Dual MAG inspection

[dooleypster]

Has anyone had an inspection (as opposed to an overhaul) of the dual MAG lately?  Were you more or less comfortable with that idea at the 500 hour point on the motor?

 

[Guest]

Regular maintenance  of the dual magneto is important, the big pitfall seems to be correct reinstallation.  There was a recent thread here full of horror stories involving crappy installs.

Clarence

[N201MKTurbo]

Every other annual, I will remove the dual MAG, check the points and reset the internal timing. I will inspect the impulse coupling and give it a good visual inspection. If the points are pitted I will replace them ($80 a set).

it is more important to set the internal timing on the dual MAG because the two mags will get out of sync as the points wear.

[Flymac]

We just had ours out at annual and sent in to Kellys for the 500 hour inspection you mentioned, which was to be $650 or so....$1500 later ended up just trading in for a 0 HR overhauled unit from them, too many "bad" parts on our unit...I learned wish i had done some more research/quotes for who still does these, what they offer in terms of D2000 vs D3000 upgrade, etc if you still have some time to do so.

[carusoam]

(From my old fuzzy memory collection)

Reusing star washers when reinstalling mags has come up recently in conversation.  A simple no no... If this applies to your mags.

I am a PP, not a mechanic.

Best regards,

-a-

[bradp]

2 minutes ago, carusoam said:

I am a PP, not a mechanic.

Best regards,

-a-

Anthony will you just up and get your A&P already.  :-).  

[1524J]

This is the second time in a week that I've found a problem and corrected the issue because I'm on this forum. My dual mags were at 680 hours since overhaul. It was the only appliance we didn't send off when we had the engine overhauled because we had replaced it when we purchased the plane. I had mentioned to an A&P that I wanted to pull the mags and send them in for inspection. His advice was not to worry.....when the mag drops get out of line we'll pull them. I even check my temperature rise now on my engine monitor and it has looked good. I don't know how serious a missing gear tooth is in a mag, but I know it's not supposed to be missing.   Anyhow, against local advice and largely due to this forum I pulled the mags anyway. i want to thank some of you....I want you to know there are those of us who appreciate all the great information you share on this site.....Mooniac58, M20doc, Carusoam, Shadrach, N201MKTurbo, and everyone else who contributes your experience and knowledge. Now that I've got the mushy stuff out of the way....if you've got 500 or so hours on your dual mags.....pull 'em!

[jetdriven]

4 hours ago, Flymac said:

We just had ours out at annual and sent in to Kellys for the 500 hour inspection you mentioned, which was to be $650 or so....$1500 later ended up just trading in for a 0 HR overhauled unit from them, too many "bad" parts on our unit...I learned wish i had done some more research/quotes for who still does these, what they offer in terms of D2000 vs D3000 upgrade, etc if you still have some time to do so.

Anything that comes from Kelly is garbage.  You only have one magneto and your family rides ib that plane too, so use anyone else, like maxwells guy. 

[Guest]

6 hours ago, 1524J said:

This is the second time in a week that I've found a problem and corrected the issue because I'm on this forum. My dual mags were at 680 hours since overhaul. It was the only appliance we didn't send off when we had the engine overhauled because we had replaced it when we purchased the plane. I had mentioned to an A&P that I wanted to pull the mags and send them in for inspection. His advice was not to worry.....when the mag drops get out of line we'll pull them. I even check my temperature rise now on my engine monitor and it has looked good. I don't know how serious a missing gear tooth is in a mag, but I know it's not supposed to be missing.   Anyhow, against local advice and largely due to this forum I pulled the mags anyway. i want to thank some of you....I want you to know there are those of us who appreciate all the great information you share on this site.....Mooniac58, M20doc, Carusoam, Shadrach, N201MKTurbo, and everyone else who contributes your experience and knowledge. Now that I've got the mushy stuff out of the way....if you've got 500 or so hours on your dual mags.....pull 'em!

Missing teeth are generally caused by the use of a gear lock tool during installation.  If the mag is twisted or the propeller is turned the tooth or teeth can fracture.  If the distributor gear slips and jumps a tooth or 2 the spark is delivered at the wrong time relative to piston location.

The worst I've heard of is 5 teeth missing in a row on a TCM Bendix mag on a Cirrus SR22, the mag overhaul shop says he's seen it before on the IO550 engine with a four blade MT prop.

Clarence

[Jim Peace]

10 hours ago, jetdriven said:

Anything that comes from Kelly is garbage.  

Why do you say that?

I just had a very experienced Reno air racer who owns a shop tell me that he only uses Kelly for ignition harnesses.....that they make a great product...

[jetdriven]

5 minutes ago, Jim Peace said:

Why do you say that?

