Slick Mag gone bad???

Today when I did my mag check prior to takeoff, I found the right (non impulse) mag totally inop. On my plane my start procedure it master on, left mag (impulse) toggle switch on, push to start. After the engine starts, I switch on the right mag toggle switch. Today on runup I got no drop in RPMs when I switched off the right mag and what would have been engine stoppage when I switch the left mag off if I would have kept it off. Obviously, the right mag was not firing at all. I tested the switch and continuity between the p-lead wire and ground back to the switch. All good. Not wanting to simply undo the connections at the mag and seeing if the mag was hot but just being grounded somehow (since I didn't want kickback with the engine starting on the right mag), I started the engine and reached under the panel and pull the ground wire from the switch. No help, still no right mag. I'm thinking I've pretty much ruled out a grounding issue and see it as a bad mag...........after only 41.1 hours!!

I've had this mag new for the past two years but only have my Phase 1 hours on the mag. I'll check with Slick and see what they say about warranty. Anyway, is there a way to check this mag, hard to take apart? to see if there is a loose wire inside or bench test to check it before I go and drop hard earned money if I don't have to. This is a Slick 4370.

HELP..........I want to fly!!

http://www.sacskyranch.com/aircraft_magneto_troubleshooting.htm

http://www.amtonline.com/publication/article.jsp?pubId=1&id=836

slick mag

I have herd of this on in a couple of cases! one was the wire going to the condenser had come off. and another the points were not tight. Take the mag off and have an A&P look inside. maybe a simple fix. Call Unison before you do so it does not void your warrenty if any!

Best regards!

Dana,

Check your PM's.

Diagnosis

I checked Unison's site and the warranty is good for 6 months after date of purchase......so off came the back of the mag. It was fairly easy to see the points were not opening. When I tried to open the points, the "arm" literally feel off. It was just hanging by a corner.



So, where does a guy get a new set of points? Anybody out there put a new set of points in a slick 4370? Any hints? Gap??

Thanks, it sure looks like it will be cheaper than $500 plus for a new mag.

Dana,

You can get the points from Aircraft Spruce - I bought a couple of sets to have on hand when I did my 500 hour inspection on the Mags, and haven't had to use them yet, but I know that eventually, they'll go in....

With that happening at so few hours, I'd personally be calling Unison and talking to their engineering staff about it - warentee or not, they might send you a set for reporting a QC problem like that!

Paul

Dana.

Check with your local A&P. That should be a stock item for them, or at least it is here. It may cost you a few bucks more than ordering them, but you will make up some of that with shipping and won't have to wait.

As a data point, this is one reason I went to EI on one side. The mag I removed and gave to another person failed about 10 hours later. Mag reliability (or lack thereof) is the reason we have two of them. In my limited flying experience I have had three fail. Glad yours went while you were on the ground. Also happy to hear you are out of Phase I. Congratulations on that!

Bob Kelly

Problem solved

Just talked with Unison QC, they stated they are aware of this happening. He said they hear of about 30 per year out of over 30K mags shipped per year. They are sending, next day, two free sets of points, a timing tool, spark plug thread chaser and a couple more "goodies" for my inconvenience. It was a pleasant conversation with the problem being rectified.

Best advice for slick mags is throw them in the TRASH before they kill you.

Multiple slick mag failures, intermitants are eeerily common. Ask around and learn from the crashes from of countless slick equiped engines. Junk them before it's to late.

My humble opinion of course... based on 31 years flying with 17 engine failures! Hopefully no more (#17 was due to both slick mags failing BTW).

Bob (LSE plasma III with a bendix mag)

17 Engine outs

Rocket Boy, If if were you I would not go outside if it were lighting.

Rocketboy said:

Best advice for slick mags is throw them in the TRASH before they kill you.

Click to expand...

Are you sure this isn't a P-mag thread?

BTW, through some odd circumstances, I have an extra 114 P-mag for sale. I would keep it but I really don't need three of them. This is low time and works great.

Let me know if any of you might want it.

Rocketboy said:

My humble opinion of course... based on 31 years flying with 17 engine failures! Hopefully no more (#17 was due to both slick mags failing BTW).

Click to expand...

I've been flying for 41 years and never had an engine failure.
Many of those years behind Slick mags.

With this kind of track record, I would'nt get within 100ft of an airplane if I were you. Obviously much more going on in these situations than just mag failures.

Rocketboy said:

Best advice for slick mags is throw them in the TRASH before they kill you.

Multiple slick mag failures, intermitants are eeerily common. Ask around and learn from the crashes from of countless slick equiped engines. Junk them before it's to late.

My humble opinion of course... based on 31 years flying with 17 engine failures! Hopefully no more (#17 was due to both slick mags failing BTW).

Bob (LSE plasma III with a bendix mag)

Click to expand...

Rocketboy said:

Best advice for slick mags is throw them in the TRASH before they kill you.

Multiple slick mag failures, intermitants are eeerily common. Ask around and learn from the crashes from of countless slick equiped engines. Junk them before it's to late.

My humble opinion of course... based on 31 years flying with 17 engine failures! Hopefully no more (#17 was due to both slick mags failing BTW).

