Slick mags and impulse coupler

[riobison]

Just a note that I have complied with the SB on pulling my slick mags on my 0360 A1A that has 570 hours TTSN. Mag drop and everything has always checked out ok but there was the occasional miss at idle that was barely detectable.

Anyway the impulse coupling was ready to fly apart. I can't believe that it was this bad a shape. I could lift the arms at least a 1/4"+, points were ok, bearings were not of a known manufacture and needed changing. The plastic gears in there were of an old vintage and were upgraded.
Installed with a set of fine wire plugs and runs sooooo smooth. I can't wait until I finish my inspection and get it in the air.

Unless you really know what you have in there, pull your mags and check them at the 500 hr mark. I don't think I would have made it another 50 hours without that impulse coupler flying apart.

There is no doubt in my mind that these mags were marginally overhauled when installed in the engine. Makes me wonder about the rest of the engine but it does not burn oil, compression is up in mid 70's and filter is clean. I just need to keep an eye on it.

[flyingriki]

Originally Posted by riobison

Unless you really know what you have in there, pull your mags and check them at the 500 hr mark. I don't think I would have made it another 50 hours without that impulse coupler flying apart..

Same experience at 500 hours. No warning or 'talking'. Could have taken me out of the air with a destroyed engine. Call it a 'product review'...not impressed with the brand, plugs either.

They recommend 500 hour inspections for good reason.

[Vlad]

Originally Posted by riobison

Just a note that I have complied with the SB on pulling my slick mags on my 0360 A1A that has 570 hours TTSN. Mag drop and everything has always checked out ok but there was the occasional miss at idle that was barely detectable.

Anyway the impulse coupling was ready to fly apart. I can't believe that it was this bad a shape. I could lift the arms at least a 1/4"+, points were ok, bearings were not of a known manufacture and needed changing. The plastic gears in there were of an old vintage and were upgraded.
Installed with a set of fine wire plugs and runs sooooo smooth. I can't wait until I finish my inspection and get it in the air.

Unless you really know what you have in there, pull your mags and check them at the 500 hr mark. I don't think I would have made it another 50 hours without that impulse coupler flying apart.

There is no doubt in my mind that these mags were marginally overhauled when installed in the engine. Makes me wonder about the rest of the engine but it does not burn oil, compression is up in mid 70's and filter is clean. I just need to keep an eye on it.

Hi Tim,
Brand beating aside, could you clarify what engine you have. Is it Lycoming new from Vans stock or from an aftermarket assembler? Please share more info. I am asking not for just curiosity my mags are well over your limits and they are still "not talking to me".

[riobison]

Hello Vlad

O360 A1A was rebuilt out of Edmonton Alberta in 1998. That company I believe is no longer in business.

The Mags were Slick 4250 and 4251

Mine were not talking to me either. From what I have been told is if the impulse coupler was to come apart it would get your attention real quick.

Tim

[osxuser]

Typically mags wear so slowly as to be unnoticeable. You only notice the change when you get the overhauled. A good mag from a reputable overhauler will typically have very little wrong with it at 500hrs, but if you do the interval, failure rate is miniscule too.