Bendix mags on an 0540

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AP
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Bendix mags on an 0540

Postby AP » Wed Aug 31, 2016 11:50 am

Question as I am not a mag expert. I have and 0540 with two Bendix Magnetos, S6LN-204 p/n 10-163050-9 and S6LN-200 p/n 10-163010-10.

What if any are the differences in these two magneto's? Also, do i need a Ignition Exciter?
these are shower of sparks magnetos with with a second P lead port for retard.

and help or information will be appreciated.

Thanks in Advance. :old_glory: :florida:
12ft Diamond back 0540

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John Fenner
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Re: Bendix mags on an 0540

Postby John Fenner » Wed Aug 31, 2016 12:26 pm

No need for an exciter, the p lead goes to your switch, the retarder port goes to a set of right hand points that fire it later than 25* in engines without impulse coupler provision.
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AP
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Re: Bendix mags on an 0540

Postby AP » Wed Aug 31, 2016 12:35 pm

thx John, Do I need to have a switch for the retard set of points as i would on the std plead, or is it nothing to worry about?
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John Fenner
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Re: Bendix mags on an 0540

Postby John Fenner » Wed Aug 31, 2016 1:23 pm

Nothing to worry about if you have impulse mag/s.
I never finish anyth,,,.

AP
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Re: Bendix mags on an 0540

Postby AP » Wed Aug 31, 2016 2:00 pm

not sure if they are straight or impulse. any way to tell without pulling them?

thx,
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John Fenner
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Re: Bendix mags on an 0540

Postby John Fenner » Wed Aug 31, 2016 3:38 pm

Pull prop through with plug wires off and listen for click or a couple clicks.
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AP
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Re: Bendix mags on an 0540

Postby AP » Wed Aug 31, 2016 4:52 pm

thx i will try that.
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cowboy
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Re: Bendix mags on an 0540

Postby cowboy » Wed Aug 31, 2016 6:24 pm

If no impulse couplings are on those mags, you will need a bendix vibrator box, or a slickstart unit to make the shower of sparks work.

The bendix vibrator box is an electro mechanical device that transforms the 12v battery power into a multiple pulse output into the lead attached to the retard point set.
Here's a u-tube of a vibrator operating without the cover on it:

These vibrators have a ton of contacts inside that look like small ignition points, and can become quite unreliable as they age. Vibrators come in 24 or 12 volt versions, so watch for that if you go looking for one.

There is a solid state alternative called slickstart: http://www.aircraftspruce.com/catalog/e ... key=183080
I replaced the old vibrator unit on my FI 200 with a slickstart, and it always fires right up with the shower of sparks. The electro-mechanical unit always gave me a ton of trouble.

I paid like $200 for my slickstart off of ebay, but they are kinda rare to see for sale on there.
The shower of sparks system will fire hot.. flooded-out.. fuel injected engines allot more reliably than an impulse coupled mag.
The spark the system develops is more like an buzzing arc, rather than a single spark.
Here's a u-tube demonstration of shower of sparks firing a plug... fast forward to about 7:20 to see the plug fire.


The shower of sparks only operates when cranking the motor on the starter, and the retard points are set to fire at 0 TDC. Once you crank-up an let off the starter button, the mag will operate like any other mag off of the primary set of points.

Anyway....
Theres enough info to get you started if you decide to operate with the shower of sparks system.
If you got a FI 540, SOS kicksass. Also eliminates the impulse couplings that have wiped the front end out of a good many 540's.

The biggest downside would be hand propping a SOS equipped engine if your starter craps out in the woods. It can be done, but you will need a remote start button in your left hand, while pulling the prop with your right.

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John Fenner
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Re: Bendix mags on an 0540

Postby John Fenner » Thu Sep 01, 2016 11:41 am

I used a dpdt toggle switch to alternate ground to either lead on a gso-540 started just fine on points alone, but get the idea of the need for the box.
I never finish anyth,,,.

AP
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Re: Bendix mags on an 0540

Postby AP » Thu Sep 01, 2016 3:23 pm

Thanx Cowboy, John..

I will let you know what I find out. The solid stay unit would seem the way to go. Or convert them to impulse.

Ap
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Re: Bendix mags on an 0540

Postby snick4340 » Sun Jan 15, 2017 10:53 pm

Does anyone know where I can get my magneto rebuilt in Okeechobee Florida

Scarecrow
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Re: Bendix mags on an 0540

Postby Scarecrow » Mon Jan 16, 2017 8:26 am

I'm sure GMAC will reply soon, he is in Lake Placid and he is the best.

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kwanjangnihm
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Re: Bendix mags on an 0540

Postby kwanjangnihm » Mon Jan 16, 2017 8:44 am

snick4340 I PM'd you GMAC76 contact number. :thumbleft:
" I don't care who you are back in the world, you give away our position one more time, I'll bleed ya, real quiet. Leave ya here. Got that? "


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