

Glenn
 
So if the internal timing is advancing and then if the egap is set theres no problem after that? Im not following Steve.
 
Set my E gaps last week and replaced two worn carbon brushs.Mag drop now less than 25rpm between mags.Check both lobes of the little cam also.Possible for one to be worn more than the other.Will screw timing all up from cyl to cyl.I don't care much for that tool it doesn't really fit well.
I take the vent plug out and put a short piece of rubber hose in it.You can then snug the plug up and the friction from the hose will hold the rotor while you adjust the gap.

Bill
 
Setting E-gap is magneto 101. Day one in magneto school. No special tools needed. Just some sensitive fingers, a piece of paper. and a screw driver.
 
E-gap is important to assure maximum SATURATION of the PRIMARY winding in the coil---only then should the points start to open--which collapses EMF in primary winding(with the help of the condenser or capacitor) and EMF now switches to SECONDARY winding in the coil thru MUTUAL INDUCTION----should have 1/2" to 3/4" (blueish) spark----Bendix mags are easy to set----you should have the tool for the Slicks----my 2 cents worth----John F
 
The points wear, cam also, remember we check and usually change the timing during the annual? That's accounting for the wear. My dad's 172 had a really hard time starting, come to find out the points were worn, it was quite amusing to see the look on his face when I had the mag all apart. I'm sure he was remembering the little kid who would take stuff apart and bring the pieces back for help getting it back together. You can set the internal timing without the tool, pain though.


Sent from my iPad using Tapatalk
 
How is the egap advancing and what stops it from advancing again?

is the cam follower wearing?

bad condenser/capacitor problem...
 
E-gap is important to assure maximum SATURATION of the PRIMARY winding in the coil---only then should the points start to open--which collapses EMF in primary winding(with the help of the condenser or capacitor) and EMF now switches to SECONDARY winding in the coil thru MUTUAL INDUCTION----should have 1/2" to 3/4" (blueish) spark----Bendix mags are easy to set----you should have the tool for the Slicks----my 2 cents worth----John F

Well said John.

How is the egap advancing and what stops it from advancing again?

bad condenser/capacitor problem...

Cam follower wearing. Cam wearing on Slicks. Points eroding. Bottom line the exact time that the points open due to wear.

I have found that the hottest spark can be achieved by feeling the peak EMF by hand and setting the points accordingly. This has been on all types of magnetos and not just on airplanes. Yes, some are more fussy than others.
 
So Steve you stated you have a idea why the egap was advancing prematurely. What is the idea? See questions above...

Years ago there was a bad batch of magneto condensers. The points were overheating and the cam followers were getting soft from the arcing/heating and wearing in no time....what is going on with these Slicks?
 
Just spoke with Joe Logie who is the Champion Magneto Tech Rep. They do not yet know what the problem is but it has effected a small percentage of magnetos manufactured in the last 4-5 months. They are getting rapid point face wear in the first 25 to 80 hours which results in an internal timing advance which makes the engine hard to start. Resetting the E-gap has proven to stabilize the wear and they are saying they believe they will make it to the 500 hour inspection without another considerable internal timing drift. They will exchange any effected magneto under warranty if so desired. They do not know the cause at this time but have a very good team working on it. I originally thought possible cam wear but that would retard the timing rather than advance.

My opinion, from being around my Dad who is a mechanical engineer and worked in the engine manufacturing and rebuilding industry for many years, they made a cost reduction change and it has effected their product. It has happened to them before, a few years ago when they had rapid carbon brush wear. They will figure it out I am sure.
 
So Steve you stated you have a idea why the egap was advancing prematurely. What is the idea? See questions above...

Years ago there was a bad batch of magneto condensers. The points were overheating and the cam followers were getting soft from the arcing/heating and wearing in no time....what is going on with these Slicks?

Exactly my thoughts and question to the insider's at Slick
 
Unison built everything in house. Champion bought them, almost doubled the price and started making product improvements (cost reductions).
 
On both of my Slicks the coil tab was not perpendicular to the carbon brush but bent into(down) the mag at about a 30 degree angle.It allows the brush to come too far out of the rotor and causes the brush to wear on the side.There is a service bulletin on this.Untrained or uncaring assemblers would be my guess.Very poor qaulity control for sure.