Bob (LSE plasma III with a bendix mag)

Click to expand...

Yea, maybe he should replace them with dual p-Mags!

Rocketboy said:

... based on 31 years flying with 17 engine failures! Hopefully no more

Click to expand...

A gold mine! It would be a big write up but 17 engines failures would be a priceless wealth of experience to share. If you were so inclined at some point I would value very much a chronological account of all the failures.

I have 32 years of flying and only 1 engine failure. I would like to get some of your info so it stays at 1.

Rocketboy said:

Best advice for slick mags is throw them in the TRASH before they kill you.

Multiple slick mag failures, intermitants are eeerily common. Ask around and learn from the crashes from of countless slick equiped engines. Junk them before it's to late.

My humble opinion of course... based on 31 years flying with 17 engine failures! Hopefully no more (#17 was due to both slick mags failing BTW).

Bob (LSE plasma III with a bendix mag)

Click to expand...

Bob,
17 failures in 31 years?? Holy Cow!
I have been flying not quite that long (28 years) but fortunately have only had 2 failures (1ea Slick and Bendix)! The Slick was a dual failure an early C-152 with the old Slicks that could not be opened for maintenance. The Bendix was a D-2000 mag which I never had much regard for. As you are aware a failure of ONE D-2000 mag equals quiet engine and sweaty pilot! I have always been a Bendix guy, but have not had much choice on what my employer had on the planes!
I have found that proper and timely preventative maintenance will head off most failures of mags and any other component.
For your longevity, I hope your average improves!

I find a dual mag failure unlikely. Did they receive normal maintenance?

Mel said:

I've been flying for 41 years and never had an engine failure.
Many of those years behind Slick mags.

Click to expand...

Well of course....

Somebody has to even out the statistics

It may sound strange, but check to see that your engine to airframe ground cable is secure and sound. I was having a starter problem and a right mag failure problem going at the same time. It took a couple of failures at the same time to associate the two problems. It turned out that the engine to airframe ground cable was broken inside the heat shrink sleeve. It would carry enough current to operate a continuity meter, but not enough to start the engine. When the key start switch is in the start position, the right mag is grounded. The starting loads were going through the magneto's primary circuit to ground, burning out the points in the process. Once the engine would start, the right mag was dead. I finally deduced that the ground cable had to be bad. It was.

The point is, that your mag problem might be more than just a problem with the mag.

I set the points using my poor man's magneto tester. With the back off the mag, hook a test lead to the high tension cable terminal on the coil, and another test lead to the magneto's case. Clip the other ends of your test leads to a piece of dry cardboard about 1/16" apart. Turn the magneto in the proper direction, using a socket in the chuck of a portable drill motor. Adjust the points till you get a good hot spark across the 1/16" gap. The points gap will be somewhere around .010". If you have the points properly set, the mag will continue to fire when turning it less than 100 RPM. Tighten the screws holding the points in, then insert the timing pin, and reassemble the mag according to the instructions. Remove the timing pin before you turn the mag. You will break the plastic timing gears if you don't.

Bob, thanks for the input and good information In my case, it turned out to be a faulty points arm. Actually it was a mismanufactured arm. The arm itself was upside down with the point pickup causing it to always be under much more stress than normal, even when the points were closed. I'm amazed it lasted 40 hours. As for timing, I'll be using the provided timing tool to set the e-gap and test the go/no go using a feeler gauge for a gap range of .008 to .0012.

I forgot to mention, when describing my method of setting the points, that you must hook the condenser into the ciruit using another set of test leads.

I've tried to set points using a feeler guage. The blades on my feeler guage are too big. I've never had satifactory results doing it that way. Someone else might, but I haven't.

Wow so many adventures...

6 engine failures on takeoff on a pitts S1S. After every forced landing I changed something big, mags, carb, pump etc. The final fix turned out to be a tank vent positioned in an area that had low pressure only during flight...go figure. I was 22 yrs old and a much better pilot then. Tanks vent are VERY important!!

Another was a blown crank oil seal on a pitts s2b. oil every where, couldn't see, losing oil etc . Had to land now


Another was a badly leaded up lyc 0-235 that lost so much power it could no longer stay in the air. Grumman yankeee.

Another was a sucked valve in a Super cub towing gliders in college.

Another was a blown off exhaust stack, again towing gliders. The engine ran but nearly caught fire so I had to shut it down.

Another was a blown blower bearing and seal in Pratt and Whitney R-985 Beech 18 freighter on takeoff.

Another was a seized GE CF-6. Landed single engine in a snow storm in Ohare one winter with that one.

Another was a quit engine in a clipped wing cub Cont c-90. Just quit from crud in the carb. Landed in a field, fixed it and flew it home.

Another lost oil pressure in a Robnson R-22. Landed that thing right now. Fixed leak, departed.

Sorry, can't remember the rest this time, getting old, tired etc., but promise they are rattling around in my head somewhere.

