Mags are shot

[Dream to fly]

Got a call from my AP and was told that the company in Montana overhauling my mags for the 500 hr inspection said that they were so bad starting this thing must have been really difficult. The truth is it was near impossible to start some days.  So my question is do I just replace them with new modern mags or is there something I should lean towards that is better.  I am still addressing the corrosion and have everything apart anyway so if I have to order parts and wait now would be a good time.

[Yetti]

Bendix mag off an A1A?  About $300 in parts should have them going again.   They make kits to rebuild them.  Plastic gears and capacitors are the things that go south.

[MB65E]

If you have old Bendix mags I would keep them and overhaul them.

-Matt

[cctsurf]

What are "modern" mags?  As far as I understand, mags produced today are essentially the same as the mags on our old birds.  I sincerely doubt you would gain anything by replacing them with new ones, they would be new of the exact same magneto.  I would say that at this point, you should be looking at the price of rebuild vs. replacement.  Do whichever is cheaper.  An overhauled mag is just as good as a new one, probably an IRAN mag is just as good, too.

There is at least one electronic ignition available for our planes, I believe.  That would be a step up, but at quite a significant price.

[Garryowen]

IRAN if they say it's an option. 

[Dream to fly]

This is why I ask questions.   I was quoted 787.12 for the left mag and 717. for the right mag.  I was told they were "waterproofed" and they could not be rebuilt.  I will need to make some phone calls.  there is a big price difference.  

[Garryowen]

Just now, cctsurf said:

What are "modern" mags?  As far as I understand, mags produced today are essentially the same as the mags on our old birds.  I sincerely doubt you would gain anything by replacing them with new ones, they would be new of the exact same magneto.  I would say that at this point, you should be looking at the price of rebuild vs. replacement.  Do whichever is cheaper.  An overhauled mag is just as good as a new one, probably an IRAN mag is just as good, too.

There is at least one electronic ignition available for our planes, I believe.  That would be a step up, but at quite a significant price.

 Sorry. Posted at same time. What he said. 

[Dream to fly]

Ok so the distributor blocks inside my mags were the old school blocks that need to be dipped and they don't make the compound to dip them anymore.  They are however Bendix mags but one of the housings is beyond rebuild and cracked.    I am so dam gun shy to give the ok with out asking questions especially when my last bill was for over 4K just for an oil cooler replacement.  Sorry I am not trying to cause chaos but I want as much info before I say yes to anything.   thanks JOE

[cctsurf]

That's why mooneyspace is here.  We're glad to help.

Sounds like you do need one replacement mag.  You should be able to replace it with a rebuilt/overhauled mag, still should be cheaper than new.

As far as I understand, unless the housing is shot like that, they can easily be IRANed (even if that goes all the way to an overhaul) for virtually anything else wrong with a mag, quite simply and quite economically.

Mike Busch has a great webinar on Mags:

 

[carusoam]

First thing to do is get up to speed on mags...

The EAA has posted a great presentation on how they are supposed to operate. There is recent discussion around here.  Use the search to find it...

What you are describing sounds like a worn out mag. But, you have left out enough detail it is hard to say.

when people are talking about their mags...  they include who made them, what model, how many hours are on them...

when it comes to starting issues, there are two types of mags that include shower of sparks and starting vibrators and other things...

When it comes to proper OH... who does it and is it worth it are good questions.

Some mags are better to throw out, some are better to have rebuilt properly...

Best regrads,

-a-

[Dream to fly]

Again my apologies for the lack of info.   They are vibrating type.  They were well beyond the 500 hr inspection which is why I sent them in and also to maybe address the starting issue at the same time.  I am getting the showers of sparks type now and getting remanufactured ones.   I am turning in the old ones and getting different housings.  Both surfaces where the shafts ride were oblong.  Now I have to find out why.  So I am heading back to the plane to start looking at drive surfaces and mounting surfaces and hope I don't find anything else.  Actually the way today is going I am fully expecting to find cam lobes where the pistons should be and my pistons rotating around my beacon light.  This is goes back to never a pre buy but a full inspection for me.  As soon as I get a camera I'll start posting pictures and maybe that will help.

[carusoam]

Posting your first photo will show how human you can be....