Bill
 
If your timing doesn`t change when you check it every 100 hrs, i think your OK ?

Frenchy
 
And it happens again, 2011 Top Cub, factory new O-360-C4P with Champion (Slick) 4371 magnetos with 140 hours total time. Very hard to start, 5 shots of prime and craoss everything you have that it starts. Call Joe Logie at Champion with my suspicions and yep, rapid point wear, set the E-gap and it will be good for 500 hours. That would have been simple enough even though it is a pain to pull mags on a Super Cub because you have to swing the engine. Tom gets the mags off and shows me one with torque seal stuffed in a screw hole but no screw. In fact there is only one screw holding the magneto halves together.
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Get the mag apart and there is a huge transfer of material between the points leaving a nice size pit at which point I decide these are going back under warranty. Champion next days me a set of mags and now the airplane starts on the first blade. Problem fixed. I felt like this was Champions fault and didn't feel like the owner should bear the cost of replacing two mags with 140 hours since new so I sent them an email. They don't feel the same way. :evil:

Kevin and Joe, Here is a picture of the magneto as removed. We stuck a scribe in the hole to remove the torque seal to remove the screw that was not there. Only one screw was holding the magneto halves together. When we looked at the points there was a large pit in them so we decided to exchange both mags instead of just adjusting E-gap and installing screws. These mags have 140 hours. Will you cover labor to R&R?
Thanks
Steve Pierce

Hi Steve,

I saw via UPS tracking that the two magnetos finally arrived last week, and I hope they worked well. I guess the really good news is that you have two brand new magnetos now, but the bad news is that we don't cover any labor associated with replacement. If they were coming off for internal E-gap setting, then hopefully it didn't set you back more than it would have cost for that. I'll be on the lookout for your old mags so I can look at the points and try to figure out how the screws we missed from the serial number.

Again, I apologize for the inconvenience, and hope that the new mags will help in the long run. Thanks for using Champion.............kevin


Kevin Gallagher
CHAMPION AEROSPACE, LLC
Piston & Airframe Manager
1230 Old Norris Road
Liberty, South Carolina 29657
Phone (864) 843-5468
Cell (864) 630-4791

Kevin,
The airplane had been very hard to start and had it not been for previous conversations with Joe I would not have been pulling a magneto with only 140 hours on it due to premature point wear. I guess I get tired of billing customers for things that a manufacturer was responsible for. I am not trying to shoot the messenger and appreciate you getting me the mags so fast I just think there needs to be a change in policy. I know for a fact people have started changing carburetors and all sorts of crazy things due to this premature point wear. I am just glad I have developed a relationship with Joe over the years and know where to go when I suspect a problem like this.


Thanks.
Steve
 

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Illegal immigrant cheap assembly labor? Seriously, to see that much point face pitting the capacitor across the points has to be bad, or the other option would be cheap Chinese point face material that erodes due to inferior or contaminated metal....Is the FAA looking at this operation? Maybe time to make them do something to earn their salaries.
 
Good luck! The way I hear it they are occupied full time pulling DPE authorizations. I am not even sure ours are there Mondays and Fridays.
 
Don't know if this has a direct effect on the problem here, but I have seen excessive cam follower wear on random Slick mags. Seems like some don't get that dab of lube when they are assembled and the nylon follower wears very quickly. I've heard the joke that if you get through the first 100 or 150 hrs on a new Slick, it will probably be okay. Just something else to be aware of

Web
 
When Champion bought the excellent Unison Slick magneto they immediately outsourced all the components Slick built in house. When the two Champion salesmen told me this at Airventure they said it was a quality improvement. I countered I had been in manufacturing long enough to recognize a cost reduction when I saw one. These invariably also result in a quality reduction as well. Oh! And they also tripled the price.

A bad side effect of the early point wear and resulting E gap slip is many mechanics don't recognize the resulting hard starting as being caused by low time relatively new mags. The aircraft owner ends up with big a trouble shooting bill or the shop owner ends up eating a large portion of it.

Large pits in points are not caused by loss of EGap. These had other problems as well as missing screws.

I use Tempest spark plugs and filters these days.
 
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