Magneto question

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6597
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Magneto question

Post by 6597 » Fri Nov 08, 2019 6:18 pm

While I'm waiting on medical stuff I pulled my old Bendix mags out for a 500hr inspection. The mag fellow here locally suggests for a little bit more I should just get overhauled mags. They currently have 1900+ on them with various parts replaced along the way. He said one of them is so old he's not sure he can get certain parts so I'm wondering if it even has a core value!

Anyway, data plates below, don't know whether to go with Slicks or stick with the Bendix. I know the Bendix mags enought to repair/replace and have the Bendix harness (obviously) already, I guess I'm looking for a nudge or suggestions and what those in the know are leaning towards.

Probably won't overhaul the engine for a bit longer so picking away at the smaller items...

Thanks in advance-
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8342
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Re: Magneto question

Post by 8342 » Fri Nov 08, 2019 7:30 pm

Personally I would replace the older one with an electronic unit.
Much longer life. 2000 plus hours for overhaul, more reliable, better spark.

And have the other one overhauled.

Rick

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6643
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Re: Magneto question

Post by 6643 » Sat Nov 09, 2019 12:14 pm

Received this email just the other day from a customer of mine:
I didn’t have a chance to respond because I’ve been distracted after having to divert to KAFP, NC, after losing power—turns out my electronic ignition timing device fried in flight. Now grounded awaiting replacement component.
(My response was "A magneto would never do that...")

Just saying...

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Re: Magneto question

Post by 8474 » Sat Nov 09, 2019 12:23 pm

Not that I disagree with you John, but mags fail as well. I had one come apart on me while doing fire patrols in a 182. I didn’t know it was a mag issue at the time as I was a 19 year old kid and was just plain scared and thought the engine was coming apart.

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Re: Magneto question

Post by 6298 » Sat Nov 09, 2019 9:15 pm

The beauty of Magnetos is that they operate independently from the electrical system. Unlike cars and most tractors. You can have failed batteries, bad charging systems and blown fuses or circuit breakers and the engine still runs. Bendix and Slick Mags are great. Repair or replace them, and keep flying. I might be old school, but I trust Mags..
Randy Thompson A&P IA Pilot
Hold STC SA547EA for installation of O-200 engine in Cessna 120/140 and 140A"s
Overhaul small Continentals

6597
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Re: Magneto question

Post by 6597 » Sat Nov 09, 2019 10:47 pm

Randy,

Wasn't there a magneto shop down in the Bay area that did pretty good work? I can't find them on a search. North end of the bay I think...

I'm leaning towards keeping the Bendix, seems Slicks have their issues too.

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Re: Magneto question

Post by 4004 » Sun Nov 10, 2019 2:53 am

I'm from the old, old, old school :D keep the Bendix - case in point, look at the data plates on your mags - "old as the hills" and never been changed and your issue is maintenance and not failure. Granted Slick has greatly improved over the years as to quality but still not like Bendix. You probably have the late coils and distributor gears so I would just go for an IRAN vs complete OH. Re data plates, they changed color to blue when had factory OH.
Incidentally, Slick just recently came out with a service bulletin stating some mags were supplied with copper metal on the distributor gear carrying the high voltage current, ie auto distributor rotor, and they are recommending inspection and replacing the copper ones with one using "monel metal" for greater service life.

2c

PS I'm not saying yours have never been worked on - just that they apparently have never been thru OH where the data plates were replaced. Also, I think one will find that all the parts are still available!

PPS Last set I did the 500 Hr on was on my Bonanza with the 1200 series and IIRC correctly I don't remember changing any parts - after all its an "inspection" and not an OH. Then again, my work, my plane, my neck!! :lol:

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Rob Swanland
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Re: Magneto question

Post by Rob Swanland » Sun Nov 10, 2019 11:41 am

6597 wrote:
Sat Nov 09, 2019 10:47 pm
Wasn't there a magneto shop down in the Bay area that did pretty good work? I can't find them on a search. North end of the bay I think...
You might be thinking of Savage Magnetos in Hayward - not sure if he is still in business as this guy is getting older. You might try Aircraft Magneto Service in Montana. They overhauled a set of Bendix mags for me about a year ago and I was impressed with the quality. They also spent 30 minutes on the phone describing in detail everything they did as part of the overhaul and sent the old parts back to me as well. Check them out.

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Re: Magneto question

Post by 8376 » Sun Nov 10, 2019 7:06 pm

Give QAA in Oklahoma a call. I replaced mags back in June and they set me up nicely. Even took back my busted up old ones when everyone else laughed at me.

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Re: Magneto question

Post by 6597 » Mon Nov 11, 2019 5:36 pm

Roger that....

Just out of curiosity, if it's an S4LN-21 10-51360 mag are there certain dash numbers that pertain to an 0-200A?

Reason I ask is that Spruce supposedly has 10-51360-45's for $639 overhauled but don't list the -12's. Didn't know if they would take the -12 and give me a -45.

Really, what is is with all the different dash numbers :roll:

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