Make friends with Marauder in advance.

How many hours were on the last OH on the mags?

Best regards,

-a-

[Dream to fly]

The last log book entry was when the engine was overhauled and that was 940 hrs ago.

[smwash02]

If they are Slicks, request a quote first to weigh your options.

I sent mine off and paid 90% as much when it was said and done for an IRAN as I would've for a brand new set. Lesson from the school of Hard Knox I suppose.

IRAN = Inspect and Repair As Necessary.

[cctsurf]

BTW, Dream to fly, I'm not that far from you.  I'm just across the border in South Dakota, close to Mobridge.

[Yetti]

A couple of things.   Since I am lazy When I get near a part with a part tag, I will take a picture and store it on the computer.  Computer is backed up to USB drive.... actually 2 USB drives.

If you get on the don Maxwell page he has where he sends stuff to including mags.

There is also a special german made bearing in the Bendix that is sometimes hard to come by.

The mags are different.   One gets grounded out when starting.  The shower of sparks takes it place. 

You got to give us engine type to go on.

[RLCarter]

2 hours ago, smwash02 said:

I sent mine off and paid 90% as much when it was said and done for an IRAN as I would've for a brand new set. Lesson from the school of Hard Knox I suppose.

 

Repair shops that pull crap like that piss me off, once opened up they should be able to guess and get within 50 bucks a mag, plus a call to let you know if it's more cost effective to replace

[Browncbr1]

it's good that you are asking questions before spending money... don't get screwed by Kelley or Quality with "overhauled" mags.

pickup your parts and ship them to Aaron here... http://selectaircraft.com/

All my stuff goes to him from now on until E-mags are certified.. 

 

[Hank]

3 hours ago, RLCarter said:

Repair shops that pull crap like that piss me off, once opened up they should be able to guess and get within 50 bucks a mag, plus a call to let you know if it's more cost effective to replace

Agreed! Sent off my Kelly-rebuilt mag to Aircraft Quality, they said it would be best to overhaul. It was the left one used for cranking. OH plus A&P markup was just over $800, plus lanor, tax and shipping.

Last year, NC where I landed with a dead mag, started charging tax on labor . . .

[N6758N]

Call Aeroinstock and get yourself a new set of mags and harness from TCM for less than $2,000.

 

[Dream to fly]

Hi there I am finally home and trying to get my head around this.  Apparently the plane originally came with a SOS system.  at some point it was changed to an impulse mag system and this is where I sit.  So after also finding out why the mag housing cracked (due to bolts in being gorilla tightened) I think it would be best for me to go back to a SOS system.  I need one mag complete anyway and the other from the rebuilder is not much better.  If I understand all of this the vibrating contactor is there its just not hooked up.  So buying two reman SOS mags hooking up the missing components and setting everything up to correct timing this would be the better way to go unless I have a dead battery.  Hand propping is not available with the SOS system.   Feed back would be greatly appreciated.  

[carusoam]

In the modern world, we stopped hand propping 180 hp motors.

Being an ordinary human, the risk of death and dismemberment is too high.

Back in the day, I tried it.  Fortunately nothing happened.

Best regards,

-a-

[Dream to fly]

Just now, carusoam said:

In the modern world, we stopped hand propping 180 hp motors.

Being an ordinary human, the risk of death and dismemberment is too high.

Back in the day, I tried it.  Fortunately nothing happened.

Best regards,

-a-

I fully agree.  I was not implying I was going to, just that it was the only down side I could see and I'm good with that.  

[Andy95W]

You can still hand prop with the shower of sparks.  The procedure is in the manual, as long as you have the stock ignition switch.

[smwash02]

3 hours ago, Dream to fly said:

I think it would be best for me to go back to a SOS system.  I need one mag complete anyway and the other from the rebuilder is not much better.  If I understand all of this the vibrating contactor is there its just not hooked up. 

I would like to suggest that you do not go back to the SOS system. The ignition switch to power it is better than $500 (A/C Spruce 10-357210-1), whereas without is readily available in aircraft graveyards or new for under $150 (11-03170) or via 337 for under $125 (11-03169). If your switch got replaced, you'll be forking over for one of those.

You should only need one mag with an impulse coupling. In the start position only the left mag is hot.