I just had a very experienced Reno air racer who owns a shop tell me that he only uses Kelly for ignition harnesses.....that they make a great product...

Maybe their harnesses are OK, but their overhauled components are pure crap. Just a new data point, our Kelly overhauled prestolite alternator failed at ~300 hours.  The Kelly overhauled Prestolite starter, still on our plane, had the bendix fail to engage. Taking it apart, there was no grease on the helix under the gear drive in the bendix. Their own documentation on the web clearly shows to lightly grease the area, but ti was dry.

I replaced the Slick mags on a factory overhauled engine with two Hartzell overhauled Bendix 1200 mags. I didnt know Hartzell is simply Kelly under a new name, same factory in Alabama, ran by people who cant assemble simple components and cant read.  7 hours since installation, the right mag fails on a fuel stop at midnight in Leesburg FL. We probsbly flew the entire florida panhandle at night on one mag. Upon opening it up, the felt crushed down and the points werent opening. We adjusted the points but now the E-gap is wrong. And the points are tweaked, theyre only hitting on one side.  Then they gave me shit asking why I am demanding another magento when the one I am sending back still runs.

Edited April 4, 2016 by jetdriven

[dooleypster]

Many thanks to all who replied.  I was not aware of the D2000 D3000 issue.  Will look into that.

[KSMooniac]

The previous owner of my plane installed an overhauled D3000 (supposedly) sourced from QAA in Tulsa.  Turns out it was actually a D2000 that was mis-labeled!  I discovered it when I sent it to an expert for the 500 hr inspection and he caught it.  QAA made it right and shipped me a real D3000, but from now on all of my mag work goes to Select Aircraft in Lancaster.

There is no shortage of horror stories regarding Kelly's laughable quality system.  When Hartzell bought most of those product lines they talked a good game of fixing those issues, but thus far it hasn't panned out apparently.  I hate that they purchased Plane Power and they'll likely screw up that good product line next.

[jetdriven]

They already have.  You run the plane power alternator for 500 hours, and when it dies you buy another one.  No repairs.  

[N601RX]

Also note that if you send a slick mag to Kelly for overhaul they will not overhaul it to the slick manual.  They have developed their own overhaul manual that does not require replacing most of the components the slick manual requires.  The overhaul price seems good compared to others, but you get what you pay for.

They also recently purchased the line of Tempest replacement mag parts for both Bendix and Slick.

[Guest]

5 hours ago, Jim Peace said:

Why do you say that?

I just had a very experienced Reno air racer who owns a shop tell me that he only uses Kelly for ignition harnesses.....that they make a great product...

It's hard to screw up wire....but the fine folks at Kelly/Hartzell will find a way!

Clarence

[LANCECASPER]

Their motto is "We're not happy until you're not happy!"

[mooniac15u]

Good news! Hartzell just bought Sky-Tec. Their starters will now be made in the Hartzell factory in Alabama. Now you will be able to find the same Hartzell/Kelly quality in this fine product line. 

http://www.aopa.org/News-and-Video/All-News/2016/April/05/Hartzell-acquires-Sky-Tec-starters-and-solenoids

[KSMooniac]

Damn

[PTK]

My dual mag has ~200 hours till next 500 hour. Looking back in logbook there's an entry from last annual "...removed magneto cap and inspected for overall condition. No deficiencies noted."

This is not a 500 hour inspection by any means nor was it logged as such but it appears it's a visual inspection without removing the magneto. Anyone have any input in this? Is this a common practice? And what can be inspected by removing the cap?

[jetdriven]

not enough to make me feel good.  Thats not a proper 500hr inspection.  Let me put it this way, a 500hr on a mag is the same as an overhaul except the replacement of the shaft bearings. Anything less than that is less. You are supposed to pill the cap and look at the points every annual. So you got that. They inspected the points and the cap.  No mention of the gears which can strip, or the impulse couple which can break and roll the timing back to zero, or the obsolete hold down clamps which cock when tightened and crack the shaft housing, et. al.

Edited April 6, 2016 by jetdriven

[N201MKTurbo]

14 hours ago, PTK said:

My dual mag has ~200 hours till next 500 hour. Looking back in logbook there's an entry from last annual "...removed magneto cap and inspected for overall condition. No deficiencies noted."

This is not a 500 hour inspection by any means nor was it logged as such but it appears it's a visual inspection without removing the magneto. Anyone have any input in this? Is this a common practice? And what can be inspected by removing the cap?

It never hurts to take a look. You can check the points, wiggle the shafts to see if a bearing is failing, look at the gears. 

Not the same as a full tear down, but not a bad idea.

I noticed the picture of the mag above has dry felts. They can be oiled during the visual inspection. This can keep the bearings from failing. The special oil is cheap and a can will last you forever.

Edited April 6, 2016 by N201MKTurbo