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  #1  
Old 05-22-2019, 11:03 PM
Robert Sailor Robert Sailor is offline
 
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Location: Nanaimo BC Canada
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Default Opinions about problem with e magnetos

I recently purchased a very nice RV6A with an IO-320 and Hartzel prop. It has a single Bendix Magneto and an electronic magneto.
When I test flew it I had a mag drop on the Bendix of around 150 rpm and about 10-15 rpm drop on the electronic magneto and the engine ran very smooth.
The lower plugs are fine wire plugs and the upper plugs are a good quality automotive plugs
I decided to put new plugs in the upper ones rather than clean and gap the old plugs.
Now the electronic magneto is dropping around 150 rpm, almost the same as the Bendix and I'm left scratching my head as to what may have caused this. The only thing done was to install new plugs. Anyone have any ideas as to what may have happened. Engine is still running well with both mags on. Robert
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  #2  
Old 05-23-2019, 02:43 PM
WingsOnWheels WingsOnWheels is offline
 
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Quote:
Originally Posted by Robert Sailor View Post
I recently purchased a very nice RV6A with an IO-320 and Hartzel prop. It has a single Bendix Magneto and an electronic magneto.
When I test flew it I had a mag drop on the Bendix of around 150 rpm and about 10-15 rpm drop on the electronic magneto and the engine ran very smooth.
The lower plugs are fine wire plugs and the upper plugs are a good quality automotive plugs
I decided to put new plugs in the upper ones rather than clean and gap the old plugs.
Now the electronic magneto is dropping around 150 rpm, almost the same as the Bendix and I'm left scratching my head as to what may have caused this. The only thing done was to install new plugs. Anyone have any ideas as to what may have happened. Engine is still running well with both mags on. Robert
Is the electronic magneto and E-Mag brand unit or something else? I would confirm that the plugs have the proper gap. I assumed you replaced with the exact same brand and part number (probably NGK-BR8ES or similar).
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  #3  
Old 05-23-2019, 03:00 PM
flyinga flyinga is offline
 
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Make sure the electrode caps are tight on the auto plugs (if they are of that type).
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  #4  
Old 05-23-2019, 03:37 PM
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Toobuilder Toobuilder is offline
 
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Did you gap and ohm check the new plugs or just install them out of the box?
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  #5  
Old 05-24-2019, 04:49 PM
Robert Sailor Robert Sailor is offline
 
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Quote:
Originally Posted by Toobuilder View Post
Did you gap and ohm check the new plugs or just install them out of the box?
I installed them right out of the box.
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  #6  
Old 05-24-2019, 04:53 PM
Robert Sailor Robert Sailor is offline
 
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Quote:
Originally Posted by WingsOnWheels View Post
Is the electronic magneto and E-Mag brand unit or something else? I would confirm that the plugs have the proper gap. I assumed you replaced with the exact same brand and part number (probably NGK-BR8ES or similar).
I have to double check the exact brand of e mag and yes I used exactly the same plugs but I didn't regap them.
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  #7  
Old 05-24-2019, 05:17 PM
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sprucemoose sprucemoose is offline
 
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The gap on the BR8ES is usually pretty tight out of the box and needs to be opened up. Don't have the spec handy but I think it's .032 for Emag.
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  #8  
Old 05-24-2019, 05:54 PM
Robert Sailor Robert Sailor is offline
 
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Quote:
Originally Posted by sprucemoose View Post
The gap on the BR8ES is usually pretty tight out of the box and needs to be opened up. Don't have the spec handy but I think it's .032 for Emag.
Is there a way to confirm the gap at .032? It's manufactured by E Mag. Would a smaller gap result in a larger mag drop? Thanks, Robert
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  #9  
Old 05-24-2019, 06:14 PM
Robert Sailor Robert Sailor is offline
 
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Quote:
Originally Posted by RV8JD View Post
Well, there is always the MFG's website for documentation. Page 8 (if this document applies to your unit):

https://emagair.com/wp-content/uploa...l-LC114v28.pdf
Thanks, looked it up and it's between .030 and .035 so .032 sounds about perfect. That aside would it have any effect on my mag drop?
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  #10  
Old 05-24-2019, 07:56 PM
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sprucemoose sprucemoose is offline
 
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It certainly could. Try gapping them and report back with the results.
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