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Mag Overhaul

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pvalovich

Well Known Member
490 hours on my -8A tach. Aerosport IO-360 with 1 mag and 1 Lightspeed EI. I realize that the published guidance is to overhaul the mag at 500 hours. However, the engine is - and has been - running perfectly, and I am pondering the wisdom of the "If it ain't broke, don't fix it" philosophy.

For the online experts with biased opinions, what has worked for you:
1) Overhaul at 500 hours?
2) Wait for signs of degraded performance before overhaul?
(if so, what are those signs?)
3) I've considered replacement of the mag with a P-mag, but like the reliability and simplicity of 1 mag / 1 EI. Any opinions?
 
Impulse mag?

A friends plane flew right on past the 500 hr mark, now the engine is being overhauled early due the impulse coupling flying apart into the gear train.
"105% on the reactor possible, but not recommended"
Tim
 
The guidance isn't for an overhaul at 500 hrs.
It is an inspection.
If all internal parts are found to meet the inspection requirements then it is good for another 500 hrs (though it is fairly common to find something to replace; such as contact points, etc.)
 
I'm about to do a 500 hour on my first run impulse coupled slick. I've done it before and it's not too bad to inspect everything yourself.

If it's impulse then pay special attention to the rivets in that assembly. Also look at the brushes, rotor and cap. If everything checks out, set the e-gap/internal timing and bolt it back on.
 
I had my Slicks done when I bought it with about 530 tach time. Both needed work, gears impulse coupler, normal stuff for a slick with 500 hours I'm told.

Now my RPM drop during run up drops about 150 RPM each side. Need to figure that out.
 
tim2542 said:
A friends plane flew right on past the 500 hr mark, now the engine is being overhauled early due the impulse coupling flying apart into the gear train.
"105% on the reactor possible, but not recommended"
Tim
Click to expand...

I sent mine in at about 500 hours. Aircraft Magneto Service called me and said the mag was good, the IRAN was reasonable but the impulse coupler was almost ready to come apart......glad I sent it in.
Great guy and a lot of fun to talk to. Been doing mags for many, many years. Very reasonable prices.
 
500 hour

The 500 hour inspection for the Bendix does have a few mandatory replacement parts.
I am told that the latest version of the Bendix impulse has issues. I have not yet verified that with Continental(Bendix).
 
slicks are junk

Every single slick I've sent in recently for inspections have had bad impulses. ....cracks found through MagnaFlux type inspection....other parts junk as well...shop I've been using is making recommendations to FAA to have slick /champion investigated for faulty manufacturing.....shop telling me to go with bendix.....they see problems all too often with the slicks across all models
 
this is a bit of russian roulette. a mag may go 10 hours or it may go 1,000 hours. this is why we have two of them. i do the 500 hour iran on my slicks. have always found something. it is kind or a ford chevy thing, i like chevy. :)
P1010536.jpg
 
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