Still consider myself lucky, not unlucky. Fly safe...toss the slicks. And always be VERY ready for when your single powerplant fails. Its not a matter of "if" but "when". If your not ready, consider yourself dead.



yep.... Another was those piece of **** Slick mags failing simultaneously on one cylinder during takeoff . Plane would not climb on 3 cylinders so right back down we went. Both mags had less than 350 hrs since new. Could not duplicate so I took off a few hours later and it ran fine. Two weeks later it did it again, this time at altitude so I had time to trouble shoot and identify it was indeed the mags.

I've been flying for 53 years. I've never had an engine failure that forced me to land. I understand my engines, and I maintain my equipment. I've had three power failures that I've sorted out before I got to the ground. I'll admitt, on the last one, I was about 10 seconds from landing in a field when I got it running.

Problem solved

No comment on throwing the Slicks away, the first problem I have had with them in all my flying.

Anyway, J. Logie, was my contact at Unison. I called them first thing Monday morning, shortly after taking apart the mag and seeing the broken set of points. He returned my phone call within 15 minutes. He offered to repair the mag at no charge, if I sent it to them, even though I purchased the mag two years ago, but only had 40 hours on the mag itself. I only wanted the points, as I plan on attending the Cincy formation clinic this weekend (oh, but that's another thread). He sent me two set of mags, OVERNIGHT, along with a harness manual, maintenance manual, 2 point kits, spark plug socket, plug feeler gauge, plug chaser, package of harness screws, 2 T-150 E-gap tools, 3 timing pins, 2 plug erosion tools, rivet gauge and a package of Vib. plug cleaners. He said he was going to throw some things in with the points for my inconvenience

Timing my mag:

The disassembly is not problem, the assembly is no problem...put the pin in the L slot, align the cam gear L mark and screw it down. Easy to do.

Setting the points, simply follow the directions. Use a buzz box along with the T-150 E-gap tool. When the gap tool touches the inside frame of the mag, slowly open the points until the buzz box just buzzes, this will give you an E-gap of between .008 & .010. Don't try and use a feeler gauge, the buzz box works much better. I tried it both ways and got a much hotter fire by use of the buzz box. Easy reassembly and off to the airport. Since I had not removed the left mag, I simply hooked the buzz box up to it and rotated to #1 TDC then moved the prop until the buzz box buzzed, checked to make sure the left mag was still 25 BTDC, after Kahuna recent mag advance. With the L pin still in the the right mag, installed it, removed the timing pin and rotated the mag until the gap opening time matched the left, locked it down, hooked up the P lead and ground and hauled Black Magic out of the hangar. Startup was normal, mag drops were normal, EGT's were not. I have always had #4 EGT lower than the other three. Now, all four EGT's are close to each other. I'm thinking now, although the right mag drop of normal, this thing was not hot from the beginning and had issues with the points. It happens, even with new stuff, I'm willing to acknowledge such.

Points made and found out here: Just because it is new does not mean it is not subject to failure. It took ME two days to get Black Magic up and running. Exactly one of the reasons I sold the Bonanza and went Experimental. I would have had to have an A&P do all the work I did, although Unison was willing to send the parts, I am assuming I could not have done the work myself on a certified airplane. I would have been out time and money. A set of points is a set of points, I'm old enough to remember distributors in cars.

Anyway, life is good again.

BTW, I still feel the need to say: Keep pounding those rivets....It's worth it

Rocketboy said:

Wow so many adventures...

6 engine failures on takeoff on a pitts S1S. After every forced landing I changed something big, mags, carb, pump etc. The final fix turned out to be a tank vent positioned in an area that had low pressure only during flight...go figure. I was 22 yrs old and a much better pilot then. Tanks vent are VERY important!!

Another was a blown crank oil seal on a pitts s2b. oil every where, couldn't see, losing oil etc . Had to land now


Another was a badly leaded up lyc 0-235 that lost so much power it could no longer stay in the air. Grumman yankeee.

Another was a sucked valve in a Super cub towing gliders in college.

Another was a blown off exhaust stack, again towing gliders. The engine ran but nearly caught fire so I had to shut it down.

Another was a blown blower bearing and seal in Pratt and Whitney R-985 Beech 18 freighter on takeoff.

Another was a seized GE CF-6. Landed single engine in a snow storm in Ohare one winter with that one.

Another was a quit engine in a clipped wing cub Cont c-90. Just quit from crud in the carb. Landed in a field, fixed it and flew it home.

Another lost oil pressure in a Robnson R-22. Landed that thing right now. Fixed leak, departed.

Sorry, can't remember the rest this time, getting old, tired etc., but promise they are rattling around in my head somewhere.

Still consider myself lucky, not unlucky. Fly safe...toss the slicks. And always be VERY ready for when your single powerplant fails. Its not a matter of "if" but "when". If your not ready, consider yourself dead.



yep.... Another was those piece of **** Slick mags failing simultaneously on one cylinder during takeoff . Plane would not climb on 3 cylinders so right back down we went. Both mags had less than 350 hrs since new. Could not duplicate so I took off a few hours later and it ran fine. Two weeks later it did it again, this time at altitude so I had time to trouble shoot and identify it was indeed the mags.

Click to expand...

You sound like the author of a book on flying in Minnesota in the 30's...he walked home every other